SCOTT SHALAWAY Here comes Peter Cottontail
Ask a botanist to name the most important species in a biotic community, and he will answer "plants," because without them, animals would have nothing to eat. A zoologist might say "mice" because they are the most widespread and abundant prey for all the predators higher in the food chain. A valid argument can be made for either case.
But in backyards and old fields across the eastern two-thirds of the continent, a strong case also could be argued for eastern cottontails. Without them, medium sized predators would disappear.
After peaking in early fall, cottontail populations are at their annual low point this time of year. But as winter winds down, cottontails bounce back.
Breeding begins in February. After a gestation period of about 30 days, the pregnant female digs a shallow hole in the ground. The nest, about the size of a clenched fist, slants about six inches inward. The female lines the nest with fur she plucks from her belly and covers the opening with grass, making it difficult to see from above. Nests usually are placed in stands of dense grass, but sometimes cottontails even sink their nests into well-manicured lawns.
Females typically give birth to four or five blind, naked young. They nurse their brood only at dawn and dusk and spend the rest of the day feeding or resting. After about a week in the nest, the young are fully furred, and their eyes and ears open. They leave the nest after 14 days. By the age of one month the young are weaned and independent.
Meanwhile, mom has been busy. She mates shortly after giving birth, so she's pregnant with a second brood while nursing the first. This is a major reason rabbits are so prolific. A single female might breed five or six times in a year and produce up to 35 babies.
Cottontails spend most of the day resting in a "form" -- a well-worn depression on the surface of the ground. It's usually nestled in a clump of dense grass in a thicket or under a brush pile. Contrary to popular belief, rabbits do not dig burrows. They occasionally seek refuge in an abandoned ground-hog den to escape predators or winter weather, but they spend most of their lives above ground.
Perhaps the most fascinating aspect of rabbit biology is their diet. Strict vegetarians, cottontails enjoy succulent greens such as dandelion leaves, clover and grasses, as well as the bark of woody species such as raspberry, apple, black cherry and sumac. They can consume up to 40 percent of their body weight every day. Evidence of rabbit browsing is easy to recognize. Their sharp incisors clip twigs cleanly and leave behind a distinct diagonal cut; deer break twigs off and leave behind ragged edges.
But a vegetarian diet is hardly unique. What makes rabbits different is they also are coprophagous -- they eat their own droppings. Cottontails increase digestive efficiency by recycling food that passes through their system. They excrete two types of droppings. After a meal first passes through the digestive system, rabbits pass soft, green "food" pellets, which they reingest as soon as they are dropped.
True end product
During the second trip through the system, vitamins and other nutrients that were not absorbed the first time are assimilated. The familiar piles of dark, round pellets you recognize as rabbit sign are the true end product of rabbit digestion.
Predators, parasites, disease and foul weather keep rabbit populations in check. Great-horned owls, red-tailed hawks, foxes, coyotes, bobcats, weasels and feral dogs and cats take a heavy toll. Heavy spring rains wash out many nests each year. And hunters kill millions annually.
The most serious long term danger rabbits face, however, is habitat loss. Every new mall, parking lot, and subdivision means fewer cottontails. And modern farming methods that require ever larger fields to accommodate bigger machinery mean fewer fence rows, fewer odd corners and ultimately, fewer cottontails.