Friday, August 23, 2013
Nest Parasites and New Birds at Pompey's Pillar
Pompey's Pillar National Monument this summer. He posted a photo online of a nest with a parasitic egg in it--wait, let me explain a minute: Some birds do not make nests of their own. Instead they sneak into the nests of other birds and lay their eggs there, sloughing off the work of incubating, feeding, and otherwise bringing up a baby bird. The nesting bird typically raises the parasitic egg as it it were her own though sometimes she catches on and kick the parasitic egg out. Quite often though its comical because the parasite (Brown-headed Cowbirds in this case) are so big and the host (Lazulli Bunting in this case) is so small. The baby will quickly outgrow the "mother." The cowbird also tends to out-compete nestmates because of the size advantage which can cause the host nestlings to perish from lack of food.