No. 530] RELATIVE CONSPICUOUSNESS OF FOWLS 113 



natural enemies. The total number of chickens involved 

 was 3,343. An account of the way in which the statistics 

 were obtained is necessary. All of these 3,343 chicks 

 were of known pedigree, and a numbered aluminum 

 leg band was attached to each one when it was re- 

 moved from the incubator in which it was hatched. A 

 record was made of each chick's number. This num- 

 bered leg band was worn by the chick throughout its 

 life. Whenever a chick died a record of this fact was 

 made opposite its entry in the pedigree book. Dur- 

 ing the season every living chick on the range was 

 handled over twice and its leg band number checked back 

 with the original entry, and at the end of the season all 

 chicks remaining on the range were checked up. 



Now it is clear that dead chicks which come to autopsy 

 will fall into two general classes : on the one hand, those 

 that died from one or another of the many diseases which 

 make the poultry raiser's life a burden in the springtime, 

 and on the other hand, those killed by some enemy but not 

 carried away. In the latter class will fall the great ma- 

 jority killed by rats, some killed by skunks, and a fair 

 proportion of those killed by foxes. Usually a direct 

 record can be obtained for practically none of the chicks 

 killed by predaceous birds and cats. In 1909 we have 

 reason to believe that substantially all unrecorded deaths 

 were caused by predaceous birds. 



At the end of the season when the birds are checked 

 up all will be accounted for as either (a) living, (b) dead 

 from some disease, (c) killed by recorded enemies, or 

 finally (d) missing. Of the missing birds there are two 

 classes again. On the one hand are those killed by ene- 

 mies which carried the carcases away, and on the other 

 hand, are those that through accident lost their leg bands, 

 and hence, while present in the flock, can not be entered 

 upon the records. With the methods of work in use here 

 the number of the latter class lias always been small. 

 Unfortunately I am not able to give exact figures for such 

 birds for the season of 1909. It can be stated with cer- 



