The majority of conservation efforts across the globe are based on the well-studied distribution of mammal, bird, and amphibian species, forming much of what we currently understand about global biodiversity. However, a recent paper in Nature Ecology and Evolution by U. Roll et al. compiled habitat and global distribution data on 10,064 species of reptiles, representing 99% of the extant terrestrial species globally. This data showed that while hot spots of biodiversity centered on the pan-tropical regions of the globe, indicating non-reptile tetrapod diversity correspond reasonably well to the overall global distribution of reptile species taken as a whole, they differ substantially from the distribution patterns seen in lizards and turtles.
Lizard diversity is high in tropical regions, but also in arid regions, including much of Australia. Arid and semi-arid habitats are generally not a focus for conservation efforts, and lizard species diversity is likely to suffer over time if this bias is not corrected. Fortunately, the costs associated with conservation in arid and semiarid habitats are considered to be lower both in terms of land values and potential costs associated with the loss of land use for agriculture, timbering etc. than what is seen, on average, in other environments. This suggests new much needed conservation projects to protect lizard diversity may be less expensive and meet with less resistance than those already established in other parts of the world. Lizard species dispersal maps also show especially rich species diversity in island habitats, with many lizard species notably inhabiting just one specific island or a handful of islands with completely different species filling the same ecological niche on neighboring islands. These isolated island species are considered to be particularly in danger because it is difficult to protect significant numbers of species (and therefore help maintain global diversity) within a single conservation area or project. Island species, with their extremely limited ranges, require complex management and may even necessitate cooperation amongst multiple governments or regulatory agencies. These efforts are likely to be costly, and while important for the ecology of the islands and species involved, are unlikely to have large impact on the global preservation of biodiversity.
Turtle species distribution is even less aligned with that of the non-reptile tetrapods. Hotspots for turtle diversity include the eastern US, Ganges river delta and parts of southeast Asia. If turtle species diversity is to be protected, it is critical conservation efforts in these regions move forward quickly. Many turtle species are under threat, and facing significant pressure from habitat loss and the results of human industry and activity across all or most of their range. Unfortunately, the costs of expanding conservation efforts worldwide to adequately protect turtle species biodiversity are likely to be higher than similar efforts for lizard biodiversity. Species ranges in areas of higher human population density increase the cost of land, as well as the associated cost of the loss of land for other purposes. Protective efforts in areas with more people are also more likely to face resistance from the community or corporate interests as conservation efforts conflict with other land use options.
Overall, effective preservation of the biodiversity of our planet is dependent on knowledge and understanding. Work such as done by Roll et al. is critical to insuring conservation and preservation projects achieve their goals and protect as many species as possible – not just serving those species we know the most about and assuming everything else will be covered in the process. Arbor Assays remains committed to respecting our environment and our planet. We are proud to offer assay kits for conservation and ecological research projects around the world, including our partnership with ISWE (International Society for Wildlife Endocrinology).