Cactus Wren Nest Orientation

BirdNote^®  

Cactus Wren Nest Building Oriented with the Season

Written by Bob Sundstrom

This is BirdNote.

[Cactus Wren song]
In late April in the Arizona desert, it’s already over 90 degrees by 11 a.m. And the mercury is still rising. A Cactus Wren sings, perched atop a many-lobed cactus. [Cactus Wren song]. Then it hops down to its nest, tucked among the spiny lobes of the prickly pear.
In a desert realm where it’s hot enough to fry an egg on a flat rock, how can the delicate nestlings of a Cactus Wren survive? Well, Cactus Wrens, which may nest several times between March and September, carefully orient their nests in tune with the season. Their bulky twig structures, shaped roughly like footballs, have a side entrance. That tubular entrance curves toward the inner chamber.
When building a nest for the hot months, the wren faces the opening to receive the afternoon breeze. This circulates cooling air through the chamber and over the chicks. [Cactus Wren song]
By contrast, a Cactus Wren building a nest in early March orients the entrance away from the cold winds of that season, keeping the chicks snug and warm.
[Cactus Wren song]
Writers for BirdNote include Bob Sundstrom, Ellen Blackstone, Todd Peterson, and Dennis Paulson. John Kessler is our producer, Chris Peterson our executive producer, and Nancy Rumbel plays the theme music. I’m Mary McCann.
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Bird sounds provided by The Macaulay Library at the Cornell Lab of Ornithology, Ithaca, New York. Recorded by W.R. Fish and G.A. Keller.
Producer: John Kessler
Executive Producer: Chris Peterson
© 2013 Tune In to Nature.org     April 2017/2019/2022   Narrator: Mary McCann
ID#    CACW-01-2011-04-29 

Background sources include: Google books: http://bit.ly/hzQKIy and BNA Online