| י266) שחפית רסן | ||||||||||
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:שחפית רסן . שחפית הנראית אפורה כהה מלמעלה, מלבד צוארה הלבן , מצחה לבן ונמשך מעל גבת עינה. כיפתה ועורפה שחורים . גחונה לבן, הזנב מקודד מאוד, אפור כהה ושוליו לבנים. מקורה ורגליה שחורים . בחורף מופיע צבע לבן בראשה, פסי העיניים לא ברורים ועל גבה נקודות לבנות . בית גידולה אזורים טרופיים וסובטרפיים באוקינוסים העשירים בפלנקטון או דיונונים . מקננת על איים חשופים או אלמוגים . בארץ מבקרת קיץ נדירה בלהקות קטנות במפרץ אילת ... ואת השחף ... ויקרא י"א, 16 | ||||||||||
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Subspecies and Distribution.
Sterna repressa Red Sea S to Somalia and Kenya, E through Persian Gulf and Oman to W India. Winters on coasts of S. a. melanoptera W Africa. S. a. fuligula Red Sea, and E Africa through Persian Gulf and Arabian Sea to W India. S. a. antarctica Madagascar, Aldabra, Seychlles and Mascarenes through Maldives to Andaman Is. S. a. anaethetus S Japan and Taiwan S through Philippines and Indonesia to Australia, Lord Howe and Norfolk Is. S. a. nelsoni W coast of Mexico and Central America . S. a. recognita West Indies, Belize and islands off N Venezuela. םםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםם םםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםם | ||||||||||
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Descriptive notes.
Semi-pelagic tern with long, deeply forked tail and long, narrow wings. 37 cm, 130 g, wingspan 75-80 cm. forehead patch white and triangular, extending short way behind eye. Crown and nape black, occasionally with narrow paler hindneck collar. Upperparts dark grey-brown, paler on rump and tail, with white outer tail feathers. Upperwing dark grey-brown, with conspicuous pale leading edge. Whitish below, with grey breast. Bill and legs black. Shorter-winged than S. fuscata, with paler upperparts contrasting with black crown, and narrow white eyebrow extending further behind eye. Unlike S. fuscata, bill tomia not serrated, and webbing of toes more deeply incised which may facilitate perching on vegetation. Races differ mainly in darkness of plumage, amount of white in outer tail, and size. melanoptera somewhat paler above, with greyish collar between nape and upperparts. Habitat. Tropical and subtropical coasts. Breeds on coral beaches and rocky and sandy slopes. Forages inshore and offshore, up to 50 km from land. Often perches on floating objects and on trees at night. Food and Feeding. Diet mainly surface-schooling fish and squid. Feeds by plunge-diving without submerging, or contact-dipping from one meter. Also by surface-dipping or aerial-dipping,often over drifting seaweed. Breeding. May-Jun in W Africa and Caribbean, Jun-Aug in E Africa and Madagascar, Oct-Dec in Australia. Colonies up to 200 pairs, often not synchronous. Nests often distributed in vegetation, rock or rubble around rim or island. Most of the birds retain nest-site from year to year, even with different mates. Nest contents normally concealed under rock or vegetaion, reducing predation. 1 egg, incubation 28-30 days. Chick finely mottled, resembles that of S. dougallii . First breeding usually at 4 years. Movements. Widespread at sea. Birds from West Indies and Atlantic probably move E to upwellings off W Africa. Some Seychelles birds appear on E coast of Africa. Australian breeders leave colonies in Mar, but movements unknown. Heavy southward autumn movement past Colombo, Sri Lanka. Status and Conservation. Not globally threatened. Total population estimated at 200,000 pairs. Israel. In Israel subspecies S. a. antarctica. Scarce summer visitor in Gulf of Eilat. |
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