Brown Skua
Stercorarius antarcticus
Large, dark brown skua with a very robust beak. Several subspecies vary in plumage from largely dark to mottled pale brown. In flight, exhibits a broad white patch on both upperwings and underwings. Usually seen well offshore, less often towards the coast; often follows boats. Lacks the capped appearance of Great and Chilean Skuas, and has darker underwing coverts than those species. The dark morph of South Polar Skua has colder tones and a smaller bill, but field separation is difficult.
Identification
This is the heaviest species of skua and rivals the largest gulls, the great black-backed gull and glaucous gull, as the heaviest species in the shorebird order although not as large in length or wingspan. It is 52–64 cm (20–25 in) in length, 126–160 cm (50–63 in) in wingspan and has a body mass of 1.2–2.18 kg (2.6–4.8 lb). S. a. hamiltoni measured on Gough Island, weighed an average of 1.43 kg (3.2 lb) in 9 males and 1.65 kg (3.6 lb) in 9 females. S. a. lonnbergi measured in the Chatham Islands weighed an average of 1.73 kg (3.8 lb) in 30 males and an average of 1.93 kg (4.3 lb) in 32 females. The latter is one of the highest colony mean body mass for any living species of shorebird.<p>A study in 2016 reported that brown skuas can identify individual human beings, possibly indicating high cognitive abilities.<p>Brown skuas have been noted for sometimes bonding with humans who live for extended periods in Antarctica, such as the Eastern Orthodox clergymen at Trinity Church, and engaging in playful or apparently mischievous behavior with them.
Taxonomy
- Scientific name
- Stercorarius antarcticus
- Authority
- (Lesson, RP, 1831)
- Order
- Charadriiformes
- Family
- Stercorariidae
- Genus
- Stercorarius
Range and habitat
- Migration
- Complete migrants
Conservation
- Population trend
- declining
Photos
Distribution
Bird Calls
Other Birds
Black-billed Thrush
Turdus ignobilis
A drab thrush, common in open habitats and woodlands in the lowlands but also wanders up into Andean foothills. Nondescript grayish-brown with a pale whitish belly. Note indistinct streaking on throat; some populations also show a white patch on chest. Sexes similar. Usually seen singly or in pairs. Conspicuous. Song is a typical thrushlike series of musical phrases.
Red-necked Falcon
Falco chicquera
A rather small but powerful falcon with fast and direct flight. It has a rufous crown, nape, and moustachial stripe. A wide yellow eye-ring is quite distinct. Its upperparts are pale gray, and fine barring adorns its white underparts, which are sometimes suffused with gray. This bird of the open country mostly hunts birds on the wing, targeting its prey from a perch, often bringing it down quite close to the ground.
Thick-billed Vireo
Vireo crassirostris
A small loquacious inhabitant of scrubland, thickets, and brushy forest edges where it typically feeds within dense cover. The similar White-eyed Vireo can be distinguished by its smaller bill, greener back, and bright yellow sides; furthermore, adults have white, not dusky, eyes. The Cuban Vireo lacks the Thick-billed Vireo’s bold wingbars. The song is a scratchy jumbled “chick, didderwid-weee-zhee, chip” or variations thereof. Calls include a “zhip” given singly or in short bursts, a drawn-out harsh “zzhhe,” and a variety of chattering sounds.
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