The Rattlesnake Ash-Flow Tuff erupted 7.05±0.01 Ma from the western Harney Basin, southeastern Oregon. The location of the vent area is inferred based on vent-ward increases in size of pumices, in degree of welding, and in degree of post-emplacement crystallization. Today's outcrops cover 9000 km2 and estimated original outcrop coverage...
The monthly occurrence of subspecies for 18 terrestrial species are given. The greatest differences in seasonal status appear to be among subspecies of the American Robin, Yellow-rumped Warbler, Savannah Sparrow, Song Sparrow, and Dark-eyed Junco.
There were 21 days with observations during 30 January-21 May 1974. Herons were already displaying on January 30, so nesting activity can occur much earlier than has been supposed. A yearling was often seen at the nests, but most nesting activity was by adults. Although eggs were laid in at...
The results of 703 observations are given; most of these were made in the 1930's by James Macnab, Jane Claire Dirks-Edmunds, Dorothy McKey-Fender, and others. These results are the most comprehensive throughout the year for any site above 1,000 ft in Lincoln County and hint that bird communities at sites...
612 Harlequin Duck records are given for Lincoln County, and another 74 records are listed for other coastal counties. In Lincoln County, Harlequins are found mostly in winter, there were often more males than females, the most ever counted was 14, and there is no indication that they nested.
In...
From 25 April through 30 October 1992, I conducted 14 waterbird and raptor censuses at Cabell Marsh. I observed 33 waterbird taxa and seven raptor species, including hatch-year individuals of five waterbird species. The records for each census are given.