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Redpoll

Redpolls are small, sparrow-sized finches in the genus Acanthis of the family Fringillidae, characterized by their compact bodies, short conical bills adapted for seed-eating, and streaked brown plumage with red crowns on breeding males.^[1] Native primarily to the Arctic tundra, boreal forests, and northern woodlands of North America, Europe, and Asia, they exhibit clinal variation in size, color, and bill shape across their range, leading to the recent taxonomic lumping of the former Common Redpoll (Acanthis flammea) and Hoary Redpoll (Acanthis hornemanni)—along with the Eurasian Lesser Redpoll—into a single circumpolar species known simply as the Redpoll (A. flammea).^[2]^[3] The paler, whiter variants (formerly Hoary) typically occur in the high Arctic, while darker, streakier forms (formerly Common) are more widespread in subarctic regions.^[1] These birds are renowned for their energetic, nomadic lifestyle, often traveling in large, boisterous flocks of hundreds or thousands during irruptive winter migrations that can extend as far south as the central United States, northern Europe, or even sporadically to milder latitudes in search of food.^[4] They forage acrobatically on seeds from birch catkins, alder cones, grasses, and thistles, frequently clinging upside down or fluttering at branch tips, and supplement their diet with insects and spiders in summer.^[4] Redpolls possess remarkable adaptations for harsh northern environments, including the ability to tunnel into snow for roosting and store seeds in expandable esophageal pouches for later consumption, enabling survival in temperatures as low as -65°F (-54°C).^[1] Breeding occurs in shrubby tundra or open coniferous woodlands around the Arctic Circle, where females construct cup-shaped nests in low shrubs or rocky crevices, laying 1–7 eggs per clutch and raising 1–2 broods per season.^[4] Males attract mates with trilling songs and buzzy calls, while both parents feed the young a mix of seeds and invertebrates.^[4] With an estimated global population in the hundreds of millions, Redpolls remain common but have shown regional declines possibly linked to habitat changes and climate shifts; they are not currently listed as threatened.^[4] Notable for their intelligence—evidenced by passing the string-pull puzzle test in captivity—these finches also frequent backyard feeders in winter, drawn to nyjer, thistle, or black oil sunflower seeds.^[1]

Taxonomy

Species classification

Redpolls belong to the genus Acanthis within the family Fringillidae and order Passeriformes.^[5] The genus Acanthis was established to separate redpolls from the broader genus Carduelis based on phylogenetic analyses distinguishing their evolutionary lineage among finches.^[6] Historically, redpolls were classified as three distinct species: the Common Redpoll (Acanthis flammea), the Hoary Redpoll (A. hornemanni), and the Lesser Redpoll (A. cabaret).^[7] This separation persisted for much of the 20th century due to observed differences in plumage, size, and habitat preferences. However, genetic studies beginning in the late 2000s and intensifying in the 2010s demonstrated clinal variation across populations rather than discrete boundaries, prompting a taxonomic reevaluation.^[8] By 2024, major authorities including the International Ornithological Congress (IOC) World Bird List (July 2024) and the Clements/eBird checklist (October 2024) had lumped all three into a single species, A. flammea, reflecting their overall genomic homogeneity.^[6]^[9] The key evidence supporting this lumping includes phenotypic continuity in traits like plumage whiteness and bill size, which vary gradually with latitude and environment; genetic analyses of mitochondrial DNA and microsatellite markers revealing minimal differentiation and no clear species-level divides; and documented hybridization in zones of overlap, such as between flammea and hornemanni populations in northern North America.^[8]^[10] A pivotal 2021 whole-genome study further identified a large chromosomal inversion (~55 Mb) as a supergene controlling linked variation in color, morphology, and potentially cold adaptation, explaining much of the observed diversity as ecotypic rather than species-specific.^[11] Despite this consensus, taxonomic debates continue, with some regional authorities retaining the option to treat the Arctic Redpoll (A. hornemanni) as distinct based on traditional morphological criteria.^[12] Emerging research on vocalizations, including analyses of call structure and repertoire, has been cited in discussions of potential future revisions, though it has not yet overturned the current lumping.^[7]

Subspecies

The Common Redpoll (Acanthis flammea) is recognized as comprising five subspecies, distinguished primarily by variations in size, plumage tone, bill morphology, and geographic range. These include the nominate A. f. flammea, A. f. rostrata, A. f. cabaret, A. f. exilipes, and A. f. hornemanni. Differences among them are often subtle, reflecting adaptations to diverse Arctic and boreal environments.^[13]^[7]

