| י26) יסעורון מדירה | ||||||||||
| ||||||||||
|
:יסעורון מאדירה צבעו הכללי חום. בשעת מעופו דומה ליסעורון וילסון, ליסעורון אטלנטי . וליסעורון קטן. גדול במקצת מהיסעורון הקטן וכנפיו ארוכות במקצת נבדל מיסעורון וילסון ברגליו השחורות והקצרות יותר, ומהיסעורון האטלנטי . בשתו הלבן יותר. זנבו מפורץ אבל קשה להבחין בכך ממרחק . בית גידולו ימים ואוקינוסים חמים. מקנן באיים מרוחקים ושוממים . בארץ מזדמן באקראי נדיר ביותר | ||||||||||
|
Subspecies and Distribution.
Oceanodroma castro E Atlantic from Portugal Is. and Azores to Ascension Is.and St Helena In the Pacific off E Japan, Hawaii and at Galapagos. | ||||||||||
|
Descriptive notes.
19-21 cm; 29-56 g, wingspan 44-46 cm. Wings shape intermediate between Oceanites oceanicus and Oceanodroma leucorhoa: tail slightly forked, unlike Oceanites: and Hydrobates,: and underwing uniformly dark. Legs do not project beyond tip of tail in flight. Juvenile has mor grey on greater upperwing-coverts. Habitat. Marine and highly pelagic,occurring in warm waters; rarely approaches land except near colonies. Breeds on undisturbed islets, in flat areas near sea or inland on cliffs. Food and Feeding Mostly planktonic crustaceans, small fish and squid; also feeds on some human refuse. Feeds mainly on wing, by pattering and dipping; also surface-seizes. Most feeding by day. Breeding. Season varies locally; in Galapagos two distinct populations breed annually, but 6 months out of phase. Colonial; nests in rock crevices or burrows. 1 egg; incubation 42 days, with stints of 4-7 days; chicks pale grey down, brooded for 7 days; fledging 64-73days. Estimated annual mortality of adults 6%; known to have reached nearly 11 years old in wild. Movements. Apparently some birds largely sedentary, since colonies visited irregularly throughout year; others disperse widely, with records from Atlantic coast N America, Britain, Cuba and Brazi Status and Conservation. Not globally threatend. Widespread, many islands holding several thousand breeding pairs; figures lacking for several areas. Main threats include exploitation by local fishermen, particularly on some Atlantic islands, and predation by introduced mammals, rats, mice, mongooses; land crabs and Barn Owls kill many birds in Cape Verde Is. Israel. In Israel subspecies Oceanodroma castro. Very rare visitor. |
| |||||||||
| HOME | NEXT | |||||||||
