Large heron-like birds, slate grey
in colouration, black wing tips and (in adults) a reddish patch
on the forehead and upper face. Most likely to be confused with
the Great Blue Heron, but flies with neck outstretched, while herons
fly with the neck curled back against the shoulders. Total length
86 -122 cm. (Godfrey, 1986).
Distribution
Columbia Basin: Southern Rocky Mountain
Trench. Possibly only one or two breeding pairs.
Global: Breeds in North America
from w. Alaska across much of the Canadian Arctic to Hudson's Bay
south to ne. California, Colorado, and Michigan. Also breeds in
Siberia. There are four distinct populations of G. c. tabida
in North America; those that occur in British Columbia winter mainly
in Baja California, s. Texas to c. Mexico. G.c. rowani probably
winter in New Mexico, Oklahoma and Texas. G. c. canadensis
winter in s. California, Texas and n. Mexico. (Cannings et al. In
prep.).
Habitat
The Sandhill Crane breeds in isolated
bogs, marshes, swamps, and meadows with heavy emergent growth such
as sedges, and bulrushes. Nesting wetlands tend to be secluded and
free from human disturbance, and have suitable foraging habitat
nearby. In British Columbia, nesting wetlands tend to be surrounded
by a narrow strip of meadow leading into coniferous forest. Forests
are used for escape cover by young cranes and provide a buffer against
disturbance (Cannings et al. In prep.).
Threats
Breeding population sizes are unknown
but are estimated to be about 1500 pairs in the central interior,
a few hundred pairs along the coast, and unknown numbers in the
northeast. Isolated populations include 1-2 pairs in the East Kootenay
Trench. Most populations are probably stable but data are lacking.
The Fraser Lowland populations have declined significantly and are
extremely endangered. South Okanagan populations have been extirpated
(Cannings et al. In prep.).
In southern lowlands, populations
have declined or disappeared as wetlands are converted or encroached
in the face of urbanization and intensive agriculture. Elsewhere,
threats are mainly from land use practices such as logging of forest
around nesting wetlands, draining or ill-timed drawdowns of wetlands
for agricultural purposes, and trampling of emergent vegetation
by cattle. In some landscapes, clearcuts have been used for nesting.
Natural mortality is estimated at 5% annually. Coyotes, Wolves,
Common Ravens, Golden Eagles, Bald Eagles, and Raccoons are potential
significant predators of eggs or young (Cannings et al. In prep.).
Biology
Nests are large heaps of vegetation,
usually built in emergent vegetation over water from a few cm to
1.5 m deep. Breeding habitat is widely distributed throughout the
breeding range. Nesting has occurred at elevations from near sea
level to 1200 metres. There are three main spring migration routes
through British Columbia: across Juan de Fuca Strait to Vancouver
Island and the Queen Charlotte Islands, the Okanagan Valley through
Quilchena/Knutsford/Kamloops to the central Chilcotin and on to
the Bulkley/Kispiox valleys and Alaska, and through the Peace River
and Fort Nelson areas and on to the Yukon and Alaska.
The Sandhill Crane has a clutch
of two eggs that are incubated for 34 days. Often only one chick
survives to fledge, after about 10 weeks. Eggs are laid from mid-April
through May and young are fledged by August (Cannings et al. In
prep.).