30 THE CONDOR Vol. XXI identified by the large number of white feathers. She has been divorced for the past ten years and is apparently living a single life. Many other species and pairs could be cited, but as yet we have only circum- stantial evidence on which to base the conclusions set forth in the first para- graph. Escondido, California, November 15, 1918. PARASITISM OF NESTLING BIRDS BY FLY LARVAE By O. E. PLATH URING the summer of 1913,while studying bird life in and about Berke- ley, California,. I fed up some fifty to sixty wild-taken nestlings which im eluded the following species: California Purple Finch (Carpodacus pur- pureus calif ornicus ) , California Linnet ( Carpodacus mexicanus f rontalis ) , Wil- low Goldfinch (Astragali,nus tristis salicamans), Green-backed or Arkansas Gold- finch ( Astragalinus psaltria hesperophilus), Lawrence Goldfinch (Astragalinus lawre?cei), and Lazuli Bunting (Passerina amoena). In most instances these nestlings were taken a few days before they were full-fledged, together with nest and surrounding branches. Before being taught to eat by themselves, they were fed by means of a curved stick in bird fashion, that is to say not forcibly, but b? maldng them realize that they could get food from the beak-shaped end of the stick as they did formerly from the beaks of their parents. This method of feeding usually extended over a period of from several hours to several days, depending upon the age and intelligence of the nestlings. After having succeeded in feeding up several broods without loss, I attempt- ed to rear a nest of five Green-backed Goldfinches, but despite the fact that all five ate readily from the stick, all but one died in a few days . On taking this nest of goldfinches, I had noticed that two or three of the nestlings had swollen eyelids, in some cases swollen to such an extent that it was impossible for the nestlings to open their eyes. Just previous to this time I had contracted a severe case of oak poisoning while roaming through the underbrush in the canyons and along the creeks, and thought that perhaps the nestlings might be afflicted with the same malady. While feeding them, I had noticed .furthermore that their mouths were considerably paler than those of the birds which had been fed up previously. They also appeared less vigorous and did not exhibit the same raven- ous appetite which healthy nestlings show. Their mouths became paler and paler and within two or three days four of the nestlings died, as I have already men- tioned, and even the remaining one looked as though it would not live long. In order to keep it warm, I removed it from the nest and placed it in some warm woolen cloth. To my surprise I noticed a number of maggots, similar in size and form to bumble-bee larvae (about ' 1.5 cm. in length and 0.5 cm. in width), crawl- ing about in the nest. Upon picking the latter apart, I found some twenty or thirty of these maggots. They were creamy white in color and the anterior end of the alimentary canal of a number of them contained a bright red substance which changed to a blackish brown color in the posterior part of the intestinal tract. The other maggots contained the same blackish brown substance, but not the red.
