Mourning dove

The mourning dove (Zenaida macroura) is a member of the dove family, Columbidae. The bird is also known as the American mourning dove, the rain dove, the chueybird, colloquially as the turtle dove, and it was once known as the Carolina pigeon and Carolina turtledove. It is one of the most abundant and widespread North American birds and a popular gamebird, with more than 20 million birds (up to 70 million in some years) shot annually in the U.S., both for sport and meat. Its ability to sustain its population under such pressure is due to its prolific breeding; in warm areas, one pair may raise up to six broods of two young each in a single year. The wings make an unusual whistling sound upon take-off and landing, a form of sonation. The bird is a strong flier, capable of speeds up to 88 km/h (55 mph).

Mourning doves are light gray and brown and generally muted in color. Males and females are similar in appearance. The species is generally monogamous, with two squabs (young) per brood. Both parents incubate and care for the young. Mourning doves eat almost exclusively seeds, but the young are fed crop milk by their parents.

The mourning dove is a medium-sized, slender dove approximately 31 cm (12 in) in length. Mourning doves weigh 112–170 g (4.0–6.0 oz), usually closer to 128 g (4.5 oz). The mourning dove has a wingspan of 37–45 cm. The elliptical wings are broad, and the head is rounded. Its tail is long and tapered ("macroura" comes from the Greek words for "large" and "tail"). Mourning doves have perching feet, with three toes forward and one reversed. The legs are short and reddish colored. The beak is short and dark, usually a brown-black hue.

The plumage is generally light gray-brown above and lighter and pinkish below. The wings have black spotting, and the outer tail feathers are white, contrasting with the black inners. Below the eye is a distinctive crescent-shaped area of dark feathers. The eyes are dark, with light blue skin surrounding them. The adult male has bright purple-pink patches on the neck sides, with light pink coloring reaching the breast. Adult males possess a distinctly bluish-grey colored crown, which females lack. Females are similar in appearance but have more brown coloring overall and are slightly smaller than males. The iridescent feather patches on the neck above the shoulders are nearly absent but can be quite vivid on males. Juvenile birds have a scaly appearance and are generally darker.

Feather colors are generally believed to be relatively static, changing only by small amounts over periods of months. However, a 2011 study argued that since feathers have neither nerves or blood vessels, color changes must be caused by external stimuli. Researchers analyzed how feathers of iridescent mourning doves responded to stimulus changes of adding and evaporating water. As a result, it was discovered that iridescent feather color changed hue, became more chromatic, and increased overall reflectance by almost 50%. Transmission electron microscopy and thin-film models revealed that color is produced by thin-film interference from a single layer of keratin around the edge of feather barbules, under which lies a layer of air and melanosomes. Once the environmental conditions were changed, the most striking morphological difference was a twisting of colored barbules that exposed more of their surface area for reflection, which explains the observed increase in brightness. Overall, the researchers suggest that some plumage colors may be more changeable than previously thought possible.

All five subspecies of the mourning dove look similar and are not easily distinguishable. The nominate subspecies possesses shorter wings and are darker and more buff-colored than the "average" mourning dove. Z. m. carolinensis has longer wings and toes, a shorter beak, and is darker in color. The western subspecies has longer wings, a longer beak, and shorter toes, and is more muted and lighter in color. The Panama mourning dove has shorter wings and legs, a longer beak, and is grayer in color. The Clarion Island subspecies possesses larger feet, a larger beak, and is darker brown in color.

This species' call is a distinctive, plaintive cooOOoo-wooo-woo-woooo, uttered by males to attract females, and it may be mistaken for the call of an owl at first. Close up, a grating or throat-rattling sound may be heard preceding the first coo. Other sounds include a nested call (cooOOoo) by paired males to attract their female mates to the nest sites, a greeting call (a soft ork) by males upon rejoining their mates, and an alarm call (a short roo-oo) by either a male or female when threatened. In flight, the wings make a fluttery whistling sound that is hard to hear. The wing whistle is much louder and more noticeable upon take-off and landing. The mourning dove can also 'clap' its wings together when taking off, in a similar manner to the rock dove.