Montana Trappers Association

Working Today For a Tomorrow in Trapping.
Furbearers Are A Natural Renewable Resource.

Management Ingredients



What makes a good wildlife manager? Managers must understand the needs of wildlife. He or she also needs to understand the factors at work that make for good, healthy wildlife populations.


HABITAT for example, includes all the things that wildlife and humans need for life - air, food, water, shelter and space to live. When these five habitat factors are in good supply and arranged properly, they contribute to the well-being of wildlife. When any of these factors is in short supply, it may limit the kinds of animals, the number of animals and where they're found. It is then called a limiting factor.


The ARRANGEMENT of food, cover, water and space in an area determines wildlife types, numbers and where you'll find them. The best arrangements are those where all of these habitat factors occur in small blocks that are close together with enough space to meet the needs of the animals. Also, animals tend to use the edge areas of food plots the most, because these areas are the closest to cover.


CARRYING CAPACITY is the number of animals an area can support throughout the year without permanently damaging the habitat or starving the animals. When there are too many animals for the habitat, the animals may eat too much of the vegetation that makes up its food and cover. Once that vegetation is gone, the habitat is damaged and the carrying capacity of the area goes down. With less habitat or poor habitat, the weaker animals will die from disease, starvation, predators or other causes. Fewer animals will be able to live there. As more food and cover return, the carrying capacity goes up again. Sometimes the vegetation is destroyed, changing the habitat and carrying capacity.


SOCIAL TOLERANCE is the number of animals a landowner or the public will allow in an area. If wildlife numbers exceed the acceptable or tolerable levels - for example, if deer or elk are damaging a farmer's crops - the animal numbers may need to be reduced. Frequently, this tolerable level is below the carrying capacity.


The POPULATION DYNAMICS of a wildlife population is the way its numbers go up and down over time. Two major factors affect this - the BIRTH RATE and the DEATH RATE.


Most wildlife species have a high BIRTH RATE. In general, the smaller-sized species of wildlife have higher birth rates than the larger species.


The DEATH RATE of most wildlife species is also high. The smaller sized species of wildlife have higher death rates than the larger species. Factors affecting the death rate are:

  • Starvation, is directly related to available food in their habitat.

  • Development/like housing, malls, other buildings and roads can cut down the cover or space in their habitat.

  • Climate extremes, such as cold, snowy winters or dry, hot summers, can reduce wildlife numbers.

  • Predation from other animals like bears, mountain lions, coyotes, wolves, foxes, skunks, raccoons, dogs.

  • Diseases and parasites can kill animals, especially if the animals are already weak from injuries or starvation.

  • Hunting in regulated seasons reduces animal numbers.

  • Other human activities, such as animals being hit by vehicles, getting tangled in fences, poison, hitting power lines, being caught in fires and poaching all take a toll on wildlife and affect the death rate.


How and why do wildlife numbers go up and down?  Let's look at a situation that generally occurs each year in deer populations.


Late in the spring, the animals old enough to have bred the previous fall begin having their young. With the existing animal herd and their new fawns, the deer population reaches it peak in the early summer. The population then begins to decline because of the factors just identified as affecting the death rate. The decline continues through the rest of the summer, the fall, winter and early spring of the following year. The remaining adult and yearling animals that survived will start the cycle all over again.


This cycle of birth and death occurs every year. The cycle is the same for most species of wildlife. Sometimes, if habitat conditions are really good and the carrying capacity goes up, animal populations will boom. At other times, severe weather, disease, predators or over-harvest by hunters can cause the population to drop further than normal.


The job of the WILDLIFE MANAGER is to control the numbers of animals at, or just below, the carrying capacity of their habitat while keeping an eye on the overall ecosystem. That way, the animals stand the best chance of staying healthy and not harming their habitat. The wildlife manager must also keep animal numbers within social tolerance - the population level that people are willing to tolerate.

Did You Know?

Jim Bridger (1804-1881). Trapper, scout, mountain man. One of first white men to see the future Yellowstone Park and Great Salt Lake, which he believed to be an arm of the Pacific Ocean. Became partner of Rocky Mountain Fur Company in 1830 and established Fort Bridger in Wyoming Territory in 1842. Laid out routes for the Central Overland Stage and Pike's Peak Express Company. Returned to Missouri in 1867 where died on his farm on July 17, 1881.


Rendezvous were held on a yearly basis at various locations until 1840, mainly in Wyoming, but Pierre's Hole in Idaho and Bear Lake in northwest Utah were favorite sites as well.


Fort Manuel Lisa was established in 1807 by Manuel Lisa at the mouth of the Big Horn River near Hysham. This was the first permanent settlement in Montana and was occupied until 1811.


John Jacob Astor was the first prominent member of the Astor family and the first multi-millionaire in the US. He amassed his wealth through fur-trading, opium smuggling, and New York City real estate. Famed patron of the arts. At the time of his death, he was the wealthiest person in the US.


In 1919, the Hudson’s Bay Company was approaching its 250th year in business. What began in a coffee house in London, in 1670, had now grown to become the undisputed leader of the international fur trade.


The desire for beaver fur hats in European men’s fashions dates back centuries and spurred the development of the 17th century North American fur trade. Beaver fur was the most prized of the fur trade because of its water repellant qualities. Encouraged by European trade goods, natives hunted beaver to extinction in some areas.