ABSTRACT
White-Winged Dove Life History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Statistical Analysis of Population, Habitat, and Harvest Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Whitewing Population Dynamics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Factors Controlling Texas Whitewing Populations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Reduction in Breeding Habitat Carrying Capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Fragmentation of Breeding Habitat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Breeding Season Food Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Nest Failure and Predation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Reduction in Wintering Habitat Carrying Capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Fall Hunting Mortality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Additional Factors under Investigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
The “landscape” for migratory bird species can involve different continents, with important habitats located hundreds or even thousands of kilometers apart. Factors controlling populations of these species are poorly understood, yet management decisions to conserve both game and nongame migrants must be made. Harvest level often is viewed as the principal management tool for migratory game birds, for example, doves and waterfowl, although populations of many species fluctuate in apparent independence of the number of birds taken by hunting each year (Nichols et al. 1995). The concept of carrying capacity provides some insight into the complexity of migrant population control,
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whether on the breeding ground, migration stopover sites, or wintering ground; it can limit populations regardless of the specific causes of mortality (Verhulst 1845, 1847). Understanding the life cycle of migratory birds is the most important starting point for successful management and conservation. Nevertheless, management during some portions of the migrants’ life cycle is likely to be beyond the control of managers. In these cases, they must obtain and use the best information available to manage those aspects over which they can have some direct effect, and consider ways in which they can influence those factors currently beyond their control.
