The nights are getting longer, the days chillier, and with each passing week there seem to be fewer and fewer birds occupying the skies. But they aren't all gone. One small bird you will see throughout the winter here in the Southwest is the Lark Bunting (Calamospiza melanocorys).
Female Lark Bunting
Male Lark Bunting
These birds can be seen in massive flocks numbering in the hundreds as they forage for insects, seeds, grains, and fruits. They are usually found in grassland areas, and you may have come across them as you drive in an area with high grass and flush them out. They have a very simple whistle, but will generate a more complex sound when the entire flock is calling.
Lark Buntings have a very unusual sexual selection pattern. While most birds will choose mates by a particular attribute like size or color, the female Lark Buntings will change how they choose their mates each season. Sometimes they will look for beak size, other times for the size of the white spot on the male’s wings, how dark the black is of their coloring, or other characteristics. This allows the females to find the best mate so that their offspring will best be able to use whatever resources are available in the area that season. Additionally, it allows for greater genetic diversity within the species, thus populations that are better able to survive through rough times.
A special thanks to Seth Hall of the LTER Jornada Experimental Range for lending his bird expertise.
For more information, check out Cornell’s Ornithology Website.
"IMG 7043 lark bunting" by Ryan Douglas - Licensed under CC BY-SA 3.0
"Lark Bunting Pawnee NG” by Hans de Grys - LIcensed under CC BY-SA 2.0