| .םייחל-ןבל ןלבט (7 | ||||||||||
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רשיו קד ורוקמ .הבוהז הציצו ינומדא ראוצ לש ףורצב רכינ :םייחל-ןבל ןלבט .ןיעה וקב תונבל םייחלו רוחש דוקוק לש דחה רבעמב ינוניבה ןלבטהמ הנוש ףרוחב .םי יפוח ףידעמ ףרוחב ,םיקותמ םימ יוקמ ,ןוניקה ןמזב ולודיג תיב .רתויב רידנ יארקאב ןמדזמ ץראב | ||||||||||
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Subspecies and Distribution.
P. a. auritus Palearctic, from Iceland to Kamchatca. P.a. cornutus C Alaska to USA. | ||||||||||
Descriptive notes.30-40 cm; 300-470 g/ Distinctive combination of reddish neck with golden yellow crest rufts. Non-breeding adult has extensive white on foreneck and face; difers from Non-breeding P. nigricollis in whiter face, bill thicker and straight, and small whitish spot on lores. Juvenil as Non-breeding adulet, with separation of dark cap from whitish face less clearly demarcated, as in P. nigricollis . Race cornutus greyer above, especially on crown.HabitatFor breeding prefers fresh water, occupying small pools and marshes with patches of open water, or secluded sectors of large lakes and rivers. In winter mostly marine, occurring in sheltered bays and occasionally pn open sea; also on fresh waters in S of breeding range, especially on large lakes and river systems.Food and FeedingArthropods normally predominate in number, but fish in weight. Highly adaptable, shifting to whatever food readily available: at autumn migration staging areas on USA. Arthropods includeadults and larvae of insects and crustaceans, also some molluscs and worms. Fish usually more important in winter, at sea, where crustaceans also taken. Remarkably agile under water, swimming at 1 m/secomb; this enables capture of sizeable fish. Main foraging method is diving, most dives averaging 20 secpmds, also feeds from surface, taming floating and aerial prey, or snatching it off aquatic vegetation.Breeding.Laying Apr-Aug, peaking in June. Usually solitary, sometimes loosely colonial; nest is platform of aquatic plants, usually floating and anchored to vegetation, but sometimes built from lake bottom or rocks at water level.Usually 4-5 eggs; incubation 22-25 days. Sexual maturity at 2 years old.Movements.Migratory. Winters along coast on inshore waters, and to lesser extent on large lakes. Some populations dispersive, moving only to nearby seas. Overland migration by night, at least in N America; coastal migration often diurnal. Some stragglers, especially to S, with records from Bermuda and Hawaii; also Tunisia, Azores and Madeira.Status and ConservationNot globally threatened. In past may have had much wider distribution in NW Europe. but acidification and increased humus content of laks probably led to range contraction; man-induced eutrophication of lakes has permitted general expansion during 20th century, but species currently declining in places.Israel.In Israel subspecies P. a. auritus.. Accidental visitor. |
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