Subspecies	Defining Traits	Geographic Associations
A. f. flammea (nominate, Eurasian)	Intermediate size (length 12.5 cm, weight 12-14 g); longer, pointed bill; streaked brown plumage with rosy pink tones in adult males.	Northern Europe and Asia, breeding in boreal forests and tundra; winters southward in irruptions.^[13]^[14]
A. f. rostrata (Greenland)	Largest common form (length 14 cm, weight 16-20 g, ~50% heavier than flammea); thicker bill; darker, browner plumage with heavier streaking.	Greenland, eastern Canada (e.g., Baffin Island), and northeastern North America; winters in southern Canada.^[13]^[14]
A. f. cabaret (Lesser, British Isles)	Smallest subspecies (length 11.5 cm, weight 9-12 g); small, pointed bill; darkest plumage with heavy brown streaking on sides and flanks.	Temperate Europe, including British Isles, northern France to southern Norway, and Alps; resident or short-distance migrant.^[13]^[15]^[5]
A. f. exilipes (Siberian)	Small to intermediate size (length 12.5 cm); shorter, stubbier bill; pale plumage with white rump and light streaking, approaching hoary tones.	Eastern Siberia, Alaska, and northern North American tundra; Holarctic low Arctic breeder, winters southward.^[13]^[14]^[16]
A. f. hornemanni (Arctic/Hoary)	Largest overall (length 14 cm, weight ~20 g); stubbier bill; palest plumage with minimal streaking, frosty white tones, and reduced pink wash.	High Arctic tundra, including Greenland and northernmost Eurasia/North America; rare irruptive winter visitor southward.^[13]^[14]^[5]

Field identification of these subspecies is challenging due to significant overlap in winter ranges across the Holarctic, where mixed flocks commonly occur during irruptions. Subtle traits like size and bill shape often require close comparison or measurements, while plumage variations (e.g., streaking density and paleness) can be influenced by age, wear, and lighting; genetic analysis is sometimes necessary for definitive separation.^[13]^[14] Taxonomic debate persists on whether hornemanni merits full species status, as explored in broader classification discussions.^[7]

Description

Morphology

Redpolls are small passerine birds in the finch family, characterized by a compact body form with a length ranging from 11.5 to 14 cm, an average weight of 14 g (typically 12–16 g, though up to 20 g), and a wingspan of 20–25 cm.^[13]^[17]^[18] Their overall structure includes a small head, a short notched tail, and pointed wings with two white wingbars, facilitating agile flight and foraging maneuvers.^[13] A prominent feature is the conical, pointed yellow bill, specialized for cracking and extracting seeds from cones, catkins, and buds, with black feathering surrounding the base.^[13] The bill exhibits slight variation among subspecies, such as a larger, thicker form in the rostrata subspecies adapted to handling birch seeds in its Arctic breeding range.^[13] Redpolls also have strong legs and feet that enable them to perch securely on slender twigs and catkins, often clinging acrobatically while feeding.^[13] Sexual dimorphism is minimal in structural terms, though males tend to be slightly larger than females, with longer wings (average 78.1 mm versus 77.1 mm) and potentially up to 1 g heavier on average.^[19] For cold tolerance, redpolls possess thick plumage with a dense underlayer that provides insulation, allowing them to increase feather mass by about 31% in winter and survive temperatures as low as –65°F.^[20]^[21] This adaptation, combined with their small body size, supports survival in subarctic environments.

Plumage variation

Redpolls exhibit notable plumage variation influenced by sex, age, season, and subspecies, characterized by a combination of brown, white, red, and black elements that aid in identification. Adult males typically display brownish-gray upperparts streaked with dark brown, a distinctive small red patch on the crown (forehead), a red rump, a black chin forming a prominent "bib," two white wing bars, and a yellow bill surrounded by black feathering. In winter, males feature a pinkish-red wash on the breast and upper flanks, providing a rosy vest-like appearance.^[13]^[17] Adult females are duller overall than males, with similar brownish-gray streaked upperparts and white wing bars, but they show reduced red on the crown and rump, a paler and less distinct black bib, and more extensive dark streaking on the whitish underparts without the pink breast wash.^[13]^[17] Juveniles are browner than adults, lacking significant red pigmentation on the crown or rump, and exhibit heavier streaking across the underparts; they undergo a post-juvenile molt by autumn, transitioning to adult-like plumage.^[22] Seasonal changes in plumage are evident, with brighter red tones on the crown, rump, and breast appearing during the breeding season due to hormonal influences on carotenoid deposition, while winter plumage is more subdued with the characteristic pink wash on males emerging after the pre-basic molt.^[23]^[17] Subspecies variations affect overall tone: the hornemanni form (Hoary Redpoll) features paler, whiter underparts with finer streaking, whereas the cabaret form (Lesser Redpoll) is darker and streakier overall.^[13]^[22] For identification, redpolls are distinguished from similar finches like the Pine Siskin by their red crown patch and lack of yellow edging on the wings and tail; the Pine Siskin, in contrast, shows yellow wing patches and a heavily streaked, darker appearance without red on the head.^[24] Subspecies size differences can subtly influence plumage perception, such as the bulkier appearance enhancing the frosty look in larger Hoary forms, though details are covered in the Subspecies section.^[13]

