Herp Help in Asia
The red-crowned roof turtle, or Kachuga, and gharial, a slender-snouted crocodilian, are both critically endangered. Habitat destruction and environmental degradation have eliminated these species across much of their historical range. The last remaining strong-hold for both species is the Chambal National Sanctuary, a river nearly 250 miles long, in north India that feeds into the Ganges River.
Adult populations are declining due to commercial harvest and subsistence consumption, as well as fisheries by-catch. Exacerbating the situation are the sand mining activities and small-scale agriculture on nesting beaches. Indian law prohibits each of these activities within the river sanctuary; however, law enforcement resources are scarce and these activities continue at an unabated pace.
Current conservation measures for both species include protection of field-collected nests from predators at in situ and ex situ hatcheries and headstarting a select number of hatchlings in captivity until they reach a size that is assumed to afford them greater survivorship when released into the wild. Unfortunately, adequate analysis and optimization of these programs have yet to be conducted.
There are four main components of this project that will facilitate more effective conservation actions for both species. First, we need to characterize the temperature-dependent sex determination patterns (two patterns, one for gharials the other for kachuga) to ensure both sexes are being produced at the hatcheries.
Second, we will conduct telemetry studies to determine the dispersal patterns of newly released animals and migratory patterns of adults to estimate home range and identify likely sources of mortality.
Third, we intend to gain a better understanding of their reproductive physiology and determine the frequency and minimum size of reproduction.
These data will be used to estimate adult population size from nest surveys and determine the age- or size-specific contribution of individuals to the population.
Finally, we will initiate a long-term program to monitor population trends and survival through systematic surveys and mark/recapture studies. The goal of this work is to increase the population size of Kachuga and gharial in the Chambal National Sanctuary and create a working model for other species of imperiled Asian river fauna.
