BIOL 1902 Lecture Notes - Lecture 24: Tree Swallow, Redwing, Cuckold

• School: Carleton University
• Department: Biology
• Course: BIOL 1902
• Professor: Michael Runtz

Document Summary

Black bears give birth to altricial young (totally helpless) It allows the bears to mate and give birth at optimal times: fishers mate in the end of march and give birth 11 months later. But the gestation is only about 1 month: bats mate in the summer and giver birth the next spring. Their gestation is only about 40 days. This occurs because the females store the sperm. Bumblebees, ants and paper wasps (and other social insects) They store the sperm and then group care is used. In more than 90% of birds biparental care is used. Female birds invest a lot both internally and externally. Ducks, grouse, sandpipers have large eggs (40% is yolk) Songbirds have small eggs (25% yolk: they have elaborate nests and much care is but into it. Ducks, grouse, and sandpipers use little effort in nest building.