302 THE BIRDS OF THE BRITISH ISLES. 



the Great Crested Grebe during nuptial display. In ordinary 

 slow progression on the surface the leg strokes are alternate, 

 but when diving or swimming at great speed they are simul- 

 taneous and lateral, in the same plane as the body. The dive 

 is its highest accomplishment ; its existence depends upon 

 great speed under water, the power to overtake swiftly swim- 

 ming fish. The method differs according to circumstances ; I 

 have seen it spring forward, almost clear of the water, to take a 

 deep header, and at other times submerge its body until the 

 head and neck alone were visible, when, dipping these, it slid 

 forward, hardly disturbing the surface. As a rule, during the 

 dive, the wings are held close to the sides. 



Holboll stated that the Loon would remain under water for 

 eight minutes, and Payne- Gall wey timed one for ten, but he 

 admits that the bird was wounded or alarmed, and under 

 these circumstances it will protrude the head only and dive 

 again at once ; probably he missed one or more momentary 

 appearances on the surface. My own times of an unsuspicious 

 bird were, amongst many short periods of absence, two of two 

 minutes and one of three ; I do not think that the bird's head 

 appeared, even during the long absence from sight. One very 

 busy bird, timed for a quarter of an hour, was out of sight for 

 14^ minutes, only remaining on the surface for a second or two 

 at a time ; I did not see it bring up a single fish, as probably 

 its prey was small. Large fish are brought up to be eaten and 

 are swallowed head first. Crustaceans and cephalopods are 

 also eaten. A little water is usually sipped immediately after 

 the dive. Rising from the surface is only accomplished after 

 thrashing the water with its wings, and it has not been seen to 

 rise from the land, where indeed it can only shuffle along in a 

 prone attitude ; it does not sit up as frequently depicted. The 

 Loon has the same distressful wail as other divers, and a 

 milder, more musical love-call, as well as a deep guttural 

 growl, which I have heard uttered by winter birds. 



