Bobcat
Bobcat | |
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File:Bobcat sitting.jpg | |
A Bobcat sitting on some hay | |
Scientific classification | |
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Species: | L. rufus
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Binomial name | |
Lynx rufus Schreber, 1777
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The Bobcat (Lynx rufus, or commonly felis rufus) is a wild cat native to North America. They are found mostly in the United States, southern Canada, and northern Mexico. The bobcat is an adaptable animal that inhabits wooded areas as well as semi-desert, urban, and swampland environments. They live in a set home range which shifts in size with the season. They utilize several methods to mark their territorial boundaries including claw marks and deposits of urine or feces.
In appearance, the bobcat has characteristic black bars on its forelegs and tail. They also have prominent, pointed ears with short tufts of black hair at the tip. The name is derived from their stubby black-tipped tails that, unlike those of other species of Lynx, have a white underside. Their coat is most often light gray or various shades of brown in color, with varying degrees of black spots either dispersed along much of their body or relegated to the otherwise white underparts. The bobcat is twice as large as a house cat but typically smaller than the related Canada lynx. The adult male, averaging 36 inches (90 cm) in length, and weighing from 16 to 30 pounds (7 to 14 kg), is generally 30-40% larger than the female.
Bobcats are carnivorous animals which will hunt anything from insects and small rodents to large deer, but often show a preference for rabbits and hares. What they hunt will depend on location and habitat, season, and scarcity of prey. The bobcat breeds from winter into the spring and has a gestation period of about two months. The kittens will stay with the mother until about a year old.
Taxonomy
There has been some debate over whether to classify this species as lynx rufus or felis rufus. Although the former is the preferred scientific name, the debate is part of a wider issue as to whether the lynx should be given its own genus, or simply placed in a more inclusive genus felis.[1] The bobcat is believed to be evolved from a Eurasian lynx which crossed into North America by way of the Bering land bridge during the Pleistocene. The first wave moved into the southern portion of North America, which was soon cut off from the north by glaciers. This population evolved into modern bobcats around 20,000 years ago. A second population arrived from Asia and settled in the north, creating the modern Canadian Lynx.[2]
Subspecies
The main subspecies, found in much of the eastern United States is the nominate: L. rufus rufus (Schreber). To the north in Maine and Canada lives L. rufus gigas (Bangs), and to the south L. rufus floridanus (Rafinesque).[3] However nine other subspecies are recognised, including L. rufus superiorensis (Peterson & Downing), L. rufus baileyi (Merriam), L. rufus californicus (Mearns), L. rufus escuinipae (J. A. Allen), L. rufus fasciatus (Rafinesque), L. rufus oaxacensis (Goodwin), L. rufus pallescens (Merriam), L. rufus peninsularis (Thomas), and L. rufus texensis (Mearns).[1]
Physical characteristics
![](http://upload.wikimedia.org/wikipedia/commons/thumb/6/63/Bobcat500.jpg/200px-Bobcat500.jpg)
In appearance the bobcat is quite similar to the Canada Lynx but is usually significantly smaller. In color they are mostly tan to grayish brown, but can vary. They also have numerous black streaks in their coat, with dark bars on their forelegs and tails. Their spotted coat allows them to blend into their environment. The ears are black-tipped and pointed with short black tufts. There is generally an off-white color on their lips, chin, and underparts. Kittens are born well-furred and already have their spots.
A few melanistic bobcats have been sighted and captured in Florida. They appear black, but may actually still exhibit a spot pattern.[4]
Adult male bobcats are 28 to 47 inches (70–120 cm) long, averaging 36 inches (90 cm), and height to their shoulders is about 14 or 15 inches (36–38 cm).[5] Included in their length is a stubby 6-inch (15 cm) tail, which has a "bobbed" apearance, which gives this species its name. They weigh about twice that of a house cat, with adult males usually ranging from 16 to 30 pounds (7–14 kg) while the females, which are smaller, average about 20 pounds (9 kg). They are muscular, and have hind legs that are longer than their front legs, giving the animal a bobbing run. They weigh 0.6 to 0.75 pounds (280–340 g) and are about 10 inches (25 cm) in length at birth. By their first year they will reach about 10 pounds (4.5 kg). They have sharp hearing and vision, and a good sense of smell. They are also excellent climbers. Bobcats can and will swim when they need to, but will normally avoid water.[6]
![](http://upload.wikimedia.org/wikipedia/commons/thumb/9/9b/Bobcat_tracks_in_mud.jpg/220px-Bobcat_tracks_in_mud.jpg)
Tracks
Bobcat tracks show four toes and no claw marks. The tracks can range in size from 1 to 3 inches (2–8 cm). When walking or trotting, the spread of the tracks are spaced roughly 8 to 18 inches (20–46 cm) apart, but can make great strides when running, often from 4 to 8 feet (1-3 m).[7] Like all cats, bobcats directly register, meaning their hind prints usually fall exactly on top of their fore prints (this is not the case in the photograph in this section). Bobcat tracks can generally be distinguished from feral or house cat tracks by their size (feral cat tracks being about 1.5 inches square (3.8 cm square) and also by the indentation at the top of the bobcat's foot pad (feral cat tracks generally show a single, rounded hump at the top of the foot pad).
