Black Bear Management
By: Bob Ballantyne Date: 01/14/2012 Category: | Wildlife Journal |
A Pennsylvania success story
It wasn't too long ago, perhaps three decades, that the black bear was an unknown quantity in Pennsylvania. The hunting season had been a rather long one, and the annual harvest was in the neighborhood of 300-400 bears. The exact population was any biologist's wild guess.
All that changed in the 1980s, however, with the advent of research and the adoption of modern management practices under the guidance of the Pennsylvania Game Commission's now famous black bear biologist, Dr. Gary Alt. His research in the early days of the program pointed to a population goal of about 7500 bears and an annual hunter harvest of about 1500 bears.
While natality is what the biologists call the birth rate of a population, recruitment - the rate that individuals reach reproductive capability in a population - is a more important number to wildlife managers. For the black bears of Pennsylvania, the goal was to have the sum of all the types of mortality (hunting, crop damage deaths, road kills, cub mortality and the like) be equal to recruitment.
Early data showed that a population of 7500 bears would be sustained with a hunter harvest of about 1500 bears because recruitment was somewhat higher than the 1500 figure and allowed for other forms of mortality in the population. Experience had also shown in the early days of the new management program that when the population in the state exceeded 7500 bears, nuisance complaints increased significantly.
When hunting of black bears reopened in Pennsylvania after a short shut down for the research program, it generated some controversy. Animal rights groups protested the hunts, and gathered annually at Pennsylvania's Promised Land State Park. The site was probably selected for its name and public relations value. It was here that protesters followed hunters into the woods, some of them ill-prepared for walking in the heavy forests and swamps where such hunts occur.
In a television interview at that time one animal rights activist noted that if Pennsylvania had 7500 bears and allowed hunters to bag 1500 a year, the population would soon be extinct. Obviously, the spokesman knew little of bears and not much about the birds and the bees.
The original research, however, did turn out to be slightly wrong. Field data collected at the end of the 1997 bear hunting season showed that the population had risen in the state to more than 10,000 bruins. When the modern program first started, bears were found in 40 of Pennsylvania's 67 counties. They are now found in more than 50 counties.
Of course, with bears occupying increased area in the state, the population of 10,000 is spread over more space, and thus the population density may not have increased all that much. Some of this movement has resulted from natural dispersal and some has resulted from trap and transfer activities of the game commission.
In Pennsylvania, every wildlife conservation officer whose district is in bear habitat is given an annual goal to trap and tag a designated number of bears. They are captured in culvert traps, harmless snare traps, and with the use of tranquilizer guns. Captured bears are marked with ear tags and with a liquid dye used to tattoo the tag number on the gum line.
If the WCO traps a bear that has been previously tagged, he or she simply records that data. This is a certification that the tagged bear is still alive. All of this data, of course, ends up in Alt's computer data base at game commission headquarters. It is from these numbers that PGC can calculate the bear population with a reasonable degree of accuracy.
Biologists use the Lincoln-Petersen index to calculate populations from capture and recapture data. For the Pennsylvania black bear, the reasoning is quite simple. A known number of black bears with tags are free in the state at the beginning of the three-day hunting season held just prior to Thanksgiving. The percentage of bears bagged by hunters closely equals the percentage of all the bears in the state that were harvested by hunters. For example, if hunters took 20 percent of the marked bears, then they probably bagged 20 percent of all the bears in the state.
In Pennsylvania, every black bear harvested by a hunter must be taken to a check station operated by officials of the game commission. Compliance with the law is nearly 100 percent.
In November 1997, 566 tagged bears were known to be alive in the woodlands of Pennsylvania, and bear hunters harvested 118, about 21 percent of the tagged bears. The total bear kill in the state was 2110 bears. These 2110 bears, then, represented 21 percent of all the bears in the state. The mathematics thus shows the population well over 10,000 bears.
What is amazing is that this steady growth in the bear population has kept ahead of the gradual increase in hunter harvest numbers in the state.
One important feature of the program is to be noted - the timing of the hunting season. Alt's research had shown that the bulk of the pregnant females denned earlier than the rest of the population, usually in early November. This provides a reservoir of bears to offset any abnormally high harvest by hunters.
There is, of course, a down side to a high bear population. Agricultural damage, especially to corn, rises. Beekeepers also have to take special precautions to protect hive clusters from marauding bears. And then there is the constant problem of bears and garbage cans in developed areas in bear country. Road kills, too, increase, with the resulting damage to motor vehicles. The latter is much more of a problem, however, with the deer population in the Keystone State.
The bottom line, of course, is a great success story for modern wildlife management techniques. There are more bears in Pennsylvania then at any time in the 20th century. This is a delight, of course, to the the "bear watcher" - a non-consumer of wildlife - while a carefully-monitored hunting season keeps bear numbers reasonable. Both people and bears share the benefits.
About The Author
All Authors Of This Article: | Bob Ballantyne |