NATURAL HISTORY

By Randy Dibblee

It is supposed that beavers inhabited many of the streams of this province before man, the arch-enemy appeared on the scene. The late Dr. Caven, * we are told, discovered traces of beaver dams on Dunk River. It is evident that our climate and natural conditions are favorable to the existence of this valuable and harmless furbearer. There are many acres of low lands that are absolutely value-less and which could be used very profitably as beaver ranches. The animals provide for themselves, do no damage to property, their food and the material they use for their dams and huts consisting almost exclusively of the small sapling trees growing on the banks of the streams in which they live.

Charlottetown Guardian, 31 October 1916

The Historical Beaver

Probably no other animal has so influenced the development of a

nation. Beavers have been pursued in North America since the mid 1500s, first for their hair, which made the best felt for hats, and, later, for their pelts for the manufacture of coats. New France was built on the back of the fur trade, and the beaver remains so identified with Canada that it even appears on our coinage.

Despite — actually, because of — its historical importance, the beaver has had a rough ride. As the fur trade

*John Caven, a long-time professor at Prince of Wales College, acquired a local reputation for his research into the Island's past.

intensified and expanded, the demand for furs increased. Centuries of unreg-ulated harvest eventually led to the decimation of the species, especially in more densely settled regions of North America.

Surprisingly, beavers managed to survive on Prince Edward Island until the late 1800s. In his Natural History of Prince Edward Island, published in 1890, naturalist Francis Bain wrote, "The beaver though not now on the Island, was once common here and remains of its dams are still to be seen on streams in many parts of the coun-try." Unregulated killing of beavers was the primary cause of their extirpation (local extinction), but loss of habi-tat due to extensive land clearing was also a major factor. Approximately 75% of the Island was cleared

land in the late 1800s, compared with less than 50% today. Living on a small island with a high human population density and no inaccessible areas, the beaver's fate was sealed.

The Island remained without beavers until 1908, when (according to the Charlottetown Guardian of 26 March 1917), the Ontario government donated two pairs to the Province. Four years later, Robert Jenkins, head of the Mount Albion Fur Farming Company, introduced another six pairs onto his property at the headwaters of the Glenfinnan River.

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The timing of the re-introduction was no accident. It was the beginning of the Island's great fox farming boom, and local entrepreneurs were eager to repeat the fabulous success of the fox breeding pioneers. Already, the first skunk ranches were being estab-lished,* and it is no surprise to find that Jenkins' company had been formed to raise beavers commercially. Indeed, Jenkins' descendants claim, the company was also responsible for introducing raccoons to the Province — but that is another story.

By 1917 there were 15 beaver dams on the Glenfinnan River, and beavers had spread to Johnson's River and the Morell. Jenkins' company estimated the population at 500 animals, and noted as a by-product of their introduc-tion, a marked improvement in trout angling opportunities since "the minia-ture lakes [created by the beavers] are teeming with trout."

On 21 April 1917, the Guardian reported an appeal in the Legislature on behalf of the Mount Albion Fur Farming Company to have beavers pro-tected by law. The Company feared that, unless beavers were afforded gov-ernment protection, high fur prices and unregulated trapping would cause their extermination. The advocates of protec-tion were all too aware of the species' vulnerability to over-exploitation. Beavers advertise their presence through their activities and trappers walking the streams can easily locate the colonies.

In typical government fashion, the matter was deferred to the "Development Commission of P.E.I." for further study. The appeal for pro-tection apparently fell on deaf ears — with predictable results. Examination of a 1935 series of aerial photographs covering the entire Island reveals no signs of beaver activity whatsoever. It seems that high fur prices during the late teens and early 1920s were suffi-cient incentive to once more extirpate beavers from Prince Edward Island.

Comeback

Despite this setback, interest in seeing beavers re-established persisted. The

*For more about skunk ranching, see Rosemary Curley's "Introducing the Striped Skunk," in Number 17 (Spring-Summer 1985).

task was taken up by Robert Jenkins' son Spurgeon in the late 1940s. According to his son Harold, Spurgeon obtained beavers from Bruce Wright, a well known wildlife biologist and writer from New Brunswick, and restocked the Glenfinnan River with them. By the late 1950s, the beavers had spread to a number of rivers in eastern P.E.I. including Clark's Brook, the Vernon River, the Morell River and the Midgell River.

