Feral house cats, Felis catus, are often overlooked in discussions of
exotic nuisance animals due to their ubiquity and our familiarity with them as
companion animals. They are, however, among the most ecologically damaging
introduced animals worldwide.
Domestic cats are characterized by a number of well-known physical
characteristics. These include a flexible and compact body, keen eyesight and
adaptations for visual acuity at night, retractable claws, sharp teeth and a
reduction in numbers of teeth (e.g., the hind chewing teeth) reflecting
adaptation as a carnivore, long vibrissae (whiskers), and a long and
flexible tail important as an aid to balance (LaBruna 2001, ISSG).
F. catus is among the smaller members of the felid family, but shares
with other family members the trait of being an agile and efficient predator.
Potentially Misidentified Species
The only felids native to Florida are the bobcat, Lynx rufus and the
highly endangered Florida panther, Puma concolor coryi. Bobcats grow to
around twice as large as Felis catus, and their distinctive black
bar-shaped markings on the forelegs and black-tipped, stump tail allow easy
differentiation between the species. Confusing a feral domestic cat for a
Florida panther is unlikely.
HABITAT AND DISTRIBUTION
Domestic Felis catus are believed to be the results of several millennia
of human domestication of one or both of two closely related wild species, the
European wild cat, Felis silvestris (probable ancestral line), and the African wild cat Felis lybica. The area of original domestication is believed to be centered in or around Egypt.
Domestic and escaped feral F. catus are now distributed worldwide,
notwithstanding a few isolated islands where the species has either not been
introduced by humans or has failed to become established (LaBruna 2001).
Feral Felis catus are well-established throughout the state, including
the 6 IRL watershed counties. A number of feral cat colonies comprised of
often large numbers of so-called "TNR" cats (individuals that have been
trapped, neutered or spayed, and released into the colony population) are also
located in the IRL region.
LIFE HISTORY AND POPULATION BIOLOGY
Age, Size, Lifespan
The life expectancy of feral cats is considerably shorter than that of their
house-kept counterparts, between 2 and 3 years of age for feral animals versus
10-15 years or longer for house cats.
The average head and body length of adult Felis catus is around 46 cm
and the tail length averages around 30 cm. Adult feral cats typically weigh
3.3-4.5 kg, with males being at the larger end of the range and females at the
lower end (ISSG).
There are an estimated 10 million owned house cats in Florida. The Florida Fish
and Wildlife Conservation Commission has estimated that the feral cat
population in Florida is roughly on the same order, i.e., between 6
to 10 million animals (FWCC 2001).
The estimated U.S. population of feral cats is 60 million (ISSG).
As with all mammals, reproduction in Felis catus is sexual and
fertilization is internal. Reproduction occurs year-round where resource
Relative to other members of the mammalian order Carnivora, F. catus
exhibits a high fecundity. This is largely related to the rapid onset of
sexual maturity in females, typically between 7-12 months of age, and the
capacity for females to come into estrous as often as 5 time a year (Ogan and
Jurek 1997, Gunther and Terkel 2002). Females can produce as many as 3 litters
in a year (Fitzwater 1994).
Gestation lasts for 63-65 days. Litter size typically averages 4-6 young ( O'Donnell 2001).
Felis catus is a highly adaptable species, but laboratory animal
husbandry authorities suggest an
optimal temperature range of 17-29°C.
As with other mammals, feral cats alter daily and seasonal foraging and
activity patterns in response to environmental temperature shifts.
Felis catus is a predatory carnivore that readily preys on birds and
small mammals as well as reptiles, and amphibians. LaBruna (2001) suggests
that house cats have retained their instinctive hunting skills to insure that specific nutritional requirements for fresh animal protein are met.
Association between Felis catus and human caregivers has occurred for perhaps 4,000 years.
Domestication of Felis silvestris and possibly Felis lybica began
around 4,000 years ago in Egypt. Domesticated Felis cattus can readily
interbreed with both of these to form viable (fertile) offspring. In fact,
recent mitochondrial DNA studies suggest that both F. lybica and F.
cattus shuld be considered subspecies of F. silvestris.
Human-aided spread of Felis cattus was facilitated both by the animals'
beneficial mousing skills and the fact that Egypt was an important trading port
in the ancient world. The Egyptians took cats with them on shipping vessels to
keep rodent populations in check, and they likely introduced domestic cats to
Europe in this manner. In turn, expansion of the Roman Empire and, later,
European missionary zeal facilitated the spread of domestic cats into Asia and
Modern house cats keep feral cat numbers high through escapes and through high fecundity and multiple estrous cycles of females.
Potential to Compete With Natives
LaBruna (2001) estimates that over a half-billion birds a year are killed
in the U.S. by a combined feral and outdoor-kept cat population estimated at
more than 90-million animals. Dewey (2005) notes Felis cattushas been
directly responsible for declines in a number of bird and mammal populations,
especially small, island populations.
Possible Economic Consequences of Invasion
Domestic house cats have significant positive economic value for companionship
and for vermin control. In the feral Felis catus population, however,
these positives are outweighed by the ecoolgical damage these animals can
In addition to the ecological impacts, Felis cattus carries a number of
diseases that are transmissible to humans, including rabies, cat-scratch fever,
and various parasitic infections (Dewey, 2005). Efforts to manage feral cat
populations are costly, and the partial solution of TNR feral cat colonies is
F. cattus species has been nominated as among 100 of the "World's
Worst" invaders by the Invasive Species Specialist Group (ISSG).
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Driscoll C.A., Menotti-Raymond M., Roca A.L., Hupe K., Johnson W.E., Geffen E.,
Harley E.H., Delibes M., Pontier D., Kitchener A.C., Nobuyuki Y, O'Brien S.J.,
and D.W. Macdonald2. 2007. The Near Eastern origin of cat domestication.
Fitzwater W.D. 1994. House cats (feral): Prevention and control of wildlife
damage. Cooperative Extension Division; Institute of Agriculture and Natural
Resources, University of Nebraska- Lincoln, United States Department of
Agriculture Animal and Plant Health Inspection Service Animal Damage Control
Gunther I., and J. Terkel J. 2002. Regulation of free-roaming cat (Felis
silvestris catus) populations: A survey of the literature and its
application to Israel. AnimalWelfare. 11:171-188.
Florida Fish and Wildlife Conservation Commission. 2001. impacts of feral and
free-ranging domestic cats on wildlife in Florida. Public education document,
published November 2001. 4 p.
LaBruna D. 2001. Introduced species summary project: Domestic Cat (Felis
catus). Available online.
O'Donnell C. 2001. Slowing down A CAT-astrophe: Keeping pet cats indoor.
Connecticut Audubon Society.
Ogan C.V., and Jurek R.M. 1997. Biology and ecology of feral, free-roaming and
stray cats. Pages 87-92 in: J.E. Harris, and C.V. Ogan, (eds.). Mesocarnivores
of northern California: Biology, management and survey techniques, workshop
maual. 127 p.