Starling populations engage in fascinating seasonal migrations. While the European Starling, a widely distributed species, is well-known for its migratory habits, the extent of travel can vary significantly. This depends on the specific species and their geographic location.
Understanding Starling Migration Patterns
Starling migration is often characterized as a “partial migration,” meaning that not every individual or population undertakes long-distance journeys. Some starlings may only move short distances, while others travel across continents. The seasonal timing of these movements is generally predictable, with southward migrations occurring around late summer and early autumn (August-October). The return northward migration to breeding grounds usually takes place in late winter and early spring (February-March).
In autumn and winter, starlings form immense flocks called murmurations. These aerial displays involve thousands of birds swirling and diving in coordinated patterns before settling into communal roosts. Murmurations provide safety in numbers against predators like peregrine falcons. Communal roosting also helps birds conserve body heat during colder nights and allows for the exchange of information about feeding grounds.
Why Starlings Migrate
The primary drivers behind starling migration are environmental and biological pressures, mainly the availability of food and suitable temperatures. As colder weather arrives in northern regions, natural food sources like insects and certain fruits become scarce. Starlings, being omnivorous, rely heavily on invertebrates during breeding seasons, and their diminishing supply compels them to seek areas with more abundant sustenance.
Migration allows starlings to escape harsh winter temperatures. By moving to milder climates, they can avoid the physiological stress of extreme cold and conserve energy. The return journey to northern breeding grounds in spring is motivated by the favorable conditions for raising young, including longer daylight hours and renewed availability of insects for their chicks.
Where Starlings Migrate
European Starlings (Sturnus vulgaris), the most common species globally, undertake extensive migrations from their northern breeding territories. Populations breeding in Northern Europe, including Scandinavia and Russia, typically migrate southwest. Their wintering grounds can stretch across Central Europe, the United Kingdom, the Mediterranean, Iberia, North Africa, and even the Middle East. For instance, many starlings from colder parts of mainland Europe cross to the UK to spend the winter, significantly augmenting resident populations.
In North America, where European Starlings were introduced, northern populations also exhibit migratory behavior. Starlings from Canada and the northern United States generally move southward for the winter, although they rarely leave the continent. Their movements often follow geographical features such as river valleys or coastal plains. While specific routes can vary, the overall pattern involves moving from colder breeding areas to warmer wintering regions where resources remain more accessible.
Resident Starling Populations
Not all starlings migrate; some populations remain in the same general area year-round. This sedentary behavior is more common in regions with milder climates where food sources are consistently available throughout the winter. For example, many starlings in the UK are resident birds that breed and winter there without migrating.
Urban environments often provide reliable year-round food sources and shelter, allowing some starling populations to be largely non-migratory. Populations located in the southern parts of their species’ range, closer to the equator, also tend to be less migratory or entirely sedentary. While migration is a prominent feature of starling behavior, especially for those in northern latitudes, it is not a universal characteristic for every starling across all species and locations.