| י260) שחפית ורדרדת | ||||||||||
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:שחפית ורדרדת . שחפית בהירה, בעלת זנב מקודד וארוך מאוד ובולט מעבר לכנפיה , נבדלת משחפיות הים והקוטב במקורה השחור, המאדים בבסיסו בקיץ ובצבעה הבהיר יותר. רגליה ארוכות יותר מרגליהן, ובתקופת הקינון החזה מקבל . גוון ורדרד בשונה מהגוון הסגול בהיר של שחפית הים . בית גידולה איים חוליים או סלעיים ואיי אלמוגים בדרך כלל עם צמחיה עבותה ובטמפ' ממוזגת . בארץ עוברת אורח אקראית ונדירה בחוף אילת ... ואת השחף ... ויקרא י"א, 16 | ||||||||||
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Subspecies and Distribution.
S. d. dougallii Nova Scotia through New York and Florida S through Gulf of Honduras, and West Indies to islands off N Venzuela, and also Azores, NW Europe, and E and S Africa. American birds may winter mainly in mid-Atlantic, E Atlantic populations winter on coasts of tropical W Africa. S. d. arideensis Seychelles S to Madagascar and Rodrigues Is. S. d. korustes Sri Lanka, Andaman Is and Mergui Archipelago... S. d. bangsi Arabian Sea, Ryukyu Is, coastal China and Taiwan S to Greater Sundas and New Guinea, Solomons, New Caledonia and Fiji, presumably also on Cocos Is. S. d. gracilis Moluccas and Australia. םםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםם םםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםם | ||||||||||
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Descriptive notes.
Very pale tern with very long tail streamers. 36 cm, 90-125 g, wingspan 70-80 cm. Mantle and upperwing very pale grey, tail entirely white and deeply forked. Black outer webs on 3 outer primaries only. Immaculate white below, tinged pink early in breeding season. Legs and feet dull to bright red. Changes in bill color vary geographically. Species differs from S. hirundo in shorter wings and longer tail,with faster, shallower wingbeats, and different bill pattern. Races differentiated by wing length, and bill length and color, but these parameters vary with latitude, apart from korustes, which has both shorter wing and bill and greyer upperparts, all racial differences covered by variation within nominate dougallii. Habitat. Breeds on sandy, rocky or coral islands, often with dense vegetation in temperate areas, or barren islets in tropics. Feeds along tiderips, in estuaries and several kilometers offsore. Food and Feeding. Diet almost exclusively small fish, rarely insects and marine invertebrates. Often feeds in flocks with other species. Plunge-dives from greater heights and submerges. Also feeds by aerial-dipping for small fish driven to surface by predators, and contact-dips for small fish and invertebrates over shoals of bonito, tuna and bluefish. Scavenges behind fishing boats. Breeding. May-Jun in USA and Europe, April in Madagascar, Sri Lanka, India and Australia. Colonies often very dense, less dense in temperate regions. Nest usually a bare scrape in sand or on coral rubble or bare rock. Sometimes on vegetation, often without nest material. 2 eggs, incubation 22-2 days. Chick mottled dark, with dark grey chin and throat and white to buffy white underparts, not speckled like most Sterna. Movements. Wintering grounds of American populations inadequtely known, though some apparently winter on N coast of South America, Birds from NE USA gather in large post breeding flocks in Aug-Sep, moving N to rich fishing areas on Maine coast, then migrate S, passing offshore, and species is very rare visitor to the Carolinas. Common migrant off Trinidad and the Guianas, but winters further S or at sea. Palearctic birds winter W Africa, mainly between Guinea and Gabon. Usually remain in tropics in 2nd years. Status and Conservation. Not globally threatened. World population 50.000 pairs. Israel. In Israel subspecies not identified. Straggler, on Beach of Eilat |
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