The European starling (Sturnus vulgaris) is one of the most numerous songbirds in North America today. However, it is not native to the continent. So how did this small, stocky songbird end up colonizing most of North America in just over a century? Here is the story of how the starling journeyed across the Atlantic and became one of the most prolific invasive species on the continent.
When did starlings first arrive in America?
Starlings were first introduced to North America in the 1890s. In 1890, a New York pharmaceutical manufacturer named Eugene Schieffelin embarked on a mission to introduce all the birds mentioned in the works of Shakespeare to North America. Schieffelin was the chairman of the American Acclimatization Society, a group dedicated to introducing European flora and fauna into North America. He released 100 starlings in New York’s Central Park in 1890 and another 40 in 1891. These birds are believed to be the founders of the North American starling population.
Why were starlings introduced to North America?
Schieffelin’s motive for releasing starlings in New York was purely sentimental and literary. An admirer of Shakespeare, he wanted to bring to life all the birds that were mentioned in the bard’s works. The starling had a brief but memorable cameo in Shakespeare’s Henry IV, Part 1. Other members of the American Acclimatization Society also aimed to introduce familiar Old World species into the New World, such as house sparrows and common nightingales. Little did they realize that these introductions could have major ecological consequences.
How did starlings spread across North America?
From that modest beginning of around 140 birds, starlings multiplied and spread rapidly across North America. Here are some key events in the starling’s expansion across the continent:
- 1903 – Starlings observed in Chicago, having traveled from New York along railroad and telegraph lines.
- 1915 – Starlings observed in Colorado and had reached California by 1942.
- 1928 – Starlings first recorded in Texas after migrating up the Mississippi Flyway.
- 1931 – Estimated starling population in North America reaches 1 million.
- 1937 – Starlings observed across Alberta, Canada after moving north along the Rocky Mountains.
- 1942 – Starlings first recorded in Florida after spreading along the Atlantic Coast.
- 1946 – Starling population in North America estimated at over 50 million.
The starling proved extremely adept at colonizing North America. Its ability to thrive in cities, suburbs, farms, and a variety of ecosystems enabled it to spread rapidly. Its migratory tendencies and ability to fly long distances allowed it to expand its range over just a few decades.
Why were starlings able to colonize North America so successfully?
Several key traits allowed the European starling to colonize North America with such speed and success:
- Adaptable diet – Starlings are omnivorous and opportunistic foragers. They eat a diverse mix of insects, fruits, seeds, human scraps, and more. This flexible diet allows them to thrive in many habitats.
- Nesting habits – Starlings nest in cavities in trees, cliffs, building crevices, nest boxes, and other sites. They readily took to nesting in human-made sites across North America.
- Sociality – Starlings feed and roost in enormous flocks, especially in winter. There is safety in numbers from predators.
- Aggressive tendencies – Their aggressive behavior serves them well in competing with native cavity-nesting birds for nest sites.
- Cold tolerance – Having evolved in cold northern Europe, starlings were well equipped to handle the winter climates of much of North America.
This combination of dietary flexibility, nesting adaptability, sociality, aggression, and cold hardiness allowed the starling to thrive from Mexico to Alaska and coast to coast in North America.
What was the impact of starlings arriving in North America?
The influx of millions of starlings in just a few decades had major ramifications across North America, including:
- Displacement of native cavity-nesting birds such as bluebirds and woodpeckers by taking over nest sites.
- Consumption of crops such as fruit, grains, and seeds, leading to economic losses for agriculture.
- Potential spread of diseases that can affect livestock and other animals.
- Collisions with aircraft and damage to aircraft from nesting in hangars and other facilities.
- Large roosts in urban areas creating noise, mess, and sanitation issues.
However, starlings also have some benefits, such as consuming insect pests and providing an abundant food source for birds of prey. Overall though, the starling is regarded as one of North America’s costliest and most problematic invasive species.
What can be done to control starling populations?
Several techniques have been implemented in an effort to reduce starling populations and their impacts since they were introduced:
- Nest boxes for native cavity nesters to provide alternative nesting options.
- Disrupting or removing starling nests and discouraging roosts in problem areas.
- Toxic perches to poison starlings at sites such as feedlots.
- Use of recordings of starling distress calls to repel them from orchards and airports.
- Removing food and water sources at roost sites to encourage dispersal.
- Applying repellent gels to ledges and surfaces to prevent roosting.
However, starling numbers remain high across most of North America. Their intelligent, adaptive, and aggressive nature makes them difficult to disperse or control. Lethal control is controversial, and current methods only seem to curtail populations at local scales.
Benefits of starlings
While starlings are regarded as pests, they do provide some ecological services. Here are some of the benefits of starlings:
- Consuming insect pests in crops and gardens
- Dispersing seeds of plants
- Providing abundant prey for raptors such as peregrine falcons
- Pollinating some species of plants
- Removing ticks from grazing animals such as deer
Problematic behaviors of starlings
Here are some of the problematic behaviors and impacts of starlings that cause them to be considered pests:
- Taking over nest cavities, evicting native birds
- Roosting and nesting in man-made structures, causing damage
- Fouling areas under roosts and nests with droppings
- Consuming crops and orchards, causing economic losses
- Colliding with aircraft and creating hazard
- Potential to spread disease to livestock in feedlots
- Forming dense and noisy roosts in urban areas
These behaviors can cause problems for humans, infrastructure, livestock, native wildlife and ecosystems. However, research continues into finding more balanced approaches to management.
Conclusion
The introduction of the starling to North America is a fascinating story of an invasive species proliferating across a continent. Motivated by literary sentimentality, a few bird lovers intentionally released just over 100 European starlings into New York’s Central Park in the 1890s. Possessing key traits like adaptability, aggressiveness, and sociality, the starling proved immensely successful at colonizing diverse ecosystems across North America. From an initial 140 birds, the starling population grew to over 50 million in just 50 years. While they provide some benefits like consuming insect pests, starlings have had major detrimental impacts displacing native cavity-nesting birds, causing agricultural damage, creating hazards at airports, and forming problematic urban roosts. Ongoing research and management effort aim at curbing starling populations in locations where they pose threats, though their numbers remain high across most of their introduced range. The starling serves as an important case study of how quickly and successfully an invasive species can colonize a new environment when introduced.