^°\^oV^' I Mattingley, Cormorants in Relation to Fishes. 21 



to keep certain species of fishes from increasing in number 

 beyond a proper limit, and so other fishes have been ordained to 

 destroy more of their brethren than the Cormorants do. Were 

 statistics collected showing the number of fish destroyed in 

 other ways beside being eaten by Cormorants the number 

 tabulated against these birds would be insignificant. Do not 

 " muzzle the ox that treadeth out the corn " is an old-time proverb, 

 and one universally admitted to be correct. Why, then, muzzle 

 the Cormorants after they have destroyed such vast numbers of 

 the enemies of fishes .'' Cormorants are but safety-valves in the 

 boilers of nature. Why do not our anglers utilize the Cormorants 

 like the Chinese, who train these birds to fish for them ? The 

 method adopted is to capture the birds when young, so as to 

 accustom them to handling, and then they are taken out in the 

 boat with experienced adult birds, which teach them how to 

 catch fish, and after the younger birds have become expert 

 fishers the Chinaman slips a rubber ring over the Cormorant's 

 neck to prevent the bird swallowing the fish when it captures it, 

 and when it finds it cannot do so it returns to the boat and 

 allows its keeper to abstract the fish from its beak. 



Erroneous ideas are rife as to the quantity of fish that a 

 Cormorant can consume. Some persons assert that these birds 

 eat as much as lo lbs, of fish daily. However, when their 

 assertion is investigated it is found to be only conjecture. The 

 digestive power of a Cormorant is regulated by the bird's size, 

 and the quantity of food demolished at one meal by the 

 different species varies according to the size of their gullet, 

 which limits their capacity for swallowing, being greater in the 

 larger species than in the smaller. The species that are 

 numerically strongest here are P. sulcirostris and P. 

 melmwleucus. The weight of the bodies of these species is 

 between 2^ and 3 lbs., and it is questionable whether they are 

 able to eat their own weight of fish daily. Their digestive 

 organs, which are but a small part of the mechanism of the bird, 

 can only cope with a given quantity of material — certainly not 

 more than i ]/z lbs. weight. On several occasions I have observed 

 Cormorants catching eels, and in one instance a bird was 

 observed, early in the morning, sitting on a log with a length of 

 eel hanging out of its mouth. To prevent it slipping out of its 

 gullet the bird had to keep its head up in the air. It had 

 swallowed the eel head first, a customary method adopted when 

 swallowing a fish. It was waiting for the fish to be digested, 

 and when passing the same spot later on, in the afternoon, part of 

 the fish was discerned projecting from its beak, and it would 

 have been dusk ere the bird had finally swallowed its prey, 

 whilst the process of digestion would have still proceeded during 

 the night. 



It is not generally known, but nevertheless it is a fact, that the 



