| י270) מירומית שחורה | ||||||||||
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:מרומית שחורה . מרומית קטנה, כהה ושכיחה. בקיץ ראשה וגופה שחורים, המקור שחור . הכנפים בצבע אפרפר בהיר, זנבה אפור ותת השת בולט בלובנו . והרגלים אדומות כהות. בחורף פניה וגחונה לבנים , נבדלת מהמרומיות האחרות בכתם הכתף הלבן התחום בברור . ובכתם השחור שבצידי החזה, במקור השחור ובזנבה המקודד פחות . הצעירים דומים לבוגרים אלא שגבם כהה יותר . בית גידולה אזורים עשירי צמחיה ליד אגמים, ביצות ומלחות . בזמן הנדידה ליד חופים ושפכי נהרות , בארץ עוברת אורח נדירה בשפלה ואזורים הנמוכים . ומבקרת קיץ נדירה ביותר בצפון הארץ שבעבר קיננה בקצה הצפוני של ימת החולה ... ואת השחף ... ויקרא י"א, 16 | ||||||||||
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Subspecies and Distribution.
C. n. niger S scaninavia S to S Spain, and E through E Europe and W Asia. Winters in Africa. C. n. surinamensis S Mackenzie and C Manitoba S to California, and E to Great Lakes, NW Pennsylvania and NW New York. Winters in Central America and N South America. םםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםם םםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםם | ||||||||||
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Descriptive notes.
Distinctive small dark tern. 23-26 cm, 65 g, wingspan 55-65 cm. Head, neck and breast black, becoming more dark slaty grey on back and belly, with grey upperwing and tail. Vent and undertail coverts white, underwing grey, bill black and legs blackish-red. Shows slight sexual plumage dimorphism, probably the only tern to do so. breeding female greyer, with dull black on head restricted to crown. Race surinamensis smaller and darker. Habitat. Breeding on well vegetated inland lakes, peat bogs and marshes, sometimes on brackish marshes. Prefers sparse, open vegetation of bulrush and cattail and other emergents, or floating water-lilies. On passage occurs on coasts and estuaries, but also at virtually any wetland, including even small ponds and ditches. Food and Feeding. Aquatic insects, small fish, tadpoles, snails and frogs. In breeding season diet based on insects. Usually feeds by aerial hawking and contact-dipping, occasionally hover-dipping, and more rarely plunge-diving. May feed up to 5 km from colony. Migrants feed in estuarine and coastal habitats, and flocks coalesce over schools of predatory fish. In Mediterranean, reported feeding in flocks over dolphins and tuna. Breeding. May-Jun in North America and Europe. Most colonies fewer than 20 pairs up to 100. Usually nests over water, also muskrat houses, boards, or old grebe or coot nests. 2-3 eggs, incubation 20-23 days. Chick similar to C. leucopterus but paler, with dark chin and throat. Movements. Palearctic birds often disperse N after breeding, with sometimes very large concentrations in S North Sea. Migrates in huge numbers through Mediterranean, and also across N Africa, to main wintering grounds on coasts from Mauritania to Namibia, some reaching South Africa. North American birds migrate to both Pacific and Atlantic coasts, wintering from Mexico and Panama S to Peru, and from the Gulf Coast to N South America. Accidental in Chile and Argentina. Status and Conservation. Not globaly threatened. world population 500.000 pairs. Israel. In Israel subspecies C. n. niger. Scarce passage migrant in low-lying across the country, very rare summer visitor in north. Former breed in Hula Valley. |
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