F. Hernandez
Clint W. Boal
Bart M. Ballard
Fred C. Bryant
D.B. Wester
J. Turner
2014
<p class="p1"><span class="s1">Predation risk has a profound influence on prey behavior and habitat use. The Rio Grande Plains ecoregion of Texas, USA, provides a unique opportunity to investigate changes in prey behavior because the ecoregion experiences a high influx of raptors every year during autumn migration. We used an 8-year data set (2000–2008) of radiocollared northern bobwhites (<i>Colinus virginianus</i>) and raptor abundance to test the hypothesis that bobwhites responded to increased raptor abundance via changes in woody-cover use at the home-range scale. Bobwhite survival was negatively correlated with raptor abundance, with red-tailed hawks (<i>Buteo jamaicensis</i>), and northern harriers (<i>Circus cyaneus</i>) accounting for 51% of the variability in bobwhite survival (<i>P</i> < 0.010). However, we documented no change in the amount of woody cover used by bobwhites in their home range between the raptor migration (6.6% ± 0.5%; <i>n</i> = 73 bobwhites) and non-migration periods (7.1% ± 0.4%; <i>n</i> = 105 bobwhites; <i>P</i> = 0.490). In addition, bobwhites that survived the raptor migration period used similar amounts of woody cover within their home range (6.3% ± 0.6%, <i>n</i> = 58 bobwhites) compared with those dying during the migration period (6.8% ± 0.4%, <i>n</i> = 100 bobwhites; <i>P</i> = 0.530). Our data suggest that bobwhites do not alter their use of woody cover at the home-range scale in response to increasing raptor abundance, but this does not preclude increased use of woody cover at the point-of-use scale.</span></p>
application/pdf
10.1002/wsb.476
en
Wildlife Society
Raptor abundance and northern bobwhite survival and habitat use
article