The Brown-headed Cowbirds are back and trailing our small herd.  I have mixed feelings about their presence though.  Cowbirds are small blackbirds with brown heads, which walk the ground among grazing cattle, to forage on insects, beetles, spiders and seeds among other things.  They can have all the flies they want, however I covet the presence of dung beetles.  Cowbirds are known as parasites.  They lay their eggs in the nests of other birds then fly away.  The nest owner mistakenly incubates the eggs along with their own.