A small dove of Mexico, northern Central America, and the southwestern United States, the Inca Dove has extended its range both north and south over the past 100 years. A conspicuous urban resident, it commonly occurs at bird feeders and on lawns and other short grass habitats. This species was originally confined to arid habitats, and its affinity to human dwellings was attributed to the easy availability of water. It continues to spread into wetter areas, retaining its attachment to towns and cities for no obvious reason.
In some of its range this dove breeds year-round, laying two eggs in an unsubstantial twig nest. The same nest may be used repeatedly, becoming reinforced as feces accumulate from continued use. A two syllable, monotonous territorial call, "No Hope," is repeated over and over for long periods, even in the heat of the day.
Inca Doves are sensitive to cold and use several means to survive it. Nocturnal hypothermia (5°12°C below normal) occurs during cold periods with simultaneous food or water shortages. Pyramid roosting is used during the day and occasionally at night to conserve heat. Five to 12 birds in 2 or 3 rows roost on top of one another in sheltered, sunny locations. Northward range expansion continues, but should eventually be limited by this cold sensitivity.
There is little work focused directly on this species. Although most aspects of its life history remain little studied, best known include physiology, especially water economy, salt balance and nocturnal hypothermia (MacMillen and Trost Macmillen and Trost 1966 , Macmillen and Trost 1967b , Macmillen and Trost 1967a ; Robertson and Schnapf 1987 ), but also factors controlling iris color ( Chiasson and Ferris 1968 , Chiasson et al. 1968 ). Quay's ( Quay 1982 ) work is one of the few field studies to focus on this species at the local population level -- seasonal changes in foraging and other aspects of life history. Increasingly well documented is the range expansion of this dove in North America, although the factors responsible for this expansion remain poorly understood.