| .בנז-דודק ףחש (253 | ||||||||||
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.רוחש רלוק וראוצלו רופא ושאר הריגדה תפוקתב .ונרוזאב דיחיה דדוקמ בנז לעב ,תיפחש ריכזמה ןטק ףחש :בנז-דודק ףחש .םירופא בגה םע דחי ףנכה ירוביחו ןבל ףנכה זכרמ רוחש הצקב "םישלושמ" השולש ויפנכב .ןבל ובנזו תורופא וילגר ,והצקב בוהצו רופא רוקמה ,המודא תעבט וניע ביבסמ .(חותפה םיה יבחרמ ) יגלפ ףרוחב ,םיבחטו תוציב יחמצ םע החל המדא לע רגוד ,תיטקרא הרנוט ולודיג תיב .רתויב רידנ ,יארקא חרוא רבוע ץראב 16 ,א"י ארקיו ... ףחשה תאו ... | ||||||||||
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Subspecies and Distribution.
X. s. palaearctica Spitsbergen to Taymyr Peninsula and Lena Delta. X. s. tschuktschorum Chukchi Peninsula. X. s. woznesenskii NE Siberia to Alaska. X. s. sabini Arctic Canada to W Greenland. Winters in SE Atlantic off SW Africa, and in E Pacific off RW South America. | ||||||||||
Descriptive notes.Highly distinctive, with slightly forked tail, unique upperwing pattern, and delicate, buoyant tern-like flight. 30 cm, 140-225 g, wingspan 80-85 cm.Hood dark slaty grey, narrowly bordered black at rear. Neck, rump and tail white. Mantle and back dark grey. inner wing from carpal to scapulars dark grey, outer primaries white-tipped black, leaving contrasting white triangle in between. Underparts white, sometimes tinged pink early in breeding season. Underwing whitish, outer primaries with black subterminal marks. Bill black,with yellow tip, legs blackish grey, iris blackish brown, whit bright red orbital ring. Races differ little, bicoming darker from E Canada E to Alaska, woznesenskii darkest, with extreme slaty upperparts and very restricted white tips to primaries. Habitat.Arctic tundra, breeding at wetlands with mosses and sedges. Pelagic in winter.Food and FeedingSmall fish and invertebrates, occasionally small birds, eggs of Sterna paradisaea and carrion. When breeding sites snow-covered at time of arrival, takes insects like Collembola and Arachnida, as well as seeds and plant matter.Swoops low over water and snatches prey from surface, sometimes swims, or feeds on land. Breeding.Lays mainly from Jun, depending on latitude and snow cover. Colony contain 6 up to 20 nests, occasionally more. Also nests solitarily. Usually breeds with Arctic Tern, often as single paers.Nest of grass, placed on rocky or bare ground with grass or moss cover, near water's edge. 2 eggs, incubation 24 days. Chick golden brown above, spotted and streaked, especially on crown and lower back, and brown below with whitish breast and belly. Movements.Migrates in flocks, mostly offshore. Winters in smaller flocks.Siberian and Alaskan birds migrate through the Bering Sea and Bering Strait, past the Californian coast to W South America, where they frequent Humboldt Current region off Peru. Large numbers of adults from E Canada and Greenland migrate SE through the Atlantic to winter off SW Africa. Autumn storms may drive many birds onto mainland coasts. Status and ConservationNot globally threatened. Total population probably under 100.000 pairs.Israel.In Israel subspecies X. s. sabini. Straggler. few records at Eilat beach and photographed. |
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