Does nest size constrain clutch size in tropical birds?
Objectives: The study of reproductive strategies is a central topic in the development of life history theory. Passerine birds show a wide range of reproductive strategies, which makes them a useful group to test hypotheses about life histories. Latitudinal variation in life history strategies along slow tropical-fast north temperate gradient has been well described, yet, it largely unexplained pattern. Small clutch size and low nest attentiveness are typical traits of slow-tropical strategies, and they are also unexplained. I focus on testing explanatory hypotheses for the latitudinal variation in those two traits. I specifically tested the hypotheses (1) that high nest predation rate in the tropics favors smaller nest sizes, which constrains clutch size, and (2) that food limitation constrains nest attentiveness in tropical birds. Progress and Status: To test predictions of the first hypothesis I compared predation rates, nest sizes (controlling for body mass), and clutch sizes among
