Joseph P. Sands

Impacts of Precipitation on Northern Bobwhite Production in South Texas

Despite a long history of research on northern bobwhites (Colinus virginianus; hereafter, bobwhites), there has not been a comprehensive assessment of how bobwhite productivity varies across a landscape in relation to environmental factors such as weather. Due to concerns of global climate change and range-wide decline of the bobwhite, further understanding the relationship between weather and bobwhite population dynamics is needed. The objectives of this study were to determine 1) how do among-year bobwhite masses, age ratios, and sex ratios change at the landscape scale, 2) can fall...

Year
2011

Exotic Grass Impacts on Northern Bobwhite Habitat in South Texas

There is growing concern about the impacts that exotic grasses may have on northern bobwhite (Colinus virginianus) and other grassland birds. Large areas of South Texas have been seeded to or have been invaded by several species of exotic grasses including Guinea grass (Urochloa maxima), Bermuda grass (Cynodon dactylon), King Ranch bluestem (Bothriochloa ischaemum), Kleberg bluestem (Dichanthium annulatum), buffelgrass (Pennisetum ciliare), and Lehmann lovegrass (Eragrostis lehmanniana). Impacts of exotic grasses on northern bobwhite are largely unknown. While exotic grasses such as...

Year
2008

Density Dependence, Harvest, and Population Dynamics in New World Quail: Implications for Harvest Theory in Upland Gamebird Management

Long-term population declines and conservation concerns resulting from large scale habitat loss have brought into question the biological justification of fixed, liberal harvest regulations as they apply to new world quail (Odontophoridae). As available quail habitat declines, biologically justifiable and sustainable methods of harvest will become essential components of quail management. Two hypotheses, the doomed-surplus hypothesis and the additive mortality hypothesis, attempt to provide a conceptual framework regarding the nature of mortality in hunted populations (i.e., compensatory...

Year
2008