| י230) חמסן גדול | ||||||||||
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:חמסן גדול . חמסן גדול וכבד, צבעו חום כהה וכתמים לבנים באברותיו . כנפיו רחבות, זנבו קצר דומה לשחף כספי מתבגר . מעופו כבד משל שחף אבל זריז ביותר ברדיפה אחרי עופות אחרים , בית גידולו חופי ים ואיים מבודדים . דוגר בצפון אנגליה ואיסלנד ובדרום אמריקה ואנטרטיקה . חורף באוקיינוס האטלנטי ובמערב הים התיכון . בארץ עובר אורח מזדמן נדיר ביותר | ||||||||||
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Subspecies and Distribution.
Catharacta maccormicki Antarctic continent, especially in Ross Sea. Winters as far N as Alaska and Greenland. םםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםם םםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםם | ||||||||||
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Descriptive notes.
55 cm, 1000-1700 g, wingspan130-140 cm. Brown plumage with much white, yelow, ginger and black flecking, individually vey variable. Birds become paler with age. Brown plumage reminiscent of dark juvenile Larus gulls, , but distinguished by white wing panels towards bases of primaries. Flight much more powerful than that of gulls, with more rapid and stiffer wing beats. Wings shorter and broader than gulls and tail relatively short. Habitat. Marine. Avoids land during migration and winter, so can often be found in unexpectedly large numvers a few km offshore from coastal seawatching sites where it is only rarely seen. Aggregates in winter in areas where it can scavenge from fisheries, Bay of Biscay and W Mediterranean. Breeds on islands, preferring flat ground with some vegetation cover. Often breeds near other seabird colonies which provide opportunities for kleptoparasitism and scavenging or predation. Food and Feeding. Opportunistic feeder. In Shetland, feeds chicks mainly on sandeels caught by surface-plunging, or on small whiting, haddock and pout discarded from trawlers. Will scavenge on goose barnacles or dead seabirds, rob Northern Gannets and Auks of fish, or kill birds, especially Rissa tridactyla and Fratercula arctica . Winter diet includes waste from fishing boats, scavenging, and fish caught or stolen. Breeding. May. Highly territorial, loosely colonial. Nest scrape usually lined with dead grass. 2 eggs, incubation 28-32 days. Chick has uniformly colored light pink grey-brown down. Sexual maturity on average at 8 years. Movements. Migrates, wintering mainly off Iberia. Leaves breeding areas in Aug-Sep and moves slowly S. Northward migration in Mar-Apr, immatures may stay south or visit high latitudes in summer. Few cross to W Atlantic and these are probably birds from Iceland. Status and Conservation. Not globally threatened. Total breeding population is 15.000 pairs. Israel. In Israel subspecies Catharacta skua. Accidental. four records, one confirmed by ring. |
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