Tests of an additive harvest mortality model for northern bobwhiteColinus virginianusharvest management in Texas, USA

Abstract

We evaluated the application of using an additive harvest mortality model (AHMM) as a harvest management strategy for northern bobwhites Colinus virginianus during the 2007/08 and 2008/09 hunting seasons in two ecoregions of Texas: the Rolling Plains (RP) and the South Texas Plains (STP). We collected field data on three study sites/ecoregion (of 400‐1,900 ha each; two treatment and one control) to estimate four demographic parameters (i.e. fall and spring density, overwinter survival in the absence of hunting and harvest rate). We used these data to parameterize an AHMM (a theoretical component of sustained‐yield harvest; SYH) for bobwhites and compare model‐based predictions of spring bobwhite populations with field estimates. Our goal was to compare predictions from the AHMM to field estimates of spring density based on known rates of harvest. Compared to field estimates, the AHMM consistently underestimated spring population density (mean % ± SE) by 55.7 ± 17.8% (2007/08) and 34.1 ± 4.9% (2008/09) in the RP and by 26.4 ± 25.3% (2007/08) and 49.1 ± 2.1% (2008/09) in the STP. Prescribing a fall bobwhite harvest to achieve a specific, target spring density may be difficult given the wide variation in the model parameters (i.e. fall and spring density, and natural mortality) that we observed.

Dynamic analysis of a fuzzy Bobwhite quail population model under g-division law

“…A original bobwhite quail population model in 25 focused only on the density of the population at spring, that is net increase, and fall, net decrease accordingly. Besides seasonal factor, living environment(brush canopy cover 26 ,the effect of natural predators trap and removal 27 , 28 , a regular harvest 29 ) influenced the process of bobwhite quail population evolution usually. Focusing trajectories of Bobwhite quail populations in four reasons is deemed sensible, our observations can be expressed in a generalization model of a form originally introduced by 30 – 32 as According to Zhang and Taşdemir’s work, the following fuzzy difference equation, typically and not unexpectedly, described a general fuzzy bobwhite quail population model (GFBQP model).…”