EVR ECOLOGY - Halton Borough Council · 2014. 5. 20. · Cheshire SK7 6JD Prepared for: Paul Oldfield Bio Diversity Officer Mersey Gateway Project The Waterloo Centre Waterloo Road

Mersey Gateway Project

EVR ECOLOGY

Common Bird Census 2011

Report number: MG-2011–CBC-01-EVR Author: Rob Smith

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Common Bird Census 2011 Mersey Gateway Project EVR Ecology

This report has been prepared with all reasonable skill, care and diligence, within the terms of the contract with the Client. EVR accepts no responsibility of whatever nature to third parties to whom this report may be made known.

Dr. E. Barratt MIEEM 3 Rutland Road, Hazel Grove, Stockport. Cheshire SK7 6JD

Prepared for: Paul Oldfield Bio Diversity Officer Mersey Gateway Project Third Floor The Waterloo Centre Waterloo Road Widnes WA8 0PR

Date of Issue 31st October 2011

www.evrecology.co.uk

mammal specialists * amphibian and reptile surveys * protected species surveys * conservation projects

Common Bird Census Wigg Island L.N.R- Widnes Warth-Astmoor Saltmarsh-Astmoor Lagoon

Report No: MG-2011–CBC-01-EVR Compiled by: Rob Smith

EVR ECOLOGY

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CONTENTS

1. SUMMARY ………….….................................................................................................................. 3

2 CONSTRAINTS OF SURVEY ........................................................................................................ 3

3 SURVEY AREAS ....................................................................................................................... 3

3.1 Astmoor Saltmarsh ........................................................................................................ 3

3.2 Astmoor Lagoon ........................................................................................................ 4

3.3 Wigg Island LNR ........................................................................................................ 4

3.4 Widnes Warth ......................................................................................................... 4

4. METHODOLOGY and RESULTS …………………….............................................................. 4

4.1 Methodology ..…………....................................................................................................... 4

4.2 Results ....................................................................................................................... 5

5. OBSERVATIONS .…………………............................................................................................. 5

5.1 Astmoor Saltmarsh …………………………………………………………………………. 5

5.2 Astmoor Lagoon ........................................................................................................ 6

5.3 Wigg Island LNR ........................................................................................................ 6

5.4 Widnes Warth .………………………………………………………………………… 7

6. PERSONNEL ............................................................................................................................... 7

7. LEGISLATION AND POLICY ........................................................................................................ 7

8. REFERENCES …………………........................................................................................................... 8

9. APPENDIX – Breeding Bird Status ………..……………………………………………………… 9

Appendix 1 – Astmoor Saltmarsh, Astmoor Lagoon & Wigg Island LNR .…………..… 9

Appendix 2 – Widnes Warth …………………………………………………………………….. 11

Appendix 3 – Survey dates & Weather Conditions …………………………….…………… 12

Appendix 4 – Maps of Key Breeding Species ……………………………………………….. 13

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1. SUMMARY In 2011, EVR Ecology was commissioned to undertake a Common Bird Census on four defined locations in Halton for the Mersey Gateway Project team. The locations comprise Widnes Warth, Wigg Island LNR, Astmoor Saltmarsh and Astmoor Lagoon on the north and south banks of the Mersey respectively. The Common Bird Census was carried out according to criteria defined by the British Trust for Ornithology (BTO) which included a minimum of 10 visits between March and July, including two evening visits to record nocturnal species. The result and methodology are summarised in section 4 and shown in Appendix 1 and 2. 2. CONSTRAINTS OF SURVEYS Constraints and limitations included:

• Access to the fenced off area in Phase 2 was delayed during the early part of the breeding survey until a key could be produced.

• Astmoor lagoon had dried out by mid-June which had impact on breeding species and in particular wildfowl.

• Cattle were introduced onto Widnes Warth in early spring creating some habitat alteration and an impact on Phragmites associated species.

• Public access was apparent on Widnes Warth throughout the duration of the survey and possibly had an impact on breeding waders and wildfowl.

