Signs of Spring: March 30, 1998
Male grackles are back in many northern areas, and as soon as the females arrive, the
males will start strutting around to attract them. Grackles can perform this display even in backyards, and it's
easy to observe.
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follow the instructions at the end of this report.)
Discussion of Challenge Question #1
In our last report, Challenge Question #1 asked, "Why do you think these mating calls of prairie chickens and grouse are deep and low, rather than high-pitched?"
As we mentioned, Prairie chickens and grouse are large, very tasty birds. Therefore, at the same time that they must be conspicuous to attract mates, they need to be inconspicuous to protect themselves against predators.
The low-pitches of their calls carry a long distance, so are very effective at drawing in females from far away. Prairie chickens and grouse do their displaying in very low-light conditions, while hawks are not about, so they don't have to worry about them.
But owls are actively hunting while these birds display. Owls hunt by hearing, and are
especially well-adapted for hunting mice. Their ears are exquisitely designed for hearing the tiniest squeaks.
But mouse squeaks are very high-pitched, and owls' specially designed ears are not so good at detecting the low
pitches of prairie chickens and grouse.
How to Respond to Today's Challenge Question
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