Distribution and habitat

Geographic range

Redpolls are native breeders across the Holarctic realm, primarily in tundra and taiga habitats spanning from approximately 50°N latitude northward to the Arctic Circle. Their breeding range includes extensive areas of Scandinavia, where they occupy northern forests and open woodlands; Russia, covering vast Siberian taiga; Alaska, with concentrations in coastal and interior boreal zones; Canada, from the Yukon and Northwest Territories to Labrador; and Greenland, particularly along the northwestern and eastern coasts.^[25]^[26] During winter, redpolls typically remain within or near their breeding ranges but undertake irregular irruptive migrations southward in response to seed shortages from poor birch or alder crops, reaching as far as 30°N latitude. These movements bring flocks to the northern United States, such as New England and the Great Lakes region, and central Europe, including parts of Germany and France; in years of abundant food, populations may be largely non-migratory, staying in subarctic areas.^[25]^[27] Introduced populations of the cabaret subspecies of Redpoll (A. f. cabaret; formerly known as the Lesser Redpoll) were established in New Zealand through releases from Europe between 1862 and 1875, with birds now breeding successfully in montane areas of the South Island, such as the Southern Alps, and scattered sites on the North Island. Minor introductions to Australia, primarily to offshore islands like Macquarie Island via spillover from New Zealand, have not resulted in widespread or self-sustaining mainland populations.^[25]^[26] Range dynamics show southward expansion in parts of Europe, but the breeding distribution in the United Kingdom has contracted by about 20% since the 1980s, with new records in lowlands post-2000 reflecting fluctuating trends; North American ranges remain relatively stable but with variable winter extents driven by food availability (as of 2023).^[27]^[7] These shifts are associated with changing environmental conditions, including warmer winters. Following the 2024 taxonomic lumping into a single species, subspecies variation persists, with overlap and intergradation occurring in key zones, such as Alaska where the exilipes subspecies intergrades with the mainland flammea subspecies in coastal and Aleutian regions, and in Greenland where the rostrata subspecies intergrades with the hornemanni subspecies (formerly known as the Hoary Redpoll form) along northwestern fjords. These hybrid zones reflect clinal variation in plumage and bill size adapted to local conditions.

Preferred habitats

Redpolls primarily breed in open boreal forests and at the edges of tundra regions, favoring shrubby areas dominated by dwarf birch (Betula spp.) and alder (Alnus spp.), as well as willow (Salix spp.) thickets in subarctic shrublands at elevations typically ranging from sea level to 2,100 m.^[28] These habitats provide essential dense cover for nesting and access to seeds from catkins and dwarf shrubs, supporting their breeding activities during short northern summers.^[17] Nests are constructed in low shrubs or trees, often 1–3 m above the ground in dense foliage for concealment, with exposed perches nearby used for singing displays.^[4] During winter, redpolls shift to weedy fields, open birch and alder stands, and suburban areas with bird feeders in their southern ranges, where they preferentially select sites offering catkins and seeds for foraging.^[28] These birds exhibit remarkable cold tolerance, enduring temperatures as low as –54°C (–65°F) by roosting in insulating snow tunnels that maintain warmer microclimates beneath the surface.^[29] In introduced populations in New Zealand, redpolls occupy alpine grasslands and areas with exotic willows, adapting to open tussock habitats and mixed conifer-open landscapes while generally avoiding dense coniferous forests.^[30] Their preference for habitats with short growing seasons aligns with boreal and taiga environments, but they face vulnerability from habitat fragmentation caused by logging in these regions, which disrupts shrubby understory and seed availability.^[31]^[32]

Behavior

Redpolls exhibit highly gregarious social structure outside the breeding season, forming flocks that typically consist of 10 to 100 individuals while foraging in open areas or at seed sources, though these can expand to thousands during periods of food abundance or movement.^[4] In contrast, during the breeding period, they shift to loose pairs or small family groups, minimizing larger aggregations to focus on nesting activities.^[33] This flocking behavior enhances foraging efficiency and provides collective vigilance against predators in harsh northern environments.^[34] As partial migrants with irruptive tendencies, northern populations undertake unpredictable southward movements primarily driven by fluctuations in seed availability, such as alder, birch, and conifer crops in the boreal forest.^[35] For instance, the 2023–2024 North American irruption saw widespread southward incursions due to poor birch seed yields in key breeding areas, leading to increased sightings across the northern United States.^[36] These movements do not follow fixed routes but respond dynamically to food scarcity, with some individuals remaining resident where resources suffice.^[37] Migration occurs in flocks via a combination of diurnal and nocturnal flights, often exhibiting restlessness at night, to cover substantial daily distances in search of suitable habitats.^[37] In spring, they return northward to breeding grounds following improving conditions. Daily activities center on active foraging from dawn to dusk, with birds hopping and fluttering in vegetation or on the ground; at night, they roost communally in snow tunnels more than 12 inches long and 4 inches deep or within dense shrubs for thermal protection against extreme cold.^[38] At winter feeding sites like bird feeders, individuals aggressively defend perches and resources through displays and chases, establishing temporary territories within flocks.^[39] Redpolls frequently associate with other species in mixed interspecific flocks, particularly Pine Siskins, during non-breeding periods to exploit shared food patches.^[4] They evade predators through erratic, undulating flight patterns that make pursuit difficult, often accompanied by sharp alarm calls during flocking.^[33]

