September 2008 Protected Areas Management and Wildlife Conservation Project ADB Loan Number 1767-SRI (SF) Consultancy Services Report BIODIVERSITY BASELINE SURVEY: RITIGALA STRICT NATURAL RESERVE Prepared for: Department of Wildlife Conservation Ministry of Environment and Natural Resources, Sri Lanka IN ASSOCIATION WITH Specialists in Natural Resources Management INFOTECHS IDEAS Pvt. Ltd. GREENTECH CONSULTANTS
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September 2008
Protected Areas Management andWildlife Conservation Project
Prepared for:Department of Wildlife ConservationMinistry of Environment and Natural Resources, Sri Lanka
IN ASSOCIATION WITH
Specialists in Natural Resources Management
INFOTECHS IDEAS Pvt. Ltd. GREENTECH CONSULTANTS
ACKNOWLEDGEMENTS
This series of biodiversity reports on seven protected areas is a product of the Biodiversity Baseline Survey undertaken in 2006-08, as a component of the Protected Area Management and Wildlife Conservation Project. Members of the team are listed below and those who have contributed directly to the production of this document are named under their respective taxonomic sections.
It has been a pleasure to work with the staff of the Department of Wildlife Conservation. The team appreciated the support of the Park Warden (W.M. Keerthi S. Chandraratne), and those of their staff who assisted with field work. Special thanks are due to the Director General (Ananda Wijesooriya) and his predecessor (Dr Dayananda Kariyawasam) for their full support of the project; H.D. Ratnayake (Director, Operations) and S.R.B Dissanayake (Deputy Director, Planning, Research & Training) for their technical, logistic and other inputs; and to Kamani Abaysirigunawardena for applying her GIS skills to producing the maps in this report.
Michael J.B. GreenTeam Leader
This document may be cited as follows:
DWC (2008). Biodiversity Baseline Survey: Ritigala Strict Natural Reserve. Revised version. Consultancy Services Report prepared by Green, M.J.B. (ed.), De Alwis, S.M.D.A.U., Dayawansa, P.N., How, R.,Singhakumara, B.M.P., Weerakoon, D.,Wijesinghe, M.R. and Yapa, W.B. Infotech IDEAS in association with GREENTECH Consultants. Sri Lanka Protected Areas Management and Wildlife Conservation Project (PAM&WCP/CONSULT/02/BDBS), Department of Wildlife Conservation, Ministry of Environment and Natural Resources, Colombo. 46 pp.
[Note: This revised version of DWC (2007d) includes additional sampling undertaken in the wet season.]
Biodiversity Baseline Survey Team
Management and AdministrationDr Michael J.B. Green, Uditha Lokuvithana
Database Management and Analysis GroupDr Ric How, Sriyan De Silva, U. Rajita R. Perera
Field Survey GroupDr Udaha Kapu Gedara Kalinga Padmalal
Mammal Group: Dr Mayuri Wijesinghe, Dr Wipula Bandara Yapa, Bandara M.C. Digana, K.I. Niluka Chrishantha Kumara, Pujitha Gamage, L.M. Saman Indika
Bird Group: Dr. Devaka K. Weerakoon, Mahendra Siriwardene, R.A. Rahula Perera, M. D. T. Asela, Chinthaka. Kaluthota, Karmen Ranatunga, Dammithra Samarasinghe
Herpetology Group: Dr P. Nihal Dayawansa, P. Roshan Kumara Rodrigo, L.J. Mendis Wickramasinghe, V.A.P. Samarawickrama, H.K.D. Kandhambi Volunteers: Deepani Jayantha, Samindra Fernando, Sanjeewa Lelwala
Fish Group: Dr S.M.D. Ajantha U. De Alwis, S. Indika, U.P. Kudage, A.M.S.M. Rohana Wasantha Jayasekara, K.M. Amith Bandara, Volunteer: A. Chamil U. Perera
Vascular Plants Group: Prof. B.M.P. Singhakumara, Thilak Nalinda Peiris, M. Rohan A.K. Peiris, H. Ravi Suranga, G.N. Dilruk Perera Volunteer: J.A. Ananda Lal Peiris
PAM & WC Project i Department of Wildlife Conservation
CONTENTS
AcknowledgementsPage
1. INTRODUCTIONBiodiversity Baseline Survey 1Purpose and content of this report 1
2. RITIGALA STRICT NATURAL RESERVE2.1 Designation, area and location 32.2 Physical features 32.3 Climate 32.4 Vegetation 72.5 Flora and fauna 72.6 Management 8
3. METHODS3.1 Survey design and sampling procedures 103.2 Biodiversity Information Management System 143.3 Herbarium and specimen collections 143.4 Data and analyses 14
8. FRESHWATER FISH DIVERSITY ANALYSIS8.1 Introduction 268.2 Diversity within sub-basins 268.3 Discussion 27
9. OVERVIEW9.1 Data limitations 289.2 Comparative analyses 289.3 Conclusions 30
REFERENCES 32
Annex 1 Geographic coordinates of sampling locations 33Annex 2 Summary of sampling effort 36Annex 3 List and reference numbers of voucher specimens 38Annex 4 List of species recorded from Ritigala Strict Natural Reserve 39
PAM & WC Project 1 Department of Wildlife Conservation
1. INTRODUCTION
Biodiversity Baseline Survey
The Biodiversity Baseline Survey is a discrete Contract within the Protected Area Management and Wildlife Conservation Project, funded by the Asian Development Bank, World Bank Global Environment Facility and the Government of the Netherlands. It has been undertaken by ARD Inc. for the Ministry of Environment and Natural Resources in accordance with the Contract for Consulting Services of Biodiversity Baseline Survey (ADB Loan No. 1767 SRI (SF).
The overall aim of the Contract is to assess the current status of biodiversity within four protected areas1 to inform their future management, using sound and practical scientific methods that can be repeated over time and applied more widely by the Department of Wildlife Conservation (DWC) to other protected areas under its remit. The Contract has been implemented during the period April 2006 – March 2007, with field work undertaken from the beginning of July 2007 until mid-January2007.
A one-year extension to this Contract was awarded by the Ministry primarily to enable three additional protected areas2 to be surveyed and further sampling to be conducted in Ritigala and Wasgomuwa during the wet season. This Extension has been implemented by Infotechs Ideas (Pvt) Ltd, in association with Greentech Consultants (Pvt) Ltd, during the period October 2007-October 2008, with fieldwork undertaken between November 2007 and July 2008.
Ritigala Strict Natural Reserve is one of the seven protected areas included in this Survey, chosen on account of its high importance for biodiversity within Sri Lanka’s Dry Zone The following six taxonomic groups were selected for purposes of the Survey on the basis of being (a) well known and of general interest to scientists and managers; (b) relatively easy to survey systematically and identify; and (c) potentially of value to protected areas management:
Mammals Reptiles
Birds Freshwater fish
Amphibians Vascular plants
Purpose of this report in relation to contract objectives
This report documents the plant and animal species recorded by this Biodiversity Baseline Survey, assesses the richness of species found within the different habitats and considers the implications of these findings for the future management of the Strict Natural Reserve. Along with reports for the other six protected areas, it addresses six of the ten objectives outlined in the Contract (Box 1.1).
This report should be read in conjunction with the Field Manual (DWC, 2007a), which documents thedesign of the Biodiversity Baseline Survey and methods used for sampling the different taxonomic groups in accordance with Objectives 1 and 2 of the Contract (Box 1.1). The Field Manual alsodescribes how the field data are electronically stored and managed within a Biodiversity Information Management System and provides details about the preservation and curation of plant and animal specimens.
This report is intended for use by staff of the Department of Wildlife Conservation responsible for the management of Ritigala Strict Natural Reserve and the educational outreach of those who live around its perimeter or visit it. It should also be readily accessible to other professional individuals and
1 Horton Plains, Peak Wilderness, Ritigala and Wasgomuwa2 Bundala, Minneriya and Udawalawe
PAM & WC Project 2 Department of Wildlife Conservation
organisations interested in adding to our knowledge of biodiversity within this site, be it through the collection of field data or further analyses.
Importantly, this report, together with the Field Manual and records from this baseline survey held in the Biodiversity Information Management System (DWC, 2007b, 2007c), provide the basis formonitoring future changes to the biodiversity of Ritigala Strict Natural Reserve and informing its management in so far as the constraints of the data allow.
Box 1.1 Contract objectives addressed in this report are highlighted
1. Establish baseline data and survey protocols for future biodiversity monitoring.
2. Establish sound, repeatable field methods appropriate for local conditions.
3. Establish rigorous methods for collection and management of data and specimens.
4. Inform management planning by defining habitat preferences and distribution of a range offauna/flora/assemblages and threats to them.
5. Identify habitats with rare, endemic and ecologically/culturally important species, guilds and assemblages.
6. Identify natural assemblages of plants/animals.
7. Provide natural history information on a range of species.
8. Inform management practices and identification of management zones, based on #5-7 above.
9. Make information, especially on the importance of each PA, available for education outreach.
10. Improve technical skills of Departmental staff by provision of on-the-job training.
PAM & WC Project 3 Department of Wildlife Conservation
2. RITIGALA STRICT NATURAL RESERVE
This section provides background information about the Strict Natural Reserve that is relevant to this Survey. Unless otherwise indicated, it has been extracted from the current management plan (DWC, 2005) and further details can be found in the resource inventory of the previous management plan (DWC, 1997). Useful background information can also be found in IUCN (1990).
Designation, area and location
Ritigala was designated a Strict Natural Reserve on 7 November 1941 (Gazette Notification No. 8809), having an area of 3,776 acres and 34 perches (1,528.2 ha)3. The Reserve takes its name from riti, a tree Antiaris toxicaria that is characteristic of the middle slopes of the forest (Fernando, 1968). It is proposed to establish Yan Oya National Park, adjacent to the eastern boundary of Ritigala, as one of two corridors for elephants migrating between Kaudulla National Park and Kahalle-Pallekele Sanctuary.
It lies in Anuradhapura District just to the north of the A11 highway between Haberana and Maradankadawala, from where it is accessible from the west via Ganewelpola or east from Galapitagala.
Physical features
Ritigala stands out as a prominent erosion remnant, rising from 180 m to 768 m above the surrounding peneplain (Figure 2.1a). This isolated hill, 6.5 km in length, is divided into northern and southern blocks by the shallow Maha-Degala Gorge. Ritigala is drained by tributaries of the Malwatu Oya, which flows north-west into the Gulf of Mannar, and is its most important water catchment area in the north-western Dry Zone (Figure 2.1b).
Geologically, Ritigala lies within a transitional zone between the Highland/Khondalite Series and the Wanni complex of the Vijayan Series, all rock formations of the Pre-Cambrian era. Granite gneiss of the Wanni complex is predominant, comprising 80% of the underlying rock. Pegmatitic granitoid gneisses intruded this underlying rock, giving rise to ridges and valleys (Figure 2.1c). The ridges, hill slopes and rock knob plain in the north-east have skeletal, shallow soils that are susceptible to drying even in short dry periods of about one month. Reddish Brown Earths have developed on more undulating or level terrain and Low Humic Gley soils in areas of poor drainage (Figure 2.1d).
Climate
The Tropical Dry Hot Monsoon climate is characterised by: a bimodal pattern of rainfall; uniformly high temperatures through the year (mean = 27.3 oC); a protracted dry period prior to the main rainy season (October-January) during the north-east monsoon (Maha); and desiccating winds during the long, hot south-west monsoon (May-September) that subject the vegetation to severe moisture stress.Rainfall peaks in April-May (Yala season) and October-November; total annual rainfall ranges from 1470 mm in the north to 1500 mm in the south. Relative humidity, recorded from nearby at Maha Iluppallama, ranges between 60% and 90% but is likely to be significantly lower on the summit of Ritigala (DCW, 1997).
3 The area given in the current Management Plan is 1,510 ha, having been taken from the Gazette Notification and converted incorrectly to metric units.
