Department of Fishery and Wildlife Biology 26 July 1976 Dr. Fred G. Evenden, Executive Director The Wildlife Society 7101 Wisconsin Avenue, N.W. Suite 611 Washington, D.C. 20014 Dear Fred: Thanks for your letter regarding birds you saw in the Aspen area. I taught ecology at an NSF Institute in Aspen one summer so am pretty well acquainted with birds of the area. Both Pine Grosbeaks and Red Crossbills are relative- ly common permanent residents around there. We saw a number of the grosbeaks with young up toward Independence Pass. The redpoll sighting seems very unlikely to me unless they were "crips" or escapees taht didn't make it back north. We get Common Redpolls in the dead of winter irregularly but last winter was a real redpoll year. We had them on all three of the Christmas counts I participated in. I presume you also saw Pine Siskins and Cassin's Finches in town. They were quite abundant nesters the summer I lived in Aspen. We have an official Colorado Field Ornithologist's records committee that reviews rare sightings. If you'd like them to evaluate your redpoll sighting I would suggest you write to the Chairman, Mr. Jack Reddall, 4450 S. Alton Ln., Englewood, Colorado 80110, for report forms they provide. I, unfortunately, don't have any at present. The Nashville, Tennessee and Mourning Warblers are so far not on Colorado's list of normally occurring summer warblers. The latest spring migrants I find recorded for this side of the mountains are (1) Nashville 5/24/64 and (2) Tennessee 6/5/71. Although, as you mentioned, MacGillvray's are common nesters near Aspen, I know of no authenticated records of Mourning Wablers although I heard rumors one of the bird banders caught one this spring; the record report of which is being reviewed by the CFO records committee. William A. Davis' "Birds in Western Colorado" (CFO Monograph No. 1, 1969, p. 31) lists three records from Gunnison for the Tennessee and considers the Nashville a "rare migrant; all records are in the fall". Realize, we have few keen birdwatchers on the western slope. The CFO committee, incidentally, hasn't accepted