The European Starling (Sturnus vulgaris) is a common bird across North America, known for its iridescent plumage and gregarious nature. Introduced to the continent in the late 19th century, the starling has successfully adapted to human-altered landscapes, often nesting in or near structures like buildings and homes. These birds are obligate cavity nesters, meaning they must find an existing hole or enclosure, rather than building an open nest in a tree.
Setting the Stage for Nesting
The starling’s breeding season typically begins in early spring, often in mid-April, though southern birds may start laying eggs in mid-March. The male starling selects a suitable cavity, which can be an old woodpecker hole, a vent in a building, or a space under a roof, and begins the nest construction. The male uses initial, often haphazard material—including grass, pine needles, and trash—to fill the cavity before building a finer cup for the eggs.
A clutch of typically four to five pale bluish or greenish-white eggs is laid, with the female depositing one egg per day. Both parents share incubation, a period lasting approximately 12 days. Once hatched, the young are altricial—helpless, blind, and covered in sparse down—and require constant feeding from both parents.
The Fledging Period
The time nestlings spend inside the nest after hatching is the longest phase of the nesting cycle. This period, which culminates in the birds leaving the cavity, generally lasts about 21 days. This duration allows the nestlings to grow from a helpless state to being fully feathered and capable of flight. The duration depends on factors such as food availability and the size of the brood.
As the young birds mature inside the dark cavity, they begin practicing the movements needed for flight and survival. In the days leading up to their departure, nestlings engage in vigorous wing-flapping exercises. They often crowd the entrance of the nest hole, strengthening their flight muscles and preparing for their first journey outside. Parents may also encourage departure by reducing feeding frequency just before the young exit the cavity.
Life Immediately After Leaving
When fledglings leave the nest, their departure is typically a sudden and coordinated event. Although they can fly reasonably well, these juveniles are not yet independent and still rely heavily on their parents for food and protection. For the first few days, fledglings stay close to the nest site, often hiding in dense vegetation like shrubs or low tree branches, which shields them from predators while they acclimate.
Adult starlings continue to feed and care for their young for an extended period after they leave the cavity. This post-fledging care usually lasts between 10 and 12 days, during which the parents slowly reduce the proportion of food they provide. This gradual reduction encourages the fledglings to begin foraging for themselves, marking a transitional phase until they achieve full independence. Once independent, the juvenile birds begin to join small family groups that eventually aggregate into larger flocks.
Multiple Broods and Seasonal Movements
European Starlings often raise multiple broods within a single breeding season, particularly in North America. Southern starlings commonly raise two broods, and sometimes three, if the climate is favorable. In contrast, starlings in northern latitudes, where the breeding season is shorter, are more likely to raise only a single brood. The adults may renew courtship and egg-laying activities for a second brood almost immediately after the first set of young has fledged.
Once the nesting season concludes, typically by late summer, starlings abandon their solitary breeding territories and begin to congregate. They form increasingly large flocks composed of juveniles and adults, a behavior that is particularly noticeable as winter approaches. While some northern populations undertake short-distance migrations to avoid harsh weather, many starlings in North America are considered resident or only partial migrants. These large aggregations often result in the spectacular aerial displays known as murmurations, defining the starling’s presence outside of the nesting season.