Hypothermia of Broad-Tailed Hummingbirds during Incubation in Nature with Ecological Correlations.

The first continuous recordings of natural hypothermia, and the only evidences of hypothermia during incubation, were obtained from temperature sensors embedded in synthetic hummingbird eggs placed in the nests. Resorting to this energy-conserving process was infrequent and could be correlated with reduced opportunity for energy intake.