Why are Vancouver Island Marmots at risk?

From: http://victoria.tc.ca/environment/biodiversity/F.W/endangered/marmot.html
Wildlife At Risk in British Columbia
A brochure series which will eventually include brochures on other
Red and Blue listed species, including fish, invertebrates and plants, and on
ecosystems.  Produced by the Ministry of Environment, Lands and
Parks, Wildlife Branch, 780 Blanshard St. Victoria, BC V8V 1X4. For copies of
this brochure, write to the Wildlife Branch. Funded by Corporate
Resource Inventory Initiative and Ministry of Environment, Lands
and Parks.
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Restricted to the mountains of Vancouver Island, this endangered
species is one of the rarest mammals in North America.

Why are Vancouver Island Marmots at risk?
The Vancouver Island Marmot occurs only on Vancouver Island. It is
one of only three species of mammals entirely confined to Canada (the
others are the Collared Lemming and the Gasp� Shrew), and the only
one of those that is endangered.

The total population of Vancouver Island Marmots is probably less
than 500 individuals, making it one of the rarest mammals in North
America. On southern Vancouver Island the largest and most stable
marmot colonies occur in only one location. Since most of the
population is concentrated in a small area, the Vancouver Island
Marmot is vulnerable to extinction from random natural events or
human influences. It has been speculated that inbreeding and loss of
genetic variability could result in early extinction of the Vancouver
Island Marmot, although initial research shows this marmot to be as
genetically variable as more widespread mainland species.

Little is known about causes of natural mortality. Some young
marmots die during their first winter�s hibernation of unknown
causes. Possible predators include Golden Eagle, Cougar, Wolf, Black
Bear, Wolverine, Bald Eagle, Red-tailed Hawk, Goshawk, and owls.
Dispersing marmots are not only vulnerable to predation and
accidents, but sometimes stray far from marmot habitat and never
enter the breeding population. Within the more or less stable colonies,
these losses are balanced by births and the population maintains itself.

Small colonies in marginal habitats periodically disappear, only to be
re-established by immigrants. How common this is isn�t known; how
long it takes for recolonization undoubtedly depends on how distant
the site is from traditional colonies. The fortuitous dispersal of a male
and female to a distant mountain at the same time could indeed take a
very long time, and may explain why so many Vancouver Island
mountains lack this engaging animal.

The effect of logging on marmot populations is unclear. While it is
obvious that marmots use logged areas, concerns that this may decrease
dispersal to more distant natural habitats, and that the animals may
hibernate less successfully in logged areas, require further study.

Human recreational activity in accessible marmot colonies could be a
future threat, particularly if large groups, dogs, or all-terrain vehicles
are involved. Access control and public education can hopefully keep
human impacts at a minimum.

What is their status?
The Vancouver Island Marmot�s range is very restricted. The major
known population lives in mountains south of Alberni Inlet, at the
headwaters of the Nanaimo, Chemainus, Nitinat and Cowichan
Rivers.

Intensive surveys of known and potential colony sites on the southern
island from 1982 through 1986 resulted in counts of 122 to 234
marmots. Over three-quarters of these were in a single block of
subalpine habitat at the headwaters of the Nanaimo River, extending
from Green Mountain south to Haley Lake and west to Butler Peak,
and comprising less than 20 square kilometres or 0.07 per-cent of
Vancouver Island. These are undoubtedly conservative figures, but
many of the best habitats were surveyed, and it seems unlikely that the
population of the southern island is larger than 300 to 400. The
population trend is not known. 

Prior to the 1970s, colonies once existed at Douglas Peak and Mount
Arrowsmith, northwest of Green Mountain near Port Alberni. North
of the Alberni area, only Mount Washington near Courtenay, where
six animals were counted in 1984, is known to have supported
marmots in recent years. However, other indirect evidence suggests
that marmots could occur over a fairly wide area on central and
northern Vancouver Island. Much of this area has not been thoroughly
searched for marmots.

Intriguing finds of 700 to 2500 year old marmot bones in two high-
elevation caves on west-central Vancouver Island, where marmot
colonies are not known to presently occur, suggest the species may
have been more widespread and abundant in prehistoric times.
Although tool markings indicate the bones were deposited in the caves
by native hunters, they were probably obtained in the vicinity, and the
large number in one cave (70 to 80 individuals) suggests that they may
have been locally abundant.

