| י256) שחפית כספית | ||||||||||
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:שחפית כספית . השחפית הגדולה ביותר, בעלת מקור גדול, כבד ואדום כדם. זנבה קדוד . Hydroprogn הבדלים אלה מבדילים אותה משאר השחפיות ולכן היא מוגדרת כסוג נפרד . שהוא על שם הים הכספי caspia שמה העיברי כספית נובע מהשם המדעי . בתקופת הדגירה כיפת הראש שחורה, וכן ציצת הנוצות הנמשכת מעורפה . חלקי הגוף העליונים אפורים כספיים. הזנב, הצואר והגחון לבנים . במעופה מתגלה תחתית כנפה הלבנה והאברות בצבע אפור כהה . בית גידולה חופי ים, אגמים בפנים היבשת. מקננת באיים סלעיים וחוליים . בארץ עוברת אורח נדירה בסתיו, נדירה יותר באביב לאורך חופי ים התיכון ומפרץ אילת ... ואת השחף ... ויקרא י"א, 16 | ||||||||||
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Subspecies and Distribution.
Hydroprogn caspia N America, N Europe, Africa and Madagascar, C and S Asia, Australia, New Zealand. Desperses more widely in winter.םםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםם םםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםם | ||||||||||
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Descriptive notes.
Largest tern. Large, stout blood red bill with variable black tip, and slightly forked tail. 50-55 cm, 570-780 g, wingspan 130-140 cm. Distinguished by black undersurface or primaries, conspicuous in flight. Eye dark brown, legs black. Non-breeding adult has forehead and crown whitish with dark spotting. Confusable only with Thalasseus maximus and T. bergii, which have orange or yellowish bill and paler under primaries, but is much more gull-like than either and never becomes as white-headed as is Thalasseus maximus for most of year. Habitat. Usually along coasts, as well as on large inland lakes and reservoirs. Breeding on sand, shell or rocky islands. feeds at freshwater lakes, inland seas, and coastal estuaries. Winter roosts at large lakes and estuaries on sandbars, mudflats, and shell banks. Food and Feeding. Diet on fish. Occasionally eggs and young of other birds, and carrion. Takes larger fish than smaller terns with which it associates. Often feeds in loose flocks, but occasionally exhibits feeding territoriality. Hovers and plunge-dives, and occasionally uses surface dipping, also pirates food from other terns and gulls. Breeding. Apr-Jun in N Hemisphere, Sep-Cec in S Hemisphere. Densely colonial to solitary, in Europe, most breed as single pairs in gull or tern colonies. Very sensitive to disturbance early in cycle and entire colony will desert. Nest a depression in sand, gravel, shell, or even ground vegetation. 2-3 eggs, incubation 27 days. Chick dimorphic, greyish brown with dark spots, sooty throat, dark skin and olive feet, or pale creamy whitish with faint or no spots, white throat, yellowish skin, and orange feet. Movements. European and N American birds show brief post-breeding dispersal. then migrate slowly South. Great Lakes birds move S and E to Gulf and Atlantic coast to winter in SE USA and Caribbean. Baltic birds pass through C Mediterranean and E Europe reaching to tropical W and C Africa, and Middle East In Australia, juveniles disperse widely. Tasmnian birds winter in New South Wales. Status and Conservation. Not globally threatened. World populations at least 50.000 pairs. Israel. In Israel subspecies . Hydroprogn caspia Rare passage migrant along Mediterranean coastal strip, and fairly rare in spring when moves through Eilat and eastern valleys. |
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