|fwg is a long-term project of the ottawa field-naturalists' club|
Eastern Cottontails at the FWG
Rabbits leap through our stories and myths with abandon. Who hasn't hopped with Peter Rabbit down the bunny trails of Beatrix Potter, or followed the White Rabbit with Alice? We keep rabbits as pets, we make cuddly bunny toys, they grace endless amounts of baby paraphernalia, in short they are almost iconic. Yet we also eat them, hunt them for sport, and resort to trapping to get rid of them. What a contradictory set of sentiments we bring to bear on these timid creatures.
Several species of cottontails inhabit North America, but here in eastern Ontario, the familiar "bunny rabbit" is the eastern cottontail (Sylvilagus floridanus). This species weighs 1.1 to 1.2 kg, and may be about 450 mm long (Banfield 1974, Forsyth 1985), with the female the larger animal. Their dense coat, or pelage, is a greyish-brown with black-tipped guard hairs. If you look closely, you can see the characteristic rusty patch on their nape. Perhaps the most familiar field mark is the short white puffy tail (the cotton tail). Twice a year they undergo a molt. Eastern cottontail can be distinguished from the other common lagomorph of eastern Ontario, the snowshoe hare (Lepus americanus), by its smaller size, colouration (it does not turn white in winter as hares do), and physical features (for example, shorter ears). It also lives in a very different type of habitat.
The eastern cottontail has benefitted greatly from land clearance. As the forests fell, this species followed along, moving further north. Cottontails may have inhabited extreme southern Ontario in pre-settlement times (Banfield 1974), but by the time settlers arrived this species was absent. Fleming (1908) comments that there was an attempted introduction of the English rabbit (Oryctolagus cuniculus) around Toronto and believes this led to some confusion regarding the first recorded observation of eastern cottontail in southern Ontario. However, Dobbyn (1994) says it was not reported in the southern part of the province until 1860, and prior to 1931 was unknown in Ottawa. Since then, the once rare eastern cottontail has spread throughout the region, wherever suitable habitat is found.
Unlike hares, rabbits prefer living on the edge. Edge habitat, that is, where thickets, hedgerows, or treed areas meet old fields, agricultural lands, or grassy meadows. Although they can be found in very open woodlands, this is not a typical habitat. Some form of escape cover is essential and rabbits never move too far away from brushpiles, thickets, rockpiles, and burrows which provide quick escape from their many predators. Any landscape that supplies a combination of the above is considered good from a rabbit's perspective.
At the FWG, we have almost perfect conditions for this species. Brushpiles of varying sizes dot the area (see photo at left). Thickets of shrubs and stands of raspberry (Rubus) are common, and the Ash Woods, New Woods, and Birch Grove provide an open wooded setting abutting onto field and thicket.
Rabbits are even found in urban parks, greenspaces, and gardens, so long as there are thickets, hedges, and places to seek cover nearby. At the FWG, rabbits were seen occasionally in the early days of the garden with one observation in 1991 and another in 1992. After that, they were either absent or not noticed, until about 1996 when we saw one hanging around the Backyard Garden. By 2000 they were common and have been observed regularly since.
Rabbit populations are cyclical, peaking and then "crashing" every 7 to 10 years. At the FWG, their lower numbers in 2006-2007 are probably a result of predation (mostly by dogs) and their population cycle being on a downturn.
Rabbits are generally quiet animals, although they may occasionally emit a few low grunts or squeals. Their primary form of communication is by stamping their hind feet. Many years ago, I heard a rabbit give a very piercing human-like scream when it was picked up. It was an unnerving sound.
These solitary animals are largely crepuscular and nocturnal. However, cold weather often prompts daytime activity. During the day, rabbits spend long hours sitting in one spot, sleeping, grooming, and occasionally standing up or nibbling some nearby food. They often return to the same location day after day. The shallow impression created by their body weight is called a "form". If you look carefully around the FWG you may see these shallow depressions in the snow (see photo at right) or, in warmer months, in the grass.
Rabbits are coprophagous, meaning that they eat their own feces in order to better digest plant material. It is also thought that "the redigestion of food may be important for the survival of an herbivore that must often interrupt its feeding to flee a predator" (Massachusetts Audubon 2007). The first excretion, moist and greenish in colour is of partially digested food. This scat is rarely seen for the rabbits quickly consume it. More familiar is the dry, brown, pellet-like scat (considered a delicacy by my dog). This is commonly found under, or around, favourite feeding spots and along their trails or runs. The scats may be accompanied by an orangey-red urine which looks a lot like blood, but isn't.
The list of cottontail predators is long. At FWG their main predators would be dogs, foxes (Vulpes vulpes), red squirrels (Tamiasciurus hudsonicus), and, when present, weasels (Mustela). Raptors such as red-tailed hawks (Buteo jamaicensis) and great-horned owls (Bubo virginianus) prey on both adults and young. Banfield (1974) adds that American crows (Corvus brachyrhynchos) and shrikes (Lanius sp.) will feed on young rabbits. Of course, humans are one of the biggest predators. Our cars kill many rabbits annually, and hunters take more.
When a predator passes by, rabbits will freeze, in an effort to go unnoticed. If found, they can run extremely fast, often restorting to a zig-zag pattern to shake their pursuer. Most of all, they rely on reaching protective shelter such as burrows or brushpiles. The rabbits killed by dogs at FWG must have been caught in the open, away from cover.
Eastern cottontails are herbivores, feeding on a variety of herbaceous plants, grasses, and shrubs. At the FWG I have seen them eating goldenrod (Solidago), various clovers (Trifolium), dandelion (Taraxacum officinale), the leaves of young saplings, and several species of grass including especially Kentucky blue grass (Poa pratensis).