PAM & WC Project 6 Department of Wildlife Conservation
Box 2.1 Descriptions and images of the main vegetation types in Ritigala Strict Natural Reserve1 (Source: MENR, 2006)
Dry-Mixed Evergreen Forest (844.7 ha, 64.9% total area)
Old-growth, well-developed Dry-Mixed Evergreen Forestoccurs on the uplands of the lower plains and also extends beyond the boundary of the Strict Natural Reserve.
This undisturbed forest has the general appearance of a closed canopy forest, with a height not exceeding 30 m. The tallest, scattered emergent canopy species are Pterygota thwaitesii and Tetrameles nudiflora. The canopy includesspecies such as Dialium ovoideum, Dimocarpus longan, Diospyros affinis, D. oocarpa, Drypetes sepiaria, Mangifera zeylanica, Mesua ferrea, Mischodon zeylanicus, Xylopia nigricans and Madhuka clavata. Understorey species, characteristic of undisturbed forest, include Dimorphocalyx glabellus, Glycosmis mauritiana, Mallotus rhamnifolius, Mitrephora heyneana, Polyalthia korinti and Streblus taxoides.
Disturbed Dry-Mixed Evergreen Forest(134.7 ha, 10.4% of total area)
Species composition of secondary forest (degraded or disturbed areas of Dry-Mixed Evergreen Forest) is somewhat different, with species such as Azadirachta indica, Drypetes sepiaria, Grewia helicterifolia, Macaranga peltata and Pterospermum suberifolium in the canopy. Understorey species include Mallotus rhamnifolius, Memecylon capitellatum, Phyllanthus polyphyllus, Polyalthia korinti, Premna tomentosa, Stenosiphonium cordifolium, Dimorphocalyx glabellus and Glycosmis mauritiana.
Short-Stature Forest (82.3 ha, 6.3% of total area)
This is a very special and unique forest formation, about 2-3 m in height and occurring along the ridge tops of Ritigala. Cloud frequently caps the hill range, which leads to appreciable condensation of moisture over the summit throughout the year, even at the height of the drought prevailing in the surrounding lowlands. The resulting high humidity, together with the relatively lower temperature, appears to favour a unique flora as described by Jayasuriya (1984). The occurrence of a number of sub-montane and montane plant species at the summit clearly indicates that its microclimate is closely comparable with that of the humid sub-montane region of Sri Lanka.
PAM & WC Project 7 Department of Wildlife Conservation
Vegetation associated with Rock Outcrops(163.6 ha, 12.6% of total area)
Rock out crops and associated vegetation are common throughout Ritigala. Tree species associated with rock out crops include: Commiphora caudate, Ficus arnottiana, Ficus mollis, Givotia moluccana, Lannea coromandelica, Memecylon petiolatum, Euphorbia antiquorum, Bambusa bambos, Sapium insigne and Wrightia angustifolia. Shrub species include Carmona retusa, Croton laccifer, Mundulea sericea, Ochna lanceolata, Osbeckia aspera andCassipourea ceylanica.
Scrub (75.3 ha, 5.8% of total area)
Scrub forms in places of chena (shifting cultivation). Soon after chena is abandoned, various herbaceous pioneer species appear and they are followed by successions of woody species, culminating in the appearance of secondary forest. Characteristic species include Azadirachta indica, Bauhinia racemosa, Carissa spinarum, Catunaregam spinosa, Dichrostachys cinerea, Flueggea leucopyrus, Gmelina asiatica, Grewia orientalis, Hugonia mystax, Ichnocarpus frutescens, Lantana camara, Limonia acidissima, Memecylon umbellatum, Phyllanthus polyphyllus, Scutia myrtina, Syzygium cumini, Toddalia asiatica and Ziziphus oenoplia.
Vegetation
The vegetation shows a clear pattern of altitudinal zonation (Figure 2.2). Most of the Wet Zone species are found at higher elevations and some of them are strictly confined to the summit areas of Ritigala. Some species occur within more or less sharp altitudinal zones. Most of the Dry Zone species are restricted to lower elevations. A Short-Stature Forest occurs on the summits and upper slopes of Ritigala. The main vegetation types are described, with images, in Box 2.
Flora and fauna
Biodiversity surveys and related research in recent decades include the National Conservation Review (Green and Gunawardena, 1997), an inventory of natural resources that includes original field work as a part of a Global Environmental Facility Project (DWC, 1997) and floral surveys by Jayasuriya (1984) and, as part of mapping the habitat of Ritigala, by MENR (2006). Existing knowledge about the diversity of plant and animal species is summarised in Table 2.1.
The Short-Stature Forest is particularly important on account of its high diversity, including an abundance of epiphytic and lithophytic species, and levels of endemism. A total of 109 species, representative of 52 families, have been recorded, of which 26 species are endemic and four taxa are unique to Ritigala (Jayasuriya, 1984).
Large mammals include a small elephant population, comprising some 18 individuals and additional migratory elephants, sloth bear, sambar and leopard. The paucity of records of amphibians is noted as being due to surveys having been conducted in the dry season (DCW, 1997).
Habitat map (MENR, 2006) Flowering plants 57 unavailable 201 251A total of 417 taxa of lower and higher plants has been recorded (DCW, 2005).2These data are included in the Management Plan (DWC, 2005); no new information has been incorporated.
Management
The vision in the Management Plan (DWC, 2005) is to conserve Ritigala Strict Natural Reserve as a catchment, with its rich site-specific biological and cultural diversity. The management goals and objectives are reproduced in Box 2.2.
Four conservation themes have been identified, namely:
strengthening protection of the Strict Natural Reserve
conserving the proposed Yan Oya National Park;
establishing a centre for conservation education;
reaching out to local communities to reduce resource dependencies and alleviate poverty;
PAM & WC Project 9 Department of Wildlife Conservation
Box 2.2 Management goals and objectives for Ritigala Strict Natural Reserve (DWC, 2005)
Management Goals
To preserve the biodiversity, hydrological value and archaeological resources of the Strict Natural Reserve.
To provide habitats for the migratory elephants between Kaudulla and Ritigala by establishing the Ritigala-Yan Oya National Park.
Management Objectives
To strengthen the protection of the natural resources of the Strict Natural Reserve and the proposed Ritigala-Yan Oya National Park.
To develop a Center for Conservation Education to provide information and awareness on biodiversity conservation, with special reference to the biological value, hydrological value, scenic beauty, cultural, and archeological resources of the Strict Natural Reserve.
To protect and improve Ritigala-Yan Oya National Park habitat for migratory elephants.
To reduce the natural resource dependencies on the surrounding forests, win the support of the people for conservation and improve village family income generation.
To reduce the human-elephant conflict in the surrounding villages
To promote limited nature tourism in Ritigala-Yan Oya National Park.
PAM & WC Project 10 Department of Wildlife Conservation
3. METHODS
Full details of the methodology developed for the Biodiversity Baseline Survey are provided in a separate Field Manual (DWC, 2007a). A brief overview is provided below, together with details of anything specific to the survey of Ritigala.
Ritigala was surveyed initially in 2006, mostly during the height of the dry season in the months of August and September (75% of quadrats) over a period of approximately six weeks but also following the rains in December (25% of quadrats). The Bird Group returned for an additional sampling session in January 2007. The Extension to the Biodiversity Baseline Survey provided a further opportunity to undertake additional surveys at the height of the wet season in December 2007 and to focus onsampling vegetation types poorly represented in the earlier survey.
Survey design and sampling procedures
The Biodiversity Baseline Survey covered terrestrial and aquatic habitats (i.e. rivers, streams, tanks, villus). Terrestrial habitats were identified using the outputs from the Habitat Mapping Project (MENR, 2006), based principally on the vegetation types while taking into account environmental gradients, such as elevation, aspect, geology and soils, for the location and alignment of transects.
Terrestrial habitats were sampled systematically for plants, amphibians, reptiles, birds and mammalsusing quadrats (100 m x 5 m) aligned at 150 m intervals along transects (1 km length). Four replicate transects were located within each habitat type. Opportunistic observations were also recorded along transects, between quadrats, and elsewhere within the Strict Natural Reserve.
Freshwater habitats were treated as a single type, which was sampled systematically for fish diversity and opportunistically for other taxonomic groups. The head, mid- and lower reaches of at least four rivers or streams within each sub-basin were sampled for fish and various measures of water quality.
The geographic coordinates of all sampling locations (i.e. quadrats and freshwater sites) are provided in Annex 1. Effort expended in sampling quadrats, freshwater and other sites using a variety of techniques is summarised in Annex 2.
Terrestrial habitats
Six vegetation types were used as a basis for sampling different terrestrial habitats for species diversity. These habitats are shown in Table 3.1, together with the number of replicate transects and quadrats located within each. Some of the 24 one-kilometre transects occupied more than a single habitat, which is why the total number of transects shown in Table 3.1 exceeds 24. This is due to the small areas of habitats at some sampling locations, making it impossible to align a transect within a single habitat.
Table 3.1 Numbers of quadrats and associated transects sampled within each habitat
1Conceptually, the number of transects equates to the number of replicates in each habitat. In practice, the total number of transects is 24 but the total number of replicates is 33, as some transects cover more than one habitat.
PAM & WC Project 12 Department of Wildlife Conservation
Quadrat locations are shown in Figure 3.1. Although some are shown as falling outside the boundary of the Strict Natural Reserve, this is not actually the case on the ground. In all cases, the Survey team was accompanied by DWC staff and the boundary, although awaiting demarcation with concrete posts, was evident from footpaths along the perimeter. It should also be noted that grassland was not differentiated as a main vegetation type (Figures 2.2 and 3.1) because of its very limited extent(MENR, 2006), nor was it included in any statistical analyses because of the small sample size and absence of replicates.
HabitatDMEF disturbedDMEFVegetation with rockScrubShort Stature Forest
2D Stress: 0.17
Figure 3.2 Multi-dimensional Scaling ordination of plant quadrats based on square root transformed abundance data and Bray-Curtis similarity
The results of a non-metric Multi-Dimensional Scaling ordination of Bray-Curtis similarities from square root transformed species abundance data from plant quadrats (Clarke and Warwick 2001) are presented in two dimensions in Figure 3.2. This shows quadrats of the same habitat type distributed in clusters in close proximity to each other, as in the case of Short-Stature Forest, Scrub and Vegetation associated with Rock Outcrops. There is some overlap between these latter two habitats. Dry-Mixed Evergreen Forest shows wider variation in floristic composition but is distinct from the other habitats. As might be expected, the composition of disturbed (secondary) forest falls within the range of variation of undisturbed Dry-Mixed Evergreen Forest. Floristic relationships are evaluated in more detail in Section 4.3.
Freshwater habitat
A total of 53 sites within eight or nine of Ritigala’s 23 sub-basins were sampled for fish and water quality. Their distribution is shown in Figure 3.3. Eighteen of these sites appear to lie outside the boundary of the Strict Natural Reserve but in most cases this may not be the reality, given that Survey team members were accompanied by DWC staff in the field who knew the location of the boundaries.The eight or nine sub-basins were amalgamated into western and eastern drainage units for analysis purposes and samplings sites were assigned accordingly.
PAM & WC Project 14 Department of Wildlife Conservation
Biodiversity Information Management System
Field data are held in the Biodiversity Information Management System, a database application designed specifically for the Biodiversity Baseline Survey. The application is described briefly in the Field Manual (DWC, 2007a) and full details about its design and use are documented elsewhere. (DWC, 2007b, 2007c).
Herbarium and specimen collections
Numbers of herbarium and animal specimens collected during the Biodiversity Baseline Survey are summarised in Table 3.2 for each taxon. Details of voucher specimens are provided in Annex 3. Plant and animals specimens are lodged with the National Wildlife Training, Giritale and, in the case of plants, a duplicate set is deposited with the National Botanic Gardens, Peradeniya.
Table 3.2 Numbers of voucher specimens collected and identified for each taxon
Field data comprise quantitative and opportunistic records. The sizes of datasets are summarised in Tables 3.3 and 3.4 for each taxonomic group. In Table 3.3 the number of records refers to records of species within quadrats; the number of individuals is the total number of individuals recorded for each species. In the case of birds, only those recorded within Bands 1 or 2 of Variable Circular Plots are treated quantitatively; those recorded in Band 3 (i.e. >20 m from the observer) are treated as opportunistic.
