National Wildlife Kefuge in 1;>;')J). 

 In the words of the refuge manager : 



as we looked over the dead SixirtiiKi 

 marsh, we saw a mai'sh hawk drop to the 

 s;round several times after prey. A few 

 mlmites later it flew out over the ad- 

 jaeent ocean beach, fairly close to us. 

 At this point an adult bald eagle which 

 liad been circling above, dropped on the 

 marsh liawk and forced it to release its 

 lirey. 'Ilie eagle quickly landed on the 

 beach and. within a few steps, seized the 

 object and was off again. Arriving at 

 the spot we picked up a few scattered 

 feathers which proved to be those of a 

 sora i-ail (Porzana Carolina). 



CANADA 



In eastern Canada, Bruce S. 

 "Wright (1948) })resented an un- 

 usual as})ect of eagle-waterfowl re- 

 lations which might easily be over- 

 looked were all pertinent facts not 

 available : 



This eagle is the most important 

 waterfowl predator on the area, but what 

 data we have show that, exclusive of 

 the hunting season where it takes many 

 cripples, the diet of the eagle is made 

 up of four-fifths fish and carrion and 

 one-fifth ducks. The most frequently 

 taken fish is tlie eastern chain pickerel 

 (Esox nif/cr), and the pickerel taken are 

 usually large enough to be duckling pred- 

 ators themselves. Therefore, it appears 

 to be good management to retain the 

 eagles as they do more damage to the 

 pickerel, an undesirable species in a duck 

 marsh, than they do to the ducks. 



At another time Wright (1953) 

 presented the seasonal picture of 

 eagle predation. 



As the winter progresses and shoi'e 

 ice forms in the shallows, they have 

 been known to concentrate around flocks 

 of wintering waterfowl and to become 

 predators of first importance. However 

 the total number of eagles remaining in 



the north throughout the winter is not 

 large, and their depreilations are only 

 of local importance. 



At the first signs of open water inland 

 they leave the coast once more for the 

 freshwater habitat and resmne tiieir fish 

 diet as soon as possible. The waterfowl 

 gradually lose the fear of the eagles they 

 have acquired during the winter months 

 and both pass the summer together in 

 harmony on the marshes. A few eagles 

 persist in taking ducks at intervals all 

 summer, but they are the exceptions. 



As a defensive measure against 

 the attacks of the biild eagle, coots 

 have evolved a unique method of 

 defense that has been observed on a 

 number of occasions. In the words 

 of James A. Munro (1988) , who has 

 witnessed the performance in Brit- 

 ish Columbia : 



When attacked the ( 'oots come together 

 in a close flock and move rapidly across 

 the water with necks outstretched ; they 

 do not dive. The pursuing eagle planes 

 down but checks its flight when a few 

 feet above the mass of birds, ascends, 

 circles over the flock, then again hurls 

 downward with tremendous force that 

 again is suddenly braked. This maneu- 

 ver may be repeated a dozen times with- 

 out a capture being made and each time, 

 terrified by the eagle's nearness, the 

 Coots surge across the water. Appar- 

 ently the eagle rarely takes a bird from 

 the midst of the flock, although it would 

 seem an easy thing to do, but pursues 

 directly any straggler, and almost invari- 

 ably captures it. 



A very similar performance has 

 been observed in Florida (Bent 

 1937), where wintering flocks of 

 coots supply a frequent item of diet 

 of the eagle. While in massed con- 

 centrations the coots appear to be 

 reasonably secure, but the moment 

 an individual bird forsakes the flock 

 it is a doomed bird. 



35 



