干旱区生态环境知识资源中心

Mourning dove (Zenaida macroura L.) densities were determined using strip census techniques over a 2-year period (spring 1996 to winter 1998) on pastures in early-, mid-, and late-seral ecological condition. This study was conducted on the Chihuahuan Desert Rangeland Research Center and adjacent Bureau of Land Management rangelands in south-central New Mexico on 6 adjoining pastures that were similar in terrain and shape. Mourning dove densities pooled across sampling periods (8) were different (P < 0.10) on pastures in mid- and early-seral condition. They averaged 10.3, 33.9, and 7.2 birds km(-2) on pastures in late-, mid- and early-seral condition, respectively. Leatherleaf croton (Croton pottsii Lam.), the primary mourning dove food on all study pastures, was more abundant (P < 0.10) on late- and mid-seral pastures than on early-seral pastures. Therefore, heavy livestock grazing may adversely affect mourning dove populations in the Chihuahuan Desert by depleting leatherleaf croton. Autumn perennial grass cover and standing biomass differed (P < 0.10) among seral stages. More optimal interspersion of bare ground and perennial grasses may further explain why mid-seral rangelands tend to favor mourning doves. Our study shows mourning doves in the Chihuahuan Desert prefer moderately grazed, mid-seral rangelands over heavily grazed, early-seral rangelands.