Red-winged Blackbirds understand Yellow Warbler alarms

Photos by BarrytheBirder

Research at the University of Illinois has shown that Yellow Warblers have an alarm call that warns others of their kind, that Browned-headed Cowbirds are nearby and present a threat to warbler nests which may imminently have cowbird eggs laid in them. The warning call is a "seet" sound.  Female warblers immediately occupy their nests until the supposed threat has passed.   It turns out that Red-winged Blackbirds understand the meaning of the "seet" alarm call, and they too return to occupy and protect their own nests.   It is known that Yellow Warblers do better when they nest near Red-winged Blackbird territories, which makes sense because the 'redwings' are extremely aggressive to threatening predators.   Nature has its ways.

 Brown-headed Cowbird

 Red-winged Blackbird

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BarrytheBirder