72 



on insect life. Apparently they never touch the products of 

 man's labor. The species most commonly killed by cats in Mas- 

 sachusetts is the short-tailed shrew, Blarina brevicauda. This 

 little mammal probably is mistaken for a small mole by most 

 people, as it somewhat resembles the common mole. 



iNIr. John Norden believes that this gluttonous animal eats 

 about twice or three times its own weight in twenty-four hours, ^ 

 but probably this is exceptional. Nevertheless, the shrew re- 

 quires an amount of food equal to nearly its own weight daily, 

 and cannot live long without food. It destroys enormous quan- 

 tities of worms and insects, and kills many field mice and other 

 mice larger than itself. Shrews may kill more field mice annually 

 than cats destroy. Mr. H. L. Babcock, who has studied the 

 shrew, considers it of great economic value.^ In killing these 

 shrews, therefore, the cat protects quantities of insects and mice 

 which these shrews and their numerous progeny might otherwise 

 destroy. 



New England bats are remarkably useful creatures, as they 

 subsist on mosquitoes and other nocturnal insects which often 

 escape the birds by day, and thus they fill a gap which can per- 

 haps be filled by no other creature. Apparently they have no 

 harmful habits, and their destruction must be set down as against 

 the cat. 



Economic Value of Amphibians and Reptiles. 



The smaller snakes and the toads, frogs, salamanders, newts 

 and lizards which are destroyed by cats all have been proved to 

 be practically harmless and very beneficial as destroyers of insects. 



The toad is an example of the beneficial character of the 

 amphibians. Kirkland finds that the food of the common toad 

 is practically all of an animal nature. Ants form 19 per cent; 

 cutworms, 16 per cent; tent caterpillars and other injurious 

 leaf-eating caterpillars, 12 per cent; June beetles, potato beetles, 

 snap beetles, weevils and allied beetles make up 18 per cent; 

 snails, thousand-legged worms, sowbugs and other injurious 

 forms compose 14 per cent; supposedly beneficial species, such 

 as ground beetles, spiders and carrion beetles, make up 11 per 

 cent, and there is 2 per cent of vegetable and mineral matter, 

 probably taken incidentally with the animal aliment. The food 

 of the toad, therefore, appears to consist mainly of 81 per cent 

 of injurious species, against 11 per cent beneficial ones. The 

 remainder is unidentified animal [insect?] food. 



> Canadian SporUman and Naturalist, Vol. Ill, 1883. 



* Baboock, H. L.: The Food Habits of the Short-tailed Shrew, Science, new seriea, Vol. XL, No. 

 1032, pp. 62(y-630. 



