| | Accession Number | 5004433 |
| | Title | North American Cowbird Advisory Council |
| | Project Description | The North American Cowbird Advisory Council serves as an authoritative source of guidance and |
| | information on ecology and management of parasitic cowbirds. Three cowbird species are found in |
| | North America: (1) the Brown-headed Cowbird (Molothrus ater) has a national range and presently |
| | causes the most problems; the South American Shiny Cowbird (M. bonariensis) invaded Florida |
| | 10 years ago and is becoming established in the southern peninsula; the Central American |
| | Bronzed Cowbird (M. aeneus) invaded Texas atleast 10 years ago and is well established in the |
| | Rio Grande valley. The North American Cowbird Advisory Council was established to serve the |
| | DOI agencies as well as state and local agencies with responsibilities for land and resource |
| | management. A particular focus is the regional monitoring and control program run by DOI |
| | agencies (FWS, NPS, BLM, BOR)in 5 southwestern states to protect the newly listed |
| | Southwestern Willow Flycatcher. The council's members include experts on the biology of cowbird |
| | parasitism and on the biology of the endangered species for which cowbird parasitism has been |
| | identified as a problem in the recovery plans. Council members include representatives of the |
| | university scientific community, federal agencies, and private environmental community. Co-chairs |
| | are Caldwell Hahn, PWRC, and Stephen Rothstein, UC Santa Barbara. These invasive cowbird |
| | species are a cause for management concern because of their extraordinary capacity for range |
| | expansion in conjunction with human development and because of the large number of songbirds |
| | that are affected by their parasitism. The Brown-headed Cowbird has expanded its range from the |
| | Great Plains to the entire continent over the course of the European colonization of North |
| | America. It has had a serious negative impact on 4 endangered species as well as on numerous |
| | other songbirds. The Brown-headed Cowbird is a complex species to characterize ecologically |
| | because it is an extreme host generalist, parasitizing 200 species and exploiting a staggering |
| | array of habitats. There is growing uneasiness at the high expense and indefinite duration of the |
| | large number of cowbird control programs that have been initiated across the nation as well as at |
| | the lack of information about basic cowbird breeding biology necessary to estimate the cowbird's |
| | impact on declining species. The two other cowbird species that have invaded the US much more |
| | recently are not as well studied or understood, but they are invading areas where songbirds are |
| | already subject to loss of habitat and heavy pressure from human development. The degree to |
| | which the 3 parasitic cowbird species will overlap and parasitize hosts in the same communities |
| | is unknown. |
| | Keywords | biological control, brood parasitism, ecosystem science, endangered species, information |
| | transfer, invasive species, monitoring, rangeland management, standards and protocols, status |
| | and trends, |
| | Principal | D. C Hahn, USGS Patuxent Wildlife Research Center: caldwell_hahn@usgs.gov; |
| | Investigators |
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