More colonies may yet be found, but experts feel that the total
population of Vancouver Island is probably less than 500 individuals.
Public and government concern for the rarity of the Vancouver Island
Marmot resulted in it being legally designated as an Endangered
Species under the British Columbia Wildlife Act in 1980. The species is
nationally designated as Endangered by the Committee on t
he Status of
Endangered Wildlife in Canada (COSEWIC).
What do they look like?
The Vancouver Island Marmot (Marmota vancouverensis) is one of
six North American species of marmots, large members of the squirrel
family commonly called woodchucks or ground-hogs. Its closest
relatives are the Olympic Marmot of the Olympic Peninsula and the
more widespread Hoary Marmot. About the size of a large house cat, an
adult marmot is 65 to 70 centimetres from nose to tip of bushy tail.
Weights show tremendous seasonal variation. Adults average only 2.5
kilograms when they emerge from hibernation, but are 6 kg or more by
September. Most of this gain is fat which sustains them during
hibernation.

The most striking feature of the Vancouver Island Marmot, and that
which distinguishes it from its grizzled, light-brown mainland cousins,
is its dark chocolate-brown coat. Patches of white on the nose, chin,
forehead, and chest contrast sharply with the rest of the body. White
hair on the underside can vary from a distinct white streak to a diffuse
pattern. As the summer progresses, the marmots take on a mottled
appearance, with patches of old faded and new dark fur. Young
marmots have a dark, almost black, woolly coat and fewer white
markings.

Like other marmots, this species has large beaver-like incisor teeth for
cutting vegetation, and strong claws for digging. Typically found
sunning on large boulders, logs or stumps, they give a loud whistle and
run to a nearby burrow when people or predators come near. No other
mammal on Vancouver Island has these characteristics.

Why are they unique?
To avoid the long subalpine winter when green forage is not available,
Vancouver Island Marmots hibernate for seven to eight months.
Entire family groups hibernate together in a deep burrow called a
hibernaculum, which is re-used in successive years. They usually
emerge from late April to mid-May and go under again in September
or early October.

Family groups typically consist of one adult male, one or two adult
females, and a variable number of two-year-olds, yearlings, and young
of the year. Colonies are made up of one or more families in close
proximity, contain about eight individuals prior to emergence of new
litters, and occupy about 3 to 5 hectares of habitat. Each colony has one
or two active hibernacula, and numerous sleeping and refuge burrows,
often under rocks or stumps. Marmots frequently carry dead grass into
their burrows, presumably for bedding. In winter, the entrance is
plugged with rocks and soil.

Marmots are most active above-ground during morning and evening,
particularly in mid-summer, resting and feeding. The marmots dislike
temperatures over 20�C and spend more time in the comfort of their
burrows on hot days than on cool ones. In spring, thin after months of
fasting, they spend more time feeding and less resting than later in the
summer.

Like most marmots, the Vancouver Island Marmot is gregarious, and
social interactions between individuals are frequent. Many such
interactions have been described, of which �greeting� and �play
fighting� were the most common. In a colony, adult males are
dominant, followed by adult females, two-year-old females, and
yearling females. Adult marmots establish territories, marking them
with scent from their cheek glands.

These marmots also communicate vocally, the most frequent call being
a high-pitched whistle. A short whistle (about 0.2 seconds) warns
colony members of predatory birds, a longer one (about 0.6 seconds)
alerts them to ground predators. Marmots respond by running to a
burrow entrance from where they try to identify the potential threat
before going under. 

Marmots living in colonies seldom travel far. Occasionally, adults will
move from one colony to a nearby one. Dispersing subadults may
move further, leaving the colonies of their birth and thus possibly
establishing colonies in newly available habitat or recolonizing
formerly used sites. Marmots that have turned up over the years near
Courtenay, Coombs, Cedar, Cassidy and Jordan River were probably
dispersing subadults that went astray.

Like many members of the squirrel family, Vancouver Island Marmots
adapt readily to non-threatening human activities, and can become
fairly tame. As a result, they are one of the most photographed of all
endangered species.

How do they reproduce?
Much of what we know has been learned from studies of other
marmot species, with little information gathered on the Vancouver
Island Marmot itself. As in other marmot species, mating probably
occurs above ground during the first three weeks after emergence from
hibernation, and the gestation period is around one month. Based on
the usual occurrence of one adult male per family group and limited
movement of males between groups, the species may be monogamous.

Female Vancouver Island Marmots may produce young at three years
of age, but most do not until four years old. The interval between litters
may be one, two, or three years; other marmot species commonly
produce litters every two years. Litter size on Vancouver Island
averages three, although up to six have been reported. Numbers of
young produced vary greatly among colonies, and from year to year
within colonies. Limited information suggests a relatively equal sex
ratio at birth, as well as among older animals. 

Young of the year emerge from their burrows from late June to early
July. Mortality is highest for young during their first winter of
hibernation, and for dispersing subadults. Maximum lifespan is not
known, but other marmot species may reach 10 or 11 years of age.
What do they eat?
Vancouver Island Marmots are specialized feeders, selecting particular
patches of vegetation and kinds of plants, while avoiding others that
are abundant. Diets vary little among colonies. In spring, grasses and
grass-like plants, including oatgrass, sedges, and woodrush, are major
food items, but herbs such as spreading phlox and lupines are also
important where available. 

