Reptile Ecology and Conservation

Reptile Ecology and Conservation Level 4 Unit 1 Unit 1

Intellectual property of Animal Biology and Care Ltd. 1

Reptile Ecology and Conservation

Level 4

UNIT 1

Approximate learning hours: 15

Ecology and Reptiles



Learning outcome

At the end of this unit, learners should be able to

1.0 Identify and describe major habitats and biomes, explain the concept of an ecosystem,

food chain and food web and, the effects of imbalances to these systems in terms of reptile

populations

Selected references: pages 22 to 23

Internet resources: page 24



1.0

Ecology and Reptiles

1.0 Identify and describe major habitats and biomes, explain the concept of an ecosystem,

food chain and food web and, the effects of imbalances to these systems in terms of reptile

populations

Introduction

Ecology is the study of the relationship between an organism and its environment both the

physical (abiotic) and the living (biotic). This course is aimed at in situ conservation of the

reptile thus an understanding of reptile ecology is vital to the success of conservation efforts.

The course should also support those who are aiming to succeed in ex situ conservation of

reptile species.

Additionally, the course can be used to support captive reptile welfare even if conservation is

not the aim given that reptiles kept out of their natural environment, suffer from ignorance

and lack of understanding of their true needs.

Self-directed research is expected to support learning and the assignment.



Biomes

A biome refers to the major type(s) of community found in a broad geographical region (figure

1) and it includes climate, geography, vegetation and soils. The defining factor of a biome is

the vegetation type. Figure 2 elaborates on biome types and their distribution.

Within each there are multiple variations and sub-classifications (e.g. within Aquatic and

wetland habitats there may be freshwater or marine, river or stream, lake or pond, marsh or

mangroves, etc.). Additionally, there are different biomes according to climate:

• Tropical

• Temperate

• Mediterranean

Within a biome, multiple habitats will occur and within those, there will be microhabitats that

certain organisms can exploit. Therefore, the definition of a habitat focuses on the

perspective of the organisms that occur there. A species’ habitat can include multiple

environmental types or, biomes. The only biome where reptiles are not found is that of the

polar and tundra regions (certain amphibia are present within the tundra).

Therefore, it may be more accurate to refer to a specific population’s habitat rather than a

species’ habitat. The habitat of a population will still comprise all the physical or non-living

elements (abiotic) and, the living element (biotic) of that environment.





Figure 1 Global Distribution of Major Biomes



Figure 2 Detailed Distribution of Major Biomes

Taiga is often referred to as the Northern Boreal Forest



The Ecosystem Concept

An ecosystem consists of the entire biotic element in a community of organisms (plants,

animals and microorganisms) that live and interact. All must interact too, with the abiotic

factors (e.g. air, water, soil or rocks, temperature, sunlight ).

There are no discrete boundaries to a natural ecosystem (they are “open”) and each

ecosystem will be structured by feeding relationships. There are complex interactions

between each part of the ecosystem and often multiple reactions occur at many different

levels of the ecosystem. With a single change at only one level of the ecosystem, an

imbalance can occur.

Various pathways of energy (figure 3), flow occur within an ecosystem including chemical

cycles. There is a concept that explains how energy is “lost” as it is passed through the

different levels of an ecosystem. Energy enters the ecosystem in the form of sunlight (light

energy), and then converted into chemical energy (sugars) by plants and microorganisms. Such

organisms can also use an inorganic form of carbon (carbon dioxide) to assimilate into their

cells. This ability causes plants to be termed “autotrophs” or, self feeders as they can produce

their own “food”. The chemical energy stored within a plant is passed onto the organisms that

consume the plant and eventually as energy “lost” in the form of thermal energy (heat)

produced the metabolic processes of the organisms. This includes reptiles. Figure 4

demonstrates this change in energy availability in terms of kilocalories and consumer level

and, a desert/semi-desert ecosystem in the from of a pyramid of energy.