• A marked deterioration in weather conditions from mid-May onwards had an impact on survey dates and recording as well as breeding indications. 3. SURVEY AREAS 3.1 Astmoor Saltmarsh Astmoor Saltmarsh covers an area of approx. 49Ha on the southern edge of the Mersey. The marsh is dotted with a number of pools and ditches and cut across by two tidal creeks. Most pools and ditches dry out by mid-summer. As with the 2002 survey, Astmoor Saltmarsh is predominantly low diversity SM24 Sea Couch saltmarsh community that is characteristic of un-grazed, upper saltmarsh habitat. With the exception of a few small patches dominated by Spear-leaved Orache, the saltmarsh is noticeably in retreat at its western extremity and as a result several areas of open water have been lost though drainage and succession. The survey results are compatible with the mitigation objectives for the conversion of the SM24/28 Sea Couch saltmarsh community to saltmarsh communities that are representative of saltmarsh in favourable ecological condition in terms of botanical species-richness and natural saltmarsh topography, and as roosting and feeding habitats for wildfowl and waders.

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3.2 Astmoor Lagoon The freshwater lagoon covers an area of approx. 15ha and is located east of Wigg Island LNR. The lagoon comprises areas of open water and several islands surrounded by dense stands of Phragmites with a deep water channel running along its northerly edge. The Lagoon has changed significantly since the 2002 survey and the rapidly spreading Phragmites australis had completely, or partially overtaken many of the previously pure stands of Typha latifolia. This species now dominates in greater part the vegetated sections of the Lagoon. As the breeding season progressed the lagoon dried out gradually and became completely dry by July. 3.3 Wigg Island Local Nature Reserve The Local Nature Reserve (LNR) occupies an area of approx. 24ha and comprises open spaces, scrub and planation woodland. The LNR is interspersed with hard and soft footpaths and has a disused section of the Runcorn canal running through its central area. The site is managed for its wildlife interest with a section of the reserve (Phase 2) restricted access for nature conservation and educational purposes. The fenced off area referred to as Phase 2 was accessed later in the breeding season once a key had been released. 3.4 Widnes Warth This area is some 44Ha in extent on the north shore of the Mersey upper estuary. The area is dominated by saltmarsh designated as SM24/28 and some areas of SM12. The dominant plant species is Couch grasses. The site is criss-crossed by creeks and punctuated by a number of pools, most of which dried out rapidly in the dry spring of 2011. The marsh was divided in to three sections the smallest area in the eastern part of the site being grazed by Longhorn Cattle for the greater part of the survey. The area is subject to tidal inundation on several occasions each year, principally in the autumn and winter months. 4 METHODOLOGY AND RESULTS 4.1 Methodology The survey was carried out on all four areas according to criteria laid down for the Common Bird Census (CBC) as defined by the BTO and according to the terms of reference agreed with the Mersey Gateway Project Bio-Diversity Officer. The survey comprised a minimum of 10 visits to the four zones between March and July 2011 and included two nocturnal visits. During each survey all birds demonstrating breeding behaviour and in particular territorial singing males were mapped in the field using standardised BTO species and activity codes. A preliminary visit was made to all four locations in March to establish survey routes and ensure a consistency to the data sets. The dusk surveys were carried out jointly by Rob Smith and Jeff Clarke.

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Data from each session was entered onto computer and into the Map Info GIS system. Data was analysed and maps of territories produced according to the terms of reference by the Mersey Gateway Project team. 4.2 Results Results of the Common Bird Census for Wigg Island LNR, Wigg Island Saltmarsh and Astmoor Lagoon are shown in Appendix 1, Tables 1- 3 and for Widnes Warth in Appendix 2, Tables 4 – 6. In most cases territories have been calculated by using the number of singing males as the primary indicator on two or more visits. But the survey also took into account signs of breeding such as adults carrying food, anxiety calls, nest, eggs and young. Maps illustrating the locations of key breeding species are shown in Appendix 4, Maps 1 - 4. 5. OBSERVATIONS Some warblers such as Chiffchaff and Blackcap were recorded as early as 29th March but the main ‘Fall’ of warblers occurred on or around the 12th April 2011, which is approximately two weeks earlier than the average. The number of singing/ calling birds at this time was high and remained so for several days making any assessment of status during this period inconclusive. As the season progressed and territories became established a more accurate assessment of status could be made. Large numbers of duck were recorded on Astmoor Lagoon on several early spring dates but only a few pair went onto set up territory or breed. With the female

