San Francisco State University
Department of Geography

Geography 316:  Biogeography

The Biogeography of Bobcat (Lynx rufus)
by Michael R. Peterson, student in Geography 316, Fall 2000

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Felidae
Subfamily: Felinae
Genus: Lynx
Species: Lynx rufus

Subspecies:
L. r. baileyi (Southwestern U.S. and Northwestern Mexico)
L. r. californicus (Pacific Coastal U.S. – California)
L. r. escuinapae (Mexico)
L. r. fasciatus (Pacific Coastal Northwestern U.S. and Canada)
L. r. floridanus (Southeastern U.S.)
L. r. gigas (Northeastern U.S. and Canada, including New Brunswick and Nova Scotia)
L. r. oaxacensis (Southern Mexico)
L. r. pallescens (Northwestern U.S. and Canada)
L. r. peninsularis (Baja Peninsula)
L. r. rufus (Midwestern and Northeastern U.S.)
L. r. superiorensis (Northern Great Lakes)
L r. texensis (Texas and Northwestern Mexico)
(Lariviere and Walton 1997)

Of interest concerning the taxonomic classification:
The genus classification, Lynx, has commonly been reported in error as Felis.  Serge Lariviere and Lyle Walton, whose indepth reporting of the species in Mammalian Species (Oct. 1997) lends itself to credibility, note that the distinction pertains to dentition, Lynx having two upper premolars, and Felis having three.  They report that the bobcat has two upper premolars – a Lynx.

Description of Species:
Lynx rufus, the bobcat of North America, is a beautiful carnivore approximately twice the size of a house cat (DiSilvester 1987). Its dense short hair is a spotted pelage that provides excellent camouflage in the shadows of filtered sunlight (DiSilvester 1987). So named for its bobbed, short tail of only one to two inches, the bobcat’s coat is regionally distinct – a gray-brown color having evolved in arid parts of the U.S., and a red-brown color (“rufus” meaning red) having evolved in the dense forest habitats of the Pacific North West and Western Canada (DiSilvester 1987). The bobcat’s northern cousin, Lynx canadensis (Canadian lynx), has bigger feet and longer legs, characteristics that are key to the northern boundary of the distribution of Lynx rufus. It simply does not have the big paws and long legs that make Lynx canadensis the better competitor in snow conditions (DiSilvester 1987).  Tufts of hair in the ears also characterize the physical appearance of Lynx rufus, and this also distinguishes the species from Lynx canadensis – the tufts being shorter and less dense in Lynx rufus, a reflection of its warmer habitat (DiSilvester 1987).

Habitat:
Lynx rufus is found in a wide variety of habitats – in rim rock and chaparral country of the arid west and in forests of the east and temperate north (DiSilvester 1987).  A good swimmer, it also is found in swampland (Burt 1980).  Imagine a cat stretched out lazily on a rock, soaking up in pure tranquility the rays of the sun – this is Lynx rufus.  It counteracts the thermoregulatory costs of its lifestyle by sunning and by selection of its microhabitat (Lariviere and Walton 1997). That microhabitat is often a rock crevice or hollow log (Burt 1980).  Generally the bobcat selects its home range at lower elevations in the winter (limited by snow), but does not exhibit particular elevation preferences in the summer (Lariviere and Walton 1997).

Natural History:
Lynx rufus is solitary and territorial, protecting its territory with visual and olfactory signs (Burt 1980).  Its range varies from 0.2 to 80 square miles (Burt 1980).  Nocturnal, it is rarely seen by humans – but is curiously known to make use of roads, trails, and snowmobile tracks, being less inclined to navigate through thicket (Lariviere and Walton 1997).  The bobcat is strictly carnivorous, its diet primarily consisting of lagomorphs (Lariviere and Walton 1997).  As a supplement to its preference for rabbits and hares, it also hunts large rodents, birds, mice, and reptiles – and the largest bobcats even possesses the ability to kill deer (Lariviere and Walton 1997).  Its killing technique is the strike and pounce method (DiSilvester 1987). Lynx rufus has the body mechanics for killing and shearing meat, adapted specifically for cutting flesh – but not possessing extraordinary power for cracking bones (Lariviere and Walton 1997).  It is known to avoid areas of intense agriculture and, to its advantage concerning relations with humankind, does not prey on livestock (DiSilvester 1987).

Lynx rufus has an average lifespan of 15.5 years in the wild or 32 years in captivity.  It is polygamous, with the male having seasonal spermatogenesis – decreased in late summer and early fall – and playing no parental role beyond conception (Lariviere and Walton 1997). Females are seasonally polyestrous, usually bearing one litter of two or three young in the spring (Lariviere and Walton 1997).  The young, blind for the first three to eleven days, are nursed for two months, and then leave the mother at approximately six months (Lariviere and Walton 1997).  Bobcats reproduce until death (Lariviere and Walton 1997).

