The bee humingbird lays the smallest eggs of any bird on Earth. According to the Guiness Book of World Records, the bee humingbird lays eggs that are 0.275 inches long and weigh only 0.0009 ounces. More »

Female birds turn the end of the oviduct inside-out to lay an egg and allow the egg to emerge. A bird currently laying an egg can be identified by a rhythmic moving and opening and closing of the bill, though time varies... More » Science Biology Zoology

All three species of bluebirds – eastern, mountain and western – lay blue eggs. The blue eggs may have white streaks that resemble scratches, which may stem from urine or fecal stains, or when the female turns the eggs. More »

The eastern bluebird lays the smallest blue egg – approximately 4/5 of an inch – of all the songbirds that lay blue eggs. The eggs of western and mountain bluebirds are slightly larger than the eastern bluebirds, but sma... More » Pets & Animals Birds

A person knows when a bird egg is going to hatch because the incubation period is up; this is the period of time it takes for eggs to develop while being kept at a steady, warm temperature. Incubation periods differ betw... More »

A mute swan lays a clutch of six eggs on average, but 11 is not uncommon. The lightly colored eggs vary from off-white to pale green. One egg is released daily; 35 days later the eggs hatch, and gray or white cygnets eme... More » Pets & Animals Birds

The number of eggs that a female owl lays depends on the species of the owl. Barn owls lay five to six eggs, while screech owls lay three to five. More »