Behavior
Bobcats are generally most active during twilight and are therefore considered crepuscular. They keep on the move from three hours before sunset until midnight, then again from before dawn until three hours after sunrise. Each night they will move from two to seven miles (3 to 11 km) along their habitual routes.[6]
Hunting
As a predator, the bobcat is able to go for long periods without food, but will eat heavily when prey is abundant. During the lean periods, they will often predate larger animals which they can cache and come back to later. The bobcat hunts by stalking or ambushing their prey and then pouncing or giving chase for short distances. Their preference is for mammals about 1.5 to 12.5 pounds (0.7 to 5.7 kg) in weight. Their main prey varies by region. In the eastern United States it is the cottontail rabbit, but in the north it is the snowshoe hare. When these prey exist together, as in New England, they make up the primary sustenance of the bobcat. In the far south, the rabbit or hare is sometimes replaced by the cotton rat as the primary food source. The bobcat is an opportunistic predator that, unlike its Canadian cousin the Lynx, can readily replace its primary prey with a variety of options.
The bobcat hunts animals of three different sizes, and will adjust its hunting techniques accordingly. On small animals they will hunt in areas known to be abundant in prey, and will lie, crouch, or stand still in wait for an animal to wander close. It will then pounce, grabbing its prey with its sharp, retractable claws. These are usually small rodents like mice and squirrels or birds, but also fish and insects. For slightly larger animals such as rabbits and hares, they will stalk from a covering and wait until they come within 20 to 35 feet (6 to 10 m) before rushing in to attack. Less commonly they will feed on larger animals such as foxes, minks, skunks, and house cats. They have been known to kill deer as well, especially in winter when smaller prey is scarce, or when deer populations become more abundant. They will do so by stalking the deer, often when it is lying down, then rushing in and grabbing it by the neck and biting through the base of the skull or chest. While they rarely kill deer, when they do, they eat their fill and then bury it with snow or leaves, often returning to it several times to feed.[8]
Additionally, bobcats are agile, good climbers and well-suited to gaining access to domestic farming operations such as chicken roosts.
Breeding
The male and female bobcats will begin breeding by their second summer, but the female may sometimes start as early as their first year. By September or October, sperm production begins, and the male will be fertile into the summer. A dominant male will travel with a female and mate with her several times, generally from winter until early spring. The two may undertake a number of different behaviours, including bumping, chasing, and ambushing. Other males may be in attendance of this, but will not become involved and remain aloof. Once the male sees that the female is receptive, he grasps her in the typical felid neck grip. The female may go on to mate with other male cats. The female is left to raise the young alone. One to six, but usually two to four, kittens are born in April or May, roughly after 62 days of gestation. There may sometimes be a second litter, with births as late as September. The female generally gives birth in some sort of enclosure, usually a small cave or hollow log. The young open their eyes by the ninth or ten day. They start exploring their surroundings at four weeks and are weaned at about two months. They will be hunting by themselves by their first fall but remain with the mother until nearly a year old.[9]
Survival
The bobcat has no major predators other than man. The coyote has been known to be a direct predator of the bobcat, but has an unknown effect on their populations. Cougars and wolves may also occasionally kill bobcats when they get the chance. Death is due to a variety of causes, such as diseases, accidents, hunters, automobiles, and starvation. Kittens however may be hunted by several predators, including owls, foxes, and even male bobcats. The young are most likely to die shortly after leaving their mothers while still perfecting their hunting technique. Of fifteen bobcats tracked, the yearly survival rate averaged 0.624, with females having the same rate as males. Many bobcats will live to six or eight years of age, with a few reaching beyond ten. The longest they have been known to live in the wild is 16 years, but in captivity have been known to live up to 32.2 years. However, when prey populations are not as abundant, fewer kittens are likely to reach adulthood. Bobcats may also harbor large parasites, mostly ticks and fleas, and will often carry the parasites of its prey, especially rabbits and squirrels. One mite in particualar (lynxacarus morlani) has to date only been found on the bobcat. It's still unclear how large of a role parasites and diseases play in the mortality of bobcats, but they seem to account for greater mortality than starvation, accidents, and predation.
