Browsing by Author "Whitaker, Darroch M."

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    A Range-Wide Meta-Analysis of Wild Turkey Nesting Phenology and Spring Season Opening Dates
    Whitaker, Darroch M.; Pack, James C.; Norman, Gary W.; Stauffer, Dean F.; Klopfer, Scott D. (Michigan Department of Natural Resources, 2005)
    Timing of nesting is an important consideration when setting opening dates for spring male-only wild turkey (Meleagris gallopavo) hunts. We conducted a meta-analysis in which we used mean dates of incubation initiation from 58 studies to evaluate a priori models hypothesized to predict turkey nesting phenology across the species’ range. Models were based on geographic setting, climate, and management activities, and had weak to moderate explanatory power (Range R2 adj = 0.12–0.55). We developed 2 post hoc models to better predict mean incubation date, and used one of these to generate a range-wide map predicting timing of nest incubation. A second model selection exercise focused solely on the eastern subspecies of wild turkey, and our best model of incubation date included population status and a cubic term for latitude (n =41, R2 adj = 0.80). Lastly, we compared incubation initiation dates to opening dates for spring male-only hunting in each jurisdiction. Of 34 states and provinces for which we obtained data, 25 opened spring hunting 2 weeks prior to the mean date of incubation initiation, and 18 of these also allowed fall either-sex hunting. This finding is noteworthy because extended fall seasons and spring hunting during the pre-nesting period can lead to additive and unsustainable levels of female kill.
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    Ruffed grouse (Bonasa umbellus) habitat ecology in the central and southern Appalachians
    Whitaker, Darroch M. (Virginia Tech, 2003-12-15)
    Ruffed grouse populations are low in Appalachian forests, possibly because low habitat quality negatively affects survival, condition, and reproduction. Through the Appalachian Cooperative Grouse Research Project (ACGRP) researchers tracked >1500 radioed grouse at 10 study sites (1996__2002). To improve our understanding of Appalachian grouse habitat ecology, I carried out two primary analyses of this database. First, grouse should be under selective pressure to minimize movements, so I studied factors associated with variation in home range size. Second, importance of a habitat is affected by an individual's resource needs, and I investigated factors associated with variation in selection of "preferred" habitats. Both approaches yielded important insights into the species' regional habitat ecology. As elsewhere, clearcuts, which afford escape cover, formed the cornerstone of grouse habitat in the region. However, a number of other factors were also important. At the root of this was a divergence in habitat ecology between grouse inhabiting the two major forest types in the region. In oak-hickory forests nutritional constraint strongly influenced habitat use. Grouse home ranges increased 2.5x following poor hard mast crops, and at these times grouse increased use of alternate foraging habitats. Grouse, especially females and broods, made extensive use of mesic bottomlands and forest edges, which in oak-hickory forests support relatively abundant soft mast and herbaceous forages. In contrast, grouse inhabiting mixed mesophytic forests were insensitive to hard mast, did not select bottomlands, reduced use of forest edges, and increased use of clearcuts. I feel that greater abundance of birch, cherry, and aspen, buds of which are a high quality winter food, relieves nutritional stress on grouse inhabiting mesophytic forests. A general inference was that grouse attempted to balance competing strategies of maximizing either survival or condition, and the expression of this tradeoff was mediated by forest composition. Also presented here were studies of radiotelemetry error, roost site selection, and suitability of prescribed burning as a habitat improvement technique. In the closing chapter I make recommendations for managing Appalachian forests for grouse, which focus on improving winter foraging habitat, brood habitat, and escape cover, all of which are limiting in Appalachian forests.