Starlings are a widespread bird species known for their glossy, iridescent plumage and their ability to form large, synchronized flocks. Their distinctive appearance and communal behaviors often draw attention, leading to questions about their reproductive lives and whether they form lasting pair bonds. This article explores the mating habits of starlings.
Understanding Starling Pair Bonds
Starlings are generally considered socially monogamous for a single breeding season, rather than forming lifelong pair bonds. A male and female will typically bond, construct a nest, and raise their young together for one reproductive cycle. After the breeding season concludes, these pair bonds often dissolve, and individuals usually seek new mates in subsequent years.
Even within their seasonal social monogamy, extra-pair copulations are common. This involves individuals mating with partners outside their established pair bond. Genetic paternity tests reveal that not all young in a nest are necessarily fathered by the social male, even when a pair cooperates in raising offspring. This flexible approach allows starlings to adapt their reproductive strategies each year.
Courtship and Nesting Behaviors
The courtship rituals of male starlings involve a series of displays designed to attract a female. Males often perch near a potential nest site, singing and puffing out their chest feathers to showcase their vigor. They may also carry leaves or other materials into and out of a chosen cavity to demonstrate its suitability. Females typically select a mate based on the male’s song quality, the intensity of his displays, and the appeal of the nest site he has chosen or begun to prepare.
Starlings prefer to build nests in cavities, such as natural tree hollows, rock crevices, or man-made structures like building eaves and nest boxes. The male often initiates construction by filling the cavity with coarse materials like grasses and twigs. The female then completes the nest, lining it with softer materials such as feathers and fine bark.
Parental Responsibilities and Rearing Young
Once eggs are laid, both male and female starlings typically share incubation duties. The female generally spends more time incubating, especially at night. The incubation period usually lasts between 11 and 13 days.
After hatching, both parents actively feed the nestlings, making frequent trips to provide soft-bodied insects and other invertebrates. The nestling period typically ranges from 19 to 23 days until they fledge. Even after fledging, young starlings rely on their parents for food and guidance for one to three more weeks as they learn to forage independently.
Factors Influencing Mating Strategies
Starling mating strategies are influenced by environmental and social factors. Resource availability, particularly suitable nest sites and abundant food, can affect breeding success and may lead to polygyny, where one male mates with multiple females. With ample resources, a male might defend multiple nest sites to attract more than one mate.
The age and experience of individual birds also influence breeding outcomes. Older, more experienced starlings may exhibit higher breeding success. While starlings do not mate for life, some pairs may return to the same breeding ground in subsequent years. If a previous breeding attempt was unsuccessful, pairs might separate and seek new mates, a behavior sometimes called “divorce.” This adaptability contributes to the species’ overall success.