Effects of silvicultural techniques and landscape management on habitat quality and relative abundance for northern bobwhites in a pine plantation forest

Pine plantation forests are increasing in scope across the southeastern United States, particularly Louisiana. These areas provide poor quality bobwhite brood-rearing habitats, and become increasingly degraded without periodic disturbance. Poor quality habitat conditions at a landscape-level scale usually results in reduced fall bobwhite body weights, creating low survival rates. We researched 4 understory vegetation management techniques (ie. mowing, no treatment, burn only, and imazapyr with burning) within pine plantations to evaluate their effects on vegetation composition and structure and on arthropod abundance and availability relative to bobwhite brooding habitat in 2002-2005. We used 1,155 human-imprinted bobwhite chicks to estimate foraging efficiency relative to the various treatments. We assumed that human-imprinted chicks foraged similarly to that of wild chicks, and that they provided a better indicator as to habitat quality in comparison to conventional entomological collection methods (ie. sweepnets and pitfalls). Foraging efficiency of human-imprinted bobwhite chicks was greatest in imazapyr/ burn (RCW) treatments relative to the other treatments. RCW treatments produced vegetation characteristics similar to what could be considered fair brooding habitat relative to the other treatments. Important vegetation characteristics found in RCW treatments were different from the other treatments. Our results suggest that the RCW treatment is more effective at enhancing quality of brooding habitats in degraded pine plantation stands relative to the other treatments. We also used bobwhite whistle counts collected from 2002-2005 to develop a GIS model that assessed landscape features associated with breeding males within a 200m spatial scale. Landscape and class-level habitat variables associated with calling bobwhites were then extrapolated to predict occurrence based on specific habitat features. Our landscape-level analysis determined that the probability of occurrence of bobwhites in an area was related positively to increasing patch diversity, but negatively to the homogeneity of patch types. At the class-level, bobwhite occurrence was positively influenced by increasing amounts of early successional habitat and edge complexity associated with two types of mature pine stands (unburned and RCW treatment). Negative bobwhite abundance was influenced by increasing amounts of 16-25 year old thinned pine plantations, and the amount of variation in patch size of unburned mature pine stands