Seedsnipes

(Thinocoridae)

Class Aves

Order Charadriiformes

Suborder Charadrii

Family Thinocoridae

Thumbnail description
Medium-sized, short-legged, cryptically colored birds with stubby bills, recalling grouse or sandgrouse

Size
6–12 in (16–30 cm); 0.1–0.8 lb (50–400 g)

Number of genera, species
2 genera; 4 species

Habitat
Desert, semi-desert, steppe grassland, and alpine cushion plant communities. From sea level to 18,000 ft (5,500 m)

Conservation status
Not threatened

Distribution
South America in Patagonia, Andes, and Pacific Peru and northern Chile

Evolution and systematics

Seedsnipes have traditionally been considered charadriiform birds, and biochemical evidence supports this relationship and places seedsnipes in the scolopacid assembly. Their closest relative is the plains-wanderer (Pedionomus torquatus), an Australian species that at one time was placed near the hemipodes (Gruiformes), and is included there in this work. However, plains-wanderers have a skeleton with a broad, twonotched sternum and a broad pelvis that is remarkably similar to that of a Thinocorus seedsnipe. Biochemical evidence also supports the relationship between plains-wanderers and seedsnipes. Seedsnipes probably had a long independent evolution and possess several derived characters such as a superficially passerine-like skull. Seedsnipes differ from most other shorebirds in having a crop, gizzard, and long intestinal caeca that evidently are adaptations to their vegetarian diet.

Physical characteristics

Seedsnipes have stubby bills and short legs. The two larger species (Attagis) superficially resemble grouse, and the two smaller species (Thinocorus) resemble sandgrouse. A membrane with narrow slits for openings, which may serve to protect against dust storms, covers the nostrils of seedsnipes. The body feathers, which are plentiful and downy at their bases, provide evidence of the extremely cold environments seedsnipes can tolerate. As seen in pigeons and some other families of birds, the feathers fall off easily, probably to confuse predators. The wings are fairly narrow, long, and pointed, with 10 primaries (outer flight feathers) and 15 secondaries (inner flight feathers). The scapulars (tracts of feathers at sides of shoulders) are long and nearly reach the tip of the wing. The tail has 12 rectrices (tail feathers) and is relatively short and rounded to slightly wedge-shaped. The feet have three long front toes and a small but distinct hind toe. Unlike most sandgrouse, the tarsi and toes are unfeathered. There are two downy plumages, the second appearing just before the emergence of contour feathers. At least in the small seedsnipes, the immature plumage may soon be replaced (perhaps only partially) by a second immature plumage. The molt of the primaries is sometimes irregular.

Distribution

Seedsnipes are entirely restricted to the Neotropical region, where they inhabit the Andes and the adjacent Patagonia and

Peruvian coast. Rufous-bellied seedsnipes (Attagis gayi) occur at very high elevations in the Andes of Ecuador and from central Peru to Tierra del Fuego—in the north they are found only above 13,000 ft (4,000 m), but in the south they are found down to 3,300 ft (1,000 m). White-bellied seedsnipes (Attagis malouinus) only inhabit a small area on the southern end of South America, where they nest below rufous-bellied seedsnipes in the Andes and descend to the adjacent Patagonian steppe in winter. Least seedsnipes (T. rumicivorus) are widely distributed in southern Argentina and Chile; in winter some migrate as far north as the plains of northeastern Argentina and Atacama, Chile. Populations of least seedsnipes also inhabit the Andean altiplano of northwestern Argentina, Bolivia, and adjacent Chile (perhaps also in southeasternmost Peru), and the coastal deserts of northernmost Chile and most of Peru. Gray-breasted seedsnipes (T. orbignyianus) are found in the Andes from northern Peru to Tierra del Fuego and on adjacent mesetas of Patagonia. They generally occur above least seedsnipes in the southern end of the continent but descend in winter, when they have reportedly been seen as far from the Andes as Córdoba.

Habitat

Seedsnipes are found in cold and windswept habitats rarely visited by humans. Rufous-bellied seedsnipes frequent rocky slopes, scree, short grass, bogs, and cushion plant communities near the snowline. White-bellied seedsnipes breed on stony slopes and bleak, windswept, alpine moorland, especially in places with crowberry heaths (Empetrum) and Azorella cushions. In winter white-bellied seedsnipes descend to stony, dry riverbeds and wide shores of partly dried-up lakes. On the Peruvian coast least seedsnipes are often seen flying through desert devoid of vegetation on their way between small patches of low vegetation formed by the sea fog. On the altiplano and on the Patagonian steppe, they occur in sandy areas with scattered bunch grass and low herbaceous vegetation. Gray-breasted seedsnipes are typical of puna grassland and prefer areas with scattered stones and cushion plants as well as short grass bordering bogs.

