THE BEAVER 0N PRINCE EDWARD ISLAND by Randy Dibblee

ThebeaVeristheworld’ssecondlargestmdmt—onlydiecapybanflmmdinSoudiAmefica) islarger. Adult beavers aVerage from40t060poundsandinrareinstaneeacanreach100pomds. Asmightbeexpected, their physiology is well suited to their lifestyle.

Rotund and awkward on land, the beaver’s shape is 'aqua-dynamic' in water, as it propels itselfwith pOWerfiil, webbed hind feet and tail. The beaver imes its most characteristic feature, the large, dorsally~flat1ened tail, to moan/re inwater, tobalance itselfonland, tosignalalarm, andasaheatexchange organ. Eyes, earsandnoetrilsareadaptedto exclude water. Thebeaver’s lipscanbecloflbehinddleincisorteethtoallowittochewwhilesubmerged. Other physiological adaptations enable the beaver to remain submerged for up to 15 minutes. These include a low heart rate, high tolerance to carbon dioxide, highly efficient oxygen exchange in the lungs, and increased oxygen flow to the brain.

The second claw on each of the beaver’s hind feet is divided in two and used like a comb in grooming. It helps in spreading an oily secretion from the anal gland that 'waterproofs' the beaver’s remarkable pelt: the stiff, brown, two inch long guard hairs and the salt, dense, wavy, grey, one-inch-long under-fur. Air trapped in the dry underfiir provides insulation. Although webless forepaws are not used in swimming, they are suited to digging and carrying sticks, stones, and mud.

The beaver’s chisel-er incisors grow constantly, and are kept sharp because the softer inside surface wears faster than the outer orange enamel. With these incisors, beavers have been know to fell trees as large as 46 inches (1.2 in) in diameter.

Population Variation:

‘—"‘__ —“—“‘"““' " ' ,1 I_SIGNIFICANT DATES IN THE HISTORY OF BEAVERS ON PRINCE EDWARD ISLAND ' .3 5 i ” . ,_.—— ———~— A UNPROTECTED. ' INTRODUCED p e to . EXTIRPATED i AGAIN BY 5. TEAIEFING $§E§p=o _ — __ mm SEASON m“ ‘ 5 . EEK/Es T " 1 TWO PAIRS ' 51x PAIRS y ‘ ~ ‘ OPENED CLOSED j EXTIESATEgéD ‘ 933mm { mew Ema?“ E§$§E§Ei$ée r $35535 $82.22” : NR ULA ‘ ‘- TRAPPING I ONTARIO R' JENKle 1AIR PHOTOS. | gsgcéwq. PROBLEMS. n - 75% LAND CLEAR. , I MT. ALBION P E] a 3 1FUR FARM ’ l ‘ " i i r g ‘ E I - ‘i 7. ' . L ___J u i 1 i '12:; 1350 .- 1,908,; 1912 ' "1935

\ AERIAL BEAVER SURVEYS i P.E.l. 1972-1996

250 -.. — m“--—~r——#—-~———-————u—.

ACTIVE COLONIES

J 1 | j o 72 73 75 77 78 79 82 88 90 9192 93 94 95 96 ‘ FLOWN OVER SAME WATERSHEE (900 80. KM)