Redpolls are small finches in the genus Acanthis that are found throughout the northern parts of Europe, Asia, and North America. There are three species of redpolls that occur in the UK: the Common Redpoll (Acanthis flammea), the Lesser Redpoll (Acanthis cabaret), and the Arctic Redpoll (Acanthis hornemanni). The Common and Lesser Redpolls breed in the UK and are resident species, while the Arctic Redpoll is a scarce winter visitor.
What are redpolls?
Redpolls are lively little birds, about the size of a goldfinch. They have streaky brown plumage, a red forehead, and a black bib. Their most distinctive feature is the crimson patch on their heads, which gives them their name. During the winter, they develop pale feather edgings that give them a frosted appearance.
Redpolls are social birds that travel in noisy flocks outside of the breeding season. They have a twittering, metallic call. Their diet consists mainly of small seeds from plants like birch, alder and willow. During winter, they often flock to bird feeders stocked with nyjer seed.
Where are they found in the UK?
Redpolls breed across Scotland, Wales, northern England and Northern Ireland. They are also widespread passage migrants and winter visitors. In winter, they can turn up almost anywhere in the UK, visiting gardens, farmland, moorland, woodland and coastal areas.
Common Redpolls and Lesser Redpolls breed mostly in coniferous forests, scrubby areas with small birch and willow, and young plantations. The Arctic Redpoll breeds in the far north of Scotland in high altitude moorland and mountain heath.
Outside of the breeding season, redpolls form large nomadic flocks that wander widely in search of food. Harsh winters sometimes bring an influx of redpolls from continental Europe to the east coast of the UK.
Are redpolls common in the UK?
The Common Redpoll is the most abundant and widespread species of redpoll in the UK. An estimated 210,000 pairs breed here, though numbers fluctuate from year to year. According to the Royal Society for the Protection of Birds (RSPB), redpolls are green-listed as a species of least concern.
The Lesser Redpoll has a more restricted range concentrated in central Scotland and northern England. There are approximately 36,000 breeding pairs in the UK. Numbers have declined slightly in recent decades, leading to its classification as an amber-listed species of conservation concern.
The Arctic Redpoll is a scarce winter visitor from Iceland and Scandinavia. Only about a dozen are recorded in the UK annually, mostly in Scotland. Being a subarctic species, it is vulnerable to the effects of climate change. The Arctic Redpoll is red-listed as a rare breeding bird in the UK.
So in summary, the Common Redpoll is abundant and widespread, the Lesser Redpoll is locally common in parts of northern Britain, while the Arctic Redpoll is a rare winter visitor. The redpoll family as a whole is doing reasonably well in the UK.
Population trends
Species | Population Estimate | Trend |
---|---|---|
Common Redpoll | 210,000 breeding pairs | Stable/Fluctuating |
Lesser Redpoll | 36,000 breeding pairs | Moderate decline |
Arctic Redpoll | Scarce winter visitor | Rare vagrant |
As the table shows, Common Redpoll numbers are stable overall in the UK, though they can vary a lot between years. Lesser Redpoll numbers have undergone a moderate decline since the 1970s, likely due to habitat loss. The Arctic Redpoll barely occurs annually in the UK.
When and where are redpolls most likely to be seen in the UK?
During the breeding season (April to July), redpolls are widespread but inconspicuous across northern and central parts of the UK. The best places to find them are conifer forests, moorland with scrubby birch, and young forestry plantations.
In winter, nomadic flocks wander more widely across the UK in search of food. Birds from Scandinavia and Russia boost winter numbers. Redpolls frequent gardens with nyjer feeders from October to March.
Some key sites and times include:
Autumn
– Garden nyjer feeders – from October
– Coastal migrant hotspots like Spurn Point and Flamborough Head in October/November
Winter
– Garden nyjer feeders from October to March
– Woodland birch trees – feed on catkins from November to March
– Farmland hedgerows with alder and birch – form large feeding flocks
Spring
– Coastal migration hotspots in April/May
– Moorland and forests in upland areas – return to breeding sites from March
During irruption years when redpolls move south en masse, they can turn up almost anywhere in the UK in winter. But garden nyjer feeders are invariably the best place to see them.
What is an irruption? How often do they occur in redpolls?
An irruption is an irregular migration event triggered by a lack of food supply in the normal wintering areas. When seed crops fail in the conifer forests of Scandinavia and Russia, redpolls are forced south in huge numbers.
Redpolls are prone to irruptions and influxes because they specialize in eating small seeds, so they are highly impacted by crop failures. This erratic movement leads to dramatic variations in winter redpoll numbers in the UK.
Major irruptions occur every few years with huge arrivals of redpolls – most recently in the winters of 2008/9, 2012/13 and 2015/16. More minor influxes are regular annual events.
The timing and scale of irruptions are unpredictable. But winter surveys have shown they result in at least a tenfold increase in redpoll numbers in the UK. Coastal watchpoints have recorded days with thousands of incoming redpolls.
Irruptions provide birdwatchers with great opportunities to see redpolls in areas they would normally avoid in winter. Even major cities like London host flocks when irruptions occur.
Why do redpoll numbers fluctuate so much?
Redpolls have an irruptive migration strategy due to their reliance on small seeds, especially birch. Seeds are an unreliable food source prone to boom and bust cycles. When crops fail, redpolls must move or starve.
Key factors behind redpoll fluctuations:
Seed crop yields
Years of bumper birch seed production allow redpolls to thrive and breed in high numbers. But seeds soon get depleted, forcing dispersal. Poor seed years cause irruptions and even breeding failures.
Winter weather
Snow cover limits access to seeds. Bitter cold forces redpolls to seek milder climes. Winters are more severe in continental Europe, driving migrant redpolls to the UK.
Gradual climate change
Makes weather increasingly erratic, leading to more frequent crop failures. Reductions in Arctic sea ice may also disrupt weather patterns.
Habitat loss
Formerly remote birch forests are being felled or fragmented, depriving redpolls of food and nest sites during the breeding season.
Competition
Redpolls must compete with other finches like siskins and twite for limited seeds in winter. More competition means fewer redpolls can be supported.
How can redpolls be encouraged in gardens?
Redpolls are regular winter visitors to gardens across most of the UK. Follow these tips to attract them:
Provide nyjer feeders
Nyjer seed is a redpoll favorite. Use wire mesh feeders to minimize waste. Hang feeders near trees or shrubs for shelter.
Supplement with other seeds
Offer black sunflower seeds, millet and suet pellets. Scatter some on the ground for shy birds.
Add a water source
Running water or a bath attracts redpolls to drink and bathe. Position near feeders.
Leave birch trees untouched
Redpolls forage in birch trees for catkins and seeds. Don’t trim or fell birch in winter.
Allow weeds like chickweed
Weeds offer natural food redpolls can forage. Leave some scrubby corners untouched.
Avoid using pesticides
Insecticides reduce food supplies so avoid overuse. Herbicides remove natural foraging areas.
Make feeders redpoll-friendly
Use small-gaped feeders they can access and perch on. Clean regularly to prevent disease.
Be patient
It may take a while for redpolls to find new feeders. They often arrive in mid-winter.
Conclusion
In conclusion, redpolls are lively finches that breed across the northern UK and migrate south for winter. The Common Redpoll is abundant, the Lesser Redpoll is declining moderately, and the Arctic Redpoll is rarely seen. Numbers fluctuate dramatically between years due to irruptions caused by food shortages. Redpolls frequent garden nyjer feeders in winter and providing these is the best way to attract them. Following the tips outlined can help encourage redpolls and provide valuable support for these charming winter visitors.