The Wilson Journal of Ornithology 123(2):332-338, 2011 
INTERACTIONS OF RAPTORS AND LESSER PRAIRIE-CHICKENS AT 
LEKS IN THE TEXAS SOUTHERN HIGH PLAINS 
ADAM C. BEHNEY.' 4 CLINT W. BOAL, 26 
HEATHER A. WHITLAW, 5 5 AND DUANE R. LUCIA 3 - 5 
ABSTRACT.—We examined behavioral interactions of raptors. Chihuahuan Ravens (Corvus cryptoleucus). and Lesser 
Prairie-Chickens (Tympanuchus pallidicinctus) at leks in the Texas Southern High Plains. Nonhem Hamers |fm.v 
cyaneus) and Swamson s Hawks (Hntea swainsoni) were the most common raptors observed at leks. Onlv 15 of 61 i25C 
raptor encounters at leks (0.09/hr) resulted in a capture attempt (0.02/hr). Mean (± SD) lime for Lesser Prairic-ChickciisH' 
return to lekking behavior following a raptor encounter was 4.2 ± 5.5 min suggesting the disturbance had little influence on 
C ® a . v,OIS ' ^ esser P ra > rie -Cbickens engaged in different escape behaviors depending on raptor species aal. 
generally did not respond to ravens suggesting they are able to assess different predation risks. The raptors in our study arts 
posed little predation risk to lekking prairie-chickens. Behavioral disturbance at leks appears minimal due to the lack of 
successful predation events low raptor encounter rates, and short time to return to lekking behavior. Received22 Autu' ! 
2010 . Accepted 3 January' 2011. 
Lesser Ptairie-Chicken (Tympanuchus pullidi- 
cinctus) populations have declined throughout 
much of their historic range (Crawford and Bolen 
1976. Hagen et al. 2004). Taylor and Guthery 
(1980) estimated that >90% decrease had oc¬ 
curred in their occupied range since the 1800s. 
Currently, small populations exist in parts of 
Colorado. Kansas. New Mexico. Oklahoma and 
Texas (Hagen and Giesen 2005). The population 
decline has resulted in Lesser Prairie-Chickens 
being designated ns a candidate species by the 
U.S. Fish and Wildlife Service for protection 
under the Endangered Species Act of 197.3 (USDI 
2008). 
Lekking species may be more susceptible to 
predation as they arc congregated, focused on 
mating and exposed (Harder 1974). Lehmann 
(1941.39) stated that "Prairie chickens on the 
courtship grounds seemed more intent on mating 
than on self-preservation; consequently, losses 
from predation were probably heaviest at mating 
'Texas Cooperative Fish and Wildlife Research Unit 
Department of Natural Resources Management. Texas Tech 
University. Lubbock. TX 79409. USA. 
W-Mit °“ ,0gi “ l Su,vc >'' T«» Cooperative Fish and 
' d f Research Unit. Department of Natural Resources 
Management. Texas Tech University. Lubbock. TX 79409 
USA. 
794uTuSA ,rkS and Wildli,c Department, Lubbock, TX 
'Current address: Cooperative Wildlife Research Labo- 
ratory. Southern Illinois University. Carbondalc. IL 62901. 
addre f '' U S - Fish ai,d Wildlife Service. Texas 
l ech University. Lubbock. TX 79409. LJSA. 
’Corresponding author; e-mail; clint.boal@ttu.edu 
time.” Wolfe el al. (2007) reported male mortal;!) 
was highest during peak lekking activity and 
suggested the cause may be male conspieuousnevs 
and/or predators focusing on lekking activity, 
although they did not report how many males 
were actually killed on leks. Schroede: and 
Baydack (2001) speculated that habitat degrada¬ 
tion at prairie grouse leks may have exacerbated 
predation risks. Few studies, however, have 
investigated predation on North American prairie 
grouse leks (e.g., Berger et al. 1963. Hartzler 
1974, Boyko et al. 2004) and no study has 
specifically identified predation on leks as a major 
source of mortality. 
Direct predation and disturbance of breeding 
activities may limit reproduction of birds I Cress- 
well 2008). Baydack and Hein (1987) reported 
female Sharp-tailed Grouse (T. phasianell M 
avoided disturbed leks (e.g.. presence of human 4 - 
dogs, vehicles, snow fences, propane exploder*- 
scarecrows, and radio noises). Alternative!)- 
congregation of birds at leks may reduce preda¬ 
tion risk due to increased probability ot detecting 
a predator before it becomes a serious threat- The 
predation risk for each individual decreases as the 
number of individuals in a group increases- -■ 
long as predation events do not increase as v U 
(Boyko et al. 2004). Flushing as a group *»> 
confuse a predator and make it harder to select jn 
individual (Lack 1968. Wittenberger I978i. LeU 
are generally in the same location year after year 
possibly because they have proven to be sate ui 
the past (Lack 1968). 
Raptors have been identified as predators ol 
Lesser Prairie-Chickens (Campbell 1950. Haukos 
3 32 