bird sitting on the nest and males moving away from the breeding zone a species can appear absent or unsuccessful until young are noted but as the riparian

vegetation grew this became difficult to confirm. As a result, breeding success was based on direct evidence of young being recorded.

In addition one of the driest breeding seasons for many years and the consequent drying out of all pools and scrapes by late spring had a considerable impact

on the numbers of breeding wildfowl and waders recorded. This makes the data set unreliable as a base line for this group of species in 2011.

5.1 Astmoor Saltmarsh After a noticeable fall of warblers in early April, Grasshopper Warbler was recorded singing on many parts of the saltmarsh and adjacent to the lagoon for several days. The species eventually settled out to a minimum of 5 pairs breeding along the scrubby areas adjacent to Wigg Island LNR and Astmoor Lagoon. This is comparable to ornithological survey carried out in 2010. Canada Geese attempted to breed on the marsh with several nest and eggs noted but by the following CBC session - 10 days later, all nests were empty and no young were seen (6 goslings were noted in a subsequent survey but assessed as having bred on the Lagoon).

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Despite the thick mat of vegetation covering the floor of the marsh, a minimum of 14 pairs of Meadow Pipit and 8 pairs of Skylark bred with most territories recorded in the mid to eastern section of the marsh. This is a considerable increase for both species on the 2010 survey results. Unlike the 2010 survey, no waders were recorded breeding or attempting to breed on the marsh. 5.2 Astmoor Lagoon Poor weather conditions and in particular persistent light to moderate cool winds from mid-May onwards, created sub-optimal conditions for recording singing males in the reed beds. As with the previous location, the fall of warblers in April resulted in considerable numbers of Sedge and Reed Warbler being recorded in virtually every patch of vegetation in, on and around the Lagoon area. Eventually breeding settled out at 15 pairs of Sedge Warbler and 10 pairs of Reed Warbler. This was a noticeable increase on 2010 survey results. A calling male Cettis Warbler was recorded on all survey dates throughout the breeding season; this is consistent with the breeding ecology of this particular species. For Reed Bunting, a minimum of 12 pairs bred which was a considerable increase on the 2010 survey results. Wildfowl had mixed success. Although good numbers of Gadwall, Tufted Duck, Shoveler and Mallard were recorded early in the breeding season, only 2 pairs of Mallard and 1pair each of Little Grebe and Shelduck, bred successfully. Of note was the presence of a Black tailed Godwit on two visits and a female Marsh Harrier quartering the reed bed in early spring. 5.3 Wigg Island Local Nature Reserve The mix of scrub vegetation and recreational planting on the LNR supported a considerable number of warblers at the beginning of April but eventually resulted in a breeding population of Blackcap (15 pairs), Chiffchaff (8), Willow Warbler (10) and Whitethroat (3). Most of these species were recorded in the main part of the LNR but some held territories in the scrub and emergent woodland, on the south bank of Astmoor Lagoon. In the fenced off Phase 2 area, Willow Tit was evident and two young were ringed by Merseyside Ringing Group. A dusk survey also revealed the presence of two young Long- eared owls which were known to have bred in this area of Wigg Island.

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5.4 Widnes Warth It was noticeable that the greatest concentration of breeding birds was to be found on the middle sector of the marsh. This is the area most affected by the

proposed bridge construction.

The species most affected would be Skylark this species has an aversion to tall structures e.g. trees, buildings etc. within a significant distance of its nesting

area (This is an anti-avian predator strategy for a ground nesting bird). The new bridge structure would create a considerable inhibitory factor for Skylark and as

such the majority of pairs currently using the marsh would be lost as a result of its construction.