Table 3.3 Breakdown of quantitative and opportunistic records of plants and animals
PAM & WC Project 15 Department of Wildlife Conservation
Opportunistic records contribute considerably to species inventories in the case of plants and all terrestrial vertebrate groups (Table 3.4). In the case of mammals, such records are based largely on indirect observations of tracks and scats or pellets.
Table 3.4 Breakdown of quantitative and all records of species of plants and animals
Species discovery curves were calculated to estimate the likely number of species to be found in each habitat type for each taxonomic group. Both the Chao2 and Bootstrap methods (Primer E, 2007) were used, following the recommendations of Macgurran (2002) who evaluated a wide range of different statistical approaches.
These estimates, provided in Tables 4.1, 5.1, 6.1, 7.1 and 8.1 for the respective taxonomic groups,indicate that surveys in further locations are necessary to check for additional species in the case of all groups.
Analyses
Analyses were undertaken principally at the protected area and habitat or sub-basin levels. While the former provides an overview of the biodiversity values of the protected area, the latter is likely to be more useful for informing management about diversity within different habitats and sub-basins. A summary matrix of species diversity within each habitat or sub-basin is provided in Annex 4.
The dominant vegetation formation in Ritigala Strict Natural Reserve is Dry-Mixed Evergreen Forest. The undisturbed forest has the general appearance of a closed canopy forest and the height of the canopy does not exceed 30 m. Some areas of the Dry-Mixed Evergreen Forest are disturbed or degraded and this is reflected in a somewhat different species composition. The Short-Stature Forest is a very special and unique vegetation type occurring on the summits and upper slopes of the Reserve. Its sub-montane and montane plant species at the summit clearly indicate that its microclimate is closely comparable with that of the humid sub-montane region of Sri Lanka. The floristic composition of the different vegetation formations is described in Section 2.4.
A total area of 4.8 ha was sampled within the different habitats, details of which are summarised in Annex 2. Voucher specimens were collected and these are listed in Annex 3.
Diversity within habitats
A total of 225 species of vascular plants were inventoried during this Survey, of which 25 species are endemic and 16 are nationally threatened. Species recorded within quadrats total 135, of which 18 are endemic, and their distribution with respect to each habitat is provided in Annex 4.
Species richness and other measures of diversity are shown in Table 4.1. While species richness is shown to be highest for undisturbed Dry-Mixed Evergreen Forest, diversity measures are higher for disturbed Dry-Mixed Evergreen Forest. Most likely this is explained by a more even distribution of abundance across species in disturbed Dry-Mixed Evergreen Forest. Data for Grassland are absent because the two Grassland quadrats were not sampled.
Table 4.1 Plant diversity indices and estimates for habitats, based on quadrat sampling
Habitat type(revised after MDS analysis)
TotalDry-Mixed Evergreen Forest Short-
StatureForest
Vegetationwith RockOutcrops
ScrubGrass-landUndisturbed Disturbed
Total number of species 135 87 74 40 37 39 -Number of endemic species 18 17 9 4 3 3 -Diversity indices/estimatesSpecies richness (S) 135 87 74 40 37 39 -Shannon Entropy (expH) 29.22 21.34 28.01 9.98 21.72 19.68 -Gini-Simpson (1/D) 16.45 13.82 16.93 6.23 15.08 12.39 -Chao 2 estimate S 165.30 117.40 86.10 54.10 99.50 96.60 -Bootstrap estimate S 150.30 98.80 84.80 46.20 44.00 47.60 -
Discussion
Significant findings
Six habitats were distinguished for purposes of this Survey, based on outputs from the Habitat Map Project (MENR, 2006) but more habitats are readily identifiable in the field. For example, rocky areas dominated with spiny bamboo have a different species composition and physiognomy to Vegetation associated with Rock Outcrops. The spiny bamboo areas were not considered as a separate habitat.
More detailed analysis of floristic data from the 94 non-grassland quadrats indicates not only a high species richness for such a small area but a high diversity of significantly different floristic associations. A total of 18 floristic associations can be statistically distinguished by applying the Simprof algorithm in the Primer E programme to a Bray-Curtis similarity matrix of these quadrats. The 50 Dry-Mixed Evergreen Forest quadrats occur in 12 of the associations, the 19 Disturbed Dry-
PAM & WC Project 17 Department of Wildlife Conservation
Mixed Evergeen Forest quadrats occur in seven associations, the seven quadrats of Vegetation associated with Rock Outcrops in four associations, the 12 Short Stature Forest quadrats in three associations and the six Scrub quadrats comprise two associations. Fourteen of the 18 floristic associations are shared by two habitat types. The complexity of this arrangement is shown in Figure 4.1 where the 18 identified associations are plotted with respect to habitat type.
Habitat AssemblagesDMEF-disturbed_aDMEF-disturbed_bScrub_bDMEF_cDMEF-disturbed_cVeg on Rock_dVeg on Rock_eDMEF_eDMEF_fShort Stature Forest_fShort Stature Forest_gShort Stature Forest_hDMEF_iVeg on Rock_i
DMEF_jScrub_jDMEF_kDMEF-disturbed_kDMEF_lDMEF_mDMEF_nDMEF_oDMEF-disturbed_oDMEF_pDMEF-disturbed_pDMEF_qDMEF-disturbed_qVeg on Rock_r
2D Stress: 0.17
Figure 4.1 Multi-dimensional Scaling ordination of plant quadrats plotted according to floristic associations in two dimensions. Habitat types are represented by different symbols and associations by different colours.
As evident from the results of this Survey and previous studies, relatively few endemic and threatened plant species occur in Dry Zone forests as compared to Wet Zone forests. A total of 55 endemic flowering species have been recorded from Ritigala Strict Natural Reserve (Jayasuriya, 1984). This represents 16% of Ritigala’s angiosperm flora (337 species), which is low compared to the national level of 30% endemism among angiosperms (Dassanayake et al., 1980-2000). That said, the Short-Stature Forest is unique and its level of endemism is relatively high for the locality. Point endemic species known only from Ritigala include Madhuca clavata (recorded in this Survey), Coleus elongates (Jayasuriya, 1984) and the Critically Endangered Strobilanthes willisii (Carine et al., 2000). A number of other species are very rare or extinct elsewhere and have not been recorded from outside Ritigala since the 19th century (Jayasuriya, 1984).
Adequacy and shortcomings of survey data
Information from other surveys indicates that this Biodiversity Baseline Survey is not comprehensive for plants. Jayasuriya (1984) recorded 337 flowering plants, which is very much more than the total of 225 species (including opportunistic records) recorded in this Survey and the 201 species inventoried as part of the recent Habitat Map Project (MENR, 2006).
A total of 119 woody plants species was recorded by the National Conservation Review (Green and Gunawardena, 1997) using just 18 quadrats (100 m x 5m), as compared with the 135 species recorded from 94 quadrats of the same size by this Survey. The difference between the National Conservation Review and this Survey can be attributed to sampling design objectives: whereas the National Conservation Review used line transects, several kilometres in length, that were orientated along environmental gradients (notably elevation and aspect) to maximise the accumulation of species records for the entire Reserve, this Survey used four 1-km length replicates to maximise adequacy ofsampling at the habitat level. Moreover, these 1-km length replicates were sometimes arranged in two parallel lines of 500 m at right angles to the altitudinal gradient, rather than as a single line along the gradient, to hasten daily of checking of mammal traps.
PAM & WC Project 18 Department of Wildlife Conservation
5. HERPETOFAUNA DIVERSITY ANALYSIS (Author: P. Nihal Dayawansa)
Introduction
A total of 235 plots (5 x 5 m2) were sampled daytime, using the Quadrat Cleaning Technique, and 24plots (2.5 x 10 m2) were surveyed at night, using the Visual Encounter Technique, providing 500 records of amphibians and reptiles including opportunistic encounters. Of the 235 plots searched, no herpetofauna were found in 159 (68%) of them. The distribution of sampling effort in each habitat is shown in Annex 2.
Eleven voucher specimens were collected during the 2006 survey and two more in the 2007 survey.Five of the specimens collected in the 2006 survey (Cnemaspis sp. 1) have been identified as C. retigalensis, a new species recently described by Wickramasinge and Munindradasa (2007). Voucher specimens are listed in Annex 3.
Diversity within habitats
Seventeen species of amphibians, 26 species of lizards, 30 species of snakes and three turtle species were recorded during the Survey. Some 60% of these species were recorded during the 2007 wetseason survey (8 km of transects) as compared with 40% recorded in the more extensive 2006 predominantly dry season survey (24 km of transects). Six species of reptiles that remain unidentified(Bungarus sp., Lankaskincus sp., Nessia sp., Typhlops spp., Uropeltis sp.), some of which could be new to science.
A list of species recorded within each habitat is provided in Annex 4. Comparison of this list with records in the Management Plan for the Reserve indicates that 31 species have been recorded for the first time in this Survey. The following points are noteworthy:
Of the 17 species of amphibians, four are endemic but none is listed as threatened by IUCN Sri Lanka and MENR (2007). Of the 59 species of reptiles, 18 are endemic and nine are threatened, including the endemic great forest gecko, Cyrtodactylus fraenatus,that is critically endangered (Annex 4).
Philautus regius (Polonnaruwa shrub frog) was recorded for the first time at Ritigala, as was Lankanectes corrugatus (corrugated water frog). The latter represents an extension to the range of this endemic genus.
Cnemaspis retigalensis (Retigala day gecko), a newly described endemic known only from Ritigala (Wickramasinge and Munindradasa (2007), is common in the Dry Mixed-Evergreen Forest and Short-Stature Forest. The genus Cyrtodactylus, represented by the endemic species fraenatus, was previously known only from the North Central Province.There is one endangered species of gecko, Cnemaspis podihuna (dwarf day gecko),which is a typical Dry Zone species. C. alwisii (Jordan’s day gecko) and Geckoella yakhuna (blotch bowfinger gecko) are both endemic.
Agamid lizards are quite common in the forests of Ritigala and Otocryptis nigristigma(black spotted kangaroo lizard), Calotes liolepis (whistling lizard) and C. ceylonensis(painted lip lizard) were found to be sympatric. Interestingly, the endemic and vulnerablewhistling lizard is normally not recorded elsewhere in the Dry Zone.
The relict genus Nessia is represented by Nessia bipes (Smith’s snake skink), a rare, endangered and endemic species otherwise restricted to the Knuckles region of Sri Lanka. The endemic Lankascincus deignani (Deignan’s lankaskink) is also rare and endangered, while L. fallax is common in areas of vegetation litter.
Five of the 30 snake species are endemic. Hypnale nepa (Merrem’s hump nosed viper) is a new record for Ritigala. A blind snake (Typhlops sp.) and Uropeltis sp., found in damp soil among rocky outcrops, are yet to be identified. Chrysophelea ornata (flying ornate
PAM & WC Project 19 Department of Wildlife Conservation
snake) normally occurs in the Wet and Intermediate zones of Sri Lanka.
The results of diversity analyses and estimates are summarised in Table 5.1, based on quantitativedata gathered from sampling plots using the Quadrat Cleaning Technique. Key points arising from this analysis are:
Undisturbed Dry Mixed-Evergreen Forest supports most of the species richness and abundance as indicated by the diversity indices (expH and 1/D) and estimates (Chao 2 and Bootstrap).
Projections of reptile diversity, based on Chao 2 and Bootstrap, lie in the region of 27-32species. These projections are low, given the knowledge that 59 species were recorded during the survey, many of which were based on opportunistic observations. (Note that sample sizes for amphibians were too small to generate diversity indices and estimates.)
