Canada Lynx

Lynx canadensis

Shad Loch
Jason Schmidt
Matthew Van Zeeland

Description

The lynx is a mid-sized felid with a short tail and broad paws. Its thick dorsal fur is commonly yellowish brown, sometimes with a frosted gray appearance. The fur has variable spots, usually occurring on the sides and legs. Its most distinctive features are the black tufts of hair on the ears that are as long as 50% of the height of the pinna (ear) and large padded feet (Figure 1). Ruffs are also present below the jaws and on the cheeks.

Fig 1. Large paws allow the lynx to maneuver in deep
snow. Source: WildlifeWebsite.com. http://www.wildlifewebsite.com/wild-cats/wild-cat-gallery-00.html

The only Wisconsin mammal that a lynx could reasonably be confused with is the bobcat (Lynx rufus) (figure 2). However, the bobcat has a longer tail and the tail is not black all around as it is in the lynx. Other differences are the shorter ear tufts in the bobcat and smaller feet (Kurta 1995).

The average total length of an adult Canadian lynx from Wisconsin specimens are between 87.5-100.cm (34.45-39.37 in); tail 10.0-12.0cm (3.94-4.72 in); hind foot 21.5-25.0cm (8.47-9.84 in.). The average weight of an adult lynx is 7-16kg (15.43-35.27 lbs). Males are typically five percent larger than females. Older males tend to develop a more pronounced saggital crest (a bony ridge on the back of the skull) (Jackson 1961).

Fig 2. Comparison of Bobcat and Lynx. Source: http://dnr.wi.gov/org/land/er/factsheets/mammals/images/cats.gif.

Lynx Skull Pictures

Lynx Skull - Front

Lynx Skull - Left	Lynx Skull - Bottom

Food Habits

Table 1 Frequency of occurrence of prey items in the diets of Canada Lynx in Alberta Canada (percentage of samples).
Prey items	Scats (n=101) Hares Abundant	Scats (n=123 Hares Scarce
Lepus americanus Snowshoe hare	76.2	66.7
Small rodents	19.8	4.1
Other Rodents		10.6
Birds	3.0	8.9
Carrion	0.9	5.7
Miscellaneous animals	3.0	4.1
Minimum number of vertebrate prey items	101	123

Source: Brand 1976

Although no specific data exist on the food habits of lynx in Wisconsin, their primary food source is the snowshoe hare (Lepus americanus). When snowshoe hare densities are high they comprise 76%-94% of the lynxs diet. When snowshoe populations are down the lynx begins to depend more and more on other prey such as red squirrels (Tamiasciurus hudsonicus), mice and voles (Cricetidae), flying squirrels ((Glaucomys spp.), ground squirrels (Citellus spp.) and grouse (Tetraonidae). Table 1 is an example of lynx feeding behavior in the presence of high and low hare abundances (Mowat 1999). The lynx occasionally prey on white tailed deer (Odocoileus virginianus), usually fawns or rarely adults in deep snow, but usually ungulates are eaten in the form of carrion. The lynx may make use of different hunting techniques as conditions dictate. When hare densities are high a technique of waiting and ambushing as they come by may be the most effective method and very energy efficient. However, when hare densities are low, hunting and actively searching may be employed more often. When a kill is made it may be eaten on site or carried to another location. Lynx may also cache part or all of a kill, and are more likely to cache food in years of snowshoe hare abundance (Sunquist 2002).

Reproduction

Lynx are polygynous, where a single male may breed with several females. Mating occurs in January or February and is marked by an increase of urine marking and calling to bring the sexes together. Lynx are thought to be induced ovulators, though they may be spontaneous ovulators when mates are abundant (Sunquist 2002). Successful breeding is followed by a gestation period of roughly 62-64 days. The mother makes a nest in a hollow tree, stump, log or brush pile by pawing together leaves and bark. The 175-235 gram (6.17-8.29 oz) kittens are born with their eyes closed for the first ten days of life. They are browner than the adults with dark spots that disappear by about nine months of age (Jackson 1961). Lynx generally have one to four young. The number of kittens per litter is closely tied to the snowshoe hare abundance, for reasons discussed in the mortality section (Mowat 1999). The kittens remain dependent on their mothers for milk for four to six months, but began to consume prey killed by her after one month (Kurta 1995). They may begin to follow their mother at five weeks of age, and actively participate in the hunt as early as 7 months of age. Kittens remain with their mother until they are about 10 months old, but do not obtain full adult size until they are 2 years of age. When prey is abundant females may breed for the first time at 10 months of age, otherwise they will wait until they are 22-23 months of age (Sunquist 2002; Tumlison 1987).

