The Tricolored Blackbird is North America's most colonial landbird. Found almost exclusively in California, its breeding colonies can teem with up to 50,000 birds, sometimes all settled into a single 10-acre field or wetland to raise their young. While similar to the more widespread Red-winged Blackbird, the Tricolored Blackbird is distinguished by its red shoulder patch with a bright white bar.
In the 19th Century, Tricolored Blackbird flocks were described as numerous. Since then, the population has declined from several million to approximately 145,000 today. Over just the last 6 years, the Tricolored Blackbird population has decreased by 64%.
The reasons for this decline are many, but the loss of marsh and nearby foraging habitats along the coast and in the Central Valley is the main issue. In more recent years, the species has become dependent on agricultural lands, with most of the largest colonies nesting in wheat fields. A real dilemma develops because Tricolored young typically have not yet left the nest before the time farmers harvest their crop, and harvesting destroys Tricolored Blackbird nests and young. In some cases as many as 20,000 nests have been lost in a single field. ...
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