Table 5.1 Herpetofauna diversity indices and estimates for habitats, based on plot sampling
Habitat type(revised after MDS analysis)
TotalDry-Mixed Evergreen Forest Short-
Stature Forest
Vegetationwith Rock Outcrops
ScrubGrass-landUndisturbed Disturbed
AMPHIBIANSTotal number of species 4 3 1 0 0 0 1Number of endemic species 1 1 0 0 0 0 0REPTILESTotal number of species 22 15 8 5 5 5 0Number of endemic species 14 12 5 5 3 3 0Diversity indices/estimatesSpecies richness [S] 22 15 8 5 5 5 0Shannon entropy [expH] 8.36 7.63 5.45 3.06 4.76 5.00 1.00Gini-Simpson [1/D] 4.92 4.86 4.25 2.31 4.50 5.00 -Chao 2 estimate S 32.08 23.00 12.00 9.50 5.00 - -Bootstrap estimate S 26.79 18.36 9.53 6.10 6.25 - -
Discussion
Significant findings
Ritigala is of high conservation value for herpetofauna, evident from its wealth of species (76)that include one point endemic species (Cnemaspis retigalensis) as well as 22 other endemic species. Furthermore, nine species are threatened, of which six are endemic including the critically endangered Cyrtodactylus fraenatus (great forest gecko).
The herpetofauna assemblage is highly complex, with representatives from the other majorclimatic zones of the country and genera that are ecologically isolated from Ritigala. Examples include: Nessia bipes (Smith’s snake skink), found elsewhere only in the Knuckles (Intermediate Zone); Chrysophelea ornata (flying ornate snake), normally found in the Wet and Intermediate zones; and Calotes leolepis (whistling lizard), not normally found in the Dry Zone. Examples of Ritigala hosting outlier populations of Dry Zone reptile species with restricted ranges include: Cyrtodactylus fraenatus (great forest gecko), previously known only from the North Central Province; and Lankanectes corrugatus (corrugated water frog).
Approximately 24 % of amphibians, 54% of lizards and 13% of snakes recorded from Ritigala in this Survey are endemic. This level of endemism is high for the dry zone, although not at a national scale - 86% of Sri Lanka’s amphibians and 57% of its reptiles being endemic (Bambaradeniya, 2006).
Dry Mixed-Evergreen Forest, especially that which is undisturbed, supports much of the species richness and abundance (Section 5.2). The importance of Short-Stature Forest for endemic reptiles should not be overlooked, particularly with respect to the point endemic
PAM & WC Project 20 Department of Wildlife Conservation
Cnemaspis retigalensis (Retigala day gecko), which is common in this habitat as evident from records in Annex 4.
Adequacy and shortcomings of survey data
Predictably, returning to Ritigala during the wet season in December 2007 under the extension to the Project made a significant difference to the overall results of this Survey. A total of 31 species of herpetofauna (six amphibians, 16 lizards and 9 snakes) were positively identified in the 2006 survey, which involved sampling 155 plots daytime and 9 plots at night as well opportunistic observations, as compared with the additional 45 species recorded during the less extensive 2007 survey (80 daytime plots, 15 night time plots plus opportunistic observations). Only nine species (two amphibians and seven reptiles) recorded in the 2006 survey were not re-recorded in the 2007 survey. This highlights the importance of ensuring that surveys include the wet season.
In terms of survey techniques and their respective efficiencies, the results from this Survey show that opportunistic walks along forest ecotones, using footpaths and wildlife trails, generated the most information about species diversity, and that night time was moreproductive than day time sampling of plots. A total of 38 species encountered opportunistically were not recorded from either daytime or night time plots. Twenty one species were recorded from 15 night time plots and 25 species from 235 daytime plots, indicating the greater efficiency of sampling at night.
Diversity estimates for reptiles, based on plot sampling, suggest that much of this fauna has been recorded but clearly this not the case based on the wealth of additional information provided by opportunistic surveys. Further sampling is warranted, particularly given the conservation importance of this site for herpetofauna. This should include the use of a variety of other capture techniques more specific to reptiles, such as pitfall traps and associated leading nets.
Three main sampling methods were used to record bird diversity in Ritigala Strict Natural Reserve: variable circular plots (VCPs), mist netting, and opportunistic encounters. A total of 384 VCPs were sampled, providing 2,779 records. A total of 200 hours of mist netting (1600 net metre hours) was carried out during the wet season resulting in 14 captures. In addition, 78 observations were made opportunistically. The distribution of sampling effort across habitats is summarised in Annex 2.
No voucher specimens or DNA samples were collected during this Survey.
Diversity within habitats
A total of 97 bird species was recorded during the Survey, including five endemic species. Of this total, only 74 species were recorded in the first two bands of VCPs and, therefore, subjected to further analysis. A total of 85 species was recording opportunistically, including 23 bird species treated as opportunistic observations from the third band of VCPs. A list of species recorded within each habitat is provided in Annex 4.
In general, the diversity of the birds recorded from Ritigala Strict Natural Reserve is typical of what might be expected in the Dry Zone. Overall, Ritigala is quite rich in indigenous species, 41% of Sri Lanka’s 220 breeding resident species having been recorded. This includes 19% of the country’s endemic avifauna (26 species4). Compared to protected areas in the Wet Zone, the level of endemism (5 of 97 species) is relatively low. Only about 12% of Sri Lanka’s 112 migrant species were recorded, which can be attributed to the survey being undertaken outside of the peak migratory season and the fact that only forest migrants, which comprise a small fraction of migratory species, are expected to be observed at Ritigala.
The bird assemblage at Ritigala includes a single nationally threatened species, Falco peregrinus(IUCN Sri Lanka and MENR, 2007), but none of the recorded species is listed as globally threatenedby IUCN.
Table 6.1 Bird diversity indices and estimates for habitats, based on species recorded within 1st
and 2nd bands of VCPs sampled in quadrats
Habitat type(revised after MDS analysis)
TotalDry-Mixed Evergreen Forest Short-
StatureForest
Vegetationwith Rock Outcrops
ScrubGrass-landUndisturbed Disturbed
Total number of species 74 57 50 9 40 18 27Number of endemic species 5 4 4 - - 1 -Diversity indices/estimatesSpecies richness (S) 74 57 50 9 40 18 27Shannon Entropy (expH) 31.60 27.11 27.83 7.64 28.08 13.05 21.70Gini-Simpson (1/D) 21.00 18.07 19.27 6.42 20.86 10.24 17.49Chao 2 estimate S 88.10 65.64 58.00 13.20 76.00 30.50 36.40Bootstrap estimate S 80.10 62.36 55.70 11.10 48.80 18.00 30.70
Levels of diversity and endemism within the different habitats are summarised in Table 6.1, accompanied by various measures of diversity. Highest species richness was recorded in undisturbed Dry-Mixed Evergreen Forest, followed by disturbed Dry-Mixed Evergreen Forest. Vegetation associated with Rock accounted for over half of the total recorded species richness. Species richness
4 Whereas the total number of endemic bird species was considered to be 25, a recent revision of Asian babblers indicates that the Scimitar Babbler (Pomatorhinus horsfieldii) is an endemic species (Coller, 2006).
PAM & WC Project 22 Department of Wildlife Conservation
was low in Grassland and Scrub, and lowest in Short-Stature Forest. Other measures of diversity are consistent with these trends, with the exception of Vegetation associated with Rock Outcrops and to a lesser extent Grassland. While lower in species richness, their higher diversity indices (comparable to Dry-Mixed Evergreen Forest in the case of Rock Outcrops vegetation) may be accounted for by the similar but low abundance of the species in these habitats.
Discussion
Significant findings
Ritigala Strict Natural Reserve is of high conservation value for birds because its supports large populations of indigenous species. It remains the only good natural habitat for most forest birds in this region of the country. Species richness, however, was found to be much lower than expected, especially as Ritigala is unique with respect to certain vegetation and floristic elements (see Section 4). Possible reasons include:
It is among the smallest of protected areas (15 km2), around which much of the surrounding land is settled and cultivated.
Ritigala is located in the Dry Zone, which supports fewer endemic and threatened species of birds. Moreover, its range and variation in habitats is low, including low structural diversity within its stunted forests along the ridges.
No major seasonal differences were found in the bird assemblages, except in the Vegetation associated with Rock Outcrops where an additional 25 species were recorded in Phase 2 (wet season). Most of these species were winter visitors to Sri Lanka.
It should be noted that the total number of species (94) recorded by this Survey is somewhat low compared with the 122 species recorded in a resources inventory compiled for the previous management plan (DWC, 1997). However, that list includes species, such as aquatic birds, recorded in the vicinity of the Strict Natural Reserve but outside its designated boundary. Further differences in the methodologies used in this Survey and previous surveys preclude any assessment of whether there have been any real changes to the avifauna over time.
Adequacy and shortcomings of survey data
This dataset provides a reliable, georeferenced baseline for Ritigala Strict Natural Reserve which can be used to inform its management. However, the data should be used judiciously, taking full account of the following limitations:
Some habitats were not sampled adequately.
Sampling did not cover the full range of seasons. The sampling periods coincided with the non-migratory season for birds, while covering both dry and wet seasons. Most of the Survey was carried out in the dry season when high winds also prevailed. The wet season sampling was conducted during heavy rain, which is likely to have resulted in fewer birds being recorded. All of these factors may have contributed to the lower diversity and abundance of birds than expected.
Records of migratory species were based on opportunistic encounters. Thus, the distribution of migratory species within different habitats could not be elucidated.
PAM & WC Project 23 Department of Wildlife Conservation
7. MAMMAL DIVERSITY ANALYSIS (Authors: Mayuri R. Wijesinghe and Wipula B. Yapa)
Introduction
This Biodiversity Baseline Survey is the first extensive survey undertaken in Ritigala Strict NaturalReserve that has used live trapping and mist-netting techniques to record the diversity of the nocturnal rodents, shrews and bats. Additionally, the presence of the animals in a particular area was observed directly and inferred from fresh droppings, foot prints and other signs.
A total of 48 quadrats was sampled quantitatively for small mammals, using traps, and the length of each transect (24 km in total) was surveyed for signs of all mammals, based on direct and indirect observations (e.g. tracks and fresh droppings). Opportunistic encounters with mammals elsewhere in the Strict Natural Reserve were also recorded.
The distribution of sampling effort across the different habitats is shown for non-volant mammals and bats in Annex 2. Three voucher specimens were collected and identified from Ritigala. Details of these specimens are provided in Annex 3.
Diversity within habitats
Twenty six species of indigenous mammals were recorded from within quadrats and an additional 11species (including two exotics) were recorded opportunistically during the Survey. A list of species recorded within each habitat is provided in Annex 4. Key points are as follows:
Mammal species recorded at Ritigala belong to 31 genera and 19 families. They comprise five species of bats, 10 rodents including four species of squirrels, one porcupine and five species of rats, hare, pangolin, sloth bear, two civet species, four mongoose species, otter, jackal, sevenspecies of ungulates, three primates including two monkeys and loris, and elephant.
Four species are endemic, namely Semnopithecus vetulus, Macaca sinica, Moschiola meminnaand Funambulus layardi.
Eight mammal species are nationally threatened and six are threatened at the global level.
The most commonly recorded species through trapping, direct or indirect observations were common house rat (Rattus rattus), sloth bear and porcupine. Although sloth bear was never seen, fresh droppings were recorded from several areas such as Unakanda, suggesting the frequent presence of this species. Of the bats, a fruit bat belonging to the genus Cynopterus was most commonly seen.
Levels of diversity and endemism, together with measures of diversity, within the different habitats are summarised in Table 7.1 for all species of mammals and in Table 7.2 for mammal species otherthan bats, for which data were too few to analyse separately. The results, which are based on relatively small samples, indicate the following:
Species richness is highest in undisturbed and disturbed Dry-Mixed Evergreen Forest. This is attributed, at least partly, to the shade and cover afforded by such habitats, particularly during the dry season when most of the sampling was undertaken,
Although many of the streams within the Strict Natural Reserve were totally dry, fresh otter scat was found on a small rocky surface.
Few mammal species were recorded in Short-Stature Forest, although sloth bear and porcupine scat were frequently encountered.
Bats were found most often in disturbed forest and scrub.
Quadrat sample sizes are small and this is reflected in the estimates of species richness (Chao 2 and Bootstrap) being much higher than the number of species recorded to date.
