Type: journal article

Article abstract: Abstract.-The breeding ecology of the Cactus Wren was studied during three years. Significant differences in clutch size, breeding success, and the timing of clutch initiation were observed between years. The differences are related to annual differences in the abundance and emergence of the major food of nestlings. Long-term temperature patterns were analyzed for predictability and show that, on the average, Cactus Wrens initiated clutches during a period when high temperatures predicted favorable temperatures for the period when they would be feeding nestlings. Several factors that appear to affect clutch initiation in the Cactus Wren are discussed.