420 Recent Literature. [jiily 



Field Studies of the Food of Nestling Birds. — Four papers ^ by 

 students at the Iowa Lakeside Laboratory, give remarkably detailed ac- 

 counts of the food of the nestUngs of three species of birds. 



These papers are selected for discussion not because they are vastly 

 different from other recent articles on their subject, nor because they lack 

 in general merit. The flaw the reviewer would point out is perhaps due to 

 over-enthusiasm on the part of the observers, or perhaps to failure to 

 reahze the difficulty of making exact identifications of insects. Neverthe- 

 less it is a fault, and a grievous one to publish identifications that could 

 not possiblj^ have been made under the conditions. 



As an example the following is quoted from paper No. 3, on the Catbird: 

 " Among the 55 beetles fed were recognized may-beetles, click beetles, tiger 

 beetles, water beetles, and snout beetles of various species. The flies were 

 mostly fish flies, though house and stable flies were noted." (pp. 179-180.) 

 A mosquito also is recorded. Now the positive identification of a mosquito, 

 and the distinguishing of the house and stable flies, two obscurely marked 

 species of the same family require far closer and more definite observation 

 than could possibly be made on specimens in process of being fed to nestling 

 birds. Sixty-five identifications of mosquitos are recorded in paper No. 2 

 (p. 55). It would be of interest to know how it was decided that these 

 insects were mosquitos rather than midges {Chironomidoe), fungus flies 

 (Mycetophilidce) or even small crane flies (Tipulidce), all of which have a 

 strong general similarity. 



These are only instances; the food notes throughout are more definite 

 than could reasonably be expected. When a writer says an adult thrasher 

 on one visit to the nest fed 4 May-flies, on another 5, or 7, or 6, we wonder 

 how they could be so accurately counted. The number of ants is some- 

 times given; it would have been an achievement merely to have recognized 

 that ants were being fed. Wire-worms are often recorded, in spite of the 

 liability of confusion with very similar Tenebrionid larva3. 



Enough of iUustrations however, the point is this : it should be recognized 

 that reporting on the food of nestling birds on the basis of field observation 

 is work for accomplished entomologists, not for amateur ornithologists. 

 Even with so experienced men on the job little would be learned in many 

 cases. In this connection it is proper to refer to Weed's report on " The 

 Feeding Habits of the Chipping Sparrow." ^ The observations were made 



1 1. Gabrlelson, Ira N. A study of the home life of the Brown Thrasher, 

 Toxostoma rufum (Linn.). Wilson Bulletin, Vol. XXIV, No. 2, June, 1912, pp. 

 65-94. 



2. Bigglestone, Harry C. A study of the nesting behavior of the Yellow 

 Warbler {Dendroica cBstiva astiva). Wilson Bulletin, Vol. XXV, No. 2, June, 

 1913, pp. 49-67. 



3. Gabrielson, Ira N., Nest-life of the Catbird, Dumeiella carolinensis Linn. 

 Wilson Bulletin, Vol. XXV, No. 4, Dec. 1913, pp. 166-187. 



4. A further study of the home hfe of the Brown Thrasher, Toxostoma rufum- 

 Linn. Proc. Iowa Acad. Sci., Vol. XX, 1913, pp. 299-304. 



2 Bull. 55, N. H. Agr. Exp. Sta., July, 1898, pp. 101-110. 



