Reptile Conservation – How Human Activities Are Affecting Their Survival

Reptiles are a keystone species that play a critical role in their ecosystem. Yet, their often small ranges and narrow niche requirements make them susceptible to anthropogenic threat processes that are causing widespread declines.

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Globally, herpetofauna are among the most threatened species. This silent crisis requires a collective effort from individuals and communities to protect them.

Lack of Females

Reptiles have a complex relationship with their environment and many are dependent on specific habitats for breeding. Vast numbers of reptiles are smuggled from wild populations into the (legal and illegal) exotic pet trade and this leads to a depletion of wild populations. In addition, many reptile species are exposed to unsuitable conditions and inadequate husbandry in captivity that lead to a poor quality of life. The plight of wild populations has made it even more important to ensure that captive reptiles are provided with the right conditions to be healthy, happy and productive.

The first comprehensive global assessment of reptiles’ extinction risk has revealed that 21% of reptiles are threatened with extinction, comparable to the rate for amphibians (24.8%) and mammals (17.1%). The threat status of reptiles was determined through an assessment process that included consultation with scientists familiar with species and careful consideration of the application of IUCN Red List criteria. Species with known threats were evaluated based on current and projected population trends and the extent to which these threaten the sustainability of the species. In a minority of cases, there was insufficient information about the distribution, population size and threats to enable an evaluation and therefore the species was assessed as ‘data deficient’.

Reptiles have a high level of phylogenetic diversity, and their loss will result in a significant loss of biodiversity. Their uniqueness in arid regions means that they will need to be conserved in different ways from other tetrapods. The findings from the reptile assessment can be used to guide conservation actions at the species level by informing the calculation of extinction risk, and at the landscape level through identification of Key Biodiversity Areas, and resource allocation using systematic conservation planning.

Habitat Loss

Reptiles require a diverse range of habitat types to survive. The loss of these habitats is the most significant factor contributing to their extinction risk, with expanding farmland and urbanisation driving the majority of habitat destruction. Habitat fragmentation – where reptiles are dispersed across the landscape – is also a major issue, particularly in tropical biomes and in areas with high numbers of range-restricted species.

Climate change is also a serious threat to reptiles. Rising global temperatures shrink the windows of time available for daily foraging (as well as for nesting) and reduce the overall habitable area for many reptiles. Cooler temperatures also favour male turtles over females, and are expected to cause many range-restricted reptile species to decline rapidly.

Until now, comprehensive extinction-risk assessments of reptiles have been rare. As a result, reptiles have generally been overlooked in conservation-priority analyses that consider birds, mammals and amphibians.

ARC is working to help reptiles and amphibians thrive by supporting conservation programs that protect ailing ecosystems, like wetland restoration and land trusts. These organizations acquire ecologically significant lands through purchase or donation and then manage them for the benefit of wildlife. They are also seeking volunteers to assist with land stewardship activities, such as surveying for amphibians and reptiles, and creating habitat through planting and mowing practices.

Pollution

Reptiles live in a delicate balance with their environment and their populations are often affected by human activities. For example, the dumping of toxic wastes disrupts the natural cycles of water, air and soil, exposing wildlife to pollutants beyond what naturally occurs in their habitats. Pollution is caused by animal agriculture, fossil fuels, metal refining, mining, and urbanization. These synthetic chemicals create conditions that are foreign to animals, altering the biological balance that nature has evolved over thousands of years.

Climate change is a significant threat to reptiles, as they are highly sensitive to their environments and have tight bell curves that define their optimal climatic conditions (Le Galliard et al. 2012). A changing climate can lead to thermal mismatches that negatively impact the health of reptile species, as well as their prey. It can also skew offspring sex ratios in reptiles with temperature-dependent sex determination, and lead to range contractions and extirpation (Van Klink et al. 2015).

Reptiles are also vulnerable to air pollution, which is associated with respiratory problems, reproductive disorders, and even death. Exposure to fine particulate matter, such as that resulting from vehicle emissions, can cause inflammation in the lungs of reptiles. Air pollutants can also damage eggs, reducing fertility rates and leading to deformed offspring (Van Klink et al. 2015.) They can also lead to increased levels of organochlorines in eggs, which can affect reproduction by influencing the calcium content in them and causing skeletal abnormalities (Bauerle et al. 1975).

Illegal Hunting

The illegal hunting of reptiles by humans is a global issue that poses a significant threat to the survival of numerous species. Illegal hunting can occur for a number of reasons including over-collection, subsistence, and the desire to make money from selling wild capture animals. The legal trade of reptiles is regulated by CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora), but illegal activities continue to occur, especially within countries that are not part of the agreement.

One common reason for illegal wildlife hunting is poverty. The link between poverty and biodiversity has been well documented by studies that examine the impacts of various types of conservation policies on poverty. However, most of these studies focus on material deprivation rather than the social and psychological aspects of poverty that may drive individuals to illegally hunt reptiles.

Some studies suggest that poverty-driven illegal wildlife hunting can be addressed by providing paid employment opportunities, such as ranger or tour guide jobs that increase levels of income and reduce the need to hunt for food. However, this does not always work and is not universally successful (Roe et al. 2014).

Increasing levels of law enforcement and the introduction of schemes to verify the identity of reptiles prior to export can help to curb the illegal trade. But more holistic approaches are needed as the problem of illegal wildlife hunting is complex, and involves a complicated interplay of laws, morality, and social acceptance.