Belviev et al. • PRAIRIE-CHICKEN BREEDING BEHAVIOR 
99 
Variables were standardized by replacing each 
observation by ix r x^/s Xi for each lek to facilitate 
dual comparison of parameter estimates as effect 
AIK (Gnison et al. 1991. Agresti 2002. Nooker 
and Sandercock 2008). The sign of the slope 
i 'efficients indicate if that variable is positively 
• negatively correlated with male mating success 
and the magnitude of coefficients are directly 
comparable indices of effect size. We used 
\kaike’s Information Criterion corrected lor 
small -amples I AIC ( ) and model averaged slope 
coefficient estimates across all models in the 
model set to avoid basing inference on a single 
model (Anderson 2008). 
We only considered models with ^3 variables 
due to small sample sizes. Each variable appeared 
an equal number of times in the model set to 
facilitate model averaging and calculating relative 
importance values (Anderson 2008). We evaluat¬ 
'd models based on all copulation attempts 
regardless of whether it was successful, and only 
successful copulation attempts. We also calculat¬ 
ed Pearson’s correlation coefficient (r) between 
each variable and the proportion of all and 
'Uccessful copulations each male obtained on 
> ls ’ respective lek. 
is generally not good practice to use all 
possible models but we believe il was justified 
due lo the exploratory nature of this type of 
analysis. Previous studies have not examined 
e *ua! selection of Lesser Prairie-Chickens and 
° Ur goal was to provide a baseline for more in- 
kp'h future experimental work. All models were 
biologically and theoretically possible and we 
USl 'd model averaging to derive parameter esti 
ina!es as indices of effect sizes so inference was 
1,111 placed on any single model (Anderson el al. 
20f| 0. Anderson 2008). 
RESULTS 
We spent 272.5 hrs observing Lesser Prairie- 
f-hicken behavior at leks during spring 2008 and 
(mean ± SE = 47.9 ± 6.9 hrs/lek/yr). Study 
averaged 10.5 males/morning (range = 4.4- 
during the spring lekking season. Wc 
Captured 22 and 14 birds in 2008 and 2009. 
Actively. Thirteen of nineteen males (M 
yearlings, 2 adults) captured during early trapping 
essions between 23 February and 13 March 2008, 
Wer e not reobserved even after extensively 
Aching within 4 km of the leks of capture. 
T to*se 13 birds were not included in the analyses. 
Additionally, two males in 2008 and 2009 were 
banded but we were unable to collect all 
morphological measurements. This left us with 7 
and 12 individuals, respectively, in 2008 and 2009 
with complete morphological measurements to 
use for analysis. 
Mean ± SE lek attendance rate of marked 
males that were reobserved on study leks at least 
once was 0.88 ± 0.04. We noted 163 and 76 
female observations on leks in 2008 and 2009, 
respectively. Female lek attendance peaked during 
the 7-day interval starting 13 April in both years 
(Fig. 1A). The maximum number of females 
observed on a lek simultaneously was 17. We 
observed females on leks during evening display 
periods on one and two occasions in 2008 and 
2009, respectively, and in 2008 we observed toui 
copulation attempts during evening lekking. 
Overall, male mating success was skewed (X - 
0.60; 5-valuc = 0.30. P < 0.001). We observed 62 
copulation attempts on leks in 2008. 30 ot which 
were deemed successful. Copulation attempts 
peaked during the 7-day interval starting 27 April 
(Fig. IB). Four males were responsible for all 
copulation attempts on lek Bl, which averaged 
15.2 males per morning!/. = 0.54; 5-value - 0.27. 
P < 0.001). Three males were responsible for 
97% of copulation attempts, two ol which were 
responsible for 82% of all copulation attempts. 
Five males were responsible for all copulation 
attempts on lek B2, which averaged 16.0 males per 
morning (X = 0.77; /7-value = 0.53. P < 0.001 . 
Three males were responsible tor 93 ’b of al 
copulation attempts, one of which performed 
79 % of all copulation attempts. We observed 2) 
copulation attempts in 2009, 12 of which were 
deemed successful. Copulation attempts peaked 
during the interval starting 13 April (Fig. I B). We 
only observed one copulation attempt on lek B , 
and this lek was removed from the skew analysis. 
Three males were responsible for all copulation 
attempts on lek B4, which averaged 9.2 males per 
morning (X = 0.58; 5-value = 0.24, P -- 0.001). 
Two males were responsible for 88% of all 
copulation attempts. Four males performed all 
copulation attempts on lek R5, which averaged 7.8 
males per morning (X = 0.52; 5-value = 0.15, P = 
0.006) with two of the males performing 82% of all 
copulation attempts. The percentage of adult and 
yearling marked birds that attempted ^1 copula¬ 
tion w'as 20 and 44%, respectively. The mean ± SE 
percentage of copulations obtained on a lek for 
adults and yearlings was 0.09 ± 0.06 and 0.18 ± 
0.05, respectively. 