Vocalizations

Redpolls produce a variety of vocalizations, including songs and calls, that serve essential roles in communication. The song is typically a high-pitched, twittering warble consisting of a series of trills and chatters, often rendered as "chit-chit-zee-zee" or a bubbly twittering combined with rattles, lasting 2–5 seconds or up to 30 seconds in extended versions.^[40]^[41] Males deliver these songs from elevated perches such as treetops or during flight displays to defend territories and attract mates during the breeding season.^[4] The repertoire includes several distinct calls adapted to different contexts. Sharp "tseek," "chit," or "zit-zit" notes function as alarm or flocking signals, often given in series during excitement or flight, while softer "peu," "che," or "swee-ee-et" contact calls maintain cohesion in foraging flocks or during migration.^[40]^[41] Fledglings emit begging calls described as "zree" or plaintive "dsooee" to solicit food from parents.^[41] A dry, harsher rattle serves as a threat or distress signal, particularly in aggressive encounters.^[41] These vocalizations promote flock cohesion during nomadic movements, warn of predators, and facilitate pair bonding, with males incorporating calls into courtship flights.^[4] Variations exist across subspecies, though overall similarity supports their treatment as a single species. The Greenland subspecies (rostrata) exhibits slightly harsher calls compared to nominate flammea, while the former Hoary Redpoll (hornemanni group) is generally less vocal, with nine identified call types—five year-round and four breeding-season specific to males—showing minimal divergence from Common Redpoll acoustics.^[41] Acoustic studies, including analyses from European and Siberian populations, confirm songs in the 4–8 kHz range, but recent genetic and morphological reviews (2024) found insufficient vocal differences to warrant separation of hornemanni, aligning with lumping into Acanthis flammea.^[41]^[42] Recordings of redpoll vocalizations are frequently obtained during winter irruptions at seed feeders, where flocks produce incessant chatter for coordination, and they exhibit minimal mimicry of other finch species compared to more versatile songsters like crossbills.^[40]^[41]

Breeding biology

Redpolls breed during the summer months, with the season typically spanning May to July in Arctic regions, where hatching often shows bimodal peaks due to variable snowmelt and food availability, and starting as early as April in more southern boreal areas; breeding is primarily triggered by increasing day length and abundance of seeds and insects.^[43] Courtship begins upon arrival at breeding grounds, where males display their bright red plumage, perform aerial flight dances in slow circles or arcs, and sing to attract females; pairs are monogamous for the season and form rapidly, often within days.^[4] Nests are open cup-shaped structures built primarily by the female using moss, lichen, twigs, and grasses, lined with feathers, fur, or plant down, and placed in the forks of low shrubs or bushes 1–3 m above ground.^[17]^[4] Clutch sizes range from 3 to 7 eggs, which are pale bluish-green with reddish-brown spots concentrated at the larger end; the female alone incubates the eggs for 10–12 days, during which the male provides food to her.^[17] Both parents participate in feeding the altricial young, which hatch naked and helpless, a diet consisting of regurgitated insects and seeds; nestlings fledge after 12–15 days, remaining dependent on parents for several additional days.^[4]^[44] Redpolls typically raise 1–2 broods per year, with renesting common after failure, potentially producing up to 20 young in successful seasons.^[44] Breeding success varies with environmental conditions, with hatching rates around 72% and fledging success of about 54%, though overall egg-to-fledgling survival can be lower at about 39% in some observed populations.^[45]

