י540) עורב מזרע

Rook
Rook
Rook








Corvus frugilegus
Corvus frugilegus
Corvus frugilegus


:עורב מזרע
. עורב גדול, שחור, לבוגר כתם לבן כתוצאה מעור חשוף נוצות ליד מקורו
. נוצות רפויות מעל שוקיו נראות כמכנסים רפויים
. הצעירים חסרי הסימנים האלה נראים כעורב אירופי
. בית גידולו משתרע על פני רחבי אירופה למעט רוב סקנדינויה, ומאנגליה עד לקוריאה
בית חיותו נופים שיש בהם עצים פזורים, נמנע מאזורים הרריים, שלג וקרח וכן מאזורים
. חמים מלבד בחורף
. בארץ מבקר חורף שכיח ובמדת מה עובר אורח, בעיקר במרכז ובצפון הארץ
... וישלח את העורב ... בראשית ח' 7
Subspecies and Distribution.
C. f. frugilegus Europe and Asia Minor E to Yenisey river, N-W Altai, and N-W Sinkiang.
C. f. pastinator from Yenisey and C Altai east to E Siberia, Japan, Korea, and E China. םםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםם םםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםםם םםםםםםםםםםםםםםםםםםםםםםםםםםםםם
Descriptive notes.
44-46 cm, 400 g, wingspan 81-99 cm. Quite large and elegant crow, with slender bill, bare, and pale face, and characteristic "baggy trousers" above legs.
Slightly smaller than Carrion Crow, proportionately smaller head with steeper forehead, and seemingly deeper body due to loose flank feathers cloaking thighs. In flight, more splayed wing-tips and rounder tail. Plumage black with heavy floss. Highly sociable at all times of year. Voice distinctive. Sexes similar, no seasonal variation.
Habitat. Breeds only in boreal and temperate middle latitudes of west Palearctic, in both continental and oceanic lowlands, but absent from warmer regions, except in winter. Strong winds, ice, and snow are avoided but rain and mist are tolerated. Range excludes most mountains regions.
Food and Feeding.
Invertebrates, mainly beetles and earthworms, plant material, small vertebrates, carrion, and scraps of all kinds.
Primarily a bird of agricultural landscapes, foraging almost exclusively on ground, only rarely in trees, taking defoliating caterpillars or swarming beetles in spring. Forages on both pasture and arable land. In spring, feeds on newly-sown cereal or follows plough, etc., for exposed invertebrates, particularly larvae, then moves to pasture, notably where water-table high.
Breeding.
Mid Mar to end of Apr in Britain, mid Apr to mid May in C Russia.
Nest site, in topmost crown of high tree, exceptionally on horizontal branch or against trunk. Tree almost always in rather isolated groups.
Nest, fairly regular hemisphere, sometimes slightly flattened. Foundation of sticks and large twigs, inside which layer of thin pliable twigs very often of birch and willow, many with leaves, followed by compact mass of rootlets, moss, etc., mixed with clay to form small cup, which is lined with grass, moss, stalks, feathers , leaves, paper, etc.
2-6 eggs sub-elliptical, smooth and faintly glossy. Light blue to dull green with olive-buff to times forming cap at broad end.
Incubation, 16-18 days, by female only.
Movements
Resident to migratory, with more birds migrating in cold winters. Winters in Eurasia, within and south of breeding range. Migrates by day in flocks, often following leading-lines such as coastlines and river valleys and frequently accompanied by Jackdaws.
Status and Conservation.
Not globally threatened. European Populations probably C 10.000.000 pairs.
Israel.
In Israel subspecies C. f. frugilegus common winter visitor, and to some extent passage migrant, of varying annual abundance.

C. f. frugilegus
in Israel

C. f. pastinator

f. frugilegus


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