Are There Optimal Densities for Prairie Birds?

The condor

Susan K. Skagen¹ 

关键词: avian density;    Calamospiza melanocorys;    commodity-selection hypothesis;    Lark Bunting;    nest survival;    Program MARK;    shortgrass prairie;   

DOI  :  10.1525/cond.2010.090155

学科分类：动物科学

来源: Central Ornithology Publication Office

【 摘 要 】

Abstract. The major forces of food and predation shape fitness-enhancing decisions of birds at all stages of their life cycles. During the breeding season, birds can minimize nest loss due to predation by selecting sites with a lower probability of predation. To understand the environmental and social aspects and consequences of breedingsite selection in prairie birds, we explored variation in nest-survival patterns of the Lark Bunting (Calamospiza melanocorys) in the shortgrass prairie region of North America. Over four breeding seasons, we documented the survival of 405 nests, conducted 60 surveys to estimate bird densities, and measured several vegetative features to describe habitat structure in 24 randomly selected study plots. Nest survival varied with the buntings' density as described by a quadratic polynomial, increasing with density below 1.5 birds ha-1 and decreasing with density between 1.5 and 3 birds ha-1, suggesting that an optimal range of densities favors reproductive success of the Lark ...

【 授权许可】

CC BY