Newsletter / Blog
2011-08-04 Tricolored Blackbird - Agelaius tricolor - a Red List Species.
The Tricolored Blackbird - Agelaius tricolor - is a near endemic California passerine and the most colonial songbird in North America. The male is glossy-black with a red shoulder patch and bright white bar, while the female is
dark blackish-brown.
Its range is limited to the Pacific coastal areas of North America, from Northern California to upper Baja California in Mexico. Found almost exclusively in California with more than 99% of the individuals in California.
This highly social and gregarious bird forms the largest colonies of any
North American landbird, with a single breeding colony often consisting
of tens of thousands of birds.
The common name is taken from the male bird's distinctive white stripes
on bottom of their red shoulder patches, or "epaulets", which are
visible when the bird is flying or displaying.
Males arrive on the breeding sites 1-3 days before the females in March. They nest twice and the second breeding attempt often occurs in a different, more northerly location. In most cases, one male breeds with two females in each breeding attempt. An open cup nest is built and three to four light blue eggs are laid. Females incubate for roughly 12 days, with young fledging between 10 to 14 days.
Tricolored blackbirds are mainly
granivores, however, they consume a wide variety of
plant and animal food and respond
opportunistically to the most abundant, readily available food resource.
The results of the 2011California Statewide Survey show a dramatic drop in the number of tricolors
statewide, from approximately 395,000 in 2008 to about 259,000 this
year, a greater than 33% decrease, this despite an increase in the
number of sites visited and an immense effort by 100 survey
participants.
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