However, unlike this form of energy which cannot be recycled, matter is continually recycled

within and between ecosystems and the chemical elements of matter move between the living

and non-living components of the ecosystem.



Figure 3 Suggested Food Web with Energy Transfer (North American example)

A combination of biological and geological processes drive the chemical cycles of an

ecosystem and disruption at any level can have severe repercussions throughout the

ecosystem. The nitrogen and carbon cycles provide good examples of how elements of an

ecosystem are inter-connected.



Figure 4 Pyramid of energy based upon a desert/semi-desert habitat and ecosystem

More productive ecosystems with plant-rich habitats would provide a greater base to the

pyramid on terms of available energy. Approximately only 10% of energy in a level is passed

onto the next.



The concepts of the carbon and nitrogen cycles, energy transfer and water cycle should be

able to be explained in terms of their nature as a concept and, their operation.

Note: For each biome and habitat there are equivalent ecosystems. For example:

Grassland (or savannah) ecosystem

Rainforest (or temperate forest) ecosystem

Beach (or coastal) ecosystem

Marine ecosystem

Freshwater ecosystem

Wetland (or marsh) ecosystem

Mountain ecosystem

Desert ecosystem



The Concepts of a Food Chain and Food Web

The pathway on which matter (in the from of nutrients), is transferred between one part of an

ecosystem and the next is called a food chain. The interactions between different parts of an

ecosystem are termed a food web.

Organisms either “make” their own food (autotrophs) by obtaining an inorganic form of carbon

or, must rely on other organisms for their carbon source. Such organisms are termed

heterotrophs as they are unable to convert an inorganic carbon source for assimilation into the

body. The first stage of most food chains involves green plants and certain microorganisms

although the plants are usually recognised as the primary producers. Primary producers are

consumed by the primary consumers and these in turn are consumed by secondary consumers.

Tertiary consumers tend to be those animals at the top of the food chain, are highly

specialised and fewer in number. In certain ecosystems, quaternary consumers are at the top

of the food chain (figure 5).

However, if an animal or part of the body is not eaten, decomposition occurs by

microorganisms termed as the decomposers. Nutrients within the decomposing animal (e.g.

nitrogen, which is the key component of proteins), are released into the soil. As such, the

cycling of nutrients is continuous within an ecosystem. Decomposition of plant materials

follows a similar path with the stored nutrients being broken down to their component parts

and released to the soil.



Figure 5 Simplified Food Chain with a Tertiary and Quaternary Consumer

(Final Consumer)

Resourced from: http://pixshark.com.htm

Decomposition refers to any biotic substance including faeces, urine, parts of and complete

organisms. The nitrogen cycle should include this pathway of nutrient recycling. Nutrients

obtained from the soil by the plant are transferred through the food chain to the secondary

consumers. However, the relationships between producers and consumers are not always

straightforward as some animals eat both plants and, other animals.

Consumers can be categorised into carnivores, omnivores and herbivores. Examples of

omnivores include many lizards but all snakes are carnivorous. Note that within the categories

of carnivores and herbivores there are various sub-categories. For example, insectivores are

animals that specialise in insects as their food source. Certain reptiles begin life as

insectivores but alter as they mature to consume plant and animal matter with the former

being the primary food source. Every living thing, irrespective of their dietary type, in a given

area can be linked either by a food web or, a food chain.



The Niche Concept

An organism is said to “fit into” a given environment or, has a place amongst all the other

living components. They have a niche or slot into which they function and influence all other

organisms within the same habitat. Niche separation describes how each organism can survive.

A top predator could be said to have the most precarious niche because they rely upon all

other biotic factors down the food chain. They can remain in their niche only as long as all

other organisms are functioning successfully within their respective niches.

The niche concept should be understood in relation to the reptile together with niche

separation as a means of existing successful within a community of species.