Although the availability of grasses increases over the summer, the
marmots switch to forbs (broad-leaved herbs), and their use of grasses
declines. Favourite forbs in summer are lupines, peavine, paintbrush,
meadowrue, cow parsnip and woolly sunflower. Particular parts of
some plants are eaten selectively. This includes the berries of blueberry
shrubs, flowers of tiger lily and Sitka valerian, and fiddleheads of the
bracken fern. Lupine and peavine make up a high proportion of the
summer diet and may be selected because of their high nitrogen
content.

Where do they live?
Ideal Vancouver Island Marmot habitats, like those in the Green
Mountain�Haley Lake area west of Nanaimo, are on steep slopes in
subalpine areas, between the 1000 and 1460 metre elevations. These
hardy animals prefer edges of open sites with lush plant growth and
good visibility to see one another or detect predators. The best habitats
face southeast to southwest, where snow melts early. They have
pockets of deep soil suitable for hibernacula and burrows, contain
scattered boulders or rock ledges used for loafing and lookouts, and are
situated below steep rock bluffs that shed snow. Snow avalanches and
snow creep help to maintain these meadow habitats, which are of
limited extent on Vancouver Island. Occasional wild-fires may also
create some subalpine openings used by marmots.

It is a puzzle, however, why apparently suitable subalpine habitats on
central and northern Vancouver Island have few or no marmots.
Perhaps they have just not been found, although many sites have been
searched without success. It is also possible that what looks suitable to
students of the marmot doesn�t really meet the needs of the animal.
More study of this intriguing problem is certainly needed.

The climate in marmot country has long though not particularly cold
winters, with snow depths of 1 to 3 m, snow patches which persist as
late as July, and a short growing season for plants (115 to 135 days).
Colonies are often in steep, rugged landscapes, but this reflects the
availability of suitable vegetation rather than any need by the marmots
for steep terrain. Hibernacula are usually situated where deep snow
provides good insulation. Typical trees in marmot terrain are
mountain hemlock and yellow cedar; common shrubs include Sitka
alder, blueberries, rhododendron, and mountain heather. 

Vancouver Island Marmots have colonized ski runs at Green
Mountain and Mount Washington, and logged areas at several
locations on the southern island. Removal of tree cover in those sites
has stimulated plant growth of value to marmots. Logging has only
lately reached upper elevation forests near traditional marmot
colonies, and successful invasion of logged areas by breeding colonies is
a recent phenomenon. Colonies in these areas are at a lower elevation
than the traditional sites (800 to 1000 m) and the plant cover is
different, but the adaptable marmots have found that road cuts are
suitable burrow sites and that woody debris provides cover and
lookouts. A sizable proportion of the marmot population on the
southern island now lives and reproduces in these disturbed habitats. 

Although forest regeneration will eventually make most logged sites
unsuitable for marmots, sustained yield logging should ensure that
some are available for a lengthy period.
What can we do?
The first inventories of distribution and abundance on the southern
island were conducted between 1979 and 1981, with more intensive
surveys occurring in 1982, 1983, 1984, and 1986. University research
studies on behaviour, foraging ecology, and genetic variability have
provided valuable background information for future management.
The first Status Report and Management Plan was prepared in 1985.

Some important habitats have been designated for marmot
conservation purposes. These include the Haley Lake Ecological
Reserve made up of 93 hectares donated by MacMillan-Bloedel in 1987
and 27 hectares donated by Fletcher Challenge in 1991, and a 300 hectare
Critical Wildlife Management Area established on Green Mountain in
1991. Potential habitat is also protected within Strathcona Provincial
Park.

A Vancouver Island Marmot Recovery Team with members
representing federal and provincial wildlife agencies, the Royal B.C.
Museum, forest companies and conservation organizations, was
formed in 1988 and produced a Recovery Plan in 1992. The goal of the
Recovery Plan is to effect population increases sufficient to justify
removal of the marmot from the Endangered Species list. Continued
and expanded support is needed to put it on the road to recovery.
Donations may be made to the �Marmot Account� of the Nature Trust
of British Columbia, 808-100 Park Royal South, West Vancouver, B.C.
V7T 1A2.

The Recovery Team is interested in hearing of any marmot sightings
in areas near Strathcona Park or in areas north or west of Port Alberni.
With information on sightings, or to receive information on viewing
marmots, phone 751-3100 or contact:
Vancouver Island Marmot 

Recovery Team,
Wildlife Management Section,
Ministry of Environment, Lands and Parks,
2569 Kenworth Road,
Nanaimo, British Columbia
V9T 4P7