Starlings are a widespread, adaptable bird species, known for their iridescent plumage and social behavior. They successfully inhabit diverse environments, including urban parks, suburban gardens, and agricultural fields. Understanding their reproductive patterns offers insight into their life cycle.
Starling Nesting Season
Starlings typically begin nesting in early spring, with the primary breeding season extending through mid-summer. In North America, this period generally spans from mid-April through mid-July. However, timing varies by geographical location; southern regions may start in mid-March, while northern areas might not begin until mid-April or even mid-June.
In the UK, for example, the breeding season usually takes place from March to April, with eggs typically laid around mid-April. This extended nesting window allows for flexibility, particularly for pairs that may attempt multiple broods within a single season.
The Nesting Cycle
The starling nesting cycle begins with site selection, where males often choose a cavity before attracting a mate. These birds are cavity nesters, utilizing natural tree hollows, old woodpecker holes, or man-made structures like nest boxes, building crevices, and even utility boxes. The male initiates nest construction, filling the chosen cavity with materials such as dry grasses, twigs, and leaves.
Once a female accepts the site and the pair forms, she often adds finer lining materials like feathers, moss, and sometimes even human-discarded items like string or cloth. Nest building can take a few days to over a week, depending on the available materials and site. Females typically lay one egg per day until a clutch of 4 to 5 glossy, pale bluish-green eggs is complete, though clutches of up to 7 eggs can occur.
Both parents share incubation duties, which lasts for about 11 to 13 days, with the female often spending more time on the nest. After hatching, the young starlings remain in the nest for approximately 19 to 23 days until they fledge, or take their first flight. Starlings in southern regions frequently raise a second brood, while those in northern areas generally have only one.
Factors Influencing Nesting
Several environmental cues prompt starlings to begin their nesting activities each year. Increasing daylight hours, known as photoperiod, serve as a primary signal for the onset of the breeding season. As days lengthen in spring, this change stimulates hormonal shifts in the birds, preparing them for reproduction.
Rising temperatures also play a significant role, indicating favorable conditions for nesting and the availability of resources. Warmer weather supports the growth of vegetation and the emergence of insects, which are important food sources for both adult starlings and their developing young. The abundance of insects, such as grasshoppers, beetles, and earthworms, influences the birds’ ability to successfully raise broods. These interconnected factors ensure that nesting coincides with optimal conditions for survival and reproduction.