The Mourning Dove (Zenaida macroura) is one of the most common and widespread birds in North America, often nesting in close proximity to human activity. Their frequent presence makes their breeding cycle a common subject of curiosity. Understanding the precise timeline of their nesting behavior, especially the duration of the egg stage, offers a clear view into their successful reproductive strategy. This species is known for its ability to raise multiple broods within a single breeding season, supported by a rapid and highly coordinated nesting process.
The Standard Incubation Period
The average incubation period for Mourning Doves is approximately 14 days, though it can range from 13 to 16 days. Parents initiate continuous incubation after the second, and usually final, egg of the clutch is laid, ensuring both offspring hatch close together.
Maintaining a stable temperature, often around 100°F (37.7°C), is necessary for proper embryo development. Minor fluctuations due to external conditions can slightly influence the total time required before hatching. The relatively short incubation period allows the pair to quickly move on to the next stage of the nesting cycle.
Shared Parental Duties During Incubation
The successful hatching of the eggs is a result of a coordinated effort between the male and female doves, who divide the incubation duties on a strict schedule. This cooperative approach ensures the eggs are protected and kept warm almost continuously. The male dove typically assumes responsibility for the nest during the day, taking over in the morning and sitting on the eggs through the afternoon.
The female partner takes the longer overnight shift, which maintains warmth during the cooler hours. This division of labor allows both parents time to forage for food and water without leaving the eggs vulnerable for long periods. The pair rarely leaves the nest unattended, which helps defend against temperature shifts and potential predators.
Life After Hatching: From Squab to Fledgling
Once the incubation period concludes, the eggs hatch into tiny, helpless young called squabs. These hatchlings are altricial, meaning they are born with their eyes closed and rely completely on their parents for warmth and nourishment. For the first few days, the squabs are fed crop milk, or pigeon milk, which is produced by both the male and female parents.
Crop milk is a unique, high-nutrient secretion containing high levels of protein and fat. It is a holocrine secretion, where cells from the lining of the parents’ crop slough off and are regurgitated to feed the young. This energy-dense substance allows the squabs to grow rapidly during their first week of life.
After three to four days, parents gradually introduce seeds, softened in the crop, into the squabs’ diet. The squabs are typically ready to fledge, or leave the nest, between 11 and 15 days after hatching. Even after leaving the nest, the fledgling doves remain dependent on the male parent for feeding for up to two more weeks as they practice flying and learn to forage independently.