Biology of the White-Tailed Deer
Odocoileus virginianus
NOTE: Reference numbers are bracketed by the asterisk (*)
References
Physical Description: White-tailed deer height at the shoulders is 90-105
cm, length 134-206 cm, weight (M) 90-135 kg (F) 67-112 kg. Whitetails are
tan or reddish brown in the summer and grayish brown in the winter. The
underside and throat are white, the tail brown above and white below. The
males have antlers with main beam foreward and several unbranched tines.
Fawns are reddish brown and white spotted *304*. Dental formula
0/3,0/1,3/3,3/3. *2188*
Reproduction: Data obtained by aging fetuses taken from whitetail does
harvested in New Jersey indicates that rutting (breeding) peaks November
3-23 for northern adults; November 17 - December 7 for northern fawns;
November 10-20 for southern adults; and December 1-21 for southern fawns.
Conception dates ranged from October to January. Estrus is about
24 hours and the estrus cycle is about 28 days. Gestation takes 200-210 days.
*258*. The majority of fawns are dropped in the last week of May and the
first two weeks of June. *12*
Male deer are generally incapable of breeding until their second fall,
when more than one year old. Many female fawns on good range breed in their
first year. *12*
Two year old females who failed to rear their first fawns bred later
and conceived more males than did successful mothers of the same age. They
remained within the matriarchal fold, which the authors speculate may have
caused psychological and/or physiological stress, leading to hormonal
imbalances and delayed breeding. The authors suggest that this is
evolutionarily adaptive because it would decrease mother-daughter
competition for fawn-rearing space. *16*
Behavior: Compilation of data from capture and marking studies in Hunterdon
County(January 1970 to July 1976) indicate the main home range size of New
Jersey deer to be one mile or less. In this study, the largest percentage of
deer, 68.2% (122/179), were recovered within one mile of their original
capture locations; 26.8% (48) ranged from one to eight miles and 4.5% (8)
ranged from 10 to 19 miles. One deer (.6%) was recovered 30 miles from the
release site.
The general range size is the same for males and females; however,
there is a greater tendency for bucks to disperse long distances. November
is the principal month for dispersal. This is the period of the rut, which
may influence movement of bucks *12*. Males tend to remain in the area they
occupied as yearlings. *162*
In an enclosed herd in Michigan, does established exclusive home ranges
for rearing their young during the 1st 4 weeks, which may facilitate bond
formation *17*. Maternal behavior traits vary with age, and success
increases with age, especially where predation is an important source of
fawn mortality. *17*
White-tailed deer are active during the period of subdued light *45*.
The feeding rhythm is cyclic with activity every 4-6 hours at sunrise,
midday, sunset and twice at night *266*. Summer coats molt to winter in
August to October, winter coats molt to summer in late March *258*. The
ecological metabolic rate per day is predicted to be lowest in late January
and highest in August. *222*
From February through August bucks are generally in small groups, during
other times, bucks are generally solitary. Large groups of deer may be
observed feeding in open areas in spring and summer *162*. The feeding
strategy is classified as concentrate selectors which select diets low in
fiber, high in cell solubles, exhibit high fermentation rates with mainly
amylolytic ruminal bacteria, participate in numerous short feeding periods,
alternating with frequent rumination *165*. Birthing occurs in the home
range of the female with little or no habitat selection. *258*
Use of a wintering site is a learned behavior passed on to fawns as
they travel with their mothers during their first year. *34*
Bucks possess a large number of glands on their forehead which become
active during the breeding season; secretions are deposited on branches as
they rub. Aromatic tree species are preferred for rubs. In Georgia, rub
density was correlated with the number of bucks >2.5 years old and abundance of
acorns. *35*
Limiting Factors: Limiting factors include predation, automobile accidents,
diseases, parasites, starvation *2188*. Predation is mainly in the form of
harassment by dogs. Fawns may be taken by bobcat *2188*, coyote, or black
bear *75*. The relatively high reproductive rate of white-tailed deer makes
population control by natural predators unlikely. *65*
Population Parameters: In the George Reserve deer herd, at low population
sizes fawn females represented a significant factor in reproduction; at
higher populations, few fawns bred. The sex ratio, based on 110 embryos, was
1.19 males to 1 female. The ratio in fawns recruited was similar to the
embryo ratio. There was a trend toward increased numbers of female fawns at
low populations, and increased numbers of males at higher populations. The
mean age of the population increased with size. *62*
Interspecific Interaction: White-tailed deer are one of the hosts of the
tick Ixodes dammini, a transmittor of Lyme disease *68*. A survey of deer at
check stations in 1981 found I. dammini present in Deer Management Zones 10,
12-24, 26-29, and 31-34. I. Dammini were not found in Zones 1, 2, 4, 5,
7, 8, and 9. Not all Zones were surveyed. *67*
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