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A Galaxy of Gulls
Colonial, convivial and cacophonous,
gulls are by far the most abundant
and commonly sighted bird species
of Great Slave Lake. They nest
in groups on bare, rocky islands,
avoiding egg-eaters such as
weasels and foxes. They are
known for their use of “mobbing”
behaviour to drive off large
predators. The 4 most common
Great Slave gulls are:
Ring-billed Gull
– Probably the most abundant
gull in North America, the medium-sized,
white-bodied Ring-billed gull
is distinguished by the black
ring that encircles the tip
of its yellow bill. Highly adaptable
to it surroundings, the Ring-billed
Gull is a voracious, indiscriminate
carnivore that prefers to eat
fish, but does not hesitate
to gobble up insects, small
animals, carrion – and
garbage. Ring-billed Gull colonies
are massive, with a minimum
size of 500 – 1,000 birds.
Herring Gull –
A large gull with a white body,
grey wings, pink legs and yellow
beak with a single red spot
on the lower tip, the Herring
Gull is one of the most widespread
bird species in Canada. Although
Herring Gulls congregate in
large colonies, each nesting
pair occupies a fixed, well-defined
area. Herring Gulls will eat
almost anything; only those
in remote wilderness areas such
as Great Slave Lake exist on
a completely natural diet. Herring
Gulls have been observed to
have a complex system of communication
and a highly-developed dedication
to their young.
California Gull
– A little smaller than
the Herring Gull, with slightly
darker grey wings, yellow legs,
and a softer, more rounded appearance
than its larger cousin, the
California Gull’s range
is restricted to the western
part of North America. Like
other gulls, the California
Gull feeds on fish, insects,
aquatic invertebrates and carrion.
Mew Gull –The
smallest of the Great Slave’s
gulls, with a narrow, peg-like
yellow bill, slight brown speckling
on the neck and dusky eye patches,
the Mew Gull has a more delicate
appearance than the larger Herring,
Ring-billed and California Gulls.
But in behaviour, it is just
as opportunistic and aggressive,
sometimes stealing food from
other birds or cannibalizing
hatchlings.
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A Birding Tour of
Great Slave Lake
Majestic Tundra Swans, graceful Lesser
Snow Geese, and a myriad of ducks - like
a giant, 28,568 square kilometre avian magnet,
Great Slave Lake attracts hundreds of thousands
of migrating waterfowl, drawn to the islands,
bays, marshes and delta wetlands that line
its shores.
The lake’s varying terrain, climate
and geology – ranging from the flat,
braided channels of the Slave River Delta
to the rocky islands of the North Arm, and
the tall cliffs of the East Arm –
also provide ideal breeding habitat for
an astonishing variety of gulls, terns,
shorebirds and songbirds. Birding “hot
spots” around Great Slave Lake include:
• The
North Arm – Designated as an
Important Bird Area (IBA) by Canadian
BirdLIfe International partners the Canadian
Nature Federation and Bird Studies Canada,
the north shore of the arm from Frank Channel
to Franois Bay (including the Beaulieu River
to Watta Lake, the Yellowknife River to
Prosperous Lake, and the City of Yellowknife)
attracts up to 100,000 northward-migrating
waterbirds each spring. Prominent visitors
include Short Grass Prairie Canada
Geese, Greater and Lesser Scaup, Northern
Pintail, Tundra Swans and
Surf Scoters. Spring migration
peaks during the 3rd week of May; many species
return in the fall as they make their way
south.
• With its comparatively shallow
depths and numerous bays, islands and marshes,
the North Arm is also a mecca for breeding
birds. The waters of the North Arm open
about 2 weeks earlier than those in other
parts of the lake, allowing species such
as Ring-billed Gulls, Common Terns,
Red-breasted Mergansers and
Mallards to begin nesting in May.
The location of the North Arm, at the boundary
of the Canadian Shield and the Mackenzie
Lowlands, draws many species of breeding
boreal ducks.
• A more tundra-like habitat
occurs in the West Mirage Islands, a cluster
of almost 100 outcroppings located just
outside Yellowknife Bay. The cooler micro-climate
of the islands appeals to northern species
that are at their southern limit, including
Red-throated Loons, Red-necked Phalaropes,
and Parasitic Jaegers.
(The Red-throated Loon is a Canadian Arctic
species that summers in the Beaufort Sea;
the Red-necked Phalarope breeds in the Arctic
and sub-Arctic, and is the only shorebird
that spends most of its life in the water;
the Parasitic Jaeger is an aggressive, gull-like
bird that feeds by stealing food from other
birds, and feigns injury to distract predators
from its nest.)
• The West Mirage Islands
are also home to large colonies of Caspian
Terns, California Gulls, Arctic Terns, Herring
Gulls, Mew Gulls, Greater Scaup and
Red-breasted Mergansers.
• East
Arm – Colder and craggier than
the North Arm, with a mixture of barren
and forested islands, the East Arm of Great
Slave Lake is characterized by deep, clear
waters and a shoreline dominated by mosses,
lichens and low-growing shrubs. The islands
of the East Arm attract nesting gulls, terns
and ducks, while the cliffs are the lake’s
headquarters for Bald Eagles
and other birds of prey.
• South
Shore and Slave River Delta –
The significance of Great Slave Lake’s
southern shore (Slave River Delta to Taltson
Bay), as a staging area for migrating waterfowl
– including up to 7,700 Tundra
Swans and 23,520 Lesser
Snow Geese – has earned the
area an Important Bird Area (IBA) designation.
Shallow bays and braided channels, thick
with horsetails and sedges, wetlands filled
with willows and banks lined with mixed
balsam poplar and spruce woods also provide
ideal breeding habitat for ducks such as
Lesser Scaup, Mallard, American
Widgeon, Bufflehead and
Blue-winged Teal. The largest gull
colony on Great Slave Lake can be found
on Egg Island, near the Slave River Delta.
• West
Shore – Edged with bays and
marshes, the habitat of the Great Slave’s
western shore is similar to that of the
North Arm. Islands are fewer, but are usually
forested, attracting a wide variety of nesting
birds. Large colonies of California
Gulls, Herring Gulls, Mew Gulls, Ring-billed
Gulls and Common Terns
can be found on the western shore. Big Island,
at the outflow of Great Slave Lake into
the Mackenzie River, is an important staging
area for migrating waterfowl. |