Redshank would be similarly affected as would Meadow Pipit to a slightly lesser degree. Most of the warblers would only be marginally affected.

6. PERSONNEL The CBC was carried out by Rob Smith and Jeff Clarke who between them have over 60 years’ experience of field surveys and studies in ornithology. Rob Smith and Jeff Clarke undertook the surveys on both sides of the R Mersey on the same dates on most, but not all, occasions throughout the breeding season - March to July, as detailed in Appendix 3 – Table 1. 7. LEGISLATION AND POLICY Wild Birds: All our wild birds and a number of animal and plant species are protected by the Habitats Directive, implemented through the UK Habitats Regulations 2010; and the Birds Directive, implemented through the Wildlife and Countryside Act 1981. These are the means by which the UK and other European countries meet their obligations under the Convention on the Conservation of European Wildlife and Natural Habitats (known as the Bern Convention) and the Convention on the Conservation of Migratory Species of Wild Animals (known as the Bonn Convention, or CMS). The Convention on International Trade in Endangered Species of Wild Fauna and Flora also helps monitor and control trade in endangered species. In the UK all wild birds are protected under the Wildlife and Countryside Act 1981, which implements the EC Wild Birds Directive in Great Britain and under which it is an offence to kill or injure any wild bird. The nests and eggs also receive protection. In some cases it can be an offence to disturb wild birds, and taking them from the wild is prohibited. The sale or trade of wild birds in some circumstances is also prohibited. Under the Wildlife and Countryside Act, a wild bird is defined as any bird of a species that is resident in or is a visitor to the European Territory of any member state in a wild state.

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The UK Biodiversity Action Plan (UKBAP) is the government’s response to the 1992 Convention on Biological Diversity. Whilst not a legislative obligation, the BAP process outlines species and habitats of priority conservation concern and plans to aid recovery. The process is supplemented by Local Biodiversity Action Plans (LBAPS), which perform a similar function at local level. The LBAP for Halton is the Halton Borough LBAP. Following recent revisions (August 2009), 59 species are listed as priority species on the UK BAP list. These species are also classified as ‘Species of Principle Importance in England’ under section 41 of the Natural Environment and Rural Communities Act (NERC) 2006. The Halton LBAP contains plans for four bird species – Redshank, Song Thrush, Reed Bunting and Skylark. The status of all British birds have also been analysed by conservation agencies, including the RSPB, and are published in Birds of Conservation Concern 3 (Eaton MA, Brown AF et al, 2009) where they are designated as either of Red or Amber status. The lists have no legal standing in themselves but are a useful guide in assessing the status of individual species in the UK. 8. REFERENCES Birds of Conservation Concern 3 - Eaton MA, Brown AF, Noble DG, Musgrove AJ, Hearn R, Aebischer NJ, Gibbons DW, Evans A and Gregory RD (2009) Bird Monitoring Methods: A manual of techniques for key species - Gilbert et al (1998). RSPB/BTO/JNCC/WWT/ITE/The Seabird Group. National Vegetation Survey 2011, Widnes Warth and Astmoor Saltmarsh; Wigg Island LNR; Astmoor Lagoon. Mersey Gateway Project. EVR Ecology

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9. APPENDIX – BREEDING BIRD STATUS The following tables detail the results of the Common Bird Census for breeding and/or potential breeding birds on all survey areas during 2011. Totals given represent minimum numbers of breeding pairs. APPENDIX 1 - WIGG ISLAND LNR; ASTMOOR SALTMARSH; ASTMOOR LAGOON Table 1: Birds of Conservation Concern (BoCC) Species Wigg

Island LNR

Wigg Island

Saltmarsh

Astmoor Lagoon

Minimum Pairs

Breeding Status

Comments BoCC Status

Common Whitethroat

4 3 - 4 Assessed Along north edge of WI LNR Amber

Grasshopper Warbler

5 5 Assessed Singing birds in fringe vegetation around edge of saltmarsh Red

Willow Warbler 8 2 10 Assessed Singing birds in scrubby areas and back of lagoon Amber

