282 Union Bay 



location, size, and the actions of the hens. The canoeists 

 watch with concern the shrinkage in the numbers of the 

 ducklings. Day by day the losses continue until the broods 

 of twelve are reduced to perhaps five or six, and the hen 

 which began with three will be swimming with one lone 

 baby trailing her. At long intervals a mink will be seen tak- 

 ing a bird or feeding on one in late evening. The result is 

 that the mink is held responsible for all the duck losses. 

 When it is mentioned it is usually referred to as that killer. 

 Now the mink, which is a member of the weasel family, 

 is a killer, which under certain conditions may be chiefly 

 responsible for the mortality among young waterfowl. Bu.t 

 in our marsh I am quite sure that this showy predator is far 

 outclassed in destruction by another mammal which does no 

 advertising but which is present in large numbers and, as 

 baseball slang has it, is always pitching, I refer to the brown 

 or Norway rat. The presence of sanitary fills in the district 

 has attracted hordes of them, and although they are trapped 

 and poisoned continually they have a cunning and adapta- 

 bility which enables them to exist in unbelievably large 

 numbers. I have seen them just before dark as they ran about 

 the marsh margins, on the prowl for nests, young, food 

 dropped by visitors, sickly or dead fish, or anything of food 

 value. I have watched them swim short distances as they 

 cut across an inlet. I have heard that in many places they 

 climb about in trees. They have been responsible for the de- 

 struction and total elimination of many ground-nesting birds. 

 They have spread to every country on the globe. They are 

 the archpredators, not because they are always more fero- 

 cious or active than the local predators which they some- 

 times replace, but because their fertility and adaptability 

 enable them to meet all conditions. In the marsh their work 

 is furtive. Now and then I hear that a rat has been seen 

 feeding on a dead bird, the implication being that some 



