by Robert McFarlane, Houston Bird Survey Coordinator
The Mourning Dove is one of the most widespread of North American species, found in all 49 continental states. It is equally at home in urban and rural habitats (see map). Another native is the Common Ground-Dove, at the northern edge of its range. This species is considered rare from March to October and uncommon during fall and winter. It appears to shun human habitations everywhere and our surveys have reported it only once, at Beltway 8 south of Interstate 10.
The Inca Dove has been expanding its range from south Texas and reached Houston in 1956. Less abundant than the Mourning Dove, it seems to prefer urban and suburban habitats (see map). More recently, the White-winged Dove has also expanded its range. They were deliberately released in Galveston in the 1950s and expanded northward to Houston in the late 1980s. They appear to have become established in a number of cities while remaining scarce in the intervening rural area. In Houston they are most abundant in the inner city and western suburbs.
Three introduced non-native doves are also found in Houston. The Rock Pigeon
can be very abundant in urban and suburban areas but less so in the surrounding
rural landscape. A key element appears to be nesting sites and the concrete
ledges associated with highway overpasses provide satisfactory nest locations.
Rock Pigeons are abundant and conspicuous along Loop 610 and Beltway 8. The Eurasian
Collared-Dove was introduced into the Bahamas, spread to Florida, and has been expanding north and westward, reaching our area by the late 1980s. Not yet abundant or widespread, it does well in urban and suburban environments (see map). The
African Collared-Dove (formerly known as the Ringed Turtle-Dove) has not become well established, with three locations inside of Loop 610 and another from Pearland just beyond Beltway 8. 
Thus, with the exception of the Common Ground-Dove, doves as a group seem well adapted to coexisting, and even preferring, human habitations. Their reproductive strategy may be the key to success. Doves build simple nests that can be constructed quickly. They lay only two small eggs (relative to their body size) that are incubated constantly, by males during the day and females at night, so they hatch quickly. Hatchlings are fed crop 'milk', rich in protein and fat, for the first few days so they grow quickly. Doves nest multiple times during a breeding season, the season is long, and young doves may mate and reproduce when only three months old. Crop milk is produced by special cells in the crop, an organ normally used to store seeds. The cells slough off and are regurgitated by both male and female doves to feed their young. Thus doves, which eat only seeds, rich in energy rich but low in protein, feed their young hatchlings 'animal' cells, rich in protein, that were created from seeds eaten by the adults days to weeks previously.
