Saturday, March 23, 2013

Lucy's Warbler and Bell's Vireo

[Sabino Canyon, Tucson, AZ. March, 2013]

Lucy's Warbler is unique in the following ways:
  • It is our smallest warbler
  • It is our only desert warbler
  • It is a cavity nester (one of only 2 warblers that do this -- the other being the Prothonotary)
  • It is our least colorful warbler -- plumaged in pale grey and white
This very special bird was named by the naturalist and surgeon James Graham Cooper after the daughter (Lucy) of the giant of American Ornithology, Spencer Baird. Lucy Hunter Baird was recognized for the help and assistance she gave her father in his work. Lucy not only transcribed his notes but also accompanied him on many of his field trips. She died in 1913.

The main identification features of this elegant warbler are the the pale plumage (grey above, whitish below), white eye-ring, small pointed bill, rufous rump and, for the male, a small patch of rusty streaks on the crown.
Male Lucy's Warbler -- this view shows a hint of the rufous rump which is diagnostic.

Conservation-wise, Lucy's warbler population trends are overall largely stable despite the loss of suitable riparian habitat and brood parasitism by brown-headed cowbirds that has caused declines in localized areas. It is assessed as "Least Concern" by the IUCN.
Lucy's Warbler singing.

These distinctive warblers were seen by the dam in Sabino Canyon in the Coronado National Forest.

The other bird that was found in full song in the same area is the Bell's Vireo. Named by Audubon after the collector and taxidermist John Graham Bell. Like other vireos, the Bell's also shows the yellow and green hues which are typical of the family.

Nonetheless, Bell's Vireo is a drab bird; mainly grey with white underparts and yellow-green on the sides and wings. A faint eye-ring is also visible as is one wing-bar.
Bell's Vireo singing.
Bell's Vireo is classified as "Near Threatened" with a huge decline (a staggering loss of two-thirds of its population) over the last 4 decades in its population. Loss of habitat has been the main contributing factor. Recent conservation efforts have been successful in helping this species recover; however, the Californian subspecies remains classified as "Endangered".
Two birds found in dry habitat -- a warbler and a vireo -- symbolize the richness of our desert avifauna and there is perhaps no better place to enjoy them than Sabino Canyon.

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