Type: journal article

Article abstract: Abstract. We studiedn est-destroyinbge havior in CactusW rens (Campylorhynchusb runneicapillus) using experimental nests containing Japanese Quail (Coturnix japonica) eggs. Because wrens did not consume the egg contents, the behavior is not predation. Wrens attacked nests only within their own territories but often in vegetation not used as nesting substrate. Hence, the behavior probably does not represent attempts at cuckoldry or mate displacement, or competition for nest sites. Nest destruction may represent intraspecific or interspecificc ompetition for (1) food or (2) predator-freen estings pace.E vidences upporting these nonexclusiveh ypothesesa re that food limits reproductives uccessin this population of wrens, and nest predation was density dependent in this population (natural nests surrounded by experimental nests showed higher predation rates than controls). Major predators included snakes, especially whipsnakes (Masticophis spp.), which are able to access Cactus Wren nests despite cholla (Opuntia spp.) spines.