Evolution:
Fossil records suggest that the genus Lynx has origins in Africa (Lariviere and Walton 1997).  Modern day cats are the descendants of the Miacidae family which persisted until the Oligocene epoch, when some members of that family began to develop the enlarged canine teeth and specialized shearing carnassial teeth characteristic of carnivores (Gittleman 1989).  More advanced carnivores (literally meaning, “eaters of flesh”) began to appear in the Early Miocene, distinguished particularly by morphological developments of the feet and teeth (Gittleman 1989).  Among these were the cat family, the Felidae, noted for its ability to climb – a feature that is attributed its origin of forested habitats (Gittleman 1989).  The modern day bobcat retains this ability; however, it prefers to reserve this skill for matters of escape (Lariviere and Walton 1997).

The bobcat belongs to panther lineage, Lynx having separated from the genus Panthera approximately 2 million years ago in the Pliocene epoch (Lariviere and Walton 1997). Panther lineage evolved parallel to two other groups: The domestic cat lineage and the ocelot lineage (Gittleman 1989).  Placement of the genus Lynx close to Panthera is based on karyotype – chromosomal morphology analysis on skin tissue – which distinguishes members of panther lineage from other felid genera (Gittleman 1989).  It is important to note that relationships within the panther lineage are not entirely resolved, and outstanding question marks exist, particularly in relation to the morphological diversity among the puma, golden cat, cheetah, caracal, and South American jaguarundi species (Gittleman 1989).

Earliest records of Lynx rufus date back 3.2 to 1.8 million years ago (Lariviere and Walton 1997).  It is the descendant of an earlier species Lynx issiodorensis, the first appearance of which dates from the lower Pleistocene epoch of the Quaternary period, prior to the first glaciation (Lariviere and Walton 1997).  It appears that a gradual size reduction characterizes the evolution of the bobcat.  A predominant subspecies of ancient times, Lynx rufus calcaratus (Irvingtonian bobcat), is known to have been slightly larger than Lynx rufus of modern times (Lariviere and Walton 1997).

Distribution:
Lynx rufus is endemic to North America. Its continuous distribution is primarily limited to the continental United States, although it extends beyond the northern border, stretching from coast to coast, British Columbia to Nova Scotia – and extends as far south as Oaxaca, Mexico (Wilson 1993).  It is absent in the U.S. only in certain pockets: The Ohio Valley, Upper Mississippi Valley, and southern Great Lakes region, where it was hunted to extinction (DiSilvester 1987). Lynx rufus populations were adversely affected in the 1970’s due to the fur trade agreement in 1973 of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) that provided protection to other cats – the cheetah, leopard, jaguar, and ocelot.  Restrictions on those cats left Lynx rufus vulnerable to hunting, until later amendments were made to include all wild cats (DiSilvester 1987).  Under protection, bobcat populations have largely recovered (Turbak 1994), and currently only a Mexican subspecies, Lynx rufus escuinapae, is listed as endangered (Wilson 1993).  Current threats to bobcat populations include the dangers of road kill and downed power lines, injury from porcupine quills (Lariviere and Walton 1997), and threats to habitat due to urban sprawl and agriculture (DiSilvester 1987).  A highly adaptive animal, Lynx rufus is the dominant American cat, able to out-compete populations of cougar and coyote, and only seceding to Lynx canadensis in the north as a result of lesser performance in snow (Turbak 1994).

Bibliography

Alden, Peter.  1987.  Peterson First Guide to Mammals of North America.  Italy: Houghton Mifflin.

Burt, William H.  1980.  A Field Guide to The Mammals.  3rd Edition.  Boston: Houghton Mifflin.

Corsi, Gerald and Buff.  2000.  California Academy of Sciences: Manzanita Project.  Bobcat photos.  [On-line] http://dlp.CS.Berkeley.EDU/cgi/img_query?special=browse&where-lifeform=Mammal&where-ph_cname=bobcat [Nov. 16,   2000].

DiSilvesters, Roger L., ed.  1987.  Audubon Wildlife Report.  New York: Academic Press, Inc.

Gittleman, John L., ed.  1989.  Carnivore Behavior, Ecology, and Evolution.  Cornell University Press.  New York.

Lariviere, Serge and Walton, Lyle R.  1997.  “Lynx rufus.” Mammalian Species.  Oct. 24, n 563, p 1-8.

National Museum of History: Smithsonian Institution On Line.  2000.  “Lynx rufus.”  [On-line]  http://www.nmnh.si.edu/cgi-bin/wdb/msw/names/query/12097  [Oct. 24, 2000]

Szalay, Frederick S., Novacek, Michael J., and McKenna, Malcolm C.  1993.  Mammal Phylogeny: Placentals.  Springer-Verlag.  New York.

Turbak, Gary.  1994.  “Bounce-back Bobcat: A True Survivor Under Pressure.”  Wildlife Conservation.  Nov/Dec,  p 22.

Vanderney, Nancy.  2000.  Welcome to the Cat House: The Exotic Feline Breeding Compound’s Feline Conservation Center (FCC).  Bobcat photo.  [On-line] http://www.cathouse-fcc.org/images/willow109.jpg [Nov. 16, 2000]

Wilson, D. E., and Reeder, D. M., ed.  1993. Mammal Species of   the World.  Washington DC: Smithsonian Institution Press.
 
 
 

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