In July 2010, Janice Kuek posted her video of an adult pigeon feeding two juveniles that needed identification. Haniman Boniran responded, identifying the bird as Pink-necked Green Pigeon (Treron vernans) – a female feeding two fledglings.
The breast of the adult has a dark pattern that makes the identification questionable. According to Haniman, “The pattern is likely water or some kind of fruit juice that had trickled down the throat while she was regurgitating the crop contents to the chicks. Another explanation would be she soaked her throat feathers in water and let the chicks drink from there. The access water then trickle down the throat causing a ‘streak’ patterning of the throat feather.”
As the video was taken in Yishun Avenue 6 (Northern), Singapore on 23rd June 2010 at about 6.30 pm, Haniman’s identification and explanation are acceptable.
The video shows how pigeons and doves feed their chicks and fledglings. The chicks and fledglings peck the adult’s bill to stimulate it to open its bill. Once opened, the chicks take turns forcing their bills into the mouth to receive crop milk. Crop milk or pigeon milk is a high protein substance secreted from the crop. Such a feeding strategy allows the adults to remain in and around the nest with the chicks almost 24 hours a day, thus protecting the chicks from possible predation. In the case of fledglings they receive regurgitated food instead of crop milk – as pointed out by Haniman in his comment below.