Foraging and diet

Redpolls primarily consume small seeds, which form the bulk of their diet throughout the year, including those from birch (Betula spp.), alder (Alnus spp.), willow (Salix spp.), spruce (Picea spp.), pine (Pinus spp.), grasses, sedges, and various wildflowers.^[46] In winter, birch and alder seeds predominate, supplemented by nyjer (thistle) or sunflower seeds at bird feeders when natural sources are limited.^[46] They occasionally eat berries and buds, but these are minor components. During the summer breeding season, the diet shifts to include a higher proportion of animal matter, with spiders and insects comprising a notable portion to meet protein needs, while seeds remain essential.^[46] Adults probe vegetation and ground for these invertebrates, but revert to seed-dominant foraging outside breeding periods. Redpolls employ acrobatic foraging techniques, often clinging upside down or hanging from slender twigs to extract seeds from catkins and cones, and they glean wind-dispersed seeds from the ground in winter.^[46] They forage in flocks, which enhances detection of food patches and allows coordinated movement between trees, though detailed social dynamics occur during migration.^[46] Their conical bill is specialized for husking and wedging small seeds, with subtle morphological variations among subspecies potentially aiding adaptation to local seed types.^[7] Physiological adaptations enable survival on this seed-based diet; an expandable esophageal diverticulum, or "false crop," stores up to 2 grams of seeds—about 15% of body weight—for later processing in sheltered spots.^[47] Their digestive system efficiently handles indigestible husks, allowing consumption of up to 40% of body weight in seeds daily to fuel high metabolism in cold climates.^[21] In winter, food scarcity triggers irruptive migrations southward when seed crops fail, leading redpolls to exploit feeders and alternative sites for sustenance.^[46] This nomadic behavior ensures access to adequate resources during harsh conditions.

Conservation

Status

The redpoll (Acanthis flammea), encompassing what were previously recognized as the common and hoary redpolls, is classified as Least Concern on the IUCN Red List, with the most recent assessment conducted in 2018.^[26] The global population is estimated at 60.5–145 million mature individuals, reflecting its extensive breeding range across the northern Holarctic.^[26] Overall population trends are decreasing, driven primarily by regional declines in North America, where numbers have fallen by approximately 77% over the past 40 years (equivalent to -30.7% per decade).^[26] These trends include cyclic fluctuations associated with irruptive migrations, which can lead to variable winter abundances but do not offset long-term losses. In Europe, populations are fluctuating, with short-term changes ranging from moderate increases in some northern countries (e.g., +2% to +32% in Finland from 2007–2018) to declines in others (e.g., -25% to -40% in Italy).^[48] Breeding population estimates vary regionally: in North America, approximately 5–50 million adults occur in Canada, representing a substantial portion of the continental total.^[49] Europe supports 4.5–9.55 million breeding pairs, concentrated in Russia (2.5–5 million pairs) and Scandinavia.^[48] Comparable or larger numbers are inferred for Asia based on similar boreal and tundra habitats, though precise figures require further validation. In New Zealand, where the species was introduced in the 19th century, the population is stable and widespread, particularly in higher-elevation grasslands, though no quantitative estimate is available.^[50] Monitoring efforts rely on citizen science platforms like eBird for year-round observations and the Christmas Bird Count for assessing winter distributions and irruption patterns, providing data on abundance trends across North America.^[51] Genetic studies, including analyses of mitochondrial DNA and microsatellites, reveal minimal differentiation among populations, confirming the species' unity and absence of significant inbreeding depression despite historical taxonomic splits.^[52] The species remains secure in its core Arctic breeding areas, where vast habitats support stable numbers, while peripheral populations show more variability, such as declines in the UK for the A. f. cabaret subspecies.^[53]

Threats

Redpolls face several environmental and anthropogenic threats that could impact their populations, particularly in breeding and wintering grounds. Climate change poses a significant risk by altering seed production cycles in key food sources such as birch and alder catkins, which are essential for their diet during breeding seasons in the boreal forest and tundra. Warmer temperatures may lead to earlier or irregular seed availability, disrupting foraging and breeding success, while habitat shifts in the taiga, including potential birch decline due to drought and pests exacerbated by warming, threaten core breeding areas. Models project possible range contractions at southern limits by mid-century under moderate warming scenarios (e.g., 2°C increase), as suitable cold-adapted habitats diminish, though northern expansions may offset some losses for resilient populations.^[17]^[54] Habitat loss from human activities further endangers redpoll breeding sites. Intensive logging in boreal forests reduces the availability of shrubby, open woodlands preferred for nesting, fragmenting habitats and exposing nests to increased predation and weather extremes. In wintering areas, agricultural expansion and conversion of weedy fields to croplands limit foraging opportunities on grass seeds and weeds. These changes are particularly acute in North American and Eurasian boreal regions, where industrial forestry has cleared vast tracts, potentially lowering reproductive rates in affected populations.^[54]^[55] Additional threats include heightened predation and indirect effects from chemical use. At backyard bird feeders, where redpolls commonly congregate during irruptive winters, domestic cats pose a major risk, killing billions of small birds annually in North America alone, with finches like redpolls particularly vulnerable due to their ground-foraging behavior. Raptors such as sharp-shinned hawks may also exploit concentrated flocks at feeders, increasing mortality rates. Pesticides, especially neonicotinoids, indirectly affect redpolls by reducing insect populations that serve as critical protein sources for nestlings, potentially impairing chick growth and survival despite their primarily seed-based adult diet. In New Zealand, where common redpolls were introduced in the 19th century and are now widespread, they may compete with native seed-eating birds for resources in modified habitats, though direct impacts remain understudied.^[56]^[50] Human interactions with redpolls are generally minor and mixed. As frequent winter visitors to feeders offering nyjer or sunflower seeds, they benefit from supplemental food during harsh conditions, enhancing survival in irruptive years. However, the aviculture trade involves redpolls only rarely, with negligible population-level effects due to their abundance and protected status in most regions. Mitigation efforts focus on preserving habitats and reducing risks. Protected areas in Arctic and boreal regions, such as national parks in Canada and Alaska, safeguard breeding grounds from logging and development, supporting stable populations. Promoting feeder hygiene—regular cleaning to prevent bacterial spread like salmonella—helps curb disease outbreaks at congregation sites. As of 2025, conservation initiatives emphasize monitoring irruptive migrations through citizen science programs to track environmental influences on movements and inform adaptive strategies.^[54]^[57]^[58]

