Swifts and Hummingbirds: Apodiformes

Swifts are sociable and live in large groups of birds called colonies. Tree swifts are usually found alone or in pairs. They may, however, form a group of ten to twelve individuals. Both birds, swifts and tree swifts, are noisy birds and may create quite a bit of noise when congregating.

Hummingbirds are solitary, pairing up only to breed. Male hummingbirds are territorial and chase other birds away from the area where they feed. When food is scare, swifts and hummingbirds may hibernate.

Swifts and hummingbirds are active during the day. Tree swifts are crepuscular (kri-PUS-kyuh-lur), meaning that they become active at twilight or just before sunrise.

Apodiformes use various materials for their nests. The birds "glue" their nests together with saliva, a watery solution in their mouths, thereby hardening and holding the nest. Swifts make nests out of twigs, feathers, and other materials that they catch as it floats through the air. Tree swifts use feathers and bark from trees for their nests. Hummingbirds weave spider webs into their nests.

Collocalia swiftlets in Asia use only saliva to make their nests. People eat these nests in bird's nest soup.

Swifts and tree swifts are monogamous (muh-NAH-guh-mus), meaning that they mate with only one partner. Hummingbirds are polygamous (puh-LIH-guh-mus) and do not mate with the same partner, but instead have a number of different partners. After mating, the male hummingbird leaves and the female lays two eggs.

The tree swift lays one egg, while the swift lays a clutch of one to six eggs. Males from both families help care for the young.

Swifts spend so much time in the air that they are usually safe from mammal predators. The birds fly rapidly, but sometimes are caught by hawks. In addition, brown tree snakes eat swifts on some islands.