Behavior

Seedsnipes spend most of their time walking slowly and quietly on the ground while feeding. Like sandgrouse, seedsnipes have the habit of turning their cryptically colored backs toward the observer, which makes them extremely difficult to detect. They will often allow close approach before they walk away or take off while emitting loud calls. The small species fly with a snipe-like, zigzag pattern. During the breeding season seedsnipes are found in pairs or groups of 5–6 birds, but in winter they usually occur in flocks, sometimes as large as 80 or more birds.

Feeding ecology and diet

Seedsnipes are entirely vegetarian. They bite off buds and tips of leaves with a downward jerk of the head and swallow them whole. Seedsnipes usually bend down to feed, but occasionally they will reach up to take a bud from an herb. Succulents form an important part of the diet, and apparently

seedsnipes do not drink. Seeds are not an important food item, except perhaps for least seedsnipes.

Reproductive biology

During breeding, seedsnipes appear to be territorial and are often found in pairs. The nest is a simple depression on the ground, loosely lined with lichens, mosses, or other plant material. The four, or sometimes three, snipe-like eggs are covered with nest lining or soil whenever the nest is left unattended. When surprised while incubating, seedsnipes feign injury in the manner of other shorebirds. The incubation period of least seedsnipes is about 26 days. No precise data exist for the other species. Soon after hatching the young are led away from the nest by both parents and are able to find food on their own. They are brooded by the female when they are small, and the male participates in guarding the chicks. After about seven weeks the young are able to fly. There is some indication, at least for the small Thinocorus species, that they become sexually mature so rapidly that they can breed in the same season they were hatched. This would enable them to take advantage of climatically favorable years, especially in the Peruvian desert where the El Niño phenomenon provides abundant food sources once every four to ten years.

Conservation status

None of the four species of seedsnipe appear to be threatened. No population surveys have been carried out, but numbers of the large Attagis species were probably always moderate and have only locally been affected by pollution and hunting in the vicinity of mines. In Ecuador, rufous-bellied seedsnipes are confined to the highest peaks for much of the year, and researchers estimate that no more than 200 or 300 pairs reside in the country, most within national parks. In Peru and Chile they also are protected in several national parks and reserves. A substantial part of the range of white-bellied seedsnipes also lies within protected areas. The Thinocorus species are common to locally abundant and have probably benefited from the grazing of the Patagonian steppe and the burning of high Andean woodland. Least seedsnipes are one of the most common birds on the Patagonian plains, and large numbers of the altiplano population have been reported from northern Chile and in winter from Bolivia. The coastal Peruvian desert population is fairly small but may increase considerably in climatically favorable years. Gray-breasted seedsnipes are common in the Andean Puna and their numbers have probably increased because of the burning of high altitude woodlands.

Significance to humans

Seedsnipes are found in habitats so inhospitable to man that they have had little significance to humans. Their loud calls have given rise to onomatopoetic local names, but the common or even abundant Thinocorus species are not sought after as game.

Species accounts

List of Species

Rufous-bellied seedsnipe

Attagis gayi

taxonomy

Attagis gayi I. Geoffroy Saint-Hilaire and Lesson, 1831, Santiago, Chile. Three subspecies recognized.

other common names

English: Gay's seedsnipe; French: Attagis de Gay; German: Rotbauch-Höhenläufer; Spanish: Agachona Grande, Agachona Ventrirrufa.

physical characteristics

10–11 in (27–30 cm); 10.6–14.1 oz (300–400 g). Upperparts, wing lining, and breast with cryptic pattern of blackish, buff, and whitish. Dorsal feathers mostly black in A. g. latreilli and densely vermiculated in the southern forms. Belly is rufous (in A. g. latreilli) or pinkish cinnamon; it is palest in A. g. gayi. Vent densely barred in A. g. latreilli and plain or faintly barred in the southern forms. In flight, it shows no wingbar. Juvenile like adult but with more finely vermiculated upperparts.

