Red phalarope
The Red phalarope (Phalaropus fulicarius) is a small, migratory shorebird in the family Scolopacidae, renowned for its reversed sexual dimorphism and predominantly pelagic lifestyle.[1][2] Measuring approximately 20–22 cm (8 inches) in length with a wingspan of 41–44 cm (16–17 inches), it exhibits striking breeding plumage where females display a brilliant chestnut-red underbody, white face, and yellow-based bill, while males are duller in comparison.[2][3] In non-breeding plumage, both sexes adopt a subdued gray-and-white appearance with a smooth, unstreaked back, aiding camouflage on the open ocean.[1] This species is one of the few shorebirds that spends most of its life at sea, breeding exclusively in high-Arctic tundra wetlands.[3] The Red phalarope breeds in coastal and interior tundra across the Arctic regions of North America, Europe, and Asia, favoring areas with shallow ponds and marshy vegetation for nesting.[3] During migration and winter, it undertakes long oceanic journeys, primarily offshore along routes in the Atlantic and Pacific Oceans, wintering in nutrient-rich waters south of the equator, such as off the coasts of California, Peru, Morocco, and Namibia.[3][2] It forages by swimming and spinning in tight circles on the water surface to stir up prey, consuming insects like midges and cranefly larvae on breeding grounds, and zooplankton such as copepods and amphipods at sea.[3][2] A defining behavioral trait of the Red phalarope is its polyandrous mating system with reversed sex roles: females, being larger and more colorful, compete aggressively for males, lay clutches of 2–4 eggs in a ground scrape lined with vegetation, and then depart to seek additional mates, leaving males to incubate the eggs for 17–26 days and care for the precocial young.[1][3][2] Its vocalizations include a sharp, metallic "kreeep" call used in flight or alarm.[2] With a global population estimated at 9,000,000–12,000,000 mature individuals (as of 2024), the species is classified as Least Concern by the IUCN, though it faces threats from climate change (including projected 93% decline in Arctic breeding habitat by 2100), ocean warming affecting prey availability, oil spills, and plastic pollution, which impacts up to 100% of individuals through ingestion.[2][3][4]Taxonomy and etymology
Scientific classification
The red phalarope was first illustrated and described by the English naturalist George Edwards in the third volume of his A Natural History of Uncommon Birds published in 1750, based on a specimen from Hudson Bay.[5] In 1758, Carl Linnaeus formally named the species Tringa fulicaria in the tenth edition of Systema Naturae, providing a brief Latin diagnosis and citing Edwards' earlier work. The genus Phalaropus was introduced by the French zoologist Mathurin Jacques Brisson in 1760, with the red phalarope designated as the type species (Phalaropus fulicarius) in his Ornithologie. It is now classified in the family Scolopacidae (sandpipers and allies) and the subfamily Phalaropodinae, as recognized by the IOC World Bird List (version 15.1, 2025).[6] The red phalarope is monotypic, with no recognized subspecies.[7] Molecular phylogenetic analyses place it within the Phalaropodinae, where it forms a close sister relationship with the red-necked phalarope (Phalaropus lobatus), and the two species together are sister to Wilson's phalarope (Steganopus tricolor).[8][9]Etymology
The genus name Phalaropus derives from Ancient Greek phalaris, meaning "coot", and pous, meaning "foot", alluding to the lobed toes that resemble those of coots.[10] The species epithet fulicarius originates from Latin fulica, denoting "coot", combined with the suffix -arius, indicating similarity or connection, thereby emphasizing the coot-like foot structure.[11] The common name "red phalarope" arises from the bird's vivid reddish plumage during the breeding season.[1] In contrast, the alternative name "grey phalarope", prevalent in European usage, reflects its muted grey appearance in winter.[12] Historically, "grey phalarope" appeared in texts from the 18th century onward, highlighting the non-breeding plumage.[13]Physical description
Plumage and morphology
The Red phalarope exhibits striking sexual dimorphism in its breeding plumage, with females displaying more vibrant coloration to attract mates. In breeding season, females have deep rufous underparts, including the neck, breast, and belly, contrasted by a black face patch, white throat and cheeks, and a mottled brown-and-black back.[14][15] Males are duller overall, featuring pale orange-red underparts, a brown cap instead of a fully black one, and similar white facial markings.[14][15] During the non-breeding season, both sexes adopt a more subdued appearance for camouflage on open ocean waters, with pale grey upperparts, white underparts, and a distinctive black eye patch.[14][15] The back remains unstreaked and smooth grey, and all adults retain a white wing stripe and dark tail stripe with contrasting white rump sides.[15] Juvenile plumage closely resembles that of non-breeding adults but includes buff scaling on the back and buff-toned underparts and head for added camouflage during their first winter.[16][15] Key morphological adaptations suit the Red phalarope's aquatic lifestyle as a wader. It possesses a straight, needle-like bill that is thicker than in related species, yellow with a black tip during breeding and darker with a lighter base otherwise, ideal for probing water surfaces.[14][15] The legs are short and yellowish-brown, paired with lobed toes that facilitate swimming by providing propulsion and stability on water.[15][10] Overall, the bird's compact build emphasizes a rounded body and short neck, enhancing its buoyancy and foraging efficiency in marine environments.[14]Size and measurements
The red phalarope (Phalaropus fulicarius) is a small shorebird measuring 20–23 cm in total length, with a wingspan ranging from 38–43 cm and an average body weight of 40–80 g.[14][17] These dimensions reflect its compact, adapted form for pelagic life, where it spends much of its time swimming on open waters. Sexual dimorphism is pronounced, with females approximately 10–20% larger and heavier than males overall; adult females typically weigh 55–80 g, while males average 40–60 g.[18][19] This size difference extends to linear measurements, including bill length (females 23.5 ± 0.8 mm, males 22.4 ± 0.9 mm).[19] The larger female size supports their competitive role in courtship and egg-laying within the species' reversed sex roles, where males handle incubation and care. Compared to the closely related red-necked phalarope (Phalaropus lobatus), the red phalarope appears chunkier with a thicker bill (2.2–2.5 cm versus the red-necked's more slender 1.9–2.3 cm), aiding in its foraging on marine prey.[14][20]| Measurement | Males | Females | Source |
|---|---|---|---|
| Weight (g) | 40–60 | 55–80 | [19] |
| Bill length (mm) | 22.4 ± 0.9 | 23.5 ± 0.8 | [19] |