Database Reference
In-Depth Information
wound site
22
. Early clinical signs may be subtle and depend on where the virus is
most concentrated in the central nervous system. Two clinical forms of rabies are
known. The furious form affects the limbic system and, thus, the animal's behav-
ior
23
. The dumb or paralytic form causes depression and lack of coordination
24
.
Once clinical signs of rabies develop, death usually occurs in 7-10 days
25
.
After the onset of clinical disease, foxes exhibit such overt behavioral changes as
restlessness, pacing, and loss of appetite followed by either aggression or confusion,
depending on the clinical form of the virus. The furious form of rabies will result in
aggressive behavior, which encourages transmission of the disease. A fox with the
paralytic form of rabies will become lethargic and confused and may only bite if
provoked or approached by others. The final stages of either form of the disease are
seizures and coma, followed by death. Normal foxes may “shy away” from rabid
foxes thereby reducing their risk of infection
26
.
15.2.5 Fox Biology
The red fox,
Vulpes vulpes
, is distributed throughout much of North America. Within
the United States, the red fox has extended its range into forested areas where wolves
and coyotes have been reduced or eliminated and where forests have been cleared
27
.
The basic social unit of the red fox is typically a group of three or four breeding
adults, and their juvenile offspring
28
. In cases where a territory includes several
adults, one male and a variable number of closely related vixens are typically in a
unit
29
. Average litter size is six pups and four pups generally survive until the time
of dispersal
30
.
Foxes are solitary, nocturnal foragers. They exploit the available food supply
within a fairly well defined home range. Members of a group tend to follow each
other from one resource patch to another and will eventually end up very close to
the original point of departure toward the end of each night
31
. The vixens have indi-
vidual ranges that overlap with each other and are encompassed by the home range
22
Fields et al. 1990.
23
West 1973.
24
MacDonald 1980.
25
Bacon, P. and D. MacDonald. 1980. New Scientist 28).
26
Baer, G.M. 1975. The Natural History of Rabies: Volume I, Academic Press, New York, NY.
27
Storm et al. 1976; T.G. Scott. 1955. Illinois Natural History Survey Division, Biological Notes.
No. 35.
28
Doncaster, C.P. and D.W. MacDonald 1997. Journal of Zoology 241 73-87.
29
MacDonald 1980.
30
Storm et al. 1976.
31
Doncaster, C.P. and D.W. MacDonald. 1997. Journal of Zoology 241 73-87.