Mortality

The lynx follows a much studied population cycle with its number one prey species the snowshoe hare. The lynx parallels, fairly rigidly, an up and down population cycle of ten years with the snowshoe. The cycle is created by changes in reproductive and mortality rates. Female lynx have fewer or no kittens when hare abundance is down, and more kittens when the population is on the rise (Mowat 1999). Mortality rates for young and adult lynx vary significantly depending on the hare cycle, with natural mortality being low when hares are abundant. Natural mortality is high everywhere when hare numbers have declined. When food is in short supply, kitten growth is retarded and few survive (Sunquist 2002). Life expectancy varies but a rough average is 4 to 6 years in the wild, and is not thought to surpass 15 years. Lynx in captivity have lived to almost 22 years of age. Although the primary mortality factor is the scarcity of prey, namely snowshoe hares, man also causes mortality. The increased price for lynx pelts has increased the harvest. The lynx is also affected by external parasites such as Ceratophlyuss denatus and C. labiatus and internal parasites such as Taenia laticollic and T. rileyi (Jackson 1961).

Home Range and Social Organization

The lynx is generally a solitary animal with the males and females avoiding each other except to mate. A lynx usually inhabits a home range of 10-50km². The boundaries are marked with urine and feces and the territories are respected by both sexes. The lynx is primarily a nocturnal hunter, spending its days under down trees or rock overhangs (Kurta 1995). A radio telemetry study of an un-harvested population in the Northwest Territories Canada has found that lynx densities peaked at 30 animals per 100 km², and declined to about three per 100 km² during the hare crash (ISEC 2001).

Dispersal

In the lynx, there are two types of dispersal: innate or juvenile dispersal and environmental dispersal, when adults emigrate in response to significant prey declines. Most adult dispersal is initiated from March to June following initial hare decline (Anderson et al. 2003). Long distance movements have been recorded up to 1,100 km (683.51 mi) in the Yukon. More locally in Minnesota lynx have been documented to move 483 km (300.12 mi) out of their normal home range due to lack of prey (Koehler and Aubry 1994). Given the available data and the propensity of lynx to disperse, at this time it is impossible to determine with certainty whether reports of lynx in many States were: (1) merely dispersing animals from northern populations that were effectively lost from the net population because they did not join or establish resident populations; (2) animals that were a part of a resident population that persisted for many generations; or (3) a mixture of both members of resident populations and dispersing animals (Federal Register 2000).

Habitat Association

Picture (361x247, 26.2Kb) Lynx are not fast runners and so depend on stealth to catch their prey (figure 3). The lynx is a diurnal hunter generally stalking prey alone, although group hunting and ambushing has been observed (Garman 1997).

They hunt by either stalking and rushing their prey, or waiting along a trail and ambushing it. The lynx prefers freshly killed prey and only seldom caches a kill for later. The lynxs large padded feet act like snowshoes in winter; spreading their weight out over a large surface area so they can walk on top of deep snow instead of in it (figure 1). This gives them an advantage over most of their prey species and keeps them on a level playing field with snowshoe hares. Its preferred habitat is a mature coniferous forest (cedar swamps and upland forests of hemlock and fir) with thick litter and rotting logs, this is also the preferred habitat of snowshoe hares (Kurta 1995).

Interaction With Other Species

Due to their highly adapted paws, lynx tend to out-compete other predators such as martins, fishers, and coyotes in areas of deep snow. Ecologically, lynx have the advantage over bobcat in areas of deep snow, whereas bobcats dominate lynx in all other areas. Trapping continues to be one of the greatest threats for the lynx, and as lynx are easily trapped, when practiced at times of low population levels it makes recovery of the population extremely difficult (Sunquist 2002).

Current Management and Legal Status

Due to the historical low numbers of lynx in Wisconsin, the federal Endangered Species Act as it pertains to the lynx is a controversial issue. One side wants the protection of possible lynx habitat, even though there is no proof of their existence in the area. The other side of the coin does not want the complete protection called for in the Endangered Species Act for a mammal that has never had a significant population in the state because it jeopardizes human interests such as logging and recreational uses. The lynx is federally listed as a threatened species in the lower 48 states, but as of 1997 Wisconsin de-listed the lynx from the state list of threatened and endangered species. As of 1998 the lynx was designated a protected wild animal in Wisconsin under Administrative Rule NR 10.02 (WDNR, 2003). The issue of listing the lynx is even more heated in Minnesota and western states where more lynx are present. Lynx research consists of monitoring reports of sightings and deaths. While no management plan is being enacted, biologists recommend that large tracts of northern forest be maintained to enable the survival of lynx in Wisconsin. As the human population increases in Wisconsin, the risk of accidental shooting, trapping, and being hit by cars likewise increases for the lynx (WDNR, 2003).

Economic Value

The market for lynx in Alaska, where trapping is allowed, is showing improvement. Highs of $125 to $140 per pelt are being commanded, although most are around $80 to $85 with the feet intact (Dozhier 2004).

Distribution in Wisconsin

Declared an endangered species in 1972 by the state, the lynxs distribution in Wisconsin is not well known. The lynx has never been all that common in the state. The fur was highly desirable, yet only a few pelts were sold each year in Wisconsin in the early 19^th century (Jackson 1961).

