Jack rabbits vanish from Yellowstone, ecologists puzzled
Jack rabbits vanish from Yellowstone, ecologists puzzled
mongabay.com
February 14, 2008
Scientists are puzzled over the apparent disappearance of jack rabbits from Grand Teton and Yellowstone National Parks, but say the local extinction may be having region-wide impacts on a variety of other prey species and their predators, according to a new study by the Bronx Zoo-based Wildlife Conservation Society.
Writing in the journal Oryx, Dr. Joel Berger and colleagues report no confirmed jack rabbit sightings in Yellowstone since 1991 and only three in Grand Teton since 1978. White-tailed jack rabbits were once abundant in the region.
“It could be disease, extreme weather, predation or other factors,” said lead author Berger, a Wildlife Conservation Society conservationist and professor at the University of Montana. “Since the rabbits blipped off without knowledge, there has simply been no way to get at the underlying cause.”
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Berger speculates that the absence of jack rabbits may be resulting in elevated predation by coyotes on juvenile elk, pronghorn and livestock, but without sufficient data, conclusions are difficult to draw. He says the disappearance of rabbits makes it tough to assess the impact of the reintroduction of grey wolves in 1995.
“Lacking a sense of historical conditions, it will always be difficult to decide whether current systems function ecologically like past ones,” said Dr. Berger. “Reintroduction [of rabbits] may result in the establishment of dynamic ecological processes that were intact before rabbits vanished from the ecosystem. From the perspective of ecological health and wildlife conservation, reintroduction would also show that species loss has serious ecological costs.”