As the population continued to increase, so did the associated prob-lems (from the human's perspective, at least). Beavers soon discover that they can create a dam by plugging highway and railroad culverts, but their enthusi-asm for this innovation is seldom shared by transportation authorities. Nor is their penchant for flooding low-lying areas always appreciated. In 1962 the Department of Industry, which was then responsible for wildlife, opened the first beaver-trapping sea-son. There was no wild furbearer man-agement program in place prior to 1971, so "beaver harvest" records are lacking. Nevertheless, discussions with trappers and the only fur buyer active at the time suggest that up to 200 beavers were trapped annually during the '60s. By 1970 it was evident that the beaver population was being over-trapped, and so, the recently

established Fish and Wildlife Division (1966) took appropriate action, closing the season and hiring wildlife biolo-gists to help manage wildlife resources, including beaver stocks.

Since 1971 a beaver management program has been in place. It consists of four basic elements: aerial surveys to census the population; monitoring of the harvest; collection of age, sex, and reproduction data from carcasses; and the setting of regulations to obtain optimum, sustained harvests. The management plan has enabled beavers to extend their range into most of Kings and eastern Queens counties. At the public's request, surplus animals were transported to west Prince County, where they had become suc-cessfully established by 1980.

Both demand and prices for beaver pelts were high during the 1970s and early '80s, and regulatory management emphasized restrictive trapping sea-sons that permitted reasonable harvest rates while allowing the population to increase and extend its range. During this period as many as 700 beavers were trapped annually. When demand and price declined in the late 1980s, harvest levels decreased, allowing beaver numbers to increase sharply. Today there are about 400 active colonies on the Island. At an average of five beavers per colony, there are now approximately 2,000 in the province.

Natural History

The beaver is the world's second largest rodent — only the capybara (found in South America) is larger. Adult beavers average from 40 to 60 pounds and in rare instances can reach 100 pounds. As might be expect-ed, 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 itself with power-ful, webbed hind feet and tail. The beaver uses its most characteristic fea-ture, the large, dorsally-flattened tail, to manoeuvre in water, to balance itself on land, to signal alarm, as a place to store fat for winter, and as a heat exchange organ. Eyes, ears and nostrils are adapted to exclude water. The beaver's lips can even be closed behind the incisor teeth to allow it to chew while submerged. Other physio-

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logical adaptations enable the beaver to remain underwater for up to 15 min-utes. These include a low heart rate, high tolerance of carbon dioxide, high-ly 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 soft, dense, wavy, grey, one-inch-long~underfur. Air trapped in the dry underfur provides insulation. Although the webless forepaws are not used in swimming, they are suited to digging and carrying sticks, stones, and mud.

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

At the Lodge Few other animals have so profound an impact on their environment as the beaver. It is the only species, other than Homo sapiens, capable of convert-ing terrestial environment into an aquatic one. Beavers require a con-stant supply of water to support their lifestyle. They will live in rivers, small lakes, and ponds, but they are better known for their ability to provide their own water requirements.

Beavers build dams for protection, to provide access to a food supply of deciduous trees and shrubs, and to store their winter food supply. The dam is constructed of sticks — usually alder — laid parallel to the stream flow with the butt end downstream. To these, mud, stones, and more sticks are added. One beaver colony will often build a series of two or more

dams. The pond that is created pro-vides beavers access to the softer hardwoods, such as poplar, willow and white birch. An extensive system of canals is often constructed to help float trees cut from adjacent hillsides. On the Island most dams are two to four feet in height and flood from one to three acres of land, although larger dams in flat terrain can flood 20 acres or more. Elsewhere in North America, dams 18 feet high and over 2,000 feet long have been found.

Beavers may burrow in stream banks or construct a lodge in mid-pond. In either case, their dwelling is topped with sticks and mud, and fea-tures a small vent hole to let in fresh air. Access to the dwelling chamber is through burrows with underwater entrances.

Beavers' appetite for work and food is proverbial. They will feed on herba-ceous aquatic vegetation such as cat-tails and water lily, but depend primar-ily on the twigs, branches, and bark of the softer deciduous trees, especially poplar and willow. They are active all winter under the ice, when they depend entirely on a store of food con-sisting of fresh green branches of aspen, willow, birch or red maple. This food cache, started in fall and laid down adjacent to the lodge, is often "topped up" with less palatable species such as alder. In winter beavers swim under the ice to the cache, select a branch and return to the lodge to dine on the nutritious inner bark and twigs.