distribution

A. g. gayi: the Andes from Tierra del Fuego to northern Chile and Argentina, above 3,300 ft (1,000 m) in the south, above 6,600 ft (2,000 m) further north; A. g. simonsi: above 13,000 ft (4,000 m) in the Andes from northern Argentina and Chile through Bolivia to central Peru; A. g. latreilli: above 14,000 ft (4,300 m) in the Andes of Ecuador.

habitat

Rocky slopes with scattered cushion plants near the snowline, scree with scattered low herbs, alpine bogs.

behavior

In pairs or small groups, rarely larger flocks. Emits loud cackling vocalizations in flight.

feeding ecology and diet

Quietly browses on buds and leaf tips of herbs and cushion plants.

reproductive biology

Monogamous. Nest is a crude scrape with little or no lining. Four eggs, covered with earth when not incubated.

conservation status

Habitat rarely visited by humans. Range includes several national parks and reserves. Numbers locally decimated by hunting in the vicinity of mines.

significance to humans

None known except for hunting very locally.

White-bellied seedsnipe

Attagis malouinus

taxonomy

Tetrao malouinus Boddaert, 1783, Islas Malvinas. Monotypic.

other common names

French: Attagis de Magellan; German: Weissbauch-Höhenläufer; Spanish: Agachona Patagona.

physical characteristics

10–11 in (26.5–29 cm). Head speckled and upperparts and breast cryptically patterned with blackish, rufous, and buff. Rump densely barred blackish and pale buff. Chin, belly, and narrow tip of tail white. In flight shows conspicuous white band on underwing.

distribution

Breeds at 2,100–6,600 ft (650–2,000 m) in southernmost Chile and Argentina. Descends to adjacent lowlands in winter. Apparently straggles to Islas Malvinas.

habitat

Scree and moorland, especially with crowberries (Empetrum) and Azorella cushions. In winter on stony, dry riverbeds and wide shores of partly dry lakes.

behavior

In pairs or family groups, in winter in large flocks. Emits loud calls in flight.

feeding ecology and diet

Reportedly feeds on crowberries and other plant material.

reproductive biology

Four eggs, little else known.

conservation status

Habitat almost never visited by humans, parts of range protected.

significance to humans

None known.

Gray-breasted seedsnipe

Thinocorus orbignyianus

taxonomy

Thinocorus orbignyianus I. Geoffroy Saint-Hilaire and Lesson, 1831, Santiago, Chile. Two subspecies recognized (T. o. orbignyianus and T. o. ingae) that differ only in size.

other common names

English: D'Orbigny's seedsnipe; French: Thinocore d'Orbigny; German: Graubrust-Höhenläufer; Spanish: Agachona Mediana.

physical characteristics

9 in (23 cm), T. o. ingae averaging smallest: 3.9–4.9 oz (110–140 g). Female slightly smaller than male. Upperparts with cryptic pattern of whitish, buff, and dusky; light borders narrowest in juveniles. Throat and belly white, demarcated with blackish towards face and breast, which are gray in male, streaked dusky and buff in female and juvenile. Tail prominently white tipped, rounded to slightly wedge shaped. In flight it shows a faint white wingbar above and a broad white wingbar below that contrast with the dark wing linings.

distribution

T. o. orbignyianus: Tierra del Fuego north along the Andes to central Argentina/Chile; T. o. ingae: Andes from northern Argentina/Chile to northern Peru.

habitat

Dry puna with scattered bunchgrass, cushion plants, low herbs, and short grass bordering highland bogs.

behavior

In pairs or family groups. Territorial males countersing from hummocks or rocks, or they perform elaborate display flight at twilight or night in which they fly in wide circles and descend with stiff, lowered wings and raised tail. When flushed, flies with snipe-like zigzag flight.

feeding ecology and diet

Browses quietly, bites off buds and leaf tips of young grass, herbs, and succulents.

reproductive biology

Possibly lays several broods in a season. Nest is a simple scrape loosely lined with plant debris. Four eggs. Length of incubation period unknown. Both parents guard the young.

conservation status

Common and widespread, benefits from clearance of high altitude woodland.

significance to humans

None known.

