Publication Date
12-1-2011
Abstract
High temperatures can negatively impact Northern Bobwhite (Colinus virginianus) populations by reducing reproductive effort or altering habitat use. In western Texas, Northern Bobwhite commonly nest in prickly pear cactus (Opuntia spp.) instead of their typical nesting substrate of bunchgrass habitat. We tested the hypothesis that bobwhites nest in prickly pear cactus because it offered a cooler microclimate than bunchgrass. Our objectives were to compare 1) operative temperature between bunchgrass and prickly pear habitat and 2) egg hatchability and clutch size between bobwhite nests located in either prickly pear or bunchgrass plants. We collected microclimate data at both habitat types during June–August 1997 and 1998 on four study areas in Shackelford County, Texas. We also monitored 218 radio- marked bobwhites during March– August 1997 and 1998 to locate nests and document clutch size and egg hatchability. Operative temperature was similar between prickly pear habitat (x _ 5 39.7° C) and bunchgrass habitat (x _ 5 40.1° C; P. 0.05). We also documented no difference in mean clutch size or egg hatchability between nests located in prickly pear (10.5 eggs, 93.2%, respectively) and bunchgrass habitat (11.9 eggs, 95.4 %, respectively; P . 0.05). Our findings do not support the hypothesis that bobwhites nest in prickly pear habitat because of cooler operative temperature. A more plausible explanation may be that prickly pear serves as a nest-predator deterrent.
Creative Commons License
Recommended Citation
Hernández, Fidel; Henke, Scott E.; Silvy, Nova J.; and Rollins, Dale
(2011)
"The Role of Operative Temperature in Prickly Pear Use
by Nesting Northern Bobwhite,"
Bulletin of the Texas Ornithological Society: Vol. 44:
Iss.
1, Article 6.
Available at:
https://digitalcommons.usf.edu/tos_bulletin/vol44/iss1/6