The beaver has made quite a comeback in Pennsylvania. They were extirpated from the state in 1912 due to the extensive logging and trapping dating from the colonial times to the early part of this century. The pelt of this animal was partly responsible for the expansion of the United States. However, they were reintroduced in 1917 and thanks to proper wildlife management are now becoming quite numerous.
They can be found along rivers, streams, ponds and lakes where there is small stands of trees. There they will build a lodge varying from 5 - 6 feet high and some 20 - 30 feet in diameter along with a dam or dams which can vary greatly in size and stretch for more than a half mile. The lodges have an inner chamber just above the water line with underwater entrances to where the beavers live. Not all beavers construct lodges and may burrow into the sides of river banks "bank beaver".
Beavers like to eat bark, twigs, leaves and roots from woody plants by the water. Aspen, birch, willow, maple, poplar and alder are some of the more sought after trees as these also make good building material for their dams and lodges. They will also eat rushes, grasses and sedges during the summer months. They cache their food for the winter by partially burying green branches and logs on the bottom of the pond surrounding their lodge. These caches may be large enough to reach the surface of the pond.
Beavers are very territorial and mark their territory by creating mud patties and smearing them with castoreum (castor mounds) which is produced from two large glands at the base of the tail. They also slap the water with their tail to warn intruders or to alert the colony to potential danger.
While female beavers may mate for life, male beavers do not neccessarily follow suit. Kits are born in May or June following a gestation period of about 107 days. Kits usually stay with the mother for two years and are then driven off or disperse on their own.
The beaver does not have very many natural predators. Occasionally a bear or coyote will attack an adult and mink, hawks and owls will sometimes take the smaller kits. Beavers can develop rabies and carry Giardia.
Suggested trap sizes: If using a leghold trap use a large size No. 3 or 4 (in Pennsylvania the jaw spread can be no larger than 6 1/2 inches), No. 220 or 330 Conibear for underwater or under ice sets.
Suggested sets: Castor mound set, bait pen set, platform sets.