Reed Bunting 13 12 – 15 Assessed Most males in main reed bed a few along marsh edge Amber

Meadow Pipit 16 14 - 18 Assessed Displaying and agitated birds on territories and several immature birds noted later in season mostly on east side of marsh

Amber

Skylark 10 8 - 12 Assessed As with meadow pipit above Red

Song Thrush 2 2 4 Assessed Restricted to bank at rear of lagoon and main LNR area Red

Bullfinch 3 Assessed 1 pair close to bridge route Amber

Willow Tit 1 1 Confirmed 2 young ringed by MRG ringer Red

Mistle Thrush 2 2 Assessed In main area of LNR Amber

Dunnock 13 4 17 Assessed 4 singing birds on south bank behind lagoon, several territories under bridge route

Amber

Little Grebe 4 1 - 2 Confirmed nest building and 1 young recorded in separate areas of lagoon Amber

Shelduck 1 1 Confirmed Up to 2 pair noted – 1 pair with 10 young on lagoon Amber

Gadwall 4 4 Unconfirmed

Over 40 birds were recorded well into the breeding season but only 4 pairs regularly seen together but still no evidence of breeding noted.

Amber

Mallard 2 2 Confirmed Many birds recorded but only 2 pairs & 7 young noted Amber

Shoveler 12 Unconfirmed Up to 12 pair noted but breeding unconfirmed Amber

Tufted Duck 2 2 Unconfirmed Present but breeding unconfirmed Amber

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Table 2: Other breeding species Species Wigg

Island LNR

Wigg Island

Saltmarsh

Astmoor Lagoon

Minimum Pairs

Breeding Status Comments

Chiffchaff 7 3 8 – 10 Assessed Most territories on WI LNR with 3 along bank at rear of Lagoon

Blackcap 15 4 15 – 19 Assessed Most on WI LNR

Reed Warbler 10 10 Assessed After a heavy ‘fall’ settled out to this level around lagoon

Sedge Warbler 1 14 15 Assessed After heavy ‘fall’ settled out to this level around lagoon + 1pair on canal

Cettis Warbler 1 1 Presumed Consistently heard on all visits during breeding season

Goldfinch 5 4 - 6 Assessed Noted regularly in areas clear of bridge route

Long eared Owl 1 1 Confirmed 2 young heard & seen on night visit to phase 2

Blackbird 17 17 Assessed Singing birds and feeding young, several under bridge route

Coot 1 10 8 – 12 Confirmed Most noted sitting on nests but very few young seen later

Water Rail 2 Unconfirmed Recorded in two locations but unconfirmed breeder

Mute Swan 1 1 2 Confirmed 5 and 7 cygnets recorded

Canada Goose 4 6 10 Confirmed 10 nests noted but only 6 goslings recorded on 6/6/11

Common Buzzard 2 Unconfirmed Noted around area on several dates but no young recorded

Table 3: Birds of interest Species Wigg

Island LNR

Wigg Island

Saltmarsh

Astmoor Lagoon

Comments BoCC Status

Marsh Harrier 1 Female on 12/5/11

Ruddy Duck 1 Female present on 1/3/11

Sand Martin 7 Small colony of 7 pairs noted on bank opposite Visitor Centre

Greylag Goose x x Up to 5 birds noted on occasions, non-breeders Amber

Lesser Canada Goose 1 Among Canada Geese on a few dates

Black Tailed Godwit 1 Seen on 12/5/11 & stayed around for 3 – 4 weeks Red

Cuckoo 1 Flew west on 12/5/11 Red

Garden Warbler A single bird noted along east edge of phase 2 on 12/4/11

Lesser Whitethroat 1 In same area and on same date as above

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APPENDIX 2 – WIDNES WARTH

Table 4: Birds of Conservation Concern Species Widnes Warth

Breeding Status Comments BoCC

Status

Gadwall 1 Confirmed Single nesting female off eggs Amber

Dunnock 3 Assessed Breeding birds already established on commencement of survey Amber

