WSB Study: How do brown-headed cowbirds pick nests to parasitize?

[Cara J]

Brown-headed cowbirds (Molothrus ater) parasitize nests of songbirds by sneaking in, laying their eggs in the nest and watching as songbirds of another species raise the cowbird chicks as their own. Previous studies have suggested that cowbirds detect the nests that they parasitize through visual cues such as nest building activity by the host bird species, nest architectural characteristics, vocalizations of host birds and proximity of nests from a cowbird perch. “Cowbirds are excellent at adapting, and they’re dynamic,” said Taylor Hackemack, lead author of the study published in the Journal of Wildlife Management, who conducted the research as an undergraduate at Mississippi State University. “They’re really opportunistic. They change their egg-laying timing and they watch the hosts.” Hackemack and her colleagues hypothesized that larger nests would more likely be parasitized by the cowbirds because the nests are easier to locate and take more time for the birds to construct, thereby increasing the likelihood that a cowbird will spot the nest. Researchers looked for nests containing cowbird eggs in shrub habitat. ©Jenny Foggia The team collected data for the study in stands of pines owned and managed by Weyerhaueser Company in Kemper County, Miss. They looked for nests of three [...]

 

Read more: http://wildlife.org/wsb-study-how-do-brown-headed-cowbirds-pick-nests-to-parasitize/