Reptile Ecology and Conservation Level 4 Unit 1


Balance and Imbalance

Due to the complexities of interactions between components of an ecosystem and food web,

interference at any level (e.g. from pollution, extinction of a species, overpopulation of a

species, loss of vegetation, introduction of a non-endemic species, illegal collecting of certain

species), can have irreversible effects on the ecosystem and all the organisms within it.

For example, the Florida everglades have been invaded by the Burmese Python reportedly

released by reptile keepers when the animals become too large to maintain. The Davidson

College Herpetology Lab (2015)*, report on various findings and methods of removing this

invasive species although they do not cite references to support their comments.

The evidence and argument of the effect of the Burmese Python and other constrictors on local

ecology is vigorous. For example, Dorcas et al (2011), suggest there may be evidence of impact

through a correlation between invasion of the Burmese Python and a decline in other indigenous

species. A correlation does not though, infer a relationship. Then again Pyron et al (2008), using

the niche model, dispute claims that these reptiles will spread continent-wide from the Florida

Everglades because their ecological niche is influenced by their ecological needs. A point of

discussion may be that many researchers focus on climate change dogma but do not seem to

consider reptile physiology.

*See internet resources and references at the end of this document.



Human activity and ecosystems

Apart from the release of species that become invasive, human activity has many facets related

to habitat disturbance:

Land degradation

• deforestation

• conversion of land to agricultural use

• pollution

• draining of marshes or wetlands

• desertification (e.g. through over-grazing)

• fire

Urbanisation

• human settlements that occupy previously natural habitats

• pollution (land, air, water) and waste production (sewage, landfill, etc.)

• agricultural run off

• roads and other infrastructure which cut through natural habitats

• resource depletion (e.g. fish stocks, fossil fuels, water, land, timber)

• fossil fuels – mining, depletion of inhabitable land, pollution

Land clearance

• habitat encroachment

• hunting

• habitat degradation or loss of prey

• poaching and bush meat trade

• restriction of migratory routes for terrestrial species



Introduction to Biogeography of the Reptilia

Biogeography refers to the location of biological forms across continents and oceans. This factor

is linked with the distribution of biomes. Although animal life is found on every continent, the

reptilia are found on six of the seven continents. Reptiles are not extant on the Antarctic

continent although fossil remains have been identified.

The majority of reptiles are located in geographic climate zones that are consistently warm and

not just seasonally warm. As a habitat can be defined as the place where an animal lives,

reptiles have adaptations to their varied habitats. For example, the marine Iguana

(Amblyrhynchus cristatus – figures 6 and 7) of the Galapagos Islands can secrete excess salt

taken up when in seawater. There are number of sub-species with adaptations to foraging in

marine water.

Figure 6 The Marine Iguana (Amblyrhynchus cristatus) basking

in the Galapagos islands. Source: Wiki Commons



Figure 7 The only marine-dwelling reptile (Amblyrhynchus cristatus),

swimming to feed on marine vegetation. Source: Wiki Commons

Iguana iguana (figure 8) is an herbivorous reptile of the American continents. When young, I.

iguana consumes animal-based foods.

Figure 8 The Green Iguana (Iguana iguana) Source: Wiki Commons

The regions of the Americas inhabited by the Green Iguana are hot, humid and receive heavy

rainfall and are identified as tropical to equatorial climatic regions (figure 8).



Figure 8 Central regions of the Americas including the Amazonian rainforest. Source: Wiki Commons

The Horned lizard (Phrynosoma platyrhinos), is an example of an omnivorous reptile that

inhabits areas of an arid, extreme temperature range climate. P. platyrhinos (figure 9) is found

in arid regions of North America (e.g. Nevada, Wyoming, and Utah). Plant material is scarce

unlike in tropical regions but, insects can thrive.

Figure 9 A Horned lizard in a dry, barren habitat found in semi-desert regions of N. America.

