Other
Ornithology: Avian Development
A good page devoted to the development process of birds. Discusses the incubating process and the stages of development.
Other
Ornithology: Avian Reproduction
Provides a good discussion of the reproductive behaviors and systems of birds. Contains information on everything from nests to incubation times.
University of Pittsburgh
Univ. Of Pittsburgh/seasonal Decline in Tree Sparrow
A HIGH level science article written about the change in clutch size through a mating season and the possible science base for this phenomena.