Least seedsnipe

Thinocorus rumicivorus

taxonomy

Thinocorus rumicivorus Eschscholtz, 1829, Concepción Bay, Chile. Three subspecies recognized (T. r. cuneidauda, T. r. bolivianus, and T. r. rumicivorus) that differ in size, hue, and details of vermiculations on the upperparts. A fourth, T. r. pallidus, from the Santa Elena peninsula in southwestern Ecuador is often listed, but it appears to be inseparable from T. r. cuneicauda.

other common names

English: Chilean seedsnipe, Patagonian seedsnipe, Pygmy seedsnipe; French: Thinocore de Patagonie; German: Zwerghöhenläufer; Spanish: Agachona Chica.

physical characteristics

6–7 in (16–17 cm), T. r. bolivianus 8 in (19–20 cm); 1.8–2.1 oz (50–60 g). Much like gray-breasted seedsnipe. Upperparts with cryptic pattern of whitish, buff, and dusky; light borders narrowest in juvenile. Throat and belly white, demarcated with blackish (more broadly so than in gray-breasted seedsnipe) towards face and breast, which are gray in male and streaked dusky and buff in female. Male with blackish borders of throat and breast connected by blackish line down center of breast. Tail prominently white-tipped and distinctly wedge-shaped. In flight shows a faint white wingbar above and a broad white wingbar below, contrasting with the dark wing linings. Juveniles much like females, but white throat not distinctly demarcated and breast diffusely spotted rather than streaked.

distribution

T. r. cuneicauda: coastal desert of Peru and extreme northern Chile, and, at least formerly, southwestern Ecuador; T. r. bolivianus: altiplano of northwestern Argentina, Bolivia, and northern Chile; T. r. rumicivorus: lowlands to 3,900 ft (1,200 m) in Patagonia and southern Chile where partly migratory, wintering north as far as the plains of northeastern Argentina and Uruguay, the mountains of Córdoba (to above 6,600 ft [2,000m]) and Atacama, Chile.

habitat

Sandy areas with scattered bunch grass, low herbs, and succulents. In Patagonia, often on wide gravelly shores and areas with tiny annual herbs around partly dry claypan lakes. In Bolivia, in highland semidesert. In Peru, in sparse fog vegetation of coastal desert. Often on cultivated land.

behavior

In pairs or family groups, in winter in larger flocks. Territorial males countersing from tops of bushes or fence posts. Display flight much like that of gray-breasted seedsnipe. When flushed, flies with snipe-like zigzag flight.

feeding ecology and diet

Like gray-breasted seedsnipe, browses on tips or buds of young grass, succulents, and small herbs, which are swallowed whole.

reproductive biology

Probably multibrooded. Young apparently sexually mature when four months old and possibly breed the same season they were hatched. Nest is a simple scrape loosely lined with plant debris. Four eggs, covered with earth or nest-lining material when not incubated. Length of incubation period about 26 days. Both parents guard the young, which fly when seven weeks old.

conservation status

Apparently favored by sheep grazing in Patagonia and irrigation in the Peruvian desert. Common to locally abundant in Patagonia. Ten specimens were collected on the Santa Elena peninsula in southwestern Ecuador in 1898. Although taken in January and February (the presumed breeding season), all were in fresh plumage and may have been mere stragglers from Peru. Subsequently there are but two possible sightings from Ecuador. If those ten specimens did breed in Ecuador, the reason for their disappearance remains unknown because plenty of seemingly suitable habitat persists.

significance to humans

None known.

Resources

Books

del Hoyo, J., A. Elliott, and J. Sargatal, eds. Hoatzin to Auks. Vol. 3 of Handbook of the Birds of the World. Barcelona: Lynx Edicions, 1996.

Fjeldså, Jon, and Niels Krabbe. Birds of the High Andes. Copenhagen: Zoological Museum, University of Copenhagen, 1990.

Monroe, Burt L., and Charles G. Sibley. A World Checklist of Birds. New Haven: Yale University Press, 1993.

Peters, James L. Peters Checklist of Birds of the World. Vol. 2. Cambridge, MA: Museum of Comparative Zoology, 1934.

Ridgely, Robert S., and Paul J. Greenfield. The Birds of Ecuador: Status, Distribution, and Taxonomy. Ithaca: Cornell University Press, 2001.

Sibley, Charles G., and John E. Ahlquist. Phylogeny and Classification of Birds. New Haven: Yale University Press, 1990.

Periodicals

Hellmayr, Charles E., and Boardman Conover. "Catalogue of Birds of the Americas and the Adjacent Islands." Zoological Series, Field Museum of Natural History Publications. Zoological Series. 13, part 1, no. 3 (1948): 1–383.

Niels K. Krabbe, PhD