References

[1]
Redpoll Overview, All About Birds, Cornell Lab of Ornithology
Basic Description. As energetic as their electric zapping call notes would suggest, Redpolls are active foragers that travel in busy flocks.
[2]
Updates and Corrections—October 2024 – Clements Checklist
Summary: (3→1 species) The Lesser Redpoll, Hoary Redpoll, and Common Redpoll are now united in a single species, the circumpolar Redpoll. Details: v2024 ...
[3]
Lumping Redpolls and Splitting Seabirds: This Year's Updates to ...
Aug 7, 2024 · Audubon Magazine Bird Names & Taxonomy ... Common Redpoll and Hoary Redpoll are combined into one species, Redpoll (Acanthis flammea).
[4]
Redpoll Life History, All About Birds, Cornell Lab of Ornithology
Redpolls are energetic little birds that forage in flocks, gleaning, fluttering, or hanging upside down in the farthest tips of tree branches.
[5]
Redpoll - Acanthis flammea - Birds of the World
Oct 22, 2024 · Until recently, the Redpoll was widely treated as three species: Common Redpoll (Acanthis flammea), Lesser Redpoll (A. cabaret), and Hoary ...Missing: classification 2021
[6]
Species Updates - IOC World Bird List
Treat all of the redpoll taxa as conspecific with the English name "Redpoll" (IOC 14.2) following Chesser et al. (2024) based on genomic homogeneity ...
[7]
Systematics - Redpoll - Acanthis flammea - Birds of the World
Oct 22, 2024 · The Redpoll was split into three species, with the Lesser Redpoll (A. cabaret) and Hoary Redpoll (A. hornemanni) treated as separate species.
[8]
Low support for separate species within the redpoll complex ...
Aug 7, 2025 · We found no structure among redpoll individuals in mtDNA haplotypes or microsatellite allele frequencies, and only marginal differences between ...
[9]
2024 Taxonomy Update—COMPLETE - eBird
Oct 22, 2024 · Three Redpolls Become One In addition to the species splits above, one notable “lump” this year is of Common, Hoary, and Lesser Redpoll into ...Missing: studies | Show results with:studies
[10]
[PDF] Differentially expressed genes match bill morphology and plumage ...
The redpoll finch complex currently includes three species, Acanthis flammea, Acanthis hornemanni and Acan- this cabaret, which are recognized by most ...
[11]
A supergene underlies linked variation in color and morphology in a ...
Nov 25, 2021 · We demonstrate that variation in redpoll phenotype is broadly controlled by a ~55-Mb chromosomal inversion.
[12]
Acanthis flammea (Redpoll) - Avibase
The common redpoll or mealy redpoll is a species of bird in the finch family. It breeds somewhat further south than the Arctic redpoll, also in habitats with ...
[13]
Redpoll Identification, All About Birds, Cornell Lab of Ornithology
Within the "Common" form, "Lesser" individuals are the smallest, while "rostrata/islandica" birds are 50% heavier than "flammea" individuals. Birds in the " ...
[14]
Subspecies of Common and Hoary Redpolls - Jean Iron
Jan 5, 2015 · The two subspecies of Common Redpoll are the smaller southern nominate A. f. flammea and the larger northern A. f. rostrata.
[15]
Lesser Redpoll Bird Facts | Carduelis Cabaret - RSPB
Length 11.5cm ; Habitats Woodland, Urban and Suburban, Farmland, Heathland, Wetland ; UK breeding birds 220,000 pairs ; Weight 9-12g ; Wingspan 20-22.5cm ...
[16]
Acanthis flammea exilipes (Redpoll (exilipes)) - Avibase
Geographic range: Acanthis flammea exilipes: tundra of northern Eurasia and northern North America.Missing: characteristics | Show results with:characteristics
[17]
Redpoll | Audubon Field Guide
Length: 4.5–5.5 in (12–14 cm); wingspan: 8–10 in (20–25 cm); weight: 0.3–0.7 oz (9–20 g). The Redpoll is small, with a red forehead, a black chin, ...Range & Identification · Behavior · ConservationMissing: lesser | Show results with:lesser
[18]
Common redpoll (Acanthis flammea) longevity, ageing, and life history
Weight at hatching: 1.3 g ; Adult weight: 14.2 g ; Typical body temperature: Not yet available ; Basal metabolic rate: 0.2888 W ; Body mass: 14.0 g ...Missing: average dimorphism
[19]
Sexing of redpolls Acanthis flammea in Iceland from morphometrics
Male Redpolls had significantly longer wings than females (male = 78.1 mm, female = 77.1 mm, t = 2.88, P < 0.01) and presented a paler plumage than the females ...Missing: weight | Show results with:weight
[20]
Redpoll Overview, All About Birds, Cornell Lab of Ornithology
