|Species: Western Wood-Pewee
are small nondescript birds (members of the Tyrannidae) that are
common across western North America. Despite the widespread
abundance of Western Wood-pewees, we know very little about their
biology during migration and wintering months. The breeding
distribution of this species is remarkable, spanning from central
Alaska through California, Mexico and possibly reaching north
central Costa Rica. The western limit of the range follows the coast
while the eastern range spans from Alaska to the Yukon, central
Saskatchewan, central Manitoba, central South Dakota, western
Nebraska, eastern Colorado, eastern New Mexico and western Texas.
Due to the striking similarities between Western Wood-Pewees and
Eastern Wood-Pewees and the potential for the misclassification of
migrating birds as wintering birds, delineating the wintering ranges
of these two species becomes a challenge. To the best of our
knowledge, Western Wood-Pewees spend their winter months in parts of
Central America and northern and western South America.
Western Wood-Pewees are fairly small birds, with relatively large
heads and “whiskers” surrounding their broad, flat bills. Adults
measure about 16 cm long and weigh 13 grams.
and Female: Males and Females tend to be very similar in appearance
with the exception the females are slightly smaller. Upperparts
mainly greyish/olive coloured, white or pale wing-bars and tertial
edges, underparts are a subdued white. Dark upper mandibles, pale
lower mandibles. Absence of eye ring.
For the most part juveniles resemble adults, with the exception that
juveniles usually appear darker and tend to have buffy wing-bars.
Very difficult to distinguish from Eastern Wood-Pewee by sight
alone. Range maps and song help to distinguish these two species.
Greater Pewees are larger, with bright pink/orange underparts and
sport a slender pointed crest. Olive-sided Flycatchers have easily
distinguishable from Western Wood-Pewees by their song, but they are
also larger and have a more prominent white chest due to darker
patches that surround the breast. Western Wood-Pewees are
distinguished from Empidonax flycatchers by their larger size,
darker head, dusky breast and longer wings.
These birds are almost never seen hopping or walking on the ground,
instead they are either perched or flying through the air. These
birds are solitary.
Common in open woodlands including mature deciduous and mixed
forests, along forest edges and riparian habitats.
Information: Western Wood-Pewees usually perch high up on the tops
and canopy of trees and dash out to catch insects. Prey items
include flying insects including flies, ants, bees, wasps, beetles
moths and bugs. They may hover in the air while flying and foraging
for food and may quiver their wings once they have returned to their
Few data exist on longevity; however, the oldest recorded individual
was at least 6 years old.
Based on the limited amount of information that is available, it
appears that Western Wood-Pewees typically lay between 1 and 5 eggs,
clutches of 3 eggs being most common. Depending on breeding habitat,
nest survival ranges from 43 to more than 60%. Predation is the main
cause of nest failure.
Status: (Least Concern)
have benefited from forest fragmentation and the creation of edge
habitats. Despite being relatively common across their range,
according to the Breeding Bird Surveys they are declining in Canada
and United States. Declines are attributed to expansion of urban
centres and land conversion for agricultural purposes that have
resulted in a loss of suitable habitat. Of particular concern is the
removal of tropical forest in their wintering habitat.
A breeding bird in Colony Farm, capture rates (2010-2012;
standardized as birds captured per 100 net hours) of the
Western Wood-pewee occur from early spring through August.
Numbers peak in June as they settle into territories then
again in August as juveniles disperse and individuals
prepare for long distance migration to their wintering
grounds in South America.