Monogamy | Nesting | Care for Young
Monogamy:
During the mating season, unmated males display for females on perches; displays usually consist of the 3 or 4 note perch-coo (Ecology and Management, 1993). While perch-cooing may also be used after agonistic displays and to incite cooing in fledglings, research has found that cooing significantly decreases after pairing off, indicating that its primary function is to attract a mate (Ecology and Management). In addition to the perch-coo, males may perform the ‘flapping/gliding flight’ where they make a noisy upward flight followed by a spiraling downward onto the same or a nearby perch (Ecology and Management). Like the perch coo, the significant decrease of this behavior after pairing off indicates that it may be to attract a female (Ecology and Management). During this period, females stay in small territories that the males will enter to display in (Goforth et al., 1971). Once the male has approached the female, he performe a ‘bow-coo’, after which the female will either why away, ignore him, or allow copulation (Ecology and Management, 1993).
Mourning doves are monogamous and perform various rituals that aid in strengthening the pair bond. The mating pair will engage in allopreening during the nesting season, which is thought to both encourage pair bonding and remove ectoparasites (Ecology and Management). Males will also ‘bill’ the females, where the female inserts her bill into the open bill of the male similar to how the parents feed fledglings (Ecology and Management). This is thought to be a part of the copulation ceremony and is usually followed by mounting (Ecology and Management).
Copyright Powdermill Avian Research Center
In many avian species, birds will pair off with the intent of monogamy but with high levels of extra-pair copulations and fertilizations, known as EPCs and EPFs. However, most pigeon species are expected to be more strictly monogamous because parents invest about the same amount of time into their eggs and hatchlings, they have a small clutch size, and the young are very altricial (meaning that they need extreme care because they are deaf, blind, and have poor motor coordination) (Patel, 2005). In fact, previous studies had not found any EPCs in multiple pigeon species (Patel). Recently, Patel used DNA fingerprinting to determine the level of EPFs in a colony of captive Mourning doves (2005). Out of 43 chick tested for DNA profiles similar to their paired parents, 30 were the offspring of the mated pair and 4 appeared to be from EPFs (Patel). Two of those four were difficult to determine because of ambiguous DNA banding patterns, but the other two looked to be genuine extra-pair offspring, or EPOs (Patel). Because the population studied was a captive flock, it is possible that females were not choosing males based on paternal investment but rather genetic superiority (more the ‘he-man’ strategy), thus increasing the number of observed EPFs (Patel). With such a low number (2 out of 30), Patel concluded that monogamy is indeed the norm for Mourning doves.
Monogamy may be the norm for many dove species because of the high rate of nest predation. Chicks that had the protection of both mother and father would be much more likely to survive to adulthood in a situation where nest predation is high. With strong selection pressure from predators, male doves that stayed at the nest for longer periods of time significantly increased their fitness and the fitness of their offspring.