Passport to Texas

This is Passport to Texas Supported by the Wildlife and Sport Fish Restoration Program

Calling a brown-headed cowbird a cowbird, is a misnomer as far as biologist Marsha May is concerned.

I think they should be called bison birds, and not cowbirds, because they evolved with the bison.

Semantics aside, the bird’s habit of laying its eggs in other birds’ nests can cause the decline of species with small populations, such as the endangered Black-capped Vireo. Additional species are also affected.

Woodland species are now being impacted by brown-headed cowbirds, because we’ve fragmented the woods. Previously those woodland species were protected by the woods. Now that it’s fragmented, the cowbirds are getting into that habitat, and they’re parasitizing birds that have never historically been parasitized before.

The cowbird is in the blackbird family. The male has a black body and brown head, while the female is mottled brown and gray. Want to intervene on songbirds’ behalf.

You can actually become certified in Texas to trap for cowbirds, and that’s mainly during the breeding season, between March first and May thirty-first. And, mainly you’re trying to trap the females.

Get ready for spring. Find certification information on the Texas Parks and Wildlife website.

That’s our show… the Wildlife and Sport Fish Restoration Program supports our series and is funded by your purchase of shooting and hunting equipment and motorboat fuel.

For Texas Parks and Wildlife…I’m Cecilia Nasti.

This is Passport to Texas Supported by the Wildlife and Sport Fish Restoration Program

The brown-headed cowbird migrated with bison across the Great Plains, and because it’s hard to raise a family on the road, cowbirds laid their eggs in other birds’ nests; host birds unwittingly raised cowbird young.

12—The problem with the cowbird eggs is that normally they’re big eggs; they hatch earlier than the host eggs do; and they’re very vocal and hungry and beg for food.

Biologist, Marsha May, says the cowbird hatchlings out compete the host’s offspring for food, starving them out, and reducing populations of that species. Back when bison roamed, cowbirds didn’t have quite the same impact.

15—Black-capped vireos, which are an endangered species now, evolved where if they were parasitized by a brown-headed cowbird, they would leave that nest and re-nest – start a new nest. Well, if the cowbirds had already moved through, that would have worked.

Without bison, cowbirds hang with cows. Because cows are fenced in and don’t migrate, neither do cowbirds.

19—They’re parasitizing all the birds in that area – their nests – and they’re having a major impact on some species like the black capped vireo, because the black-capped vireo keeps re-nesting and that’s wasting a lot of energy, and if it’s constantly being parasitized, then no young will be reproduced at all that year.

We’ll have more on cowbirds tomorrow.

That’s our show… we receive support from the Wildlife and Sport Fish Restoration Program… funded by your purchase of fishing and hunting equipment and motor boat fuels.

For Texas Parks and Wildlife…I’m Cecilia Nasti.