Brown-headed Cowbird
Molothrus ater

f5 @ 1/5000s, ISO:1000, Nikon d3S w 500mm

"Brown-headed Cowbird," Wikipedia, the free encyclopedia. It seems that brown-headed cowbirds periodically check on their eggs and young after they have deposited them. Removal of the parasitic egg may trigger a retaliatory reaction termed "mafia behavior". According to a study by the Florida Museum of Natural History published in 1983, the cowbird returned to ransack the nests of a range of host species 56% of the time when their egg was removed. In addition, the cowbird also destroyed nests in a type of "farming behavior" to force the hosts to build new ones. The cowbirds then laid their eggs in the new nests 85% of the time.
Ash Canyon, Sierra Vista, Arizona