Cassin's & Chipping Sparrows, Douglas

[Hugh Kingery]

Further to my post from last week about Chipping sparrows & Cassin's sparrows in the Castle Rock North Atlas block. Last week Bob Andrews prowled around rattlesnake hill and vicinity and he found Cassin's nest with eggs. He said the birds had their nests about a foot off the ground in a yucca. Four unmarked white eggs, male singing nearby.

I haven't heard any comments about the Chipping Sparrow molt/monsoon-nesting migration hypothoses. Doesn't anyone have some thoughts about whither and why?

Hugh Kingery
Franktown, CO