Assessing genetic diversity and population structure for prioritizing conservation of the critically endangered Great Indian Bustard (Aredotis nigriceps)

The critically endangered Great Indian Bustard Ardeotis nigriceps (GIB) is on the verge of imminent extinction, and exists as fragmented populations with 100-150 birds in India and a few in neighbouring Pakistan. Rajasthan holds the largest population of similar to 128 birds, Gujarat has similar to 5, and Maharashtra-Karnataka-Andhra Pradesh having similar to 10 birds. Their range and abundance have reduced by 90% within last 50 years, primarily due to hunting, habitat loss to agriculture and industry, and power-line collisions. Conservation agencies are implementing habitat protection/ restoration and conservation breeding as insurance against extinction and for future reintro-ductions/supplementation. To guide these ongoing in-situ and ex-situ conservation measures, we examined patterns of genetic diversity, population structure, bottlenecks and dispersal using microsatellite and mitochondrial markers. Analyses of 73 individual GIB revealed low mt-DNA (h=0.554, pi = 0.001) and microsatellite diversity (Ho=0.32). Bayesian clustering analysis identified three genetic populations. Migration between these populations was low and asym-metric, highest being from Rajasthan into Maharashtra (9%) and Madhya Pradesh (4%), perhaps due to extreme habitat fragmentation and small numbers. Rajasthan population encompassed the maximum genetic diversity, that along with its large size and availability of breeders, made it ideal for sourcing founders for conservation breeding. However, the presence of private alleles in other populations implies that additional sourcing of birds from Andhra Pradesh and Gujarat may be required to capture the extant gene pool of GIB in captive founder population.

Automated summary

The critically endangered Great Indian Bustard is facing imminent extinction due to hunting, habitat loss, and power-line collisions. Conservation agencies are implementing habitat protection and conservation breeding as measures to prevent extinction. Genetic diversity analysis suggests that the largest population in Rajasthan is ideal for sourcing breeders, but additional birds may be needed from other regions to fully capture the extant gene pool of the species.