Thứ Ba, 21 tháng 2, 2012

Kestrel

 
  
The Life of Animals | Kestrel | The name kestrel, (from French crécerelle, ie crécelle derivative from Ratchet) is given to Several different members of the falcon genus, Falco. Other Falcons are more adapted to active hunting on the wing.  Kestrels require a slight headwind in order to hover, Hence a local name of Windhover for Common Kestrel. Kestrels are bold and have adapted well to human encroachment, nesting in buildings and hunting by major roads.


Kestrels do not build nests Their Own, but use nests built by other species. Most species termed Kestrels Appear to form a distinct clade Among the Falcons, as suggested by comparison of mtDNA cytochrome b sequence data (Groombridge et al., 2002) and morphology.  The most basal "true" Kestrels are three species from Africa and its surroundings the which lack a malar stripe, and in one case have, like other Falcons true but unlike other large Kestrels areas of gray in their wings.


Approximately during the Gelasian (Late Pliocene or Early Pleistocene, around 2.5-2 mya), the main lineage of true Kestrels emerged; this contains the species characterized by a malar stripe.  More enigmatic is a group of 3 predominantly gray species from Africa and Madagascar.  The American Kestrel is the only New World species termed "kestrel".

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