Article Abstract:
Data on 13 aspects of parental defense behavior exhibited by Tree Swallows (Tachycineta bicolor) is presented. Males exhibited greater aggressiveness in defending behavior, and ferrets were defended against more strongly than were snakes. Many potential determinants of variance in parental defense behavior are discussed, although it is admitted that most of the variance is unexplained. Variation in parental behavior could be a strategy to avoid localization of nests, or it could be due to low selection pressures or low frequency of predator-prey encounters.
User Contributions:
Comment about this article or add new information about this topic:
Article Abstract:
Observation of tree swallows found them foraging near the surface of a several experimentally designed ponds in times of increment spring weather. Earlier introductions of nutrients and the removal of fish from the ponds, which expanded the populations of insects emerging from the ponds, were found to affect their use of ponds for foraging. Tree swallos may need to take advantage of local concentrations of food to be able to go back to the breeding grounds before aerial insects become sufficiently available.
User Contributions:
Comment about this article or add new information about this topic:
Article Abstract:
Tree Swallows are aerial insectivores and are valuable subjects in the study of foraging behavior and ecology. A study undertook to test whether parents decreased foraging selectivity as the chicks grew older. Foraging behavior and diet were studied at two sites over five seasons. The study showed little variability due to fluctuations in environmental conditions during the nestling period. Consistent patterns in prey choice and site usage were discovered.
User Contributions:
Comment about this article or add new information about this topic: