165.★ Seiurus noveboracensis. Northern Water-Thrush.—One or two seen nearly every day the last week in August at Camp 11, Little Sandhill Creek, specimens, August 20 and 21. These are referable to S. n. notabilis.
166.★ Oporoenis philadelphia. Mourning Warbler.—At Camp 1, where warblers were scarce, this was the species most often met with. A mated pair were taken just below Camp 4 near Nevis. In all these birds the abdomen was bare and thickened so they were undoubtedly breeding. Young took another at Camp 11, Little Sandhill Creek, August 17. The male of the Camp 4 pair, is typical philadelphia but the female has the eyelid spots as pronounced as in many female Macgillivray’s Warblers. It is evident that females of the two species may be difficult of separation. This specimen unaccompanied by its mate would almost unhesitatingly be referred to O. tolmiei. The Camp 11 specimen is also interesting. By skull structure it is a juvenile but is very different in coloration from any other specimen in our collection. It is Empire Yellow below warming to Primuline Yellow,[25] instead of Lemon Chrome changing to Sulphur Yellow on neck and throat as is shown by comparable August and September material from Point Pelee, Ontario. However, fall specimens of this species are scarce in collections and I have no fall juveniles of tolmiei for comparison and include it under philadelphia on the strength of accompanying specimens.
167.★ Geothlypis trichas. Maryland Yellow-throat.—Sparingly distributed but seen practically throughout the trip and becoming a little more common as we descended. The last week in August they were fairly common at Camp 11 on the Little Sandhill Creek but thinned out after the first of September. Specimens from Camps 4½, 8 and 11. In harmony with the findings of the A. O. U. Committee as indicated in the ‘Check-list,’ I am inclined to refer our Canadian prairie Yellow-throats to occidentalis rather than to trichas, of brachydactyla, as some of them have been designated by Oberholser. In fact I find them easily distinguishable from birds of eastern Canada and almost if not quite inseparable from B. C. specimens determined as arizela by the same authority. For the present, I prefer to regard these birds as G. t. occidentalis.
168.★ Wilsonia pusilla. Wilson Warbler.—Not seen until August 21 at Camp 11 on the Little Sandhill Creek after which one or two were seen every other day until September 18. Specimens, August 21 to September 18. These were well marked W. p. pileolata. Some are rather small for this form but the colors are distinctive.
169. Wilsonia canadensis. Canadian Warbler.—Reported by Young at Camp 1, but not noted again.
170.★ Setophaga ruticilla. Redstart.—Only seen at Camp 11 on the Little Sandhill Creek between August 26 and September 6. Specimen, Camp 11, August 27.
171.★ Anthus rubescens. American Pipit.—Pipits appeared in large flocks on the prairie level near Camp 11, Little Sandhill Creek, September 12, but were not noted after the 17th.
172.★ Anthus spraguei. Sprague’s Pipit.—Only seen once by Young at Camp 11, Little Sandhill Creek, September 13. He says it hid in the holes made by the feet of horses and cattle, allowed close approach, flushing like a grouse. Specimen Camp 11, September 13. From Farley’s notes it evidently occurs at Red Deer but is more common in the vicinity of Camrose.
173.★ Dumetella carolinensis. Catbird.—Fairly common along the whole river. At Camp 11, Little Sandhill Creek, they fed upon Buffalo berries. None were noted after September 7. Specimens, Camp 2 and 11.
174.★ Toxostoma rufum. Brown Thrasher.—Only seen occasionally at Camp 11 on the Little Sandhill Creek. None observed after September 1. Specimen, Camp 11, August 6.