PENN
STATE OUTDOOR NETWORK
WHEN TIME IS RIGHT, YOUNG BUCKS MOVE ON - SOMETIMES A LONG WAY
Nov. 4, 2002
UNIVERSITY
PARK, Pa. - When scientists from Penn State's College of Agricultural
Sciences and the Pennsylvania Game Commission began tracking young,
male white-tailed deer last winter to learn how they disperse, the researchers
weren't sure what to expect.
For years it was believed that deer in Pennsylvania don't move around
much. But wildlife experts knew that for genetic reasons deer populations
should minimize inbreeding, so it made sense that the males would leave
the area where they were born. Now, almost a year into the study, a
fascinating picture of young buck dispersal is emerging.
"Movement of young bucks is certainly not related to quality of
habitat of a deer's home range," says Duane Diefenbach, adjunct
assistant professor of wildlife resources with the Pennsylvania Cooperative
Fish & Wildlife Research Unit, a joint effort of Penn State, the
Game Commission, the Pennsylvania Fish & Boat Commission and the
U.S. Geologic Survey. "We see young bucks leaving natal home ranges
with good habitat and traveling to other areas of good habitat. It's
almost like the doe gives them the message that it is time to go."
Researcher and graduate student Eric Long has been intrigued by the
dispersal paths of the young bucks he is tracking. One swam the Allegheny
River and crossed several highways during his 15-mile journey.
"We have found that 40 percent of male fawns born the year before
leave their mother the following spring at about the time she is ready
to have a new litter of fawns," Long says. "Then during the
rut in early fall, many of the rest leave. We don't know whether the
does somehow tell them they should leave, or if the young bucks get
wanderlust from wanting to be involved in breeding activity. Maybe both."
The joint three-year study -- intended to be the most extensive radio-telemetry
study of male deer dispersal, survival and the effects of antler restrictions
for hunting ever attempted in the United States -- started last December
when 141 male deer were captured in Armstrong and Centre counties. Those
deer -- caught using helicopters, drop nets, walk-in traps and tranquilizer
dart guns -- were radio-collared and released unharmed. Researchers
have been tracking their movements ever since.
The two sites offer dramatically different landscapes, Long points out,
and that probably accounts for a difference in dispersal rates of young
bucks. "At the Armstrong County site near Kittanning, which is
mostly rolling hills with patches of forest and open agricultural areas
often divided by roads, 44 percent of bucks that were collared left
their mothers in the spring. On average they went about seven miles.
"At the Centre County site, which is less fragmented and features
continuous forested ridges, 24 percent of young bucks dispersed in the
spring," says Long. "They didn't move as far on average -
about five miles. The maximum dispersal distance we have seen in Centre
County was 13 and a
half miles."
Mortality of animals has been about what researchers expected. At the
Armstrong County site, four were killed by vehicles on roads, two were
killed by poachers prior to hunting seasons and two were harvested during
the first week of archery season. One of those was a 13-point buck --
one of the few older bucks included in the study.
At the Centre County site, just one deer in the study has been killed
on highways, and so far, archers have killed no deer in the study area.
According to Long, the Centre County site has a higher human population,
but far fewer miles of road than the Armstrong County
site.
"There has been very little mortality and no predation of study
animals," Diefenbach says. "Hunting is clearly the big factor
in deer management. But we knew that."
Early information yielded by the research dispels some myths about Pennsylvania
deer, Long notes. "From a management perspective, we know that
we can't manage deer in a small area," he says. "There is
a lot of interchange between animals and areas. Landowners should realize
that
there is a good chance that the bucks they see on their property probably
weren't born there. There is a lot more interchange than people were
expecting."
This information likely will be of great interest to hunters, Long speculates.
"There have been suggestions that landowners could introduce big-racked
bucks to pass on their genes to offspring males that will have bigger
racks," he says. "But we are seeing now that the young male
deer
probably won't stay in the area. They more likely are producing bucks
for landowners in the next valley, or even the next county."
Moreover, Gary Alt, deer management section supervisor for the Game
Commission, points out that Pennsylvania deer don't need better genes,
they just need to live a year longer. "We know from our research
that two-and-a-half-year-old Pennsylvania bucks sport a seven- or eight-point
rack with an outside spread of 15 inches," he says.
The Pennsylvania Game Commission's Web site, http://www.pgc.state.pa.us,
is keeping a running journal of the study. For more information, click
on "Wildlife," then "Deer in Pennsylvania" and then
"Antlered Deer Study."
Editors: Contact Duane Diefenbach at (814) 865-4511 or drd11@psu.edu.
For more news from Penn State's College of Agricultural Sciences, visit
http//aginfo.psu.edu.
Jeff Mulhollem
Writer/Editor
Penn State Ag News & Information
135 Ag. Admin. Bldg.
University, Park. Pa. 16802