11/18/2023 0 Comments Are rabbits apex predators![]() Here, we use a before-after-control-impact-paired design to test predictions generated from trophic cascade theory (TCT) and mesopredator release hypothesis (MRH) by experimentally introducing dingoes into a 37-km 2 paddock and measuring the resultant effects on mammal assemblages. However, a criticism of studies investigating the ecological role of apex predators is that understanding does not come from manipulative experiments. ![]() And so reproduction will, as we’ve seen already, stay very low.Recent studies suggest that apex predators play a pivotal role in maintaining healthy, balanced ecosystems. “But it’s not going to be enough to make up for the loss of cottontails, probably. “We expect them to broaden their diet,” said Preston. “And in time, populations will rebound.”īut right now, the dramatic effect of RHDV2 is decimating not only the rabbit population, but the golden eagles and other predators that feed on the rabbits.Īnd he said there’s no way to tell what the long-term effect will be on the Golden Eagle population. “It may be that some rabbits have a natural immunity, just like we do to certain diseases,” he said. Preston said in time, the rabbit population will come back up, as those rabbits with immunity pass that along to their offspring. “And so for the last several decades, prairie dog populations are probably about 70% lower than would be the natural background for them.” “There’s a plague that goes through prairie dog colonies,” Preston said. Preston said that eagles will take other prey, such as ravens, great horned owls, coyotes, pronghorn fawns and even prairie dogs.īut disease has hit the prairie dog population as well. “Anywhere from 60 to 80% of the diet is made up of cottontails – during the nesting season, at least.” “Through these cycles, we find that the Golden Eagle still focuses primarily on cottontails,” he said. “Rabbits really take it on the chin,” he said.Īlthough Golden Eagles are versatile predators, Preston pointed out that even when cottontail rabbit populations are low, they are still the preferential prey of raptors. Preston stressed, though, that RHDV2 is in no way dangerous to humans or other pets – simply to rabbits. “Sometimes if they have enough nutrition, they can lay the eggs, but they just don’t have the energy, the nutrition to incubate the eggs, or – if the eggs hatch – to feed the young,” said Preston. He explained that when food abundance is low, the female golden eagle that is laying the eggs is not in top physiological condition, and so might not even lay eggs. ![]() “We now have 14 years of data showing cyclic ups and downs of Golden Eagle reproduction that match the ups and downs of cotton tail abundance,” said Preston. He said this is the most dramatic decline in population they’ve observed. “In fact, it even would affect pica, close relatives of the rabbits that live in the higher elevations.”Īlong with staff and volunteers at the Buffalo Bill Center of the West in Cody, Preston has been studying the Golden Eagle population since 2009. “Here in our area, this virus affects both jackrabbits and cottontails – every species of cottontail,” he said. And not just in cottontails, the eagle’s primary food source. Preston said that this year has revealed the lowest abundance of rabbits that they’ve seen since the study began in 2009. “And again in 2021, 2022, they’ve really stayed down in the tank.” ![]() “What we found was that not only did rabbits not rebound, but they declined from their lowest before,” Preston said. Researchers expected a rebound in the rabbit population in 2020, which should have resulted in an uptick in the numbers of golden eagles. Preston said that a regular fluctuation in rabbit numbers occurs every 6-8 years. It kills up to 80% of infected animals and is rapidly spreading throughout parts of North America. He explained that the rabbit disease first showed up in the U.S. Preston is the founding and senior curator emeritus of the Draper Natural History Museum at the Buffalo Bill Center of the West in Cody, and a research associate at the Teton Raptor Center in Wilson. “In the 1980s, and 1990s, this Rabbit Hemorrhagic Disease Virus was found in Europe, and it really devastated European hares and rabbits – and therefore devastated the ecosystem, in a sense.” “Rabbit Hemorrhagic Disease Virus (RHDV2) is a highly contagious disease that is passed among rabbits and hares,” he told Cowboy State Daily. Charles Preston, one of the world’s leading experts on raptors like the golden eagle. But a deadly disease has decimated the rabbit population, which are a key food to many different predators - so any decline in their numbers will affect the entire ecosystem. In the Big Horn Basin, golden eagles are the apex predator, and their primary prey is cottontail rabbits.
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