Raptor community composition in the Texas Southern High Plains lesser prairie‐chicken range

Abstract

Predation can be a factor in preventing prey population growth and sustainability when prey populations are small and fragmented, and when predator density is unrelated to the density of the single prey species. We conducted monthly raptor surveys from February 2007 to May 2009 in adjacent areas of the Texas Southern High Plains (USA) that do and do not support lesser prairie‐chickens (Tympanuchus pallidicinctus), a candidate for protection under the Endangered Species Act. During the summer period corresponding to prairie‐chicken nesting and brood‐rearing, Swainson's hawks (Buteo swainsoni) were the most abundant raptor. During the lekking and overwintering period, the raptor community was diverse, with northern harriers (Circus cyaneus) being the most abundant species. Raptor abundance peaked during the early autumn and was lowest during the spring. Utility poles were a significant predictor of raptor density at survey points and Swainson's hawks and all raptors, pooled, were found in greater densities in non‐prairie‐chicken habitat dominated by mesquite (Prosopis glandulosa). Avian predation risk on prairie‐chickens, based on presence and abundance of raptors, appears to be greatest during winter when there is a more abundant and diverse raptor community, and in areas with utility poles. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

Causes of mortality and temporal patterns in breeding season survival of lesser prairie‐chickens in shinnery oak prairies

“…Previous studies have suggested survival during the breeding season is driven by vulnerability of predation due to prairiechickens being exposed on leks and distracted by courtship displays (Hartzler 1974, Schroeder and Baydack 2001, Wolfe et al 2007); most of these mortalities would be expected to be caused by sight-hunting predators such as raptors, especially when large numbers are migrating through the study area. Raptor migration on the study area occurred in late Marchearly April (Behney et al 2011(Behney et al , 2012a, which is when we documented high survival rates for both sexes. Although predation attempts were noted, Behney et al (2011) found no evidence of successful predation of lesser prairie-chickens by raptors or mammals on leks in the study area.…”

“…We classified the mortality as an avian predation if the carcass was decapitated, showed signs of feather plucking (particularly on the breast muscle), showed single crimps on the antenna, showed beak marks on the transmitter, and/or if whitewash diagnostic of a raptor (Rezendes ) was present around the recovery site. Red‐tailed hawk ( Buteo jamaicensis ), Swainson's hawk ( B. swainsoni ), ferruginous hawk ( B. regalis ), northern harrier ( Circus cyaneus ), prairie falcon ( Falco mexicanus ), peregrine falcon ( F. peregrinus ), and great horned owl ( Bubo virginianus ) are potential avian predators in the area during the breeding season (Behney et al ). We classified the event as an unknown predator if there was enough evidence remaining at the site to attribute the mortality event to predation, but not enough to classify the event as avian or mammalian (e.g., a combination of mammal and avian evidence left at the site).…”

“…Lesser prairie-chickens in this ecoregion are susceptible to drought, which results in inter-annual variation of nesting behavior (Grisham et al 2013(Grisham et al , 2014. Thus, an assessment of the temporal patterns and causes of mortality and the factors that influence breeding season survival is warranted because birds in shinnery oak prairies are exposed to hotter, drier environmental conditions and different predator guilds compared with lesser prairiechickens in northern climes (Behney et al 2012a).…”

Factors Influencing Reproductive Success Of Ferruginous Hawks in the Uintah Basin, Utah

“…This correlation may reflect the quality of the habitat surrounding wells, or the ease of foraging in a landscape with more perch sites. Presence and higher abundance of raptors have been associated with increased number of perch sites (Behney et al 2012). Our results were similar to those of Zelenak and Rotella (1997), who found Ferruginous Hawks nesting in habitats altered by humans produced more young, potentially as a result of increased prey of Richardson's ground squirrels (Urocitellus richardsonii).…”

The landscape of fear as an emergent property of heterogeneity: Contrasting patterns of predation risk in grassland ecosystems

“…High quail mortality in the winter was consistent with the cumulative densities of Red‐tailed Hawk and Northern Harrier at that time of the year and was higher compared to the breeding season. Several species of raptors winter in the Southern Great Plains (Behney, Boal, Whitlaw, & Lucia, , ). For example, Northern Harrier does not breed in any of our study sites but arrives as early as July and leaves late in spring.…”