Life Cycles

Although capable of reproduction at two years of age, beavers usually do not breed until they are three or four on Prince Edward Island. Breeding occurs under the ice in February or March, and after a gestation period of t06' days (3.5 months) a litter of four, fully furred kits is born. The adult

female produces one litter per year, with the young from the first litter remaining in the home colony for two years. The two-year-olds are evicted prior to the birth of the third litter, and must relocate and establish new colonies on the own.

Beavers have few natural enemies. Among them, dogs, coyotes, red fox, and mink have minimal impact. Wolves are the only significant predator but, of course, they do not occur on Prince Edward Island. In fact, humans consti-tute the major source of mortality for beavers through trapping or shooting. Like all wildlife, when beavers overpop-ulate (exceed the carrying capacity of the habitat that supports them), they become stressed and much more vul-nerable to diseases such as tularemia, which can decimate populations. On the Island, it is not uncommon to find ten-year-old beavers; the oldest yet encountered here, a twenty-year-old, was trapped on the Morell River near Bangor in 1977.

The Good Neighbour

Parts of modern Prince Edward Island provide excellent beaver habitat. Beavers prefer second-growth hard-wood trees and shrubs such as poplar, willow, white birch and alder. Abandoned farmland and cut-overs in the eastern region and the extensive burned-over areas found in west Prince County have regenerated in poplar, cherry, alder, and white birch (among other species). The combina-tion of these early successional hard-woods with meandering streams and constant groundwater flows provide ideal habitat for beaver on the Island.

What's good for the beaver is good for much else besides. Not only do beaver dams provide secure habitat for the beaver, but they also create wet-lands — one of the most productive ecosystems on earth. On Prince

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Edward Island, the unusual combina-tion of constant, cool, groundwater flow with the province's sandstone-dominated geology creates an immensely fertile environment. Diverse plant life prospers there. Micro-organisms provide food for invertebrates, which are in turn eaten by vast numbers of other species, including ducklings, trout, frogs, newts, salamanders, water birds, and the young and adults of terrestial species such as warblers, sparrows, and kingbirds. Beaver ponds support herons, bitterns, rails, soras, grebes, minks, muskrats, water shrews, and other small animals. A recent study in New York State found that no fewer than 106 species of birds that nested in the state (58% of the total) used beaver-dam habitat. Although beavers have intrinsic value as a wildlife species and are prized furbearers, their greatest benefit, by far, is their ability to contribute to ecological diver-sity by creating productive wetland habitat for other species. If for no other purpose, this would be sufficient reason to maintain them on Prince Edward Island.

While beaver habitat contributes to Nature's food chain, the beaver itself has played a role in the human diet. Beavers are still trapped in many northern communities as a staple food item. Archaeological records for most of its range, including Prince Edward Island, show that the beaver has been a vital food source for native peoples for thousands of years. Unlike the meat of most wild mammals, such as deer and snowshoe hare, beaver meat is high in fat. Quite probably, it enabled indige-nous peoples to survive.

In an article titled, "Archaeological Evidence for the Use of Furbearers in North America," J. V. Wright notes that beaver flesh provides approxi-mately three times the caloric value of other red meats. He goes on, "Because the human body cannot properly assimilate the protein in the lean meats of such animals as caribou and moose in the absence of fats or carbo-hydrates, the fatty meat of beaver could have been critically important for survival during winter and early spring "*

Achieving A Balance

Not everyone considers the beaver a benefactor. From a human perspective, the ability to create valuable wetlands can also cause destruction. Like most wildlife, beavers are perceived as prob-lems when their activities are at odds with human objectives. Their ability to block water flow, plug culverts, and flood cultivated land, plantations, high-ways, and access roads — not to men-tion their woodcutting acumen — puts beavers at the top of the "problem wildlife" list for North America.

Wildlife agencies have traditionally coped with beaver problems by using special fences, pipes, and other devices in an attempt to outwit the persistent dam builders. On Prince Edward Island, live-trapping and transportation of prob-lem beavers to suitable vacant habitat was standard management practice in the past. This strategy has become less common in recent years, as beaver pop-ulations increased to fill most appropri-ate areas for reintroduction. The

"beaver problem" has been exacer-bated since the late 1980s

by low demand in the

world fur market, resulting in low prices for trappers. Beavers require more hardwork to trap than other furbearers, and more effort and skill is needed to prepare their fur for market. Conse-quently the pelt price is a crucial factor in determining whether or not a trapper will harvest beavers. As a result, beaver populations have increased beyond tol-erable levels in many regions in North America.

