REPORT OF THE ORNITHOLOGIST AND MAMMALOGIST. 233 



19. In your opinion, are Skunks beneficial or injurious? On what facts is this 

 opinion based? 



20. Do you know of one or more instances in which tJie increase of a species of 

 economic importance has been Kmite J by the abundance of its natural enemies ? If 

 so, give ))articular.s. 



In tiie Mississippi Valley, and- the region between it and the Pacific, numerous 

 small rodents called Gopliers do great damage to farms and crops. There are two 

 principal kinds, Pocket Gophers, which hve mostly under ground, and are charac- 

 terized by external cheelc-pouclies and unusually large fore-claws {Oeomya and 

 Thomomys), and Gophers or Ground Sepiirrels, which live mostly above ground, and 

 have neitlier external cheek-pouches nor claws of unusual size {Spermophilus and 

 Tamias). Of these the common little Striped G<.)\)\iqy {SpermopJdlus tridecemline- 

 aUis) and the large gray " Line-tailed" Spermophile {Sjierinophilns gravimtirus) and 

 its varieties are most abundant and widely disti'ibuted, and occasion tlie greatest 

 losses to grain crops. Numerous other species, more or less local, atfect the farmer's 

 interests very appreciably. 



Detailed information is desired concerning the habits and ravages of all these 

 Gophers. Such information should be accompanied by a specimen (a rough skin 

 will suffice) for positive identification. 



The above remarks apply with equal force to the various small mammals known 

 as Kangaroo Rats and Mice, Pocket Rats and Mice, Wood Rats and Mice, &c. 



In answering this circular please mention your occupation. If a farmer, state 

 the size and character of your farm, and mention the principal crops which you 

 cultivate. 



Write your name and xjost-oflice address as plainly as possible. 



[Circular No. 4.] 



INSTRUCTIONS FOR THE COLLECTION OF STOMACHS. 



In investigating the economic relations of birds and mammals it is necessary to 

 determine with accuracy the character of the food upon which the various kinds 

 subsist. This is particularly important in the case of species which are known to 

 exert an influence, beneficial or otherwise, upon certain farm and garden crops. 

 Hence the Department of Agriculture desires to secure a collection of the stomachs 

 and gizzards of our native mammals and bu'ds, i^articularly of those which are sup- 

 posed to affect asi-icultural interests. 



Method of preparation. 



All specimens should be preserved in 90 per cent, alcohol. 



A stout paper tag should be attached to each stomach or gizzard by means of a 

 sti'ong thread or fine wire, which should be passed dii-ectly through its substance. 

 Each tag should be numbered (in hard pencil) to correspond with the number given 

 the specimen on the accompanying blank. Some bu-ds, particularly in the breeding 

 season, carry food in the gullet or crop. In such cases these portions of the aliment- 

 ary tract should be preserved, and should bear the same number that is given the 

 gizzard of the same individual. 



Stomachs of the following species are especially desu'ed: 



Bt/'ds.— Hawks, Owls, Crows, Jays, Blackbirds, Cowbird, Slnrikes, Cuckoos, Caro- 

 lina Dove, Woodpeckers, Quail, English Sparrow, Bobolink or Rice-bird, Kingbird 

 or Bee Martin. 



Mammals.— Fox, Skunk, IVIink, Weasels, Badger, Raccoon, Opossum, Squirrels, 

 Ground Squirrels, Gophers, Mice, Moles, Shrews, Bats. 



In the case of Mice, Moles, Shrews, and Bats, the entire animal should be sent, in 

 order that the species may be fully identified. 



A number of specimens may be preserved in a single wide-mouthed bottle or jar. 



Persons willing to aid in the collection of stomachs will be furnished with blanks 

 on which to record the necessary data. 



Transportation charges will be paid by the Department. 



