358 CORMORANTS 



before them partly disabled birds ; though in cases of emergency, or 

 when exceptional efforts are required, the wings may occasionally be 

 used. When not under water the cormorant swims like other water- 

 birds, but frequently submerges its body, so that little more than 

 the head is seen from a distance. The fish, when caught, is regularly 

 brought up to the surface and swallowed entire, but very small ones 

 are also, according to some writers, swallowed under water. The 

 voracity of the species is enormous, and one observer states in the 

 Field that one hundred and eighty small fish were eaten within 

 an hour and a half. 1 Even in the roughest sea cormorants can fish 

 successfully. 



When resting, cormorants frequently shake their wings or stand 

 for long periods with them spread out as do falcons, eagles, and vultures. 

 The bill is frequently opened, and this is perhaps due to the nostrils 

 being almost entirely closed, so that breathing becomes only possible 

 through the mouth. The flight of cormorants is fairly fast, and they 

 fly with outstretched necks and feet. F. Davies saw a cormorant 

 ascending in a regular spiral " until it became a mere speck and finally 

 disappeared from view" (Field, 1901). This habit is probably unusual, 

 though often observed in certain hawks, especially when nesting or 

 pairing. The same wheeling round and upwards, until nearly out of 

 sight, is also described in the Zoologist, 1875, p. 4327. 



Cormorants in winter often collect together in great numbers, 

 and doubtless those nesting on inland waters in northern latitudes 

 must resort to the sea-shores, when the lakes or rivers are frozen over 

 in cold weather, but they do not emigrate. According to Radde and 

 other observers, when massed together 2 they fish systematically in 

 co-operation, proceeding in a long line, and thus searching the shallow 

 waters for a couple of miles or more (Radde, Ornis Caucasica, p. 468). 



1 Radde found that a cormorant in captivity ate in the morning twenty-six and in the 

 afternoon seventeen fish, of an average length of 20 cm., and he reckons that an adult bird 

 requires four pounds of fish within twenty-four hours. 



* Radde saw from six to eight thousand massed together on the Caspian Sea, and many 

 thousands can be seen in company in Egypt in winter. 