The bobcat has long been hunted and trapped by humans. They are listed in the CITES treaty which allows them to be hunted so long as doing so is not detrimental to their population. However bobcats have maintained a high population, even in the south where they are extensively hunted. Kittens are most vulnerable to hunting, albeit indirectly, due to their dependence on an adult female for the first few months of its life. In the 1970s and 1980s their furs saw an unprecedented rise in price, causing further interest in hunting them. However, these furs are worth little today. They are nevertheless still hunted, with half the mortality of some populations being attributed to this cause. As a result, the rate of bobcats dying in winter when hunting season is generally open is skewed. There have also been reports of cannibalism occurring when prey levels are low, but it is very rare and does not overtly influence the population.[10] If chased by a dog, which in human-inhabited areas are a major source of predation, they will usually climb up a tree.[11] Additionally the bobcat does not tolerate deep snow, and will hole-up and wait out heavy snow storms.[12]
Distribution
The original range of the bobcat was from southern Canada to throughout the eastern United States, and down as far south as Oaxaca, Mexico. The bobcat still occurs in much of this range, from Maine to Florida and westward to Mississippi. They will often inhabit areas near large cities. However they are thought to no longer exist in certain habitats such as western New York and Pennsylvania, and much of the Midwest, such as southern Minnesota, eastern South Dakota, Iowa, and much of Missouri.[13] Their activities are confined to well-defined territories which vary in size depending on sex, season, and distribution of prey. The home range is marked with their feces, urine scent, and by clawing prominent trees in the area. In this territory the bobcat will have numerous places of shelter, usually a main den and several auxiliary shelters on the outer extent of their range such as hollow logs, brush piles, thickets, or under a rock ledge. The odor of their den is strong. In summer the range of a male can reach roughly 16 square miles (41 km2) or be less than a square mile (2.5 km2), while the range of the female is less than half that. In winter bobcat territories may expand up to 40 square miles (100 km2), often overlapping those of other bobcats. While male bobcats are more tolerant of this overlap, females rarely wander into other females' ranges. However two or more females may reside within a male's home range. When multiple male territories overlap a dominance hierarchy is often established resulting in the exclusion of some transients from favored areas. Generally though there exists about one bobcat per every five square miles (13 km2), or perhaps slightly less depending on the location.[14] Additionally there seems to be a link between population density and sex ratio. One study noted that a dense, unharvested population in California had a sex ratio of 2.1 males per female. When the density decreased, the sex ratio skewed to 0.86 males per female. Another study observed a similar ratio, and added the possible explanation that males were better able to cope with the increased competition, and that this would help limit reproduction until various factors would lower the density.[10]
![](http://upload.wikimedia.org/wikipedia/commons/thumb/6/66/Bobcatonwires.jpg/240px-Bobcatonwires.jpg)
The bobcat is an adaptable animal, able to survive in numerous environments. Unlike the lynx it does not depend on the deep forest, but will also live in swamps as well as mountainous and wooded areas. If rocky ledges, swamps, or forested tracts are present, they will also make their home near agricultural areas. Their need is simply for land which will give them activity and rest, typically provided by woodlands (both deciduous and coniferous, or mixed). Much of their activity centers around swamps or ledges where they utilize their spotted coats for camouflage. Their range does not seem to be hindered by human populations, as long as they can still find a suitable habitat. However their population in the north seems to be limited due to both snow depth and the presence of the lynx.[15] They are nevertheless well-suited to human caused changes in the environment, unlike the lynx, and some researchers believe there are more bobcats today in the United States than in colonial times.[12]
Notes
- ^ a b Fischer, William C.; Miller, Melanie; Johnston, Cameron M.; Smith, Jane K. (February 1, 1996). Fire Effects Information System. DIANE Publishing. ISBN 0788145681. p.83.
- ^ American Marten, Fisher, Lynx, & Wolverine in the Western U.S. DIANE Publishing. ISBN 0788136283. pp. 77-8
- ^ Whitaker et al. 1998, p. 496
- ^ Ulmer, Jr., Fred A. 1941. Melanism in the Felidae, with Special Reference to the Genus Lynx. Journal of Mammalogy, Vol. 22, No. 3. pp. 285-288.
- ^ Cahalane, Victor H (March 1, 2005). Meeting the Mammals. Kessinger Publishing. ISBN 141799522X. p. 64.
- ^ a b Fergus, Charles (August 1, 2003). Wildlife of Virginia and Maryland Washington D.C. Stackpole Books. ISBN 0811728218. p. 119.
- ^ Peterson Roger Tory; Murie, Olaus Johan (January 15, 1998). A Field Guide to Animal Tracks. Houghton Mifflin Field Guides. ISBN 0395910943. p. 115.
- ^ Whitaker et al. 1998, pp. 494-5
- ^ Whitaker et al. 1998, p. 495
- ^ a b Feldhamer, George A; Thompson, Bruce C; Chapman, Joseph A (January 1, 2004). Wild Mammals of North America. Johns Hopkins University Press. ISBN 0801874165. pp. 769-70.
- ^ Whitaker et al. 1998, p. 496
- ^ a b National Park Service. Yellowstone National Park. Bobcat. Retrieved on August 24, 2006.
- ^ Whitaker et al. 1998, pp. 493-4.
- ^ Whitaker et al. 1998, pp. 495-6
- ^ Whitaker et al. 1998, p. 494
References
- Whitaker, John O; Hamilton, W J (January 1, 1998). Mammals of the Eastern United States. Cornell University Press. ISBN 0801434750.