Despite the long-held perception that reptiles are robust and resilient, their often small ranges and narrow niche requirements render them susceptible to many of the same anthropogenic threat processes as amphibians. Consequently, one-fifth of reptilian species are currently threatened with extinction.레오파드게코
While global assessments of extinction risk have documented the amphibian crisis1,2, reptiles remain largely overlooked in conservation-prioritization analyses3. A recent study in Nature revealed that 10,196 reptilian species are threatened with extinction.
‘From turtles that breathe through their genitals to chameleons the size of a chickpea, reptiles are an eclectic bunch and, like our amphibians, are at risk from humans. Their extinction would spell the end of not only unique species that play key ecosystem roles but also billions of years of evolution.’
For the first time, researchers have used a global, data-driven approach to assess the threat status of 10,196 reptile species. They found that 21.1% of reptiles were classified as Vulnerable, Endangered or Critically Endangered – more than twice the proportion of threatened amphibians.
The report’s authors identified habitat loss and fragmentation as the main threat to reptiles, particularly in tropical areas where rates of deforestation are highest. This is exacerbated by the often solitary nature of these animals and their low population numbers, which make them more vulnerable to human pressures.
In addition, invasive species are a significant issue for reptiles. For example, the chytrid fungus has decimated frog populations worldwide and domestic animals can also impact native reptiles; at SAGU, we’ve seen shell trauma on desert tortoises caused by free-roaming domestic dogs. Lastly, climate change is a looming threat to reptiles as it reduces the window each day when temperatures are ideal for foraging, skews offspring sex ratios in species that have temperature-dependent sex determination, and shrinks their ranges.
Reptiles are under threat around the world, but their declines don’t grab as many headlines as those of furry and feathered animals. But a new study 레오파드게코 finds that 41% of evaluated reptile species are Near Threatened, Threatened (Vulnerable, Endangered or Critically Endangered) or data deficient globally.
Researchers used the first global analysis of reptile extinction risk to inform conservation decisions, and found that land protection is key for buffering many threatened species from agricultural activities and urban development. In addition, curbing unsustainable harvests and stemming the spread of invasive species is crucial.
In arid habitats, reptiles face unique challenges. For example, desert tortoises depend on the presence of native annual plants, but the proliferation of introduced annuals such as red brome and buffelgrass can cause changes in vegetation composition and increase fire frequencies, which directly impact these tortoises. In these cases, we need to better understand the underlying causes of the changing landscapes so that we can address them.
The study also found that reptiles have broadly similar geographic patterns of extinction risk to birds, mammals and amphibians, which suggests that geographical prioritizations previously performed for other tetrapod groups can serve as surrogates in reptile conservation-prioritization analyses. Nevertheless, for reptiles with the most range-restricted threats, case-by-case assessment is necessary. This is especially important when considering the potential disproportionate loss of reptilian phylogenetic diversity if these species go extinct.
Reptiles suffer from a number of infectious diseases. Skin infections occur frequently and may involve the lungs, respiratory tract, or gastrointestinal tract. Fungal infections are common in turtles and tortoises and can cause slow-healing internal sores. Parasitic infections may also be serious, causing intestinal disease. Bacterial disease is a common problem, primarily caused by opportunistic commensals that infect immature or malnourished reptiles. Septicemia is often seen in severe cases.
Abdominal prolapses may be observed in frogs and toads, snakes, and lizards. A prolapsed cloaca, colon, oviduct, or hemipenes/phallus can cause straining when defecating and lead to edema. These prolapses can be treated by your veterinarian by gently exposing the organ and replacing it. He/she will also try to determine what caused the prolapse in order to prevent recurrence.
Focal infections can also form abscesses in the body of a reptile, usually from bite wounds, but sometimes made more likely by poor husbandry. A variety of bacteria, including Peptostreptococcus, Aeromonas, Salmonella, Serratia, and Micrococcus have been isolated from reptilian abscesses.
Reptiles that eat eggs may develop a condition called hypercalcemia, which is associated with high levels of calcium in the blood and calcification of soft tissues, especially the beaks of frogs. The cause is not known, but removing eggs from the diet has been shown to be helpful.
As wild reptile populations decline, the demand for them drives illegal wildlife trade. Reptiles are often kidnapped from the wild and transported thousands of miles across the globe to be sold in ill-equipped facilities. This depletes ecosystems of key species and causes many of those shipped to suffer from diseases, parasites, and other ailments during their perilous journey to the buyer. Species like the Borneo earless monitor lizard and Madagascar leaf-tailed gecko are among those that have suffered from this cruel trade.
The study, published in Nature, used a software tool to scrape the Internet for online listings of reptiles for sale. Researchers tallied 3,943 reptile species for sale, including some that aren’t legal to sell internationally. The team also compared their findings to data from the CITES trade database and the U.S. Fish and Wildlife Service’s Law Enforcement Management Information System (LEMIS), which tracks the importation of wildlife into the United States.
Both LEMIS and CITES monitor only a fraction of global reptile sales. Using these data, Hughes and her colleagues found that 79% of species sold online are not regulated by CITES and could be legally imported.
As a result, they are vulnerable to unsustainable harvest, invasive species introduction, and other threats. The study demonstrates that the online reptile trade is more widespread than previously thought and highlights a need to address shortcomings in species conservation assessments. Species that are not evaluated for their threat status are particularly vulnerable to the legal trade in their ranges, and those with small and isolated ranges may be more likely to be captured. Land protection, and expanding the scope of the Lacey Act to include species traded outside of their range, are needed to mitigate this risk.