| י262) שחפית קוטב | ||||||||||
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:שחפית קטב . דומה לשחפית ים, נבדלת ממנה בכנפיה הלבנות שפס דק מעטר את קצותיהן . מקורה קצר יותר ואדום כדם, בדרך כלל אין לו קצה שחור ורגליה קצרות יותר . בחורף המצח מלבין, ומקורה ורגליה משחירים . נוצות זנבה החיצוניות ארוכות, אפורות וכהות . בית גידולה חופים ופנים היבשת באזורים ארקטיים ממוזגים וחמימים . חורפת בקצה השני של כדור הארץ - באנטרקטיקה . בארץ עוברת אורח אקראית נדירה במפרץ אילת ... 16, את השחף ... ויקרא י"א | ||||||||||
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Subspecies and Distribution.
Sterna paradisaea Iceland, Britain and Netherlands through Scandinavia, across Asia to Bering Strait. Aleutians and N Alaska to Greenland, and S to British Columbia and New York. Migrates to Antarctica, where spends much of N winter in pack ice zoneםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםם םםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםם | ||||||||||
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Descriptive notes.
Slimmer, little tern whit forehead and crown black. 30-35 cm, 85-125 g, wingspan 75-85 cm. Plumage rather uniform grey, including underparts, but with narrow white cheeks and white rump and tail, latter with very long streamers. Bill usually completely bright red, but rarely with dark tip. legs red. Very similar to S. hirundo, but darker below, with narrower wings and longer tail streamers, shorter legs and shorter, all red bill. Non-breeding adult has white forehead, and sometimes shows dark carpal bar like S. hirundo. Bill and legs blackish. Habitat. Arctic regions, mainly coastal, but also far inland. Nests on shingle beaches, gravel ridges, earth dykes, bog hummocks, tundra, barren fields, peat moss, and grassy meadows. Prefers more barren areas than S.hirundo , and where both occur together it occupies rocky shore more than grassy heath. Fishes in ice-filled bays and offshore, and over wet tundra and ponds. In winter pelagic, ranging from open sea to pack ice zone. Often seen resting on flotsam. Food and Feeding. Mainly diet based on small fish, also molluscs, crustaceans and insects. In spring occasionally feeds on berries, fish offal and even bread, also takes caterpillars and earthworms. Has daily feeding cycles, even in continuous daylight. Feeds mainly within 3 km of colony, but op to 20 km from colony. Often a victim of piracy from skuas and Common Tern. Breeding. Jul in N of range, May-Jun. Colonies from few pairs to several hundreds. Often changes sites from year to year, but some colonies persist many years, and some birds have strong territory fidelity. Nest on artificial structures, often unlined. 2-3 eggs, incubation 22-27 days. Chick usually brownis or grey, with greyish cast to belly. First breeding usually at 4 years. Movements. Renowned for exceptionally long and unparalleled migrations between high Arctic breeding sites and Antarctic wintering grounds. Birds from Finnish archipelago depart in Jul, high Arctic birds may linger until Sep. Most migration well offshore. From Siberia and W North America, moves S through E Pacific. Southbound migrants in Atlantic move SE, and juveniles reach Africa by Aug. Reaches S Africa by Oct. Crossing of Antarctic sea aided by westerly winds which drift some birds E in Southern Ocean. Many winter in Antarctic pack ice between Magnet Bay and Oates Land. Accidental in S South America and New Zealand. Return migration mostly in W Atlantic, but mainly offshore. Status and Conservation. Not globally threatened. World population estimated at least 500.000 pairs. Israel. In Israel subspecies . Sterna paradisaea. Occasional visitor mainly on spring and summer migrant in waters of Eilat. |
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