In winter they turn to the buds, stems and bark of shrubs and trees, particularly (Rhus typhina) sumac, which seems to form a good part of their winter diet at the FWG. I have also seen them eating raspberry stems (Rubus), the dry leaves of Canada thistle (Cirsium arvense), stems of common burdock (Arctium minus), the bark of red osier dogwood (Cornus sericea), young birch trees (Betula), wild rose (Rosa), and a number of other species. Rabbits are also quite happy to forage on garden plants. This habit does not endear them to gardeners, although at the FWG, we tolerate their excesses in the BYG, even if we don't always appreciate it. They will also feed on spilled seed from bird feeders.
Territory and Home Range
Rabbits inhabit a relatively small home range. Banfield (1974) says this varies from 0.5 to 9 hectares, but notes that "recent studies have indicated a larger home range, dependent to some extent on terrain and food supply, but in the neighbourhood of 8 acres [3.24 hectares]." At the FWG, our 5-hectare site could support 5 to 10 rabbits. We have certainly had that many in recent years.
Female cottontails are more territorial than males, particularly during breeding season. Otherwise, it seems that rabbits are not particularly protective of their turf.
Rabbits are generally creatures of habit, sticking fairly close to their familiar surroundings, unless forced to move. This means that once you get an idea of their favoured location, you may see them regularly in that area.
Rabbits breed like, well, like rabbits. They are notoriously prolific and if they lived in an ideal world with no predators, they would soon overpopulate. In fact, their fecundity is a response to their high mortality. Without the ability to breed rapidly and often, they would have little chance of thriving as a species.
Eastern cottontails breed in late February to early March and continue until September. Courtship is said to be quite energetic. Banfield (1974) describes it as an "interesting mating dance" in which "the buck chases the doe in a lively pursuit around the meadow. Eventually she turns and faces the buck and spars at him with her front paws. As they crouch facing each other, a few inches apart, one of the pair suddenly leaps about two feet in the air and the other runs nimbly underneath it." This usually occurs after dark and may be accompanied by squeals and grunts.
The female may produce 3 to 5 litters a year with an average of 5 young per litter, but many newborns do not survive. Females will breed when they are only 3 months old; therefore, it is easy to see how populations could explode if there were no checks. While it is thought that they could live up to 7 years under ideal conditions, most rabbits, not surprisingly, don't make it past their first year and many, according to Forsyth (1985) live no longer than 6 months.
After a short gestation period, averaging 30 days according to Banfield (1974), females give birth in a shallow nest or "scrape," hollowed out of the ground and lined with vegetation and fur from her belly (Forsyth 1985, Banfield 1974). These nests are well concealed under shrubs or tall grass but can be very vulnerable to disturbance from dogs and humans. At the FWG I have not found any such nests, but then I rarely look for them, not wishing to disrupt the animals. However, I have seen quite a few young, evidence of successful breeding.
Within about two weeks of being born the young are ready to leave the nest. By this time, their mother is probably pregnant again and will soon be ready to give birth once more. Solitary animals that they are, Banfield (1974) says that the young will only stick together for the first 7 weeks before heading off alone.
Winter can be a very tough time for wildlife although some fare better than others. Eastern cottontails are fairly well adapted to surviving the cold as long as they have adequate food. Perhaps the biggest problem they face in this season is their vulnerability to predators. Unlike snowshoe hares, they do not turn white, and are therefore very visible against the snow. During the day, they usually remain sitting in a well-concealed location, blending with the landscape. At FWG, raspberry thickets are a favourite hiding place. Around the Old Field habitat, there is a good thick growth of this species, although as winter wears on, the canes tend to get beaten down by the snow and the safety factor diminishes.
Rabbits are often more active during daylight in the cold weather. They will even sit under the bird feeder in the BYG eating spilled seed in the middle of the day. This is a dangerous activity, for there is no real protection in the immediate vicinity for an animal of that size. On sunny days, rabbits may seek the sun's warmth where it penetrates sheltered spots.
On particularly cold days, they may take advantage of old groundhog dens for cover and warmth. At the FWG, we have very few burrows, apart from a couple of groundhog holes and several old fox dens (see photo). On the CEF, there are dozens of groundhog burrows, and there is ample evidence of rabbits using some of them.
The eastern cottontail frequently creates well-worn trails, particularly noticeable in winter, leading between burrows or brushpiles and a feeding area. I have seen some paths so well-trod they look like major rabbit highways. These are especially common along fencerows or hedgerows. Here you may also see where the animal has made numerous sidetrips to investigate a food source, but always heading back to the protective cover. One very well-worn rabbit run I investigated in winter, led from an old groundhog burrow, in a rose thicket, to a sumac stand on which the rabbit was feeding. One of the resident foxes soon discovered this site and caught the rabbit. During summer, these trails or runs are not as easy to find, being well-concealed by long grass.
At the FWG, we often find regular runs leading from the BYG and the Bill Holland Trail into the Ravine; around the Old Field thickets, and in a number of other locations. Their tracks are numerous at the FWG and the Arboretum, and not only along their runs. One morning, after an overnight snowfall, I arrived at the FWG to find fresh and very distinct rabbit tracks leading across the pond (see photo). Another time, I saw tracks heading across a field at the Central Experimental Farm (CEF) followed by a set of very clear fox prints!
Eastern cottontails are beautiful little animals and the young are, dare I say, absolutely adorable. Rabbit watching is fun, and you may find yourself becoming quite attached to them, particularly if you get to "know" an individual by watching where it sleeps, eats, and spends the day.