RECENT ADVANCES IN GRASSLAND BIRD RESEARCH: WHERE DO WE GO FROM HERE?

摘要: IT'S NO SECRET anymore. Populations of many species North American grassland birds are declining and have been for at least the last 30 years. According to Breeding Bird Survey (BBS), populations 13 declined significantly between 1966 1996, whereas only 2 increased during that period (Peterjohn Sauer 1999). As a group, experienced "steeper, more consistent, geographically widespread declines than any other behavioral or ecological guild" (Knopf 1994:251). Those appear be result primarily loss degradation habitat (e.g. Noss et al. 1995). Not surprisingly, such consistent stimulated great deal recent research attempting determine underlying reasons declines. Interest in has high, particularly because general view better understanding requirements is needed help land managers planners mitigate reverse some those Until recently, however, nearly all focused on breeding-season events; studies examined selection response management as prescribed fire grazing Bowen Kruse 1993, Johnson Zimmerman Griebel 1998, Herkert Glass 1999, Madden Shriver Temple Winter 1999), nest success 1990, McKee Hughes Rohrbaugh Brown-headed Cowbird (Molothrus ater) parasitism 1983, Robinson Davis Sealy 2000, Koford Peer 2000),