PAM & WC Project 24 Department of Wildlife Conservation
Table 7.1 Mammal diversity indices and estimates (all species) for habitats, based on quadratsampling
Habitat type(revised after MDS analysis)
TotalDry-Mixed Evergreen Forest Short-
StatureForest
Vegetationwith Rock Outcrops
ScrubGrass-landUndisturbed Disturbed
Total number of species 26 16 10 3 11 7 4Number of endemic species 3 3 1 0 1 0 1Diversity indices/estimatesSpecies richness [S] 26 16 10 3 11 7 4Shannon entropy [expH] 14.80 9.92 7.75 2.65 6.75 6.73 3.22Gini-Simpson [1/D] 10.20 7.43 6.40 2.46 5.19 6.40 2.78Chao 2 estimate S 68.25 27.25 19.00 3.00 11.00 7.00 4.00Bootstrap estimate S 31.20 17.80 12.30 3.32 14.36 9.07 5.00
Table 7.2 Mammal diversity indices estimates (all species except bats) for habitats, based on quadrat sampling
Habitat type(revised after MDS analysis)
TotalDry-Mixed Evergreen Forest Short-
StatureForest
Vegetationwith Rock Outcrops
ScrubGrass-landUndisturbed Disturbed
Total number of species 21 15 8 3 10 3 4Number of endemic species 3 3 1 0 1 3 1Diversity indices/estimatesSpecies richness [S] 21 15 8 3 10 3 4Shannon entropy [expH] 12.73 9.58 6.24 2.65 6.31 2.00 3.22Gini-Simpson [1/D] 9.23 7.36 5.06 2.46 4.96 2.00 2.78Chao 2 estimate S 41.20 32.00 12.00 3.00 10.00 2.00 4.00Bootstrap estimate S 24.70 19.20 9.60 3.30 13.00 2.60 5.00
Discussion
Significant findings
Ritigala is an important protected area for the country’s mammal fauna, with 35 indigenous species including four endemics present. It also supports eight nationally threatened mammal species.
Rattus rattus, Cremnomys blanfordi, Tatera indica, Millardia meltoda, Funambulus sublineatus, F. layardi and five bat species, which include one megachiropteran and four microchiropterans, are first-time records for Ritigala.
Forest habitats support the richest assemblage of mammals.
A number of species previously recorded at Ritigala (DWC, 1997), such as grey langur, jungle cat, leopard, pangolin and the fruit bat Pteropus, were not recorded during this Survey.
Adequacy and shortcomings of survey data
The additional sampling undertaken at Ritigala during the wet season in December 2007 did result in a greater diversity and abundance of mammals being recorded. Comparisons between dry and wet season records show that a number of species, such as spotted deer, elephant, squirrel species, mouse deer and many bat species, were recorded more frequently during thewetter months.
PAM & WC Project 25 Department of Wildlife Conservation
Despite the additional survey work undertaken at Ritigala as part of the Project extension, it is clear from the statistical analyses and records from other surveys that sampling of species richness is incomplete.
Mist netting could not be carried out in certain areas, such as Unakanda, because they were not readily accessible after dark due to potential threats from elephants and the difficult terrain.
PAM & WC Project 26 Department of Wildlife Conservation
8. FRESHWATER FISH DIVERSITY ANALYSIS (Author: S.M.D. Ajantha U. De Alwis)
Introduction
A variety of streams and tributaries drain Ritigala during the rainy seasons but these dry out during the dry seasons. Sampling was done during the dry season and at the onset of the rainy season.
Very little attention has been paid to the fish fauna. A resources inventory for the Management Plan lists 25 species belonging to 11 families and 17 genera, of which 4 species are endemic (DWC, 1997).
Diversity within sub-basins
A total of 16 species of fish were recorded from eight or nine sub-basins during the present Survey, with 14 species, including four endemics, in the Eastern drainage units and 15 species, including five endemics, in the Western drainage units (Table 8.1). These species belong to 4 families and 10 genera. The most abundant family is Cyprinidae and the most common genus is Puntius of the same family. The Eastern drainage supports the endemics Chela laubuca, Esomus thermoicos, Puntius amphibius and P. ticto. These endemic species also occur in the Western drainage, together with an additional endemic, Puntius singhala. Villagers reported the presence of exotic species which they believe migrate from lakes surrounding around the Reserve into its streams by means of flood waters during the rainy season. None was recorded during this Survey, possibly because the additional wet season sampling in December 2007 included only the onset of the rains before much flooding had occurred.
Species richness, species diversity and dominance are marginally higher in the Western drainage (Table 8.1). Estimates of species diversity are not much higher than recorded from the Survey. Thissuggests that most of the fish species diversity has been sampled, based on the Chao2 and Bootstrap projections. Although only eight or nine of the 23 sub-basins were sampled, those drainages not surveyed are unlikely to hold many additional species unless they are very different.
Table 8.1 Freshwater fish diversity indices and estimates for drainages, based on sampling protocol
Drainage unit Western drainage Eastern drainage Total
Total number of species 15 14 16Number of endemic species 5 4 5Diversity indices/estimatesSpecies richness (S) 15 14 16Shannon entropy(exp H) 8.35 7.08 8.44Gini-Simpson [1/D] 6.13 4.65 5.86Chao2 estimate S 17.67 14.00 18.00Bootstrap estimates S 16.83 14.25 16.90
Contrary to expectations, fewer species (11) were recorded in the wet season than in the dry season (16). However, this may reflect the more limited sampling in the wet season and the fact that it was undertaken at the onset of the rains.
Water quality
Mean values of various measures of water quality are provided in Table 8.2. In general, water quality in those drainage units covered by this Survey falls within accepted levels for aquatic life (CEA, 2003). Further sampling of other sub-basins and analysis is required to examine potential relationships between these measures and fish diversity.
PAM & WC Project 27 Department of Wildlife Conservation
Table 8.2 Physical and chemical measures of water quality within drainage units(Values are means ±1SD.)
Water quality measure
pH Con
duct
ivit
y
Tur
bid
ity
Tot
al
Dis
solv
ed
Soli
ds
Dis
solv
ed
Oxy
gen
Tem
pera
ture
Dep
th
Fis
h s
peci
es
Unitmhos/cm
NTU ppt ppm oC cm No.
Eastern drainage 7..31±0.46
0.18±0.16
26.36±30.95
0.07± 0.23
8.55±0.49
25.04±1.03
24.27±20.01
13
Western drainage 7.31±0.29
0.14±0.03
19.37±31.55
0.08±0.02
8.52±0.57
25.38±1.51
20.25±8.99
13
Discussion
Significant findings
This Survey indicates that the fish fauna is relatively diverse in Ritigala Strict Natural Reserve,with at least 16 indigenous species present (including five endemics) and more if species previously recorded are still remaining. This represents 20% of Sri Lanka’s indigenous freshwater fish fauna (82 species including endemics).
Five species are endemic, representing 11% of the 44 species endemic to Sri Lanka.
Observed anthropogenic activities, such as felling of trees along the banks of streams, can be of potential threat to the freshwater fish fauna.
Villagers reported that the fish fauna in the tanks located around the Reserve migrate into its streams during the rainy season. This is a matter of potential concern as exotic species from these tanks could threaten the survival of indigenous fish in Reserve. The earlier resources inventory (DWC, 1997) and this study, combined with more field work, provide a basis for identifying changes to the fish fauna.
Adequacy and shortcomings of survey data
Only eight or nine of 23 sub-basins were surveyed. However, statistical analyses suggest that most of the species diversity has been captured.
Fewer fish species were recorded than expected, which is attributed to the commencement of the survey during the dry season in 2006, when most of the streams were completely dry, and to the wet season survey being too early, at the onset of rains. The limited number of fish records precludes more detailed analysis, including any assessment of the influence of water quality on fish diversity and abundance.
PAM & WC Project 28 Department of Wildlife Conservation
9. OVERVIEW (Authors: Michael J.B. Green and Ric How)
Data limitations
Examination of sampling effectiveness for plants, fish and all terrestrial vertebrate groups indicates that further sampling would be appropriate to better document the biodiversity of Ritigala Strict Natural Reserve. Sampling effort generated reasonably comprehensive sets of data in the case of fish, with only one or two more species predicted from Chao2 and Bootstrap estimates of diversity (Table 8.1). Estimates of species diversity for plants and birds, for which data are the most extensive of all taxonomic groups surveyed, are noticeably higher than actually recorded (Tables 4.1 and 6.1). Although some further analysis of diversity can be justified, subsets of the total data need to be interpreted with caution as such data are still preliminary in terms of sample size. Insufficient data have been captured for herpetofauna and mammals (Table 3.3), the most difficult taxonomic groups to survey quantitatively, and this is reflected in the high discrepancy between the species richness recorded and estimates of species diversity (Tables 5.1 and 7.1).
Comparative analyses
Flora and fauna diversity within habitats
Species richness and diversity indices are shown in Table 9.1 for all terrestrial taxonomic groups within the six habitats surveyed at Ritigala. Undisturbed Dry-Mixed Evergreen Forest has the highest species richness for all taxonomic groups. Diversity for plants is highest in disturbed Dry-Mixed Evergreen Forest, while for birds it is greatest in Vegetation associated with Rock Outcrops. This latter observation can be explained by a relatively high evenness of species recorded, evident from the Shanon entropy [expH] index.
Table 9.1 Flora and fauna diversity indices and estimates within terrestrial habitats
Examination of floristic relationships in the 94 quadrats surveyed for plants resulted in the identification of 18 statistically different associations, the highest number in the seven protected areas covered by the Biodiversity Baseline Survey5. Some overlap between habitat type and association type is evident (Figure 4.1). For example, two higher elevation Dry-Mixed Evergreen Forest quadrats share the same floristic composition as one of the Short-Stature Forest associations. Quadrats of disturbed Dry-Mixed Evergreen Forest and undisturbed Dry-Mixed Evergreen Forest, both structural habitat categories, cover 14 floristic associations, representing most of the floristic diversity found at Ritigala. Two associations are uniquely associated with each of Short-Stature Forest and Vegetation associated with Rock Outcrops.
5 Eighteen floristic assemblages have also been identified in Wasgomuwa National Park.
PAM & WC Project 29 Department of Wildlife Conservation
Elevation, probably in combination with soil and slope, plays a significant role in determining floristic composition. There are 13 associations in the 46 quadrats above 250 m, decreasing to 8 associations in the 28 quadrats above 350 m and five associations in the 17 quadrats above 450 m (Figure 9.1).Four associations are recorded only from above 350 m, an elevation above which no sampling was undertaken in Wasgomuwa National Park.
Elevation m
650-750
550-650
450-550
350-450
250-350
150-250a b c d e f g h i j k l m n o p q r
Associations
Figure 9.1 Distribution of 18 floristic associations with elevation
DMEF-dry
dDMEF-dry
Scrub-dry
SSF-dry
VegRock-dry
DMEF-wet
dDMEF-wet
Grassland
VegRock-wet
2D Stress: 0.01
Figure 9.1 Multi-dimensional Scaling ordination from a Bray Curtis coefficient of similarity of bird assemblages for the six habitat types at Ritigala in dry and wet seasons. Similar assemblages are represented by the same colour. Note that some habitats were sampled only in a single season.
The results of an analysis of the relationships between bird assemblages with respect to habitat are shown in Figure 9.2. Key points that emerge from this analysis are as follows:
The assemblage of birds in Short-Stature Forest differs in its composition markedly from all
PAM & WC Project 30 Department of Wildlife Conservation
other habitats.
Bird assemblages in disturbed and undisturbed Dry-Mixed Evergreen Forest differ little in composition from each other. Differences between wet or dry seasons for each habitat are also insignificant.
Vegetation associated with Rock Outcrops, Scrub and Grassland also support distinct assemblages of birds. In the case of Vegetation associated with Rock Outcrops, assemblage composition differs significantly between wet and dry seasons.
Conclusions
Key findings arising from this Survey and their implications for conservation and management are summarised below. Future priorities for biodiversity monitoring and related research are identified.
Key biodiversity values
There is a high diversity in the floristic composition of plant associations at Ritigala Strict Natural Reserve, as high as in any of the seven protected areas covered by the BiodiversityBaseline Survey. This is strongly associated with elevation and possibly other environmental gradients (e.g. slope) present.
Four species of plants are endemic to Ritigala, including the Critically Endangered Strobilanthes willisii. At least seven other species are very rare or extinct elsewhere in Sri Lanka, having not been recorded from outside Ritigala since the 19th century6.
