Allofeeding
Allofeeding is a type of food sharing behaviour observed in cooperatively breeding species of birds.
And the far more practical barn owl, of course, peer allofeeds merely to reduce sibling rivalry/competition during meal times.
[4] During the incubation period, a male songbird will feed its mate through beak-to-beak interaction, while she sits on the eggs.
[4] A recent study by Halley et al., 2015, examined allofeeding in twenty-four nests of sagebrush Brewer's sparrows.
[4] This study suggests that allofeeding is an intraspecific signal required to maintain social bonds between mates, in addition to increasing the nutrition levels of females and concealment of the nest.
[6] It is proposed that mate allofeeding in chinstrap penguins was performed to strengthen the bond between the pair.
[6] Courtship allofeeding is hypothesized to strengthen the bond between pairs or increase a female's nutritional level before laying eggs.
[5] A parent feeding a non-biological chick via bill-to-bill interactions is a form of allofeeding.
[9][10] Parental allofeeding occurs in all altricial species of birds to ensure proper growth, development, and to prevent starvation of their offspring.
[9] King penguin chicks form dense groups called crèches during winter for social thermoregulation when food availability is low.
[9][10] The formation of crèches results from the parents interchangeably leaving starving chicks to gather food from the sea.
[9][10] A study by Lecomte et al., 2015 examined the allofeeding behaviour in king penguins, in which they marked the white underbellies of 74 non-breeding adults and 103 breeding pairs with a unique dark colouring called dye-mark code of Nyanzol-D.[9] Lecomte et al. (2015) found 22% of the marked adults feed 65% of the chicks in crèches, revealing that allofeeding behaviour was most common during the breeding season.
[10] From these results, Lecomte et al. (2015) concluded that allofeeding increased the survival rate of chicks in crèches.
[7] For example, the Arabian babblers (T. sqamiceps) are a territorial, desert-inhabiting species of bird that participate in cooperative breeding.
[7] In this species, non-breeders show numerous types of cooperative behaviour, including allofeeding.
[8] Barn owl nest siblings establish a hierarchy for the sharing of food resources via vocal negotiations.
[8] Peer allofeeding observed in 60 nestling pairs revealed that the behaviour occurs by a donor sibling placing the food item on the ground in front of the receiver sibling, which transfers the food item to its bill using its talons.
[8] Intraspecific allofeeding in Sichuan jays (P. internigrans) is performed during the nestling and fledging period by non-breeders.
[5] One to three non-breeders support a nesting breeding pair by feeding the chicks, regurgitating the food from their throat pouches.
[5][12] In 2009, Jing et al. determined that two non-breeders contributed to 44% of feedings in the nest of two Sichuan jays.
[5] Jing et al. (2009) suggest that allofeeding behaviour contributes to increased nest survival.