Common Whitethroat 16 - 21prs Assessed Commonest breeding warbler Amber

Grasshopper Warbler 3 - 4prs Assessed Probably under-recorded Red

Grey Partridge 0 - 2 prs Assessed Based on calling males Red

Linnet 1 - 2 prs Assessed Present thoughout Red

Meadow Pipit 16 – 32 prs Assessed Actual total likely to be at upper end of estimate Amber

Redshank 2 –3 prs (failed) confirmed Probably predated Amber

Reed Bunting 2- 4 prs Assessed Limited by Phragmites growth Amber

Skylark 20 - 27 prs Assessed Actual total likely to be at upper end of estimate Red

Willow Warbler 1-3 prs Assessed Marginal habitat. All birds on territory edges. Amber

Table 5: Other breeding species Species Widnes Warth


Blackcap 1 pr Confirmed Confined to limited habitat on northern fringe of site

Chiffchaff 1pr (feeding young) Confirmed Nested on edge of territory

Lesser Whitethroat 0-1pr Assessed Single territorial male over a period of weeks.

Reed Warbler 2 - 3 prs Assessed Limited by Phragmites growth

Sedge Warbler 8 - 10 prs Assessed Only 1 male failed to attract a mate.

Table 6: Birds of Interest Species Widnes Warth


Waxwing 70+ On northern fringe of site on 15th March

Yellow Wagtail 1 Migrant dropped in briefly to cattle grazed area.

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Appendix 3 - Survey Dates and weather conditions Most of the early recording sessions were carried out in fair to good conditions but as the spring progressed poor weather conditions prevailed which had an impact on a number of surveys beyond mid-May.

Visit Date Time Conditions Site

1 1st & 2/3/11 9.00 – 11.00 Plotting surveys WI / AST/WW

2 15/3/11 7.00 – 11.00 Dull & overcast, cool, misty, damp, 100% cloud WI / AST/WW

3 29/3/11 7.15 – 11.10 Dull & overcast, cool, damp, 70% cloud WI / AST/WW

4 12/4/11 7.30 to 11.30 19.30 – 21.30

Bright, Sunny & warm, light breeze - Dusk survey Evening survey

WW WI / AST

5 26/4/11 7.00 – 11.20 Dull & overcast, cool, light W wind, 75% WI / AST/WW

6 6/5/11 7.00 – 11.30 Dull & overcast, light-mod SE wind, light rain, 100% WI / AST/WW

7 12/5/11 7.00 to 10.30 20.00– 22.30

Dusk Survey – cool, bright, l-mod W, 80%

WW WI / AST

8 17/5/11 7.30 – 11.45 Dull & overcast, light SW wind, drizzle at times, 80% WI / AST/WW

9 27/5/11 8.15 – 12.00 Cool & damp, light to mod W, light occasional rain, 80% WI / AST/WW

10 2/6/11 6.30 – 10.00 15c, 100% cloud, light nw winds f2, dry WW

10 6/6/11 7.30 – 11.30 Bright & sunny, light W wind, 60% WI / AST

11 10/6/11 21.00– 23.00 Dusk survey - Bright & sunny, cooling, light W, 10% WI / AST

12 21/6/11 7.00 – 11.35 Dull & overcast, warm, light N wind, 90% WI / AST/WW

13 13/7/11* 7.00 – 10.00 Bright & sunny, 15% cloud, 15c+, F2 ENE wind WW

* Although a survey was carried out results were poor and indicative of a breeding season effectively finished. This data set was excluded from the final

analysis but is available if required.

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EVR ECOLOGY - Halton Borough Council · 2014. 5. 20. · Cheshire SK7 6JD Prepared for: Paul Oldfield Bio Diversity Officer Mersey Gateway Project The Waterloo Centre Waterloo Road

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