The Short-Stature Forest is unique and supports a relatively high proportion of endemic plant taxa, as well as a markedly high proportion of endemic reptiles.
The herpetofauna community is notably diverse, with numerous endemic taxa and one point endemic recorded only from this site. This includes the newly described day gecko (Cnemaspis retigalensis), which is an important discovery that further highlights the unique importance of Ritigala Strict Natural Reserve and demonstrates the potential for discoveries of new species with more intensive surveys.
Ritigala Strict Natural Reserve is of high conservation value for other vertebrate groups. Itsupports it a relatively diverse indigenous fish fauna, large populations of indigenous bird species and its diverse mammal fauna includes eight nationally threatened species.
All terrestrial faunal groups showed major differences in abundance between wet and dry seasons, indicating the significance of Ritigala as an isolated refugium for many species in the dry zone. This also emphasises the importance of seasonal sampling.
Conservation and management implications
The field survey of different habitats shows that the vegetation formations are both floristically diverse and relatively intact within the boundary of the Reserve. However, the surrounding forests are degrading rapidly under the influence of growing human population and theirprotection is very important to maintain the integrity of the protected area.
The migration of exotic fish species from tanks around the periphery of the Reserve during the wet season, as reported by local villagers, probably represents a threat to indigenous species in the Reserve.
Ritigala Strict Natural Reserve contains archaeological remains of an ancient monastery complex, constructed over a long interval between the second century BC and 9th century AD.
6 Anodendron rhinosporum, Ipomea jacunda, I. wightii, Cleidion nitidum, Acampe rigida, Bulbophyllum crassifolium and Cheirostylis parvifolia (Jayasuriya, 1984).
PAM & WC Project 31 Department of Wildlife Conservation
These monuments, enshrouded in biodiversity, are an important part of the national heritage and deserve a special integrated conservation effort in terms of public access and appreciation of their values.
In particular, the cultural site and its immediate surroundings are excellent for bird watching due to the high visibility and presence of many species of birds, providing a good opportunity to create or raise awareness among visitors to the Reserve.
Data gathered from this Survey can be used to inform management activities, notably through the management planning and implementation process, and to provide new information on biodiversity for community outreach work and for the benefit of visitors. The special importance of the Reserve as a refugium in the Dry Zone for some unique species of plants and herpetofauna should feature in such information.
Future directions and priorities
Ritigala has the advantage over many biodiversity ‘hot spots’ of being small and reasonably well inventoried during the last few decades (see Table 2.1). There are now four good datasets relating to surveys of the flora undertaken in the last few decades and their thorough analysis should be a priority to guide future management and research. Thus, there is a wealth of information to complement this Survey and establish a baseline for future biodiversity monitoring. Priorities are considered to be as follows:
In the short-term, over the next five years, collate and analyse existing survey data in order to identify outstanding gaps for further surveys and research. This should include a detailed seasonal appraisal of plant and avifaunal diversity. It should be noted that time did not allow for Short-Stature Forest to be sampled in the wet season.
In the longer term (7-10 years hence), monitoring should commence with repeat surveys undertaken in the same locations covered by this Survey and any subsequent surveys completed.
Specific research should include more detailed study of the fish fauna in relation to possible changes in its composition and potential impact from exotic species that are believed to migrate into the Reserve when its streams are flowing.
PAM & WC Project 32 Department of Wildlife Conservation
References
Bambaradeniya, C.N.B. (ed.) (2006). The fauna of Sri Lanka: Status of taxonomy, research and conservation. The World Conservation Union, Colombo, Sri Lanka & Government of Sri Lanka. 308 pp.
Carine, M.A., Jayasekara, P. and Scotland, R.W. (2000). A new species of Strobilanthes Blume (Acanthaceae) from Sri Lanka. Kew Bulletin.
CEA (2003). Proposed inland water quality standards for different uses. Central Environment Authority, Battaramulla.
Clarke, K. R. and Warwick, R. M. (2001). Changes in marine communities: an approach to statistical analyses and interpretation. 2nd edition. PRIMER-E, Plymouth, U.K.
Coller, N.J. (2006). A partial revision of the Asian babblers (Timulidae). Forktail 22: 85-112.
DWC (1997). Resources inventory of Ritigala Strict Natural Reserve. Volume I. The Global Environment Facility Project, UNDP and Department of Wildlife Conservation, Colombo. 147 pp.
DWC (2005). Ritigala Strict Nature Reserve and very important proposed Yan Oya National Park: Management Plan. Final Draft. Protected Area Management and Wildlife Conservation Project, Department of Wildlife Conservation, Colombo. 113 pp.
DWC (2007a). Biodiversity Baseline Survey: Field Manual. Consultancy Services Report prepared by Green, M.J.B. (ed.), De Alwis, S.M.D.A.U., Dayawansa, P.N., How, R., Padmalal, U.K.G.K., De Silva, S., Singhakumara, B.M.P., Weerakoon, D.,Wijesinghe, M.R. and Yapa, W.B. ARD Inc in association with Infotech IDEAS and GREENTECH Consultants. Sri Lanka Protected Areas Management and Wildlife Conservation Project (PAM&WCP/CONSULT/02/BDBS), Department of Wildlife Conservation, Ministry of Environment and Natural Resources, Colombo. 43 pp.
DWC (2007b). Biodiversity Information Management System: Users guide. Consultancy Services Report prepared by De Silva, S. ARD Inc in association with Infotech IDEAS and GREENTECH Consultants. Sri Lanka Protected Areas Management and Wildlife Conservation Project (PAM&WCP/CONSULT/02/BDBS), Department of Wildlife Conservation, Ministry of Environment and Natural Resources, Colombo.
DWC (2007c). Biodiversity Information Management System: Technical design guide. Consultancy Services Report prepared by De Silva, S. ARD Inc in association with Infotech IDEAS and GREENTECH Consultants. Sri Lanka Protected Areas Management and Wildlife Conservation Project (PAM&WCP/CONSULT/02/BDBS), Department of Wildlife Conservation, Ministry of Environment and Natural Resources, Colombo.
DWC (2007d). Biodiversity Baseline Survey: Ritigala Strict Natural Reserve. Consultancy Services Report prepared by Green, M.J.B. (ed.), De Alwis, S.M.D.A.U., Dayawansa, P.N., How, R., Singhakumara, B.M.P., Weerakoon, D.,Wijesinghe, M.R. and Yapa, W.B. ARD Inc in association with Infotech IDEAS and GREENTECH Consultants. Sri Lanka Protected Areas Management and Wildlife Conservation Project (PAM&WCP/CONSULT/02/BDBS), Department of Wildlife Conservation, Ministry of Environment and Natural Resources, Colombo. 41 pp.
Green, M.J.B. and Gunawardena, E.R.N. (1997). Designing an optimum protected areas system for Sri Lanka's natural forests. 2 volumes. Environmental Management in Forestry Developments Project, Forest Department, Government of Sri Lanka, Colombo. 399 pp.
IUCN (1990). IUCN Directory of South Asian protected areas. Compiled by Green, M.J.B., World Conservation Monitoring Centre. IUCN, Gland, Switzerland and Cambridge, UK. 280 pp.
IUCN Sri Lanka and MENR (2007). The 2007 Red List of threatened fauna and flora of Sri Lanka. The World Conservation Union (IUCN) and Ministry of Environment & Natural Resources, Colombo, Sri Lanka. 148 pp.
Jayasuriya, A.H.M. (1984). Flora of Ritigala Strict Natural Reserve. Sri Lanka Forester 16 (3&4): 61-156.
Magurran, A. (2004). Measuring biological diversity. Blackwell Publishing. Oxford, UK.
MENR (2006). Habitat maps for selected areas in Sri Lanka: Ritigala Strict Nature Reserve. Final Report. Prepared by EML Consultants. Ministry of Environment & Natural Resources. Colombo. 79 pp.
Primer E. (2007). Plymouth Routines in Multivariate Ecological Research. Roborough, Plymouth, UK.
Wickramsinghe, L.J. Mendis and Munindradasa, D.A.I. (2007). Review of the genus Cnemaspis Strauch, 1887 (Sauria: Gekkonidae) in Lanka with the description of five new species. Zootaxa 1490: 1-63.
PAM & WC Project 35 Department of Wildlife Conservation
Tra
nse
ct
Qu
adra
t
Hab
itat
Co
de
GP
S s
tart
Eas
tin
g
GP
S s
tart
N
ort
hin
g
Alt
itu
de
m
Lo
cali
ty
13 B Dry-Mixed Evergreen Forest DMEF 187007 325836 345 Amrawathi
13 C Dry-Mixed Evergreen Forest DMEF 186961 325986 360 Amrawathi
13 D Dry-Mixed Evergreen Forest DMEF 186862 326087 375 Amrawathi
14 A Disturbed Dry-Mixed Evergreen Forest DMEF-D 186857 326236 205 kanda
14 B Disturbed Dry-Mixed Evergreen Forest DMEF-D 186825 326494 238 kanda
14 C Dry-Mixed Evergreen Forest DMEF 186732 326463 260 kanda
14 D Dry-Mixed Evergreen Forest DMEF 186651 326526 310 kanda
15 A Dry-Mixed Evergreen Forest DMEF 185052 323315 200 Karamba
15 B Dry-Mixed Evergreen Forest DMEF 185289 323216 240 Karamba
15 C Dry-Mixed Evergreen Forest DMEF 185381 323201 245 Karamba
15 D Dry-Mixed Evergreen Forest DMEF 185243 323328 210 Karamba
16 A Dry-Mixed Evergreen Forest DMEF 185372 323070 260 Kanda
16 B Dry-Mixed Evergreen Forest DMEF 185406 322706 265 Kanda
16 C Dry-Mixed Evergreen Forest DMEF 185416 322595 250 Kanda
16 D Dry-Mixed Evergreen Forest DMEF 185448 322493 240 Kanda
17 A Dry-Mixed Evergreen Forest DMEF 188453 325536 175
17 B Grassland G 188417 325667 178
17 C Grassland G 188532 325753 179
17 D Disturbed Dry-Mixed Evergreen Forest DMEF-D 188499 325910 179
18 A Disturbed Dry-Mixed Evergreen Forest DMEF-D 188327 325851 169
18 B Disturbed Dry-Mixed Evergreen Forest DMEF-D 188269 325817 166
18 C Disturbed Dry-Mixed Evergreen Forest DMEF-D 188164 325764 156
18 D Disturbed Dry-Mixed Evergreen Forest DMEF-D 188089 325685 192
19 A Disturbed Dry-Mixed Evergreen Forest DMEF-D 188017 325672 181
19 B Dry-Mixed Evergreen Forest DMEF 187819 325760 216
19 C Dry-Mixed Evergreen Forest DMEF 187795 325784 200
19 D Dry-Mixed Evergreen Forest DMEF 187718 325781 240
20 A Dry-Mixed Evergreen Forest DMEF 187639 325751 241
20 B Dry-Mixed Evergreen Forest DMEF 187639 325748 243
20 C Dry-Mixed Evergreen Forest DMEF 187600 325709 267
20 D Dry-Mixed Evergreen Forest DMEF 187574 325720 247
21 A Vegetation associated with Rock Outcrops RO 188544 321548 186
21 B Dry-Mixed Evergreen Forest DMEF 188603 321581 188
21 C Dry-Mixed Evergreen Forest DMEF 188480 321176 196
21 D Dry-Mixed Evergreen Forest DMEF 188518 321754 192
22 A Disturbed Dry-Mixed Evergreen Forest DMEF-D 188333 321007 163
22 B Disturbed Dry-Mixed Evergreen Forest DMEF-D 188225 321060 164
22 C Disturbed Dry-Mixed Evergreen Forest DMEF-D 188286 321122
22 D Disturbed Dry-Mixed Evergreen Forest DMEF-D 188417 321213
23 A Dry-Mixed Evergreen Forest DMEF 187870 321050 160
23 B Dry-Mixed Evergreen Forest DMEF 187940 321161 186
23 C Dry-Mixed Evergreen Forest DMEF 188026 321257 174
23 D Dry-Mixed Evergreen Forest DMEF 188088 321375 181
24 A Vegetation associated with Rock Outcrops RO 188501 321639 198
24 B Vegetation associated with Rock Outcrops RO 188402 321764 229
24 C Dry-Mixed Evergreen Forest DMEF 188317 321829 227
24 D Dry-Mixed Evergreen Forest DMEF 188223 321914 226
ANNEX 2 SUMMARY OF SAMPLING EFFORT: RITIGALA STRICT NATURAL RESERVE (Survey period: August – September, December 2006)
Key to habitats: D DMEF; Dd DMEF-disturbed; SS Short-Stature Forest; RO Vegetation with Rock Outcrops; Sc Scrub; Op Opportunistic (all habitats)
PAM & WC Project 36 Department of Wildlife Conservation
Taxonomic group
Sampling effort achieved in the field
Method: descriptionNo./km transect
Sampling intensity per habitat type(based on 4
replicates/habitat)Method
Sampling effort per habitat type (N = no. quadrats)D33
Dd 9
SS12
RO 4
Sc 6
Op
Small mammals
No. traps set 176 44 66 33 33Sherman traps: located at 10 m intervals within 2 vegetation quadrats (100m x 5m), for 4 nights
22 traps22 x 4 x 4 = 352 trap nights/ habitat
Total no. trap nights 704 176 264 132 132
No. quadrats sampled 16 4 6 3 3
Larger mammals
No. traps set 32 8 12 6 6Tomahawk traps: located at each end of 2 vegetation quadrats (100m x 5m), for 4 nights
4 traps4 x 4 x 4= 64 trap nights/ habitat
Total no. trap nights 128 32 48 24 24
No. quadrats sampled
Bats
No. mist nets set 8 4 12 Mist nets: 2 nets (at canopy and ground levels) manned by 2 persons at 6-9am and at 4.30-6.30pm at appropriate location along transect
2 mist nets
2 x 2 x 4 = 16 mist net sessions (totalling 40 mist net hours)/ habitat
Total hours of mist netting 24 12 36
No. quadrats 2 1 3
No. mist nets set Mist nets: 2 nets (at canopy and ground levels) manned by 2 persons at 6-9am and at 4.30-6.30pm along selected waterholes, trails and near roosts
2 mist nets
2 x 2 x 4 = 16 mist net sessions (totalling 40 mist net hours)/ habitat
Total hours of mist netting
No. locations
All mammals No. quadrats 33 9 12 4 6Direct observations: along 1 km transects, recording perpendicular distance from transect to mammal sighted/ spoor
1 km4 km, variable width/ habitat
Birds on land
No. VCPs completed 132 36 48 16 24 Variable Circular Plots: 8 VCPs (radius = 0-10m, 11-20m and >20m) aligned at each end of 4 vegetation quadrats (100m x 5m): birds recorded for 10 minutes within each VCP, once at dawn and once at dusk
8 VCPs8 x 2 x 4 = 64 VCP visits/ habitatNo. quadrats sampled 33 9 12 4 6
No. transects surveyedDirect observations: record birds along 1 km transects between vegetation quadrats
600m 2.4 km/habitat
Birds on water
No. locations on waterbodies counted Total counts: for discrete water bodies, using one or more stations from which to record birds, as appropriate.
