Breeding Biology of the Eastern White-Winged Dove in Southern Texas

Abstract

coast of Tamaulipas, Mexico (Bent, 1932; Saunders, 1968). In the lower Rio Grande Valley (LRGV) of Texas, an estimated 4,700 ha of riparian forest and chaparral plus 11,760 ha of citrus groves are currently available to whitewings as nesting habitat (G. L. Waggerman, pers. comm.). Because >99% of their prime native nesting habitat has been modified (Cottam and Trefethen, 1968; Marion, 1974), whitewings have become increasingly dependent on citrus for nest sites. Unfortunately, citrus trees are killed during severe freezes, such as occurred in 1951, 1962, and 1983 and numbers of breeding doves also decreased markedly following freezes (Cottam and Trefethen, 1968; Waggerman, in litt.). Native vegetation remains relatively undamaged by freezing (Cottam and Trefethen, 1968; Lonard and Judd, 1985, 1991). The Texas Parks and Wildlife Department (TPWD) has made acquisition, re-establishment, and management of native nesting habitat the top priority of the white-winged dove management program (Brown, 1977; G. L. Waggerman, pers. comm.). TPWD assumes that whitewing breeding populations will increase by increasing the amount of available nesting habitat. This assumption is based on the premise that density-dependent factors (e.g., intraspecific competition for nesting territories) control the size of the breeding population. That assumption had not been tested prior to this study. Thus, our objective was to determine effects of intraspecific competition for nesting territories on breeding population sizes of white-winged doves in south Texas.