They are sometimes called erroneously, Horned Toads. Source: Wiki Commons

Caribbean region

Brazil

Venezuela, Costa Rica, Guiana, Guyana,

Panama, Nicaragua, Columbia



Some reptiles favour an aquatic habitat, rarely coming emerging from the water except to bask

and lay eggs. The Crocodilia, turtles and the related terrapins are examples. Turtles live their

whole life in the deep ocean but favour the upper waters and coral reef habitats of a marine

environment. The related Terrapins however(figure 10), are found across temperate and

warmer regions from the United States of America to the Far East. They are found in many

habitats but water habitats feature strongly including brackish water, and freshwater ponds and,

marshland.

Source http://vintageprintable.swivelchairmedia.com/animal/animal-reptile-amphibian/

*See Swain and Kearsley, (2001).

Figure 10 Malachlemeys terrapin*.

The common name and scientific name

are the same (unless called the

Diamond Back terrapin).



Completion of unit 1.



Selected references

Chapin, F. S., Matson, P. A. & Mooney, H. A. (2002) Principles of Terrestrial Ecosystem

Ecology. Springer-Verlag, New York ISBN 0-387-95443-0 Available from:

http://www.crc.uqam.ca/Publication/Principles%20of%20terrestrial%20ecosystem%20e

cology.pdf. (Accessed 15.5.15)

Cox N.A. and Temple H.J. (2009). European Red List of Reptiles. [Online] Available from:

http://ec.europa.eu/environment/nature/conservation/species/redlist/downloads/Eur

opean_reptiles.pdf. (Accessed 13/05/2015)

Davenport, J. (2011) High-Trophic-Level Consumers: Trophic Relationships of Reptiles

and Amphibians of Coastal and Estuarine Ecosystems. In: Wolanski E and McLusky DS

(eds.) Treatise on Estuarine and Coastal Science, Vol. 6, pp. 227–249. Waltham:

Academic Press Available from:

http://www.seaturtle.org/PDF/DavenportJ_2011_TreatiseEstuarineCoastalSci.pdf.

(Accessed 16.5.15)

Dorcas, M. E., Willson, J. D., Reed, R. N., Snow, R.W., Rochford, M. R., Miller, M. A.,

Meshaka Jnr., W. E., Andreadis, P. T., Mazzotto, F. J., Romagosa, C. M. & Hart, K. M.

(2011) Severe mammal declines coincide with proliferation of invasive Burmese pythons

in Everglades National Park. PNAS, Vol. 109, 7, 2418-2422. Available from:

http://www.pnas.org/content/109/7/2418.full (Accessed 13.5.15)

Harings, N. M., Boykin, K. G. & Oligschlaeger, L. (2014) Reptile Occurrence and Habitat

Associations on Holloman Air Force Base. Herpetological Conservation and Biology

9(1):57−66. Available from:

http://www.herpconbio.org/Volume_9/Issue_1/Harings_etal_2014.pdf. (Accessed

16.5.15)

Hastings, A. K., Krigbaum, J., Steadman, D. W. & Albury, N. A. (2014) Domination by

Reptiles in a Terrestrial Food Web of the Bahamas Prior to Human Occupation Source:

Journal of Herpetology, 48(3):380-388. Available from:

http://www.researchgate.net/publication/275271413_Domination_by_Reptiles_in_a_Ter

restrial_Food_Web_of_the_Bahamas_Prior_to_Human_Occupation (Accessed 13.5.15)



Howard, K. E. & Hailey, A. (1999) Microhabitat separation among diurnal saxicolous

lizards in Zimbabwe. Journal of Tropical Ecology (Impact Factor: 1.22). 04/1999;

15(03):367 - 378. Available from:

http://www.researchgate.net/publication/231806580_Microhabitat_separation_among_

diurnal_saxicolous_lizards_in_Zimbabwe (Accessed 16.5.15)

Noble, T., Bunbury, N., Kaiser-Bunbury, C. N. & Bell, D. J. (2011) Ecology and co-

existence of two endemic day gecko (Phelsuma) species in Seychelles native palm forest.