n/a n/aTotal no. waterbodies surveyed
Birds
No. mist nets set 10 Mist nets: 2 nets (at canopy and ground levels) manned by 2 persons during daytime (total of hours)at appropriate location adjacent to transect
2 mist nets
2 x 4 x 6 = 48 mist net hours/ habitat
Total hours of mist netting 200
No. locations 1
Reptiles and amphibians
No. QCTs completed 80 25 30 5 15 Quadrat cleaning (daytime): 5 quadrats (5m x 5m) in open habitat, 10m x 2.5m in closed habitat) cleared in each of 2 vegetation quadrats (100m x 5m)
Key to drainage units: 1 = Eastern drainage; 2 = Western drainage
Freshwater fish
Sub-basin ref. no. 1 2 1+2 Water quality: pH, conductivity, phosphate, nitrate, dissolved oxygen, turbidity, temperature recorded at head, mid- and lower reaches of river
ANNEX 2 SUMMARY OF SAMPLING EFFORT: RITIGALA STRICT NATURAL RESERVE (Survey period: December 2007; Transects 17-24)
Key to habitats: D DMEF; Dd DMEF-disturbed; SS Short-Stature Forest; RO Vegetation with Rock Outcrops; Sc Scrub; Op Opportunistic (all habitats)
PAM & WC Project 37 Department of Wildlife Conservation
Taxonomic group
Sampling effort achieved in the field
Method: descriptionNo./km transect
Sampling intensity per habitat type(based on 4
replicates/habitat)Method
Sampling effort per habitat type (N = no. quadrats)D17
Dd10
SS0
RO3
Sc0
Gr2
Op
Small mammals
No. traps set 88 55 22 11Sherman traps: located at 10 m intervals within 2 vegetation quadrats (100m x 5m), for 4 nights
22 traps22 x 4 x 4 = 352 trap nights/ habitat
Total no. trap nights 352 220 88 44
No. quadrats sampled 8 5 2 1
Larger mammals
No. traps set 16 10 4 2Tomahawk traps: located at each end of 2 vegetation quadrats (100m x 5m), for 4 nights
4 traps4 x 4 x 4= 64 trap nights/ habitat
Total no. trap nights 64 40 16 8
No. quadrats sampled 8 5 2 1
Bats
No. mist nets set Mist nets: 2 nets (at canopy and ground levels) manned by 2 persons at 6-9am and at 4.30-6.30pm at appropriate location along transect
2 mist nets
2 x 2 x 4 = 16 mist net sessions (totalling 40 mist net hours)/ habitat
Total hours of mist netting
No. quadrats 0 0 0 0
No. mist nets set Mist nets: 2 nets (at canopy and ground levels) manned by 2 persons at 6-9am and at 4.30-6.30pm along selected waterholes, trails and near roosts
2 mist nets
2 x 2 x 4 = 16 mist net sessions (totalling 40 mist net hours)/ habitat
Total hours of mist netting
No. locations 0 0 0 0
All mammals No. quadrats 8 5 2 1Direct observations: along 1 km transects, recording perpendicular distance from transect to mammal sighted/ spoor
1 km4 km, variable width/ habitat
Birds on land
No. VCPs completed 64 40 16 8 Variable Circular Plots: 8 VCPs (radius = 0-10m, 11-20m and >20m) aligned at each end of 4 vegetation quadrats (100m x 5m): birds recorded for 10 minutes within each VCP, once at dawn and once at dusk
8 VCPs8 x 2 x 4 = 64 VCP visits/ habitatNo. quadrats sampled 16 10 4 2
No. transects surveyedDirect observations: record birds along 1 km transects between vegetation quadrats
600m 2.4 km/habitat
Birds on water
No. locations on waterbodies counted Total counts: for discrete water bodies, using one or more stations from which to record birds, as appropriate.
n/a n/aTotal no. waterbodies surveyed
Birds
No. mist nets set Mist nets: 2 nets (at canopy and ground levels) manned by 2 persons during daytime (total of hours)at appropriate location adjacent to transect
2 mist nets
2 x 4 x 6 = 48 mist net hours/ habitat
Total hours of mist netting
No. locations 0 0 0 0
Reptiles and amphibians
No. QCTs completed 40 25 10 5 Quadrat cleaning (daytime): 5 quadrats (5m x 5m) in open habitat, 10m x 2.5m in closed habitat) cleared in each of 2 vegetation quadrats (100m x 5m)
Key to drainage units: 1 = Eastern drainage; 2 = Western drainageFreshwater fish
Sub-basin ref. no. 1 2 1+2 Water quality: pH, conductivity, phosphate, nitrate, dissolved oxygen, turbidity, temperature recorded at head, mid- and lower reaches of river
PAM & WC Project 40 Department of Wildlife Conservation
Family Genus Species
Geo
grap
hic
Sta
tus
Con
serv
atio
n st
atus
-na
tiona
l
Tota
l no.
opp
ortu
nist
ic re
cord
s
Tota
l no.
indi
vidu
als
/rec
ords
for
quad
rats
[N=9
6]
No. quadrats within which species recorded in each habitat type
Prio
r rec
ords
Dry
-Mix
ed E
verg
reen
Fo
rest
[N=5
0]
Dry
-Mix
ed E
verg
reen
Fo
rest
-di
stur
bed
[N=1
9]
Shor
t-Sta
ture
For
est
[N=1
2]
Roc
k O
utcr
ops
[N=7
]
Scru
b [N
=6]
Gra
ssla
nd [N
=2]
Cycadaceae Cycas circinalis I +Datiscaceae Tetrameles nudiflora I +Dracaenaceae Sansevieria zeylanica I +Ebenaceae Diospyros affinis I VU +Ebenaceae Diospyros ebenum I EN 12 7 3 0 0 1Ebenaceae Diospyros ferrea I 15 0 8 0 1 1Ebenaceae Diospyros malabarica I +Ebenaceae Diospyros oocarpa I VU 339 43 7 0 0 1Ebenaceae Diospyros ovalifolia I 203 31 12 1 0 1Erythroxylaceae Erythroxylum zeylanicum E 31 0 0 4 0 0Euphorbiaceae Acalypha fruticosa I +Euphorbiaceae Antidesma alexiteria 7 I VU +Euphorbiaceae Bridelia retusa I 5 0 1 0 0 3Euphorbiaceae Cleistanthus pallidus E 286 6 1 12 0 1Euphorbiaceae Cleistanthus patulus I 837 33 4 12 0 0Euphorbiaceae Croton laccifer I 2 1 0 0 1 0Euphorbiaceae Croton officinalis I +Euphorbiaceae Dichrostachys cinerea I 252 35 12 0 0 1Euphorbiaceae Dimorphocalyx glabellus I 7 1 4 0 0 0Euphorbiaceae Drypetes gardneri E 372 27 10 0 4 1Euphorbiaceae Drypetes sepiaria I 5 2 2 0 1 0Euphorbiaceae Euphorbia antiquorum I 1 0 0 0 1 0Euphorbiaceae Euphorbia tirucalli X 1 0 0 0 1 0Euphorbiaceae Euphorbia trigona I NT 1 0 0 0 0 1Euphorbiaceae Excoecaria crenulata 8 I VU +Euphorbiaceae Flueggea leucopyrus I 1 0 0 0 1 0Euphorbiaceae Givotia moluccana I 48 8 6 1 0 3Euphorbiaceae Glochidion stellatum E +Euphorbiaceae Macaranga peltata I NT 10 4 0 2 0 0Euphorbiaceae Mallotus philippensis I +Euphorbiaceae Mallotus resinosus I 751 44 14 10 1 2Euphorbiaceae Mallotus rhamnifolius I 371 22 7 2 4 1Euphorbiaceae Mischodon zeylanicus I 38 5 5 1 2 1Euphorbiaceae Phyllanthus cinereus 9 E VU +Euphorbiaceae Phyllanthus polyphyllus I 1 0 0 0 1 0Euphorbiaceae Phyllanthus reticulatus I +Euphorbiaceae Sapium insigne I 16 0 2 4 0 1Euphorbiaceae Suregada lanceolata I 28 0 4 0 0 5Fabaceae Abrus precatorius I +Fabaceae Bauhinia racemosa I 1 0 1 0 0 0Fabaceae Bauhinia tomentosa I +Fabaceae Cassia auriculata I 3 1 1 0 0 0Fabaceae Cassia fistula I 2 0 0 0 0 2Fabaceae Cassia spectabilis X 7 1 2 0 1 1Fabaceae Crotalaria laburnifolia I +Fabaceae Dalbergia pseudo-sissoo I +Fabaceae Derris parviflora E 20 14 0 0 0 1Fabaceae Dialium ovoideum E 5 0 1 0 0 2Fabaceae Dichrostachys cinerea I 13 1 1 0 3 0Fabaceae Mimosa pudica X +Fabaceae Mundulea sericea I 25 11 3 0 0 0Fabaceae Tephrosia purpurea I +Flacourtiaceae Hydnocarpus venenata E 3 1 1 0 0 0Hernandiaceae Gyrocarpus americanus I +Hippocrateaceae Salacia reticulata I 7 1 0 5 0 0Lamiaceae Coleus barbatus I +
7 Listed under Phyllanthaceae in 2007 IUCN Red List.8 Listed as E. oppositifolia in 2007 IUCN Red List.9 Listed under Phyllanthaceae in 2007 IUCN Red List.
