494 MURIDAS—ARVICOLA 
does not scruple to call it an omnivorous consumer of frogs, 
toads, crayfish, dead fish, and swan mussels. 
The dead fish question he proved by observation and by 
pegging down a roach with the special object of catching the 
criminal. As to the deliberate catching of live fish, the Rev. 
F. R. Jourdain’ has seen one eat a small trout, Mr W. P. Birch? 
reports an instance of a live minnow being taken when used as 
bait, and Mr H. H. Gray® believes that trout are taken up to 
10 inches in length. Altogether there can be no doubt that the 
Water Rat will eat dead fish, but the evidence for its active 
piscivorous propensities in other directions, although supported 
by Charles St John, is meagre, and it certainly has not the 
Otter’s ability to capture fish in fair pursuit. 
The fact that Water Rats may eat fresh-water mussels was 
long ago suspected by J. H. Gurney,* R. F. Tomes,’ and Sir 
Edward Newton, the latter of whom made the suggestion to 
Mr A. Patterson.’ All three found very suspicious heaps of 
dead shells always perforated either nearly opposite, or else at 
the hinge. Mr Patterson has since seen one carrying a mussel, 
and the ‘‘signs” of the animals all around the heaps of broken 
shells—in this case always perforated on one particular side. 
Mr C. E. Wright’ has also sent me an account of one eating 
a dead mussel which he observed himself, and he has also 
watched another fishing for water snails (Lzmnea stagnalis), 
one of which was devoured in his presence. 
A quite exceptional observation is that of Mr Charbonnier, 
who saw a Water Rat trying to drag into the river Trym 
a young rabbit larger than itself. Mr Charbonnier does not, 
however, think that the Water Rat had any intention of eating 
the rabbit, which screamed and escaped. 
Water Rats are exclusive animals. A Brown Rat, if 
captured alive and caged with others of its species, usually— 
1 In Millais, ii., 295. Field, 16th July 1887. 
3 Field, 17th January 1903, 110. Zoologist, 1849, 2887. 
5 Journ. cit., 1850, 2638. Of. cit. 
7 Wright observed a fight between a Brown Rat and a large crayfish, in which 
the latter by getting its pincers around the mammal’s throat became the victor ; and 
Adams has known Brown Rats to eat crayfish frequently. It is not always possible 
to distinguish the work of these two rodents, but undoubtedly the cap sometimes fits 
the Water Rat. 
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