02161nas a2200217   4500008004100000245006400041210006400105300001100169490000700180520151900187653000901706653002201715653001801737653001101755653002201766100001501788700001801803700001801821700001801839856008601857       2004                        eng d00aInfluence of prey abundance on raptors in tallgrass prairie0 aInfluence of prey abundance on raptors in tallgrass prairie  a23 -320 v363 a<p>We examined relationships between winter abundance of diurnal raptors (red-tailed hawk, Buteo jamaicensis; rough-legged hawk, B. lagopus; ferruginous hawk, B. regalis; and northern harrier, Circus cyaneus) and both the abundance of microtine rodents (prairie vole, Microtus ochrogaster; and southern bog lemming, Synaptomys cooperi) and aboveground net primary productivity (ANPP) in tallgrass prairie. We used Christmas Bird Count data for each year during 1975 through 1999 from Manhattan, Kansas to index winter raptor abundance (number of hawks per party hour). Microtine rodent abundance (average number of microtine rodents per trapline in burned and unburned prairie) was estimated by using long-term data gathered from autumn and spring surveys along 14 permanent traplines from autumn 1981 to spring 2000 in tallgrass prairie on the Konza Prairie Biological Station. An estimate of ANPP for each year during 1975 through 1999 was provided by the Konza Prairie Long-Term Ecological Research Program. Winter raptor abundance was related positively to ANPP during the preceding growing season (P = 0.01) and to microtine abundance in the previous spring (P = 0.03). Based on a stepwise regression, 39% of the annual variation in winter raptor counts was explained by ANPP and the log of spring microtine abundance. Overall, our analyses suggested that winter raptor abundance was higher in years with higher than lower prey availability, but that other factors also influenced winter raptor abundance.</p>10aANPP10amicrotine rodents10apredator-prey10araptor10atallgrass prairie1 aReed, A.W.1 aKaufman, G.A.1 aRintoul, D.A.1 aKaufman, D.W.  uhttp://knz.lternet.edu/content/influence-prey-abundance-raptors-tallgrass-prairie