Can hummingbirds survive in Europe?

Hummingbirds are found naturally only in the Americas, but some species have been introduced to Europe in recent years. Their ability to survive and establish populations in the European climate is an interesting question. In this article, we’ll examine the key factors that determine whether hummingbirds can survive in Europe.

Introduction to Hummingbirds

Hummingbirds are small, fast-flying birds that can hover in midair by rapidly flapping their wings 12-80 times per second. There are over 330 described species, all found naturally in the Americas from Alaska to Chile.

Some key facts about hummingbirds:

• They are the smallest birds, ranging from 2-8 inches long and 2-20 grams in weight.
• They have the highest metabolism of all animals – their hearts beat up to 1,260 times per minute.
• They can fly forwards, backwards, upside down, and hover in place.
• They live 3-12 years on average.
• They eat nectar, tree sap, small insects and spiders.
• Their long, specially adapted tongues allow them to drink nectar.

Hummingbirds fill an important ecological niche in the Americas as pollinators. Their ability to hover allows them to access tubular flowers that other birds and insects cannot.

Introduced Hummingbird Species in Europe

Hummingbirds are not native to Europe, Africa or Asia. However, a few species have been introduced to Europe in recent decades, either through zoo escapes or intentional releases:

• Rufous Hummingbird – mostly in England
• Black-chinned Hummingbird – Spain and England
• Anna’s Hummingbird – England
• Calliope Hummingbird – England
• Allen’s Hummingbird – Spain

These hummingbirds were introduced in small numbers, likely less than 100 birds total for each species. Only the Rufous Hummingbird has been seen regularly returning and potentially breeding in Europe.

Could Hummingbirds Survive in the Wild in Europe?

For an introduced tropical species like hummingbirds to survive and establish breeding populations in Europe, they need to be able to:

• Withstand the cooler temperatures
• Find enough food year-round
• Build nests and breed successfully
• Compete with native birds
• Deal with native predators

Let’s look at each of these factors:

Withstanding Cooler Temperatures

Hummingbirds have high metabolisms adapted to tropical climates. They are prone to starvation in cold weather when food is scarce. Most hummingbird species enter a state of torpor at night to conserve energy.

Europe has a more temperate climate. The average winter lows are often at or below freezing, which could be deadly to a tiny hummingbird. However, some tough species like the Rufous Hummingbird may be able to survive periods of cold weather by entering torpor.

Finding Food

Hummingbirds eat nectar, tree sap, and small insects. They require frequent feeding – up to every 10-15 minutes at times. This means an abundant supply of flowers and insects year-round.

Europe has many flowering native plants, which could provide nectar during the spring-fall seasons. Gardens also provide exotic flowers. Tree sap, such as from birch or maple trees, could also help hummingbirds survive the winter.

A key factor is the availability of insects and spiders as a protein source. Hummingbirds consume hundreds of small bugs daily. The drop in insect populations over the winter could lead to malnutrition.

Building Nests and Breeding

Hummingbirds build small, compact nests out of plant fibers, feathers, hairs, and spider webs. The female lays 1-3 tiny eggs. Incubation lasts 14-23 days, and chicks leave the nest after 18-35 days.

Building a sturdy nest and successfully breeding in Europe’s climate would be challenging. The Rufous Hummingbird’s nests may occasionally survive in England. But raising chicks would require a constant food supply through summer.

Dealing with Competition from Native Birds

Europe has many small songbirds that occupy ecological niches similar to hummingbirds, such as tits, goldcrests, and warblers. These birds would likely compete for food resources and nesting sites.

Hummingbirds can be aggressive and have been observed chasing off European bees and songbirds from feeders. But defending territories against flocks of tits or migrant warblers would be difficult over the long term.

Surviving Predators

Predators of hummingbirds include larger birds, snakes, cats, squirrels, and other mammals. Hummingbirds have evolved with predators in the Americas. But new threats like the European sparrowhawk or domestic cats could endanger them.

The hummingbird’s small size, camouflage, and aerial agility help against predators. But a single crash into a window or cat attack could wipe out a fragile introduced population.

Evidence of Hummingbirds Overwintering in Europe

There are a handful of reports of individual Rufous and Calliope hummingbirds surviving European winters, primarily in England. Examples include:

• A Rufous Hummingbird overwintered in England in 2001-2002, being spotted from November to March.
• Another Rufous Hummingbird overwintered in an English garden in 2006-2007 despite freezing temperatures.
• A Calliope Hummingbird was reported in England over six winters from 2008-2013, apparently surviving on tree sap.

These examples suggest that hardy individuals, perhaps with ideal habitat and supplemental feeding, have the potential to overwinter in Europe’s milder regions. But luck and a constant food supply would be key.

Attempts to Establish Breeding Populations

There have not been any dedicated efforts to establish breeding hummingbird populations in Europe so far. This would be extremely difficult to achieve successfully.

A pair of hummingbirds would somehow need to survive over multiple winters, build a nest, hatch eggs, feed the chicks adequately all summer, and repeat the process annually. This would require:

• Selecting a suitable hardy species like the Rufous Hummingbird
• Locating in southern England, Spain, or Portugal with milder climates
• Providing non-stop supplemental feeding and habitat enrichment
• Rigorously monitoring and protecting nests from threats

Even with intense support, the odds are stacked against hummingbirds establishing breeding populations Europe. There simply may not be enough insects and flowers over winter for sustained survival and reproduction.

Potential Impact of Climate Change

Climate change could potentially make Europe’s climate more hospitable to tropical species like hummingbirds over time. Predicted impacts include:

• Higher average temperatures, especially in winter
• Longer growing seasons with earlier springs and later falls
• Expanded ranges of southerly plants and insects

These changes could provide more food for hummingbirds and reduce the risk of freezing in winter. However, migration patterns of insects may be disrupted. More research is needed into how climate change could impact the overall ecosystem’s ability to support hummingbirds.

Diseases like avian malaria carried by warmer-climate mosquitoes also pose a new threat. The costs and benefits of climate change are difficult to predict precisely.

Projected Impacts of 2°C Warming in Europe:

Overall, warming could make survival marginally easier for hummingbirds in Europe. But successful breeding would still face substantial hurdles due to ecosystem differences.

Conclusion

In summary, a few tough hummingbird species like the Rufous may be able to occasionally overwinter and survive short-term in Europe’s milder regions. But successfully breeding and establishing long-term populations appears highly unlikely at this point.

The differences between tropical and temperate ecosystems present major obstacles. Climate change may shift the baseline to be slightly more favorable, but ecosystem disruptions could also negatively impact hummingbirds.

Occasional wintering hummingbirds in Europe should be celebrated as rare beautiful vagrants. But hopes of them thriving permanently in areas outside their native ranges are unfortunately slim. Protecting tropical habitat so these amazing birds continue flourishing in their evolutionary homes remains key. Careful ecosystem management is needed so delicate species like hummingbirds aren’t pushed past their limits of adaptability.