Journal of Zoology, 283, 73–80. Available from:

http://core.ac.uk/download/pdf/2777108.pdf. (Accessed 16.5.15)

Planka, E. R. (undated) Fire Succession in the B-Area Available from:

http://uts.cc.utexas.edu/~varanus/BFS.html (Accessed 13.5.15)

Pyron, R. A., Burbrink, F. T. & Guiher, T. J. (2008) Claims of Potential Expansion

throughout the U.S. by Invasive Python Species Are Contradicted by Ecological Niche

Models. PLOS ONE, 3(8): e2931. doi: 10.1371/journal.pone.0002931. Available from:

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0002931#references

(Accessed 13.5.15)

Swain, P.C. & J.B. Kearsley (2001). Classification of the Natural Communities of

Massachusetts. Version 1.3. Natural Heritage & Endangered Species Program, Division of

Fisheries & Wildlife. Westborough, MA. Available from:

www.mass.gov/eea/docs/dfg/nhesp/natural-communities-facts/maritime-dune.pdf

(Accessed 13.5.15)



Internet Resources in no particular order.

Amphibian and Reptile Conservation. www.arc-trust.org/. (Accessed 13.5.15)

Biodiversity Group Available from: www.biodiversitygroup.org. (Accessed 13.5.15)

Conservation Gateway

www.conservationgateway.org/Pages/COL.aspx?Src=workspaces/cbdgateway/cap/index

_html (Accessed 12/05/2015).

Davidson College (USA) http://sites.davidson.edu/dorcas/invasive-pythons-in-the-

everglades/ (Accessed 13.5.15)

Recommended: Endangered Species International

http://www.endangeredspeciesinternational.org/reptiles.html pages 1 to 4 (Accessed

13.5.15)

International Reptile Conservation Foundation. http://www.ircf.org/ Accessed (13.5.15)

National Wildlife Federation (USA) www.nwf.org/news-and-magazines/national-

wildlife/animals/archives/2009/everglades-invasion.aspx (Accessed 13.5.15)

The Nature Conservancy (USA)

http://www.nature.org/ourinitiatives/regions/northamerica/unitedstates/florida/howw

ework/in-the-belly-of-a-python.xml (Accessed 13.5.15)

The Wild Classroom (USA) Recommended for updating knowledge and, as an

appropriate resource for gaining knowledge of the concepts and principles behind ecology

as a subject http://www.thewildclassroom.com/biomes/ (Accessed 13.5.15)

http://www.endangeredspeciesinternational.org/reptiles3.html

http://opwall.com/ (undated) MM277 Microhabitats and niche partitioning in

chameleons, skinks, geckos or snakes in Madagascar. Available from:

http://opwall.com/wp-content/uploads/MM277-Microhabitats-and-niche-partitioning-

in-chameleons-skinks-geckos-and-snakes.pdf.



Nutrient Cycling

http://sky.scnu.edu.cn/life/class/ecology/chapter/Chapter19.htm (Accessed 03.05.15)

http://www.fao.org/docrep/w0312e/w0312e06.htm (Accessed 03.05.15)

http://www.slideshare.net/FAOoftheUN/creating-virtuous-cycles-through-agroecology (Accessed

03.05.15)

Kozlowski. S., Plumley, M. & Adamia, D. (undated) Deserts Powerpoint Presentation Available

from:

http://www.u.arizona.edu/~jrjurjev/Geo101_files/Deserts%20Powerpoint%20Stephen.pptx.

Ecological Niche

https://www.learner.org/courses/envsci/unit/text.php?unit=4&secNum=7

How nutrient cycles can motivate animal conservation

http://www.environmental-research.ox.ac.uk/nutrient-cycles-can-motivate-animal-

conservation/

Reptile Ecology and Conservation

Documents