20 CATALOGUING AND LABELING 



courage you. An expert can make ten birdskins an hour, and you need 

 only practice to approach this. 



Sexing. A specimen without a sex mark on its label is of com- 

 paratively little value. The sexes in many birds can of course be dis- 

 tinguished by their color, but the young male frequently resembles 

 the female, while in some instances the female has been known to as- 

 sume the plumage of the male. Dissection, therefore, is the only safe 

 way to determine sex. Upon reaching stage 36, in the operation of 

 making a birdskin, cut through the left side of the body from the vent 

 to the neck, taking care not to disturb the internal organs. Force the 

 edges of the opening apart, and, pressing the intestines gently to one 

 side, look for the sexual organs, which will be found on the walls of 

 the small of the back very near to the backbone. The male organs 

 (testes), two in number, are usually dull- white, elongate bodies lying 

 side by side. The female organs (ovary) are composed of numerous 

 round bodies lying in a mass or cluster. In the breeding season the 

 sexual organs of birds become much enlarged, and at this season the 

 testes of a male Chipping Sparrow are about the size of a pea, while 

 the ovary of the female has been likened to a bunch of grapes, the 

 largest being the size of the yolk of the egg of this species. After the 

 breeding season the sexual organs decrease in size, and in adults in the 

 winter and young birds are sometimes difficult to find. The testes of 

 a male Chipping Sparrow at that season are about as large as a small 

 pinhead, while a hand-lens is required to plainly distinguish the ovary 

 of the female. The arrow of Mars (rf) is used to indicate the male sex; 

 the mirror of Venus (?) the female sex. 



Cataloguing and Labeling. Before skinning your birds you should 

 catalogue them. The catalogue should have columns giving (1) the 

 date, (2) your serial collection number, (3) name of the bird, (4) sex 

 and condition of the sexual organs, (5) place of capture, (6) name of 

 collector, and (7) remarks. In the last column enter any notes on the 

 color of the eyes, or parts which will change color when drying, con- 

 tents of the stomach, and other notes. In addition to this 'day-book' or 

 'blotter' some ornithologists open a ledger account with their collection 

 and devote a folio to each species, on which are posted the entries 

 made in the collection register. 



Labels should be of strong bond paper, two inches and a half long 

 and half an inch wide. They are attached to the crossed legs of the 

 bird by linen thread strung through their left end. The face of the 

 label bears the name and sex of the bird, place and date of capture, 

 name of collector, and serial collection number. The label shown in 

 Fig. 4 is small, but will illustrate the appearance and manner of 

 attachment. The name of the owner of the collection is printed on the 

 back of the label, preceded by the words "Collection of." 



Many collectors prefer to use as a field label a small jeweler's tag 

 upon which the collection number, sex and date are written. The 

 large label is added after the specimen is dry. 