### Summary of Common Redpoll Physical Morphology and Adaptations
[21]
The Clever Ways Common Redpolls Survive Harsh Northern Winters
Nov 28, 2016 · Redpolls feed on birch and alder seeds that are available throughout the winter, no matter how deep the snow. They do it in the cleverest of ways through a ...
[22]
Field Identification - Redpoll - Acanthis flammea - Birds of the World
Oct 22, 2024 · Much variation between the various subspecies (or species), but generally streaked brownish or grayish above, with pale greater covert tips ...
[23]
Carotenoid ornamentation of adult male Common Redpolls predicts ...
Oct 10, 2005 · Furthermore, testosterone levels are unlikely to be elevated during winter months, and testosterone does not appear to be associated with ...
[24]
Redpoll Similar Species to, All About Birds, Cornell Lab of Ornithology
Similar SpeciesPine Siskin Pine Siskin is darker overall and more heavily streaked than Redpoll. Pine Siskin has yellow edging on the wings and tail and lack ...
[25]
Distribution - Redpoll - Acanthis flammea - Birds of the World
In Palearctic, breeds in eastern (Scoresbysund region) and northwestern Greenland. Winter Range. A. f. exilipes: Winters within breeding range (except some of ...
[26]
Redpoll Acanthis Flammea Species Factsheet | BirdLife DataZone
In the north of this species's range it breeds in lowland treeless tundra and dry heath with dwarf birch (Betula) and stunted shrubby osiers (Salix), as well as ...Missing: characteristics | Show results with:characteristics
[27]
Redpoll - BTO
Distribution. Lesser Redpoll breeds widely throughout Ireland, Wales, most of Scotland and northern England, and more patchily further south. In winter they ...
[28]
Habitat - Redpoll - Acanthis flammea - Birds of the World
Oct 22, 2024 · Common Redpoll In north of range, breeds in lowland treeless tundra and dry heath with dwarf birch (Betula) and stunted shrubby osiers (Salix); ...
[29]
Common Redpoll - Wildlife in Winter
Feb 15, 2022 · Redpolls increase the mass of insulating feathers before winter by more than 30%, much like adding a heavier blanket to your bed in winter.Missing: downy underlayer
[30]
[PDF] SHORT NOTE Sodium-rich clay soil geophagy by common redpoll ...
In New. Zealand, redpolls appear to favour habitats with a mixture of young conifers and open habitat (Clout. & Gaze 1984). Geophagy is the deliberate ...<|separator|>
[31]
Redpoll - Montana Field Guide
Common Redpolls are busy, acrobatic little finches, spending much of their time flitting about, feeding, and calling with their incessant calls.Missing: subspecies | Show results with:subspecies
[32]
Are Boreal Birds Resilient to Forest Fragmentation? An ... - jstor
Abstract. We studied the effect of habitat fragmentation on the richness, diversity, turnover, and abundance of breeding bird communities in old, ...
[33]
Behavior - Redpoll - Acanthis flammea - Birds of the World
Oct 22, 2024 · Sexual Behavior. Common Redpoll. Mating System and Sex Ratio. In general, apparently monogamous, but see below. Sex ratio presumably 1: ...
[34]
Flocking – Maine Birds - Web – A Colby
Dec 29, 2011 · Ornithological research has indicated two major advantages of this social behavior. The first is an increase in foraging success, that is an ...Missing: patterns scientific
[35]
Irruptive Migration of Common Redpolls - Project FeederWatch
Irruptive migration means redpoll winter movements are inconsistent, not following a pattern. They seek different wintering ranges each year, not moving ...Missing: social behavior flocking
[36]
See where finches might appear this winter! - Flocking Around
Nov 14, 2023 · Common Redpoll Irruption Map. Common Redpolls are coming. They are coming. Preferred seed: Nyjer™ seed (#ad). Hoary Redpoll Irruption Map.Missing: birch | Show results with:birch
[37]
Movements and Migration - Redpoll - Acanthis flammea
Oct 22, 2024 · Common Redpoll. Some individuals remain within breeding range in winter where and when food is available. A few individuals present in arctic ...Missing: flocking | Show results with:flocking
[38]
Common Redpoll – November Bird of the Month – 2018
Nov 1, 2018 · Preferred Habitat: In winter, the Common Redpoll prefers open woodlands, brushy edges, weedy fields, and is a regular visitor at bird feeders. ...
[39]
One Bird to Look For This Winter | Experience Our Adirondacks
