Foster Care

A Little Bit More

Since the Brown-headed Cowbird is so common across North America, it’s quite likely you’ve seen this bird at your feeder or in a local park. But the male and female look quite different, and this has made identification confusing for some. The male has a glossy, black body with a brown head – hence the name - but the female is brown all over and is easily mistaken for something else – it’s quite nondescript!.

male Brown-headed Cowbird

Before Europeans arrived, Brown-headed Cowbirds were a bird of the Great Plains. Cowbirds followed the Bison herds feeding on insects that were stirred up by these large mammals. Since the Bison constantly moved across the plains, this bird developed a nesting strategy that allowed it to reproduce without remaining in any one location. Once the eastern portions of the continent were opened up by deforestation, cowbirds were able to expand eastward and began parasitizing birds there. Eastern birds that had never developed a defense to counteract this parasitism were faced with an intruder they couldn’t always thwart.

Parasitized White-eyed Vireo nest

Parasitized White-eyed Vireo nest © Solon Morse

As populations of cowbirds increased in the East, many conservation organizations became alarmed and began programs to reduce their impact. Many of the programs to eliminate cowbirds worked but later research has shown that these birds really don’t have the negative impact on most host species that was once believed. No doubt bird lovers still won’t find this bird a favorite but at least they’ll know that this species isn’t as bad as it has been made out to be.

Activities

Science & Art – Shine It Up

Objectives: Better understanding of what make an object look shiny

Materials: Reference material, printout of ill, and coloring materials

If you look at any photo of the Brown-headed Cowbird in sunlight, it’s immediately apparent that the male has iridescent/shiny plumage. Coloring feather so they look like they’re iridescent isn’t easy but is a good exercise for students to attempt.

Although the male Brown-headed Cowbird may look mostly black, in sunlight there is a definite bluish or purplish sheen to its feathers. Print out the illustratrion provided and have your students color it in.

If you’d rather have your students work with a more familiar object, look around the room and you’re sure to find a shiny everyday object they can use.

Hint: be sure the iridescent areas are those areas on the bird that are getting the most sun. Also note that if your colors go from black to very light purple in a small space, the feathers will be more likely to look like they have a sheen.

Key Concepts

Populations and Ecosystems, Life Cycles, Identification, Behavior and Regulation, Adaptations and Diversity

Questions

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Filed under: Birds