Yes, starlings eat baby birds, a documented behavior, though it is not a primary food source. The European Starling, introduced to North America in 1890, is now one of the most abundant birds in the United States and is considered an invasive species. Understanding this aggressive behavior requires looking at the starling’s flexible diet and its fierce competition for nesting sites.
The Starling’s Omnivorous Diet and Opportunistic Feeding
European Starlings are true omnivores, meaning they consume a wide variety of plant and animal material. Their typical diet consists primarily of invertebrates like earthworms, beetles, and caterpillars. They also readily consume fruits, seeds, grains, and human food scraps from urban environments. This dietary flexibility is a major factor in their widespread success and high population numbers.
The consumption of nestlings is considered an opportunistic extension of their invertebrate-heavy diet. During the breeding season, a baby bird, being soft-bodied and full of nutrients, represents a readily available, high-protein meal. This tendency highlights the starling’s general willingness to exploit any accessible food source, including small vertebrates, to meet their nutritional needs.
Predation, Infanticide, and Nest Competition
The act of a starling attacking or consuming a baby bird is often driven by territorial motives. European Starlings are aggressive cavity-nesters, meaning they must find a pre-existing hole in a tree or structure for their nest. This puts them in direct competition with native North American birds that rely on the same limited resource, such as Tree Swallows and Eastern Bluebirds.
When a starling targets a nestling or egg, it is frequently a form of infanticide or nest usurpation. The starling actively seeks to eliminate the young of a competitor to make the cavity available for its own use. Observations of starlings killing young have been linked to the intense competition for these limited nest sites. This aggressive strategy of eliminating competition for territory is a key element of the starling’s invasive nature.
Broader Ecological Effects of European Starlings
The starling’s aggressive nesting behavior and high population density have broader implications for the ecosystem in North America. Their ability to aggressively displace native cavity-nesting species, such as sapsuckers, from desirable tree holes and nest boxes is a recognized problem. The competitive pressure they exert is undeniable.
Beyond their direct impact on bird nesting, starlings cause significant economic damage, particularly in agriculture. Large flocks consume or damage vast amounts of fruit and grain crops, leading to estimated losses in the millions of dollars annually. Starlings are also known to transmit diseases to livestock, contaminating feed at concentrated animal feeding operations. Their success as an invasive species is tied to their adaptable nature and dominance over resources.