the timing of their breeding varies by year. The peak breeding times for these desert doves occur from May–June to July–August. Breeding in urban areas also occurs in two peaks, but may be somewhat offset in timing compared to the desert birds. Eggs are relatively small compared to body weight, as white-winged doves invest more energy in feeding altricial young instead of laying large eggs that would enable precocial young. Males attend to the nest for the majority of the day, except for foraging breaks during the midmorning and late afternoon while the female watches the nest. At night, females watch the nest, and the male roosts nearby. Juvenile feathers begin to replace the natal down by seven days old. The pre-juvenile molt is complete around 30 days old. By early September, most of the adult birds have already begun the migration south. The young leave soon after. Feeding White-winged doves are granivorous, feeding on a variety of seeds, grains, and fruits. 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. They also visit feeders, eating the food dropped on the ground. Unlike mourning doves, they eat corn and wheat right off the head. This gregarious species can be an agricultural pest, descending on grain crops in large flocks. White-winged doves have been found to practice collaborative feeding. 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. Agricultural fields, especially cereal grains, are a major source of forage, but they provide less protein content, which limits productivity. Having access to significant amounts of native seed is important to ensure that nestlings fledge and are healthy. 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. Survival White-winged doves are subjected to the usual arid-land predators, including foxes, bobcats, snakes, and coyotes. Aerial predators include owls and hawks. Domestic cats and dogs also take doves. The oldest recorded wild individual lived to 21 years and 9 months, though the typical lifespan is closer to 10 or 15 years. In