Polioptila caerulea (Blue Gray Gnatcatcher) is a species of birds in the family gnatcatchers. They are found in The Nearctic and The Neotropics. Individuals are known to live for 4.2 years.
Definition: The largest scale biogeographic division of the earth's surface based on the historic and evolutionary distribution patterns of plants and animals.
Definition: Single birth offspring quantity. The proportion or number of offspring produced from a single pregnancy (mammals) or ovulation (fish) or nesting (birds).
Definition: A landform that extends above the surrounding terrain in a limited area. A mountain is generally steeper than a hill, but there is no universally accepted standard definition for the height of a mountain or a hill although a mountain usually has an identifiable summit and a local relief of more than 300m.
Definition: The duration of the development from fertilized, deposited or implanted egg to hatching/birth. Corresponds to egg incubation duration in oviparous animals and to gestation period duration in viviparous animals.
