Summer Field Report, June-July 2006

Under Old Business , numbers of Black-capped Chickadees are beginning to recover, but several observers mentioned that American Crows and, most recently, Black-billed Magpies are still suffering lowered numbers. On the plus side, Scissor-tailed Flycatchers continue in increasing numbers, including a pair (or at least one of a pair) that returned to the same location where they nested successfully last year and succeeded again this year. And now \u27\u27New Business . Evidence came to hand that both Western and Clark\u27s Grebes may have suffered poor breeding success due to poor water conditions at traditional breeding sites. An intriguing observation on 28 Jul by Helen Hughson at Wind Springs Ranch of increased numbers of individuals unexpected at that date was attributed to the serious forest fires on the Pine Ridge some 50 miles to the north. Included were Red-eyed Vireo, Pinyon Jay, Yellow Warbler, and Western Tanager. Elsewhere, grassland birds showed some marked displacements, although most are quite well-adapted to undertake such movements as needed when grassland conditions change from year to year. A major westward movement of Dickcissels took place in spring and early summer, and young were raised by these birds, in contrast with the usual situation of westerly arrival in mid- to late summer, singing by males, no apparent breeding, and departure a few weeks later. Lark buntings were noted in good numbers eastward. Sedge Wrens normally appear in large numbers in late Jul, and may breed then. Some evidence was obtained that Henslow\u27s Sparrows may do something similar but without the major north-south movement, merely moving from field to field as the season progresses, perhaps, however, for the same reasons Sedge Wrens (and other grassland species) undertake significant movements in mid- to late summer