Conservation of the eastern imperial eagle (Aquila heliaca) in Central Asia: Using molecular techniques to investigate raptor ecology and noninvasively monitor raptor populations

Jamie Rudnick, Purdue University

Abstract

The eastern imperial eagle (Aquila heliaca; EIE) is a large raptor found throughout central Europe and Asia. The biology of EIEs is currently of considerable conservation interest because the species experienced rapid population declines during the middle of the twentieth century and is now extirpated or very rare in many areas. EIEs are challenging to study by conventional means, primarily because both juveniles and adults are exceedingly difficult to capture and mark. To circumvent the difficulties associated with traditional eagle research, I used genetic analyses on noninvasively collected feathers to investigate numerous aspects of EIE biology. For the first chapter of my dissertation I characterized the EIE mating system and estimated annual adult turnover for a breeding population in north-central Kazakhstan. My results supported the expectation that EIEs are genetically monogamous, and I found no evidence for a relatedness-based system of mate choice. While the average number of adults lost from the breeding population each year was higher than levels reported for other raptor species, a simple mathematical model suggested the population's rate of reproduction is sufficient to maintain the current number of breeding adults. The remainder of my dissertation focused on the non-breeding portion of an EIE population. To verify that feathers collected at communal roosting sites were EIE in origin, I developed a molecular assay for identifying EIE samples in large collections of naturally shed feathers. I used hundreds of feathers collected from multiple communal roosting sites to estimate the total number of non-breeding EIEs present, characterize roost usage, and investigate natal origins. Through a genetic mark-recapture analysis, I estimated that over 300 non-breeding EIEs were present at a nature reserve in Kazakhstan. I also demonstrated that individuals routinely move among roosting areas and that non-breeders are likely congregating from natal areas outside the study site. Collectively, my research illuminated previously unstudied aspects of all EIE life stages (i.e., chicks, pre-adults, and adults) and characterized the biology of a top predator in an important Central Asian ecosystem.

Degree

Ph.D.

Advisors

DeWoody, Purdue University.

Subject Area

Ecology|Genetics|Zoology|Forestry

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