"Tolerable" is the operative word here; beaver populations can remain healthy and productive at higher levels than people can tolerate in the settled regions of the continent. In this sense, then, beavers are one of the best exam-ples of a species that must be trapped to maintain populations at "tolerable" lev-els. If they are not trapped at appropri-ate harvest rates, high beaver popula-tions begin to conflict with human activ-ities. Conversely, as history has demon-strated, beavers are vulnerable to over-trapping and extirpation if given insuffi-cient protection. The objective is, there-fore, to maintain a balance between over-harvest on the one hand and over-population on the other.

To achieve this balance, authorities estimate, one-third of the population must be trapped annually. The timing and length of the trapping season can be adjusted to achieve this goal, pro-vided pelt prices are sufficiently high to interest trappers. When prices fall too low, the costly cull must be con-ducted by the wildlife agency or others under special permit.

*Beaver flesh is very palatable (I speak from per-sonal experience), and the potential exists for marketing beaver meat commercially, perhaps fill-ing a specialty organic meat market niche.

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Into the Future

In a province as densely and thorough-ly populated with humans as Prince Edward Island, beaver management represents a complex balancing act. In the context of Islanders' current land use, it is more desirable to have beavers in certain watersheds than in others. Their current distribution in the eastern and western parts of the province and their virtual absence from central Prince Edward Island is seen as desirable. It also reflects the physiographic suitability of the habitat.

Even within the current beaver range, decisions must be made as to where beavers should and should not be. The primary consideration in these areas should be ecological, based on where beaver activity can provide max-imum benefits to the environment by developing valuable wetlands and con-tributing to biological diversity.

In a province where 90% of the land is privately owned, it is essential to have public support for the species. To achieve that support, it is vital to miti-gate actual conflicts between human and beaver activities. Education is another key element because some "conflicts" are, in fact, misconceptions. On Prince Edward Island, for example, there are perceived problems between beavers and species management pro-grams directed toward trout and salmon. Beaver activities are frequent-ly blamed for the degradation of trout habitat and low trout catches. There is no doubt that too many beavers can be destructive to all habitat, including that of trout and salmon, but recent

research has shown that beaver dams provide, among other benefits to fish, habitat essential for the winter survival of salmonid* We are still very much at the learning stage in determining the significance of the interrelationships between these species — the jury is still out on the issue. But we do know that both salmonids and beavers co-existed for millennia prior to human interference. Moreover, it is widely recognized that poor fish habitat and low populations at present are primari-ly the result of habitat degradation and over-exploitation by — humans.

Conclusion

The beaver will, no doubt, remain a controversial species on Prince Edward Island. Perhaps the fundamen-tal Canadian association with the beaver will ensure a continued desire to have them on the Island. To be cer-tain, their continued survival in the province very much depends on the attitudes of its human inhabitants. Some Islanders may look at their scrub woodlot as an ideal location for beaver. To others, the same type of woodland represents their winter fuel-wood, and they regard beaver activity with annoyance. Certainly, if landown-ers learn as much about the positive aspects that accrue from beaver activi-ties as they now know about the draw-backs, they may be more inclined to

*That is, salmon-like fish, including trout and salmon.

share a portion of their low, scrub woodland with them. Let's hope that when the arguments abate, there will still be room for beavers in the Island's diverse and productive landscape.

Sources

There are numerous state and provin-cial publications dealing with the beaver in North America, including the popular "Hinterland Who's Who" series, pub-lished by the Canadian Wildlife Service, Ottawa. I also recommend L. E. Rue Ill's The World of the Beaver (Philadelphia: Lippincott, 1964).

The scientific literature is reviewed and digested best in Milan Novak's paper, "Beaver," in Wild Furbearer Management and Conservation in North America, published by the Ontario Ministry of Natural Resources in 1987 (compiled by M. Novak et al.). The book also includes sections on archaeology, history, management, trapping, and the fur industry.

I would like to thank Harold Jenkins, Walter Maclntyre and Frank "Duck" Acorn for contributing histori-cal information about beaver on Prince Edward Island. Harold, who is a grand-son of Robert Jenkins, still owns the original property, and continues to manage it for wildlife. I would also like to express my gratitude to Rosemary Curley and Alan Godfrey for critically reviewing the manuscript. Milan Novak of the Ontario Ministry of Natural Resources, the foremost authority on beavers in North America, has patiently answered many questions for me. Last but not least my thanks to Ed MacDonald without whose persistence and encouragement the article would never have been completed, im

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