Since 1870 there have only been 28 verified records of lynx in Wisconsin, occurring most frequently in the northern portion of the state. Between 1962 and 1973, 16 lynx were killed in the state; that is half of all the records from 1870 to the present. A similar rise of mortalities during this time period also occurred in Minnesota, North Dakota and Montana, the reason is unknown. Since that time only two more lynx have been found in Wisconsin, both in 1992 in Bunette and St. Croix Counties, these lynx are both a part of the University of Wisconsin-Stevens Point mammal collection (McKelvey 1999). A breeding population has never been discovered and it is believed that most occurrences are drifters coming through Michigan or Minnesota from Canada. In fact in 1997 the lynx was removed from the states endangered species list as it has not been a recent or current breeder. In 1998 it was added to the states list of protected animals. (See current management)

History of Lynx in Wisconsin

Picture (198x256, 14.7Kb) Before they were protected, lynx were valued for their pelt and the few times they were successfully killed; from 1865 through 1957 there was a state financed bounty placed on the lynx in Wisconsin (figure 4).However, even more detrimental is the habitat destruction caused by humans; clear-cutting and plantations of red pines are not suitable for lynx. According to the Wisconsin DNR lynx sighting have correlated directly with the 10 year cycles of the snowshoe hares in Canada. When snowshoe hare populations crash, lynx migrate south through Minnesota into Wisconsin. Lynx carcasses have been found as far south as Sauk, Green Lake, and Vernon counties during these years (WDNR, 2003).

Interesting Facts: Hair Sample Investigation Issue

The most famous controversy over listing the lynx as an endangered species was the falsification of lynx hair samples in Gifford Pinchot National Forest and Wenatchee National Forest in Washington to prove that lynx inhabited the area and to protect the area. It was later discovered that the hair sample was from a captive lynx and had been planted by the U.S. Forest Service biologists. The biologists responsible for the hoax claim to have been testing the ability of the laboratory to correctly identify lynx and were not attempting to falsely increase the range of the lynx (Pierce 2001). A meaningful punishment was not administered because it is not thought that there was criminal intent. Instead the forest service administered corrective action, meaning the employees involved are no longer allowed to work with the lynx survey (Bosch 2002).

Lynx Links

Lynx Skull- http://animaldiversity.ummz.umich.edu/site/accounts/specimens/Lynx_canadensis.html

http://www.fs.fed.us/rm/pubs/rmrs_gtr30.html

www.dnr.state.wi.us

http://dnr.wi.gov/org/land/er/factsheets/mammals/lynx.htm

http://dnr.wi.gov/org/caer/ce/eek/critter/mammal/lynx.htm For children

Literature Cited

Anderson, E. M., M.J. Lovallo. 2004. Wild Mammals of North America. Biology, Management, and Conservation. Second edition G. A. Feldhamer, B. C. Thompson, & J. A. Chapman. Pages 758-786.

Bosch, M. 2002. Lynx investigation summaries, 2002. United States Forest Service. Available at http://www.fs.fed.us/r1/wildlife/carnivore/Lynx/survey.htm Accessed 15 April 2004.

Dozhier, Parker. 2004. Fur Market Report. The Trapper and Predator Caller. Vol. 29/3/ page 12-16.

Federal Register: March 24, 2000. Rules and Regulations. Volume 65,

	Number 58 16051-16086 pp. From the Federal Register Online

	via GPO Access wais.access.gpo.gov

Garman, A.1997. Big Cats Online. http://ds.dial.pipex.com/agarman/canlynx.htm Accessed 15 April 2004.

International Society for Endangered Cats Canada (ISEC Canada) 2001. http://www.canuck.com/iseccan/index.html Accessed 15 April 2004

Jackson, H.H.T. 1961. Mammals of Wisconsin. The University of Wisconsin Press, Madison, 395-400.

Kurta, A. 1995. Mammals of the Great Lakes Region. University of Michigan Press, Ann Arbor, 252-254.

Koehler, G. M., K.B. Aubry. 1994. The Scientific Basis for Conserving Forest Carnivores: American Marten, Fisher, Lynx, and Wolverine in the Western United States. USDA Forest Service General Technical Report RM-254, 74-94.

McKelvey, K.S., K.B. Aubry, and Y.K. Ortega. 1999. History and Distribution of Lynx in the Contiguous United States. RMRS-GTR-30WWW-Ecology and Conservation of Lynx in the United States. Hard copy published by the University of Colorado, 207-253.

Mowat, G., K.G. Poole, and M. ODonoghue. 1999. Ecology of Lynx in Northern Canada and Alaska. RMRS-GTR-30WWW-Ecology and Conservation of Lynx in the United States. Hard copy published by the University of Colorado, 265-298.

Pierce, J., T. Quinn, and J. Scott. 2001. Statement from Washington Department of Fish and Wildlife Chief Scientists Regarding the Submittal of False Data for Interagency Lynx Study. http://www.forwolves.org/ralph/lynx-false-wash-state.htm.

Sunquist, M.E., F. Sunquist. 2002. Wild cats of the world. University of Chicago Press, Chicago. Pgs. 154-163.

Tumlison, R. 1987. Felis lynx. Mammalian species. No. 195-296:269 1-8.

WDNR. 2003. Wisconsin Department of Natural Resources. http://dnr.wi.gov/org/land/er/factsheets/mammals/lynx.htm Accessed 15 April 2004.