Treesearch

We report statewide linear and non-linear trends in density from 1992 to 2001 for six common bird species in the riparian areas of Utah. The six species examined here represent over 24 percent of all observations in the period. Four of the six species showed linear declines (Black-headed Grosbeak [Pheucticus melanocephalus], American Goldfinch [Carduelis tristis], American Robin [Turdus migratorius], and Broad-tailed Hummingbird [Selasphorus platycercus]) over this period, but the decline in only one species—the Broad-tailed Hummingbird—was considered significant here (F = 19.45, P =...

Conservation of species with high Partners in Flight concern scores may require active habitat management. Cerulean Warbler (Dendroica cerulea) occurs at low numbers in the Lower Mississippi Alluvial Valley in the western part of its breeding range. A study of the breeding ecology of the species was initiated in 1992 on three sites there. Characteristics of individual trees used by the birds have been measured in detail. Elements of the vegetation utilized by male Cerulean Warblers, by female Cerulean Warblers, and as nests have been identified. A silvicultural prescription designed to...

Systematic surveys of hardwood forests along the Buffalo National River, the St. Francis Sunken Lands Wildlife Management Area, St. Francis National Forest, Bayou Meto Wildlife Management Area, and the White River National Wildlife Refuge in eastern and northern Arkansas were undertaken between 5 April and 30 June 2000 and 2001 to document current status, distribution, and habitat requirements of Swainson’s Warblers (Limnothlypis swainsonii) in Arkansas. Swainson's Warblers (SWWAs) were detected at 16 sites in deciduous forests at the Buffalo National River, 11 locations at the St. Francis...

Woodland habitat types in the northern Great Plains compose only a very small fraction of the total land surface. These woodlands occur primarily as natural riparian forests or as scattered anthropogenic woodlots and shelterbelts. Natural riparian woodlands have been markedly reduced over the past century, but anthropogenic woodlands have increased during this same period. In this paper, we review and synthesize mist net and point count data from riparian corridor woodlands (Missouri and Big Sioux rivers) and farmstead woodlots in southeastern South Dakota to compare neotropical migrant...

Cattle were removed from the high desert riparian habitats of Hart Mountain and Sheldon National Wildlife Refuges in 1990. This study compares songbird abundance in 2000-2001 to that in 1991-1993 on 69 permanent plots. Of the 51 species for which detections were sufficient to calculate changes in abundance, 71 percent (36/51) exhibited a positive trend and 76 percent (16/21) of species exhibiting a significant change (either positive or negative) increased. The average increase among the 51 species was equivalent to 3.0 detections/km². Increasing species included species of concern in the...

Riparian forests have long been considered important habitats for breeding western landbirds, and growing evidence reinforces their importance during the migratory period as well. Extensive modification of natural flow regimes, grazing, and forest clearing along many rivers in the western U.S. have led to loss and simplification of native riparian forests and to declines and endangerment of riparian-dependent birds species. Efforts to conserve, restore, and manage the distinctive biological diversity of riparian ecosystems must rest upon a clear understanding of the primary physical and...

We made preliminary observations on the winter distribution, ecology and behavior of Louisiana Waterthrushes (Seiurus motacilla) in Costa Rica during January 1999 and 2000. We visited 24 headwater streams in three of the four principal mountain ranges in the country (Cordilleras Tilarán, Central, and the Talamanca) and confirmed the presence of waterthrushes on ten of these. In all three regions waterthrushes occurred on medium to high gradient streams, averaging 3.5 meters across (range, 1-8m) and at estimated densities of 2-10 birds per kilometer of reach length. Individuals of one to...

A restoration effort, primarily focused on reducing stranding and improving passage of anadromous fish, has been undertaken along sections of lower Clear Creek, Shasta County, California. Similar projects are occurring throughout California and, indeed, all of North America. To monitor the effects of these efforts at Clear Creek we implemented a multi-faceted songbird monitoring study. We have collected three years of data on abundance, diversity, reproductive success, and habitat associations of songbird populations at Clear Creek study plots where extensive watershed/salmonid restoration...

Our objective was to develop a survey technique and watershed-scale design to monitor trends of population size and habitat associations in stream-foraging birds. The resulting methods and design will be used to examine the efficacy of quantifying the association of stream and watershed quality with bird abundance. We surveyed 60 randomly selected 2-km stream reaches of all stream orders in the Smith River watershed in northern California. In addition to counts and foraging activity of American Dippers (Cinclus mexicanus) and other bird species that forage in the stream, we collected a...

On certain soil types in the Northern Great Plains, mechanical treatment such as contour furrowing is used to break up “claypan” soils and increase grass production. The effect of this treatment on breeding bird communities has not been documented. I compared soil characteristics, vegetation, and the breeding bird community on two sites over three years in southwestern North Dakota. One site was contour furrowed in 1968 and the other, adjacent site, was not treated. The chