Egg embryo is adequately developed it hatches, i.e. breaks out of the egg's shell. Some embryos have a temporary egg tooth they use to crack, pip, or break the eggshell or covering. The largest recorded egg is from a whale shark, and was in size. Whale shark eggs typically hatch within the mother. At and up to , the ostrich egg is the largest egg of any living bird, though the extinct elephant bird and some dinosaurs laid larger eggs. The bee hummingbird produces the smallest known bird egg, which weighs half of a gram (around 0.02 oz). Some eggs laid
Say's phoebe fashion. They attach their nests under bridges, canyon walls, wells and abandoned mine shafts. The nest is made by the female and is cup-shaped. It is made of grass, forbs, moss and plant fibers lined with hair and other fine materials. She lays three to seven, but usually four or five, white, mostly unmarked, eggs. Some have red spots. The eggs are roughly . Say's phoebe The Say's phoebe ("Sayornis saya") is a passerine bird in the tyrant flycatcher family. A common bird in the western United States. It prefers dry, desolate areas. This bird was named for Thomas Say,