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 110 THE CONDOR Vol. XVII The Olive-backed Thrush (Hylgcichla ustulata swainson) is by far the most abundant bird about the station. Up till late July these birds sang very frequently. Often eight different birds were heard in song at the same time. The songs were heard throughout the greater part of the day, only ceasing for a few hours at noon. This song, while pleasing at first, is of much poorer quality than the less frequent songs of. other thrushes, so that in time it loses its charm and becomes decidedly monotonous. The nests of this thrush are easily found. They outnumbered all others to uch an extent that I found an average of nearly three of them to one nest of any other bird. I had not been at the station long before the first addition to the list of Flathead birds was made. This was a male Rocky Mountain Pine Grosbeak (Pinicola enucleator mo.tana) that was discovered on the morning of June 27 by Dr. M. J. Elrod, Director of the Station, in the fir trees not far back of the Station building. We watched the bird for some time and easily identified it before it flew off. It is quite probable that this bird is a common summer resi- dent of the higher mountains nearby, but what it was doing here in the Transi- tion zone, and in the breeding season, is a puzzle. It was not seen again and probably returned to the higher mountains where it belonged. Fig. 40. OSPREY ISLAND FLATHEAD LAKE, MONTANA On the same day that this bird was found, a trip was made to one of the numerous small islands near the southern end of the lake. A pair of Ospreys (Pandion haliaetus carolinensis) was occupying a large and conspicuous nest placed in a dead fir at one end of the island. Their presence here for a number of seasons had given this the name of Osprey Island. It is evident that the Osprey is one of the birds that is decreasing in numbers in this locality. Nests that had been occupied in former years were common about the lake shore; but this was the only occupied nest that I saw during the entire season. (See fig. 40.) The top of Osprey Island is covered with a dense thicket of bushes, and about its edges are numerous dead fir stubs and a few live cottonwoods. The whole island is small, only a few acres in extent, but the bird life on it is abund- ant. Nests were numerous, and altogether I found on it, in the course of half an hour, more nests than I found in all other places about the lake put together during the entire summer. Yellow Warblers (Dedroica aestiva aestiva) were perhaps the most numerous, but Olive-backed Thrushes, Robins (Plaesticiis ,igratorius propiqus), and Catbirds (Dmetella caroliesis) were not far