Jan 9, 2015 · Redpolls battle each other over many things – perches at feeders, snow burrows, and locations on the snow for seed-eating. To show aggression, ...
[40]
Redpoll Sounds, All About Birds, Cornell Lab of Ornithology
Redpolls form vocal, chattering flocks characterized by three main calls: a chatter of several sharp, zapping notes; a nasal, rising whistle lasting nearly half ...
[41]
Sounds and Vocal Behavior - Redpoll - Acanthis flammea
Oct 22, 2024 · Given singly or in series with pauses between notes, mainly by perched birds. Used by feeding or resting birds, as well as in excitement and ...
[42]
[PDF] North and Middle America Proposal Set 2024-B 18 December 2023 ...
Apr 10, 2024 · The main advance provided by the whole-genome dataset was the discovery of an inversion polymorphism that is strongly associated with redpoll ...
[43]
Breeding - Redpoll - Acanthis flammea - Birds of the World
Oct 22, 2024 · Nest placed up to 5 m above ground in shrub or tree, preferentially juniper, spruce, larch, birch, and pine and occasionally apple (Malus), ...Missing: perches singing
[44]
[PDF] Indications That the Common Redpoll is Double Brooded in Alaska
during the breeding season, the female, often attended by the male, takes about three days to build a nest, then lays a clutch of three to five eggs; incubation ...
[45]
[PDF] Nesting Habits of the Common Redpoll
Sometimes, however, if an intruder was standing near the nest when a female returned with food, she would perch in a conspicuous spruce top and utter the nasal,.Missing: microhabitat | Show results with:microhabitat
[46]
Redpoll Life History, All About Birds, Cornell Lab of Ornithology
### Summary of Common Redpoll Diet and Foraging Behavior
[47]
The Annual Lipid Cycle and Feeding Behavior of Alaskan Redpolls
Fisher and Dater (1961) state that the redpoll diverticulae, or "false crops," which can contain up to 2.0 g of seeds, have a much greater holding capacity than ...
[48]
[PDF] Acanthis flammea (Redpoll) European Red List of Birds ... - NET
THE IUCN RED LIST OF THREATENED SPECIES™. BirdLife International (2021) European Red List of Birds. Figure 1. Breeding population sizes and short-term trends ...
[49]
Common Redpoll (Acanthis flammea) - Wildlife, plants and species
Aug 19, 2015 · Low · At an Acceptable Level. Population estimate. Geographic area or population, Population estimate. Canada, 5,000,000 - 50,000,000 adults ...
[50]
Common redpoll | New Zealand Birds Online
However, the sparrow is a larger bird with a heavier bill, and it also lacks any red or pink in its plumage.
[51]
Summary of the 125th CBC (2024-2025) - National Audubon Society
Tracking Population Trends for over 540 Bird Species. Audubon scientists use CBC data to provide up-to-date processed abundance indices and abundance trends.
[52]
[PDF] Low/no genetic support for separate redpoll species Carduelis ...
I have extended on the above mentioned genetic studies on redpolls by analyzing highly mutable microsatellites, and adding mtDNA control region sequences ...
[53]
[PDF] Lesser Redpoll - BTO
Most Common Redpolls are encountered in the east of the UK. Arctic Redpolls are sporadic visitors and are very rare in UK gardens. In Lesser Redpolls the 'base ...Missing: increasing warming
[54]
Threats to Boreal Birds
Two of the largest threats facing boreal birds are habitat loss and climate change. Although much the northern boreal has so far been mostly spared from ...
[55]
Threats to the Boreal
Threats to the Boreal. Industrial Development. Although significant expanses ... Logging and forest product extraction remains the largest impact in terms of size ...
[56]
The Same Pesticides Linked to Bee Declines Might Also Threaten ...
Neonicotinoids are washing off of their host seeds and into water bodies—threatening not just aquatic insects but the birds that rely on them.Missing: redpoll | Show results with:redpoll
[57]
Common Redpoll (Acanthis flammea) - Canada.ca
Aug 19, 2015 · IUCN (Global) ... 2010. Population status. Click here for more details. Geographic area, Status, Reliability. Canada, Little Change · Low ...<|separator|>
[58]
Winter Finch Forecast 2024-2025 - FINCH RESEARCH NETWORK
Sep 29, 2024 · Watch for Redpolls on birches, in weedy fields, and at bird feeders that offer Nyjer® and black oil sunflower seeds. In 2024 Common Redpoll, ...