Should I shoot cowbirds?

My father, who knew a great deal about the natural world, nonetheless felt that foxes were less desirable than rabbits.  After all, foxes were predators and rabbits were “nice” animals that ate plants.  Plus foxes eat chickens.  According to Natalie Angier, who wrote about prejudices against certain animals, Dad’s attitude would have been an example of “biobigotry.”  

She said we tend to think of animals using human judgements.  Cowbirds lay their eggs in other birds’ nests, bluebirds for example.  Cowbird eggs tend to hatch earlier than most bird species, so the host birds then feed the cowbird babies.  The cowbird chicks will eventually toss the other birds out of the nest.

To a human, the cowbirds represent laziness of the worst type.  They seem parasitic.  Plus they are among the “ugliest” of birds with drab brown and black feathers.

I’ve had this discussion with my daughter, who thinks shooting cowbirds is wrong.  However, cowbirds are in no danger of extinction.  In fact, they are thriving.  Eastern bluebirds, on the other hand, have declined precipitously in the last 50 years, mostly due to suburbanization, industrial farming, and loss of habitat.  Cowbirds love bluebird nests.  My argument is that we have already screwed up the environment, and since we have tinkered with it to such a large extent, we are justified in trying to rectify some of our mistakes.

This is why we cannot allow certain exotic non-native species to gain a foothold.  Perhaps the worst example of introduced species messing up an ecosystem is Australia.  Here we have our own problems with feral house cats, kudzu, and even white-tailed deer, a native species that has lost its predators.  We need to put our thumb on the scale.