California Gull
Larus californicus
Medium-sized gull, a bit larger than Ring-billed Gull and smaller than Herring Gull. Adults have medium-gray upperparts (slightly darker than Herring Gull), and red and black markings on the bill. Takes four years for immatures to progress from mostly brown to fully white and gray adult plumage; intermediate plumages are often mottled and messy. Many immatures show a pink bill with a contrasting black tip, and dull pinkish or greenish-gray legs. Always note dark eye. Common and fairly widespread in western North America, inland and along the coast. Can be found at parking lots, beaches, or lakes, often in flocks with Herring and Ring-billed Gulls.
识别特征
Adults are similar in appearance to the herring gull, but have a smaller yellow bill with a black ring, yellow legs, brown eyes and a more rounded head. The body is mainly white with grey back and upper wings. They have black primaries with white tips. Immature birds are also similar in appearance to immature herring gulls, with browner plumage than immature ring-billed gulls. Length can range from 46 to 55 cm (18 to 22 in), the wingspan 122–137 cm (48–54 in)[citation needed] and body mass can vary from 430 to 1,045 g (0.948 to 2.304 lb).
分类信息
- 学名
- Larus californicus
- 命名信息
- Lawrence, 1854
- 目
- Charadriiformes
- 科
- Laridae
- 属
- Larus
分布与栖息地
Their breeding habitat is lakes and marshes in interior western North America from the Northwest Territories, Canada south to eastern California and Colorado. They nest in colonies, sometimes with other birds. The nest is a shallow depression on the ground lined with vegetation and feathers. The female usually lays 2 or 3 eggs. Both parents take turns feeding their chicks.<p>They are migratory, most moving to the Pacific coast in winter. It is only then that this bird is regularly found in western California.
- 繁殖区
- NA : c Northwest Territories to c Manitoba (c Canada) to ne South Dakota; e Washington to Montana and s to Colorado and c California
- 非繁殖区
- e North Pacific coast from s British Columbia (sw Canada) to wc Mexico
- 迁徙
- Complete migrants
行为
These birds forage in flight or pick up objects while swimming, walking or wading. They mainly eat insects, fish and the eggs and young of other birds, especially ducklings. Opportunistic feeders, they also scavenge at garbage dumps, marinas and docks. They frequently beg for food at public beaches, parks and other locations where people will hand feed them. They have been known to steal food directly from people at picnics and outdoor restaurants. They may follow fishing boats or plows in fields for insects stirred up by this activity.<p>California gulls are also known to eat various vegetables and fruits, particularly cherries. As a result, in some areas it may be regarded as a crop pest.
保护状况
- 种群趋势
- declining
照片
分布
鸟叫声
其他鸟类
Chinese Monal
Lophophorus lhuysii
An inhabitant of rocky highland meadows, this glorious pheasant often forages in boulder fields in early morning and late afternoon. Adult male a veritable phoenix, with glittering blue back and tail, flame-colored neck, glossy green head, and black underparts. Blue patch of skin between eye and bill unique among monals. Less colorful female streaky brown with pale skin around the eye. Male gives a whistle recalling a rusty door hinge and high-pitched piping calls.
New Caledonian Goshawk
Tachyspiza haplochroa
Medium-sized distinctive raptor. Unmistakable adult has a slate-gray hood and upperparts strongly contrasting with a white belly, yellow legs, and bright red eye. Juveniles more patterned: dark brown upperparts and boldly marked brown and white below, spotted on the chest and barred on the belly. Compare juvenile to Brown Goshawk, which is slightly larger and longer tailed, with more rufous tones to the plumage. Found throughout New Caledonia, but prefers areas with taller forest than Brown Goshawk.
Brownish Elaenia
Elaenia pelzelni
Medium-sized nondescript flycatcher. Has a dull brown back, whitish underparts, and three distinct pale wingbars. The white crown patch is often concealed. Inhabits forest along wide lowland rivers, including older river islands. Calls include a low double note: “chick-ert.”
开始您的观鸟之旅
在户外识别鸟类，并在下一次观察时随手查阅鸟类图鉴。