Sanderling
Calidris alba
Small, sprightly shorebird. Breeding plumage shows rusty tones on upperparts, often with a frosty appearance when fresh. By mid-summer, the frosty feather tips fade away and the neck can be deep, rich red—not to be confused with the much smaller Red-necked Stint! Very pale in winter. Juveniles are nearly spangled with black-and-white above. At all seasons, note larger size and somewhat thicker bill than other peeps or stints, along with bold white wing stripe in flight. Flocks are usually seen on open beaches, well known for running back-and-forth chasing waves and feeding actively in the sand. Also occurs on mudflats, especially in migration. Extensive global range, breeding on high Arctic tundra and wintering on coastlines on every continent except Antarctica.
识别特征
The sanderling is a small plump sandpiper, 18–20 cm (7.1–7.9 in) in length. Its weight ranges from 40–100 g (1.4–3.5 oz). The winter bird is very pale, almost white apart from a dark shoulder patch. This is the source of the specific name, alba, which is the Latin for "white". Later in the summer, the face and throat become brick-red. The juvenile bird is spangled black and white, and shows much more contrast than the adult.<p>If its size is misjudged, a sanderling in breeding plumage can be mistaken for some varieties of stint, or a sanderling in winter plumage can be mistaken for a dunlin or red knot. It can be told from other small wading birds, given good views, by its lack of a hind toe. Its behavior is also distinctive.
分类信息
- 学名
- Calidris alba
- 命名信息
- (Pallas, 1764)
- 目
- Charadriiformes
- 科
- Scolopacidae
- 属
- Calidris
分布与栖息地
- 繁殖区
- NA, PAL : high Arctic tundra wetlands of Holarctic: nw, se Greenland, Svalbard (n of Norway), n Taymyr Pen. and Severnaya Zemlya (to n), Lena Delta and New Siberian Is. (nc Siberia), Alaskan North Slope (rare), Canadian Arctic islands from Banks to Ellesmere and s to Southampton
- 非繁殖区
- Worldwide : sandy coastal beaches from temperate to tropical zone: British Is. and Macaronesia (nw of n Africa) through Africa, Malagasy region, Middle East, s, se Asia through Indonesian Arch. to Australia, Melanesia, Philippines and s, c Japan (but rare New Guinea and New Zealand); sw, se Canada and Caribbean s to Tierra del Fuego and including remote islands through e Polynesia
- 迁徙
- Complete migrants
行为
Sanderlings feed on invertebrate prey buried in the sand in the upper intertidal zone. In North America, this diet largely consists of the isopods Excirolana linguifrons, Excirolana kincaidii, and the mole crab, Emerita analoga. When the tide is out, these crustaceans live in burrows some way beneath the surface. When the tide comes in, they move into the upper layers of sand and feed on the plankton and detritus that washes over them with each wave. They then burrow rapidly down again as the water retreats. They leave no marks on the surface, so the sanderlings hunt for them by plunging their beaks into the sand at random, consuming whatever they find. Their bills can penetrate only 2 or 3 cm (0.79 or 1.18 in) and as the water swirls around and retreats, the sand is softer; this makes it easier for the birds' beaks to penetrate further. In the spring, when much breeding activity is taking place in the benthic community, there may be as many as 4000 invertebrates per square metre, but their average size is smaller than later in the year. The birds appear to rush madly around at the edge of the surf, but in reality they are maximising their chances of catching as many prey animals as possible when they are at their most vulnerable near the surface.<p>At breeding time sanderlings are territorial, with the male aggressively defending its territory. They may either form monogamous pairs or polyandrous (one female and two male) pairings.
保护状况
- 种群趋势
- unknown
照片
分布
鸟叫声
其他鸟类
Delicate Prinia
Prinia lepida
Tiny, disproportionately long-tailed, active, and vocal. The upperparts are gray-brown with heavy dark streaking, the underparts are pale, and each tail feather shows both pale and dark tips. Generally found in rather moist habitats within arid zones, including field margins, riparian woodland, scrub, gardens, and wetlands; can be quite numerous. Very vocal, especially in spring. The song is a rattling series of dry chirps, subtly different from the slower-paced song of Graceful Prinia. Males often sing from obvious perches. Visually extremely similar to Graceful Prinia, but there is little overlap in range. In any areas of overlap, best separated by song, but Delicate is also slightly longer- and narrower-tailed and browner.
Victoria Crowned-Pigeon
Goura victoria
An enormous pigeon of lowland swamp forest. Blue-gray body and maroon chest. Differs from other crowned pigeons by its long white-tipped crest and pale gray wing patch tipped with maroon. Claps its wings very loudly when it takes off. Forages on the forest floor for fallen fruit. Courtship display includes rocking whole body forward and fanning tail, then lifting wings. Unmistakable and does not overlap with other crowned-pigeons. Voice a deep, upslurred booming call. Also regular deep hooting notes.
Cream-backed Woodpecker
Campephilus leucopogon
Remarkable large woodpecker, mostly black with a red head and a large cream patch on the back. Females have a cream moustachial stripe and a black forehead. Occurs in open woodlands and savanna. The call is a nasal “pi-ow” and the drum is a double tap.
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