* The Cowbird eggs I have seen are LARGER than House Sparrow eggs. The Peterson guide numbers for Brown-headed are 21.45x16.42 mm for Brown-headed, vs 23.11x18.29 for Bronzed. I have listed the Birds of North America number)
Peterson Field Guide of Eastern
Birds' Nests, by Hal H. Harrison, 1975
Peterson Field Guide of Western Birds' Nests, by Hal H. Harrison, 1979
BNA - The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu
EGGS AND NESTS - click here to
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Unfortunately all the photos are not on the same scale.
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