Their diet consists mostly of grains, but will also include pollen and nectar, especially from the saguaro cactus, which is a vital source of water.

The advent of agriculture in North America greatly expanded its range by providing a reliable food source.

[4] English naturalist George Edwards included an illustration and a description of the white-winged dove in his A Natural History of Uncommon Birds, which was published in 1743.

[5] The dove was also briefly described by Irish physician Patrick Browne in 1756 in his The Civil and Natural History of Jamaica.

[6] When in 1758, Swedish naturalist Carl Linnaeus updated his Systema Naturae for the tenth edition, he placed the white-winged dove with all the other pigeons in the genus Columba.

Linnaeus included a brief description, coined the binomial name Columba asiatica, and cited the earlier authors.

Adults have a ring of blue, featherless skin around each eye and a long, dark mark on the lower face.

Males do have a more iridescent purple color to the crown, neck, and nape, as well as a more distinctive ear spot, though the differences are slight.

Males are usually heavier on average, but differences in daily weight due to feeding make this an inaccurate field tool.

David Sibley describes the call as a hhhHEPEP pou poooo, likening it to the English phrase "who cooks for you".

[4] Additionally, individuals of both sexes will use a muted trumpeting errUah call to announce and contest presence on popular preening branches and bird feeders.

Nonvocal sounds include a wing whistle at take-off, which is similar to that of the mourning dove, albeit quieter.

[4] They are found increasingly farther north, now being visitors to most of the United States, and small parts of southern Canada.

[12] In recent years with increasing urbanization and backyard feeding, it has expanded throughout Texas, into Oklahoma, Louisiana, and coastal Mississippi.

[19] Before the advent of widespread agriculture, they may not have been widely present in what is now the United States, as evidenced by a lack of fossil remains and absence from the journals of early European explorers.

The historical range of the dove closely mirrors that of the saguaro cactus, on which it relies heavily for nectar and fruit where it is found.

A 2015 study showed that by tracking the amount of various isotopes, researchers could accurately identify a white-winged dove's migration origin.

The white-winged dove builds a flimsy stick nest in a tree of any kind, and lays two cream-colored to white, unmarked eggs.

One recorded instance includes a nest built atop a light pole in Corpus Christi, TX.

Western white-winged doves (Z. a. mearnsii) migrate into the Sonoran Desert to breed during the hottest time of the year because they feed on pollen and nectar, and later on the fruits and seeds of the saguaro.

Observations in Texas revealed that some birds were shaking seeds from a Chinese tallow tree for the benefit of those on the ground.

Doves may represent a vector to spread the invasive Chinese tallow tree, by defecating undigested seeds.

[26] Agricultural fields, especially cereal grains, are a major source of forage, but they provide less protein content, which limits productivity.

This is made even more critical because white-winged doves do not supplement their diet with insects while raising young, unlike many other grain-eating birds.

[25] White-winged doves are subjected to the usual arid-land predators, including foxes, bobcats, snakes, and coyotes.

The decline is likely due to loss of large nesting colonies in the 1960s and 1970s from habitat destruction, shifts in agricultural trends, and over-hunting.

Though it is the second-most shot-hunted bird in the United States, it remains poorly studied, especially in California and Florida, as well as in Mexico.

[29] Climate change is expected to expand their range to the north, but will also threaten populations with increased drought and fire, which destroy habitat, and spring heatwaves, which can kill young in the nest.

The main causes were brush clearing to make way for agricultural or urban development (leading to habitat loss), extreme weather such as droughts and hurricanes, and over-hunting.

Despite this, the white-winged dove has proved adaptable to human disturbance, and is regarded as a species of least concern by the International Union for Conservation of Nature.