|Species: Yellow Warbler
This small warbler
appears at a glance to be all yellow – hence its common name. It is
a common summer breeding visitor all across Canada and US, except
the very far north (beyond the tree line) and the southern States.
In the Vancouver area, it is one of the most commonly seen warblers,
arriving about May and departing in September.
It may be found in
a variety of locations, such as gardens, parks, alongside lakes and
streams, and especially in alder or willow thickets, preferring
Characteristics are typical of a warbler such as the small size and
thin short bill, and continual foraging among leaves for insects and
grubs. It is usually unmistakable – the only overall bright yellow
bird, and the only one with diagnostic yellow patches in the tail in
any plumage. Its length is about 12.5 cm; weight 9.5g.
Upperparts mostly yellowish olive-green, becoming more yellow or
yellow-orange on crown. Face and under parts rich yellow, with the
sides, breast and flanks streaked with chestnut-red. Wings are
darker yellow-brown with yellow edging. The short tail has yellow
patches on inner webs. The bill is black and stouter than most
This is similar to the adult male, but is duller and slightly more
greenish above and paler yellow below. Usually, there is much less
bold or no chestnut streaking on the breast, sides and flanks.
autumn): Generally similar to adult female, but much more dull
overall, and less obviously yellow.
In the Pacific region it is only likely that the female or juvenile
might be confused with the slightly smaller female Wilson’s Warbler,
but the latter does not have the diagnostic yellow inner webs in the
Forages in thickets and undergrowth for insects and grubs, so it is
often observed near eye level. Easily recognized by its song which
is sweet and high, with clear notes, sounding like swee swee swee ti
ti ti swee.
Common in willow and alder thickets in moist areas such as bogs,
stream sides, and lake edges. Also found in gardens and parks.
The Yellow Warbler
is classed with the other Wood Warblers, all small active birds with
short, pointed bills. The nest is usually found as a neat cup in a
willow bush, fastened to a fork in a branch just a few feet off the
ground. Eggs, usually 4-5, are white or bluish white, spotted mostly
around the large end in brown or purplish grey. Incubation by the
female is about 11 days. Yellow Warblers winter from Mexico and the
Bahamas south to Peru and Brazil. Interestingly, Yellow Warblers
have populated the Galapagos Islands as residents.
A widespread and
abundant warbler but little is known about continent wide population
trends. Although listed as LC (Least Concern) the species is
vulnerable in western North America where its preferred riparian
habitats are affected by intense grazing and habitat loss and
degradation due to development.
A migrant species, a small number of Yellow Warblers breed
in the riparian deciduous thickets of Colony Farm while the
rest continue north to breed. Capture rates (2010-2012;
standardized as birds captured per 100 net hours), starting
in May and continuing through September/beginning of
October, reflect the migrants passing through Colony Farm as
well as the breeding population’s presence during the summer
months of June and July. The peak during August reflects
dispersal of both migrant and breeding individuals.