Northern bobwhite (Colinus virginianus) populations have been declining due to habitat loss and fragmentation. The decline of this popular game species has generated research on many levels with the goal of halting the decline. Fragmentation of the habitat may isolate populations, thus affecting dispersal, genetic diversity, and structure of populations. I analyzed effects of the landscape on genetic diversity and structure of northern bobwhites in Texas and the Great Plains. I determined genetic relatedness within and among northern bobwhite coveys in over 2 winters in South Texas. I evaluated home range and dispersal for northern bobwhites in South Texas. Genetic diversity, averaged across loci, was moderate (AR = 4.7, HO = 0.63). Populations exhibited a weak genetic structure (FST = 0.023) and most variation was within populations (97.64%). In the overall study area, barriers were correlated to genetic distance (BG.D: R = 0.227, P = 0.015, BG.L6 of 7: R = 0.251–0.357, P = <0.001–0.010), but in the Great Plains‒Central Texas region, populations appeared to be isolated by distance (DG.B: R = 0.285, P = 0.046, DG.L7 of 7: R = 0.339–0.447, P = 0.002–0.014). In South Texas, populations were isolated by landscape resistance (LG.D5 of 7: R = 0.349–0.467, P = 0.017–0.044, LG.B3 of 7: R = 0.380–0.446, P = 0.025–0.034). Among the winter coveys in South Texas, there was moderate genetic structure (FST was 0.063, P < 0.001). Relationship coefficients (R) within and among coveys ranged from -0.744–1.00 (average R = -0.006 ± 0.005 SE). From 2,887 pairwise comparisons in 2010–2011, Colony assigned 1–4 full sibs, 130–149 half sibs, and 0–3 parent-offspring relationships. The remaining pairs (94–95%) were unrelated. Relatedness within coveys did not change over time (n = 4 coveys in December, 4 in January, and 5 in February). In 2011–2012, Colony assigned 0–1 full sibs and 5–7 half sibs. The remaining pairs were unrelated (93–96%, n = 161 pairs). For northern bobwhites in South Texas, home ranges were significantly larger in normal years (16.17 ± 0.58 ha) than moist years (12.68 ± 0.31 ha). Average daily movements (46.40 ± 1.31 m‒47.90 ± 1.14 m) were smaller than those found in other studies, possibly due to the heterogeneous and contiguous quail habitat of South Texas. The shift in home ranges and movements among years may mean that in normal years birds were forced to move around seeking cover and food, but in moist years ample food and cover was available. The effects of distance (Great Plains) and landscape resistance (South Texas) appear to isolate populations, and this may affect gene flow in the future. It is important that biologists consider northern bobwhite management at broader scales in terms of large areas of habitat with corridors rather than at a local level.
January 12, 2017
The right to download or print any of the pages of this dissertation (Material) is granted by the copyright owner only for personal or classroom use. The author retains all proprietary rights, including copyright ownership. Any reproduction or editing or other use of this Material by any means requires the express written permission of the copyright owner. Except as provided above, or any use beyond what is allowed by fair use (Title 17 Section 107 U.S.C.), you may not reproduce, republish, post, transmit or distribute any Material from this web site in any physical or digital form without the permission of the copyright owner of the Material. Inquiries regarding any further use of these materials should be addressed to Administration, Jernigan Library, Texas A&M University-Kingsville, 700 University Blvd. Kingsville, Texas 78363-8202, (361)593-3416.