Apart from publishing a number of scientific papers, he popularised his findings in a book The Private Life of the Rabbit, which is credited by Richard Adams as having played a key role in his gaining "a knowledge of rabbits and their ways" that informed his novel Watership Down. One was the naturalist Ronald Lockley, who maintained a number of large enclosures for wild rabbit colonies, with observation facilities, in Orielton, Pembrokeshire. Much of the modern research into wild rabbit behaviour was carried out in the 1960s by two research centres. Unlike the related hares ( Lepus spp.), rabbits are altricial, the young being born blind and furless, in a fur-lined nest in the warren, and they are totally dependent upon their mothers. The European rabbit is well known for digging networks of burrows, called warrens, where it spends most of its time when not feeding. It is known as an invasive species because it has been introduced to countries on all continents with the exception of Antarctica, and has caused many problems within the environment and ecosystems in particular, European rabbits in Australia have had a devastating impact, due in part to the lack of natural predators there. Its decline in its native range due to myxomatosis, rabbit hemorrhagic disease, overhunting and habitat loss has caused the decline of the Iberian lynx ( Lynx pardinus) and Spanish imperial eagle ( Aquila adalberti). It has been widely introduced elsewhere, often with devastating effects on local biodiversity. Rivers that had become wide and shallow with the absence of wolves became narrow and deeper, creating habitat for creatures that had not been there in decades.Ī recent review of “How Wolves Change Rivers” summed up this “trophic effect” eloquently: “Human/wildlife conflict is a reality of growing populations around the world, and the fact is that we need to learn to live beside wildlife if we are to maintain our wonderful thriving ecosystems in the future.The European rabbit ( Oryctolagus cuniculus) or coney is a species of rabbit native to the Iberian Peninsula ( Spain, Portugal and Andorra), western France, and the northern Atlas Mountains in northwest Africa. When more native trees were allowed to grow along the banks of the rivers, the banks were reinforced and the channels of the rivers deepened. Because of the reintroduction of wolves into Yellowstone Park, the nature of the rivers actually changed. Bears, who also eat carrion, returned too.īut the ultimate changes in the ecosystem of the park were even more significant. Ravens and bald eagles returned to feed on the carrion left by the wolves. The return of small rodents-prey of animals like weasels, hawks and foxes-caused more of those species to move back into the park. The wolves also preyed on coyotes, which reduced their population and caused the population of rabbits and mice to increase. They dammed the river, because that is what beavers do, causing ponds to develop and providing habitat for creatures like river otters, muskrat, fish and ducks. Beavers, who eat the bark of the trees and use the branches for lodges and dams, moved back in. When aspen, willow and cottonwood trees started to grow again, native birds returned. The native plants in the areas the elk avoided regenerated. As a result, the elk began to avoid certain parts of the park where they were more vulnerable to wolves. When wolves were reintroduced, they naturally killed some of the elk. The unnaturally large population of elk had grazed much of the park down to bare roots and many of the park’s native plants were destroyed. Since wolves had been gone from the park for nearly 70 years, the native elk had few natural predators and the elk population exploded. Although criticized by some as a bit over-simplistic, the film’s thesis is worth re-telling here as an example of the influence apex predators have on an entire ecosystem. Called “How Wolves Change Rivers,” the film describes the environmental changes that occurred when wolves, hunted out of Yellowstone National Park in the 1930s, were re-introduced to the park in the mid-90s. An apex predator is one at the top of the food chain, or one who “as an adult, has no natural predator within its ecosystem.” In Santa Clara County, apex predators would include mountain lions, bobcats, coyotes, hawks, falcons and large owls.Ī 2013 film explains the importance of apex predators in simple, beautifully illustrated terms. There has been a lot of discussion lately about the critical role apex predators play in the ecosystem.
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