PAM & WC Project 43 Department of Wildlife Conservation
Family Genus Species
Geo
grap
hic
Sta
tus
Con
serv
atio
n st
atus
-na
tiona
l
Tota
l no.
opp
ortu
nist
ic re
cord
s
Tota
l no.
indi
vidu
als
/rec
ords
for
quad
rats
[N=9
6]
No. quadrats within which species recorded in each habitat type
Prio
r rec
ords
Dry
-Mix
ed E
verg
reen
Fo
rest
[N=5
0]
Dry
-Mix
ed E
verg
reen
Fo
rest
-di
stur
bed
[N=1
9]
Shor
t-Sta
ture
For
est
[N=1
2]
Roc
k O
utcr
ops
[N=7
]
Scru
b [N
=6]
Gra
ssla
nd [N
=2]
AMPHIBIANSBufonidae Bufo melanostictus I 6 1 1Bufonidae Bufo scaber I 7Microhylidae Kaloula taprobanica I 2Microhylidae Microhyla rubra I 1Microhylidae Ramanella variegata I 5Microhylidae Uperodon systoma I 1Ranidae Euphlyctis cyanophlyctis I 13Ranidae Euphlyctis hexadactylus I 9Ranidae Fejervarya limnocharis I 26 2 1 1Ranidae Hoplobatrachus crassus I 3Ranidae Lankanectes corregatus E 1Ranidae Philautus regius E 1Ranidae Polypedates cruciger E 11 1 1Ranidae Polypedates maculatus I 13Ranidae Rana gracilis E 2Ranidae Sphaerotheca breviceps I 2Ranidae Sphaerotheca rolandea I 1 1
REPTILESAgamidae Calotes calotes I 5Agamidae Calotes ceylonensis E VU 1Agamidae Calotes liolepis E VU 8 1 1Agamidae Calotes versicolor I 8Agamidae Otocryptis nigristigma E 13 3 2Bataguridae Melanochelys trijuga I 3Colubridae Ahaetulla nasuta I 2 1 1Colubridae Ahaetulla pulverulenta I NT 1Colubridae Amphiesma stolatum I 1Colubridae Boiga beddomei I 1Colubridae Boiga ceylonensis I 1Colubridae Boiga forsteni I 1Colubridae Boiga trigonatus I 2Colubridae Chrysopelea ornata I NT 1Colubridae Chrysopelea taprobanica E 1 1 1Colubridae Dendrelaphis tristis I 1Colubridae Dryocalamus nympha I NT 1Colubridae Liopeltis calamaria I VU 1Colubridae Lycodon aulicus I 3Colubridae Lycodon osmanhilli E 1Colubridae Lycodon striatus I 1Colubridae Oligodon arnensis I 1Colubridae Oligodon sublineatus E 1 1 1Colubridae Ptyas mucosa I 1 1 1Elapidae Bungarus caeruleus I 1Elapidae Bungarus sp1. I 1 1Elapidae Naja naja I 3Gekkonidae Cnemaspis alwisi E 14Gekkonidae Cnemaspis jerdonii E 5 2 1Gekkonidae Cnemaspis podihuna E EN 12 2 1 1Gekkonidae Cnemaspis retigalensis E 42 33 9 4 4 1 1Gekkonidae Cyrtodactylus fraenatus E CR 1 1 1Gekkonidae Geckoella yakhuna E 2 2 2Gekkonidae Gehyra mutilata I 3Gekkonidae Hemidactylus brookii I 7Gekkonidae Hemidactylus depressus E 10 2 1 1Gekkonidae Hemidactylus frenatus I 2Gekkonidae Hemidactylus leschenaultii I 4Gekkonidae Hemidactylus triedrus I 2Pythonidae Python molurus I 1
PAM & WC Project 44 Department of Wildlife Conservation
Family Genus Species
Geo
grap
hic
Sta
tus
Con
serv
atio
n st
atus
-na
tiona
l
Tota
l no.
opp
ortu
nist
ic re
cord
s
Tota
l no.
indi
vidu
als
/rec
ords
for
quad
rats
[N=9
6]
No. quadrats within which species recorded in each habitat type
Prio
r rec
ords
Dry
-Mix
ed E
verg
reen
Fo
rest
[N=5
0]
Dry
-Mix
ed E
verg
reen
Fo
rest
-di
stur
bed
[N=1
9]
Shor
t-Sta
ture
For
est
[N=1
2]
Roc
k O
utcr
ops
[N=7
]
Scru
b [N
=6]
Gra
ssla
nd [N
=2]
Scincidae Dasia halianus I 1Scincidae Eutrophis carinata I 3 1 1Scincidae Eutrophis macularia I 15 9 3 2Scincidae Lankascincus (cf)deignani E EN 54 1 1Scincidae Lankascincus fallax E 12 6 2 2 1Scincidae Lankascincus DWSL200605001 E 37 7 3 2 1 1Scincidae Lygosoma punctatus I 1Scincidae Nessia bipes E EN 6 2 1 1Testudinidae Geochelone elegans I VU 1Trionychidae Lissemys punctata I VU 2Typhlopidae Typhlops sp I 1 1 1Typhlopidae Typhlops sp2 I 1Uropeltidae Rhinophis oxyrynchus E 1Uropeltidae Uropeltis sp1. I 1 1Varanidae Varanus bengalensis I 6Viperidae Daboia russelii I 1Viperidae Hypnale hypnale I 3 2 1 1Viperidae Hypnale nepa E NT 1
BIRDSSource of information for prior records: DWC (1997)Accipitridae Accipiter badius I 2 0 0 0 Accipitridae Accipiter trivirgatus I 1 0 0 1Accipitridae Haliaeetus leucogaster I 1 1 0 1 Accipitridae Ichthyophaga ichthyaetus I 2 0 0 0Accipitridae Ictinaetus malayensis I 4 0 0 0 Accipitridae Pernis ptilorhyncus I 1 0 0 1Accipitridae Spilornis cheela I 16 1 0 0 1 Alaudidae Mirafra assamica I 1 2 0 0 2Alcedinidae Ceyx erithacus I 2 4 3 0 1Apodidae Apus affinis I 2 2 0 1 1 Apodidae Collocalia unicolor I 1 3 0 1 1 1Apodidae Cypsiurus balasiensis I 1 3 0 1 1 Bucerotidae Anthracoceros coronatus I 1 2 0 2Bucerotidae Ocyceros gingalensis E 31 22 5 7 1 1 1 Centropodidae Centropus sinensis I 88 5 2 2 Charadriidae Vanellus indicus I 2 0 0 0 Cisticolidae Prinia inornata I 1 0 0 1Cisticolidae Prinia socialis I 4 0 0 0 Columbidae Chalcophaps indica I 13 9 5 2 1 Columbidae Streptopelia chinensis I 11 7 3 4 Columbidae Treron bicincta I 1 0 0Columbidae Treron pompadora I 2 5 3 0 2 Corvidae Aegithina tiphia I 47 71 24 14 2 2 4 2 Corvidae Coracina macei I 2 0 0 0 Corvidae Coracina melanoptera I 2 2 1 1 Corvidae Corvus macrorhynchos I 1 0 0 0Corvidae Dicrurus caerulescens I 5 6 3 3 Corvidae Dicrurus paradiseus I 3 0 0 0Corvidae Hemipus picatus I 1 1 1 0 Corvidae Hypothymis azurea I 10 32 15 6 1 Corvidae Oriolus xanthornus I 19 12 4 3 1 Corvidae Pericrocotus cinnamomeus I 2 1 0 0 1 Corvidae Pericrocotus flammeus I 3 2 0 Corvidae Rhipidura aureola I 1 0 0 0Corvidae Tephrodornis pondicerianus I 1 1 0 1 Corvidae Terpsiphone paradisi I 14 33 14 6 2 1 Cuculidae Cacomantis passerinus M 2 0 0 0 Cuculidae Cuculus micropterus I 1 0 0 0Cuculidae Eudynamys scolopacea I 3 0 0 0 Cuculidae Phaenicophaeus viridirostris I 2 1 0 1 Falconidae Falco peregrinus I 1 0 0 0
PAM & WC Project 46 Department of Wildlife Conservation
MAMMALSSources of information for prior records: DWC (1997), Green and Gunawardena (1997), Miththapala (2006).Bovidae Bos indicus X 1 0Bovidae Bubalus bubalis X 1 0Canidae Canis aureus I 19 11 1 Cercopithecidae Macaca sinica E NT 24 4 1 Cercopithecidae Semnopithecus vetulus E VU 13 0 Cervidae Axis axis I 5 5 1 1 1 Cervidae Cervus unicolor I 2 12 3 6 1 1 1 Cervidae Muntiacus muntjak I 2 0 Elephantidae Elephas maximus I VU 10 17 5 4 1 Herpestidae Herpestes edwardsii I 2 0 Herpestidae Herpestes brachyurus I 1 1 Herpestidae Herpestes smithii I 2 0 Herpestidae Herpestes vitticollis I 1 1 1Hystricidae Hystrix indica I 14 1 3 1 Leporidae Lepus nigricollis I 1 0 Lorisidae Loris lydekkerianus I NT 2 0 Megadermatidae Megaderma lyra I 1 1Muridae Bandicota indica I 1 1 Muridae Millardia meltoda I 1 1Muridae Cremnomys blanfordi I 7 1Muridae Rattus rattus I 5 34 7 3 1 1Muridae Tatera indica I 6 0Mustelidae Lutra lutra I VU 1 0 Pteropodidae Cynopterus sp.A I 5 1Pteropodidae Cynopterus sphinx I 2 1Rhinolophidae Rhinolophus rouxii I 3 1 1 1Sciuridae Funambulus layardi E VU 1 1 1Sciuridae Funambulus palmarum I 3 1 1 Sciuridae Funambulus sublineatus I VU 4 2 1 1Sciuridae Ratufa macroura I VU 1 3 1 2 Suidae Sus scrofa I 2 3 2 1 Tragulidae Moschiola meminna E 4 5 2 2 1 Ursidae Melursus ursinus I EN 14 9 4 1 Vespertilionidae Kerivoula picta I EN 1 1Vespertilionidae Pipistrellus tenuis I 1 1Viverridae Paradoxurus hermaphoditus I 3 0 Viverridae Viverricula indica I 1 5 4 1
Mammals: Values are based on either direct observations or signs (tracks, droppings etc) confirmed with confidence.
Family Genus Species
Geo
grap
hic
Sta
tus
Cons
erva
tion
stat
us -
natio
nal
Opp
ortu
nist
ic re
cord
s
Tota
l no.
indi
vidu
als
[N=
53]
No. sites within which speciesrecorded in each drainage
Prio
r rec
ords
East
ern
drai
nage
[N =
36]
Wes
tern
dra
inag
e[N
=17]
FISHBagridae Mystus vittatus I 0 23 6 5Channidae Channa punctata I 0 32 4 5Cobitidae Lepidocephalichthys thermalis I 0 48 8 3Cyprinidae Amblypharyngodon melettinus I 0 27 3 3Cyprinidae Chela laubuca E 0 22 2 2Cyprinidae Devario malabaricus I 0 94 12 2Cyprinidae Esomus thermoicos E NT 0 14 3 3Cyprinidae Puntius amphibius E DD 0 55 6 6Cyprinidae Puntius bimaculatus I 0 52 7 4Cyprinidae Puntius chola I 0 2 2 0Cyprinidae Puntius singhala E 0 3 0 1Cyprinidae Puntius ticto E 0 9 5 2Cyprinidae Puntius vittatus I 0 203 6 1Cyprinidae Rasbora caverii I 0 276 14 9Cyprinidae Rasbora daniconius I 0 38 3 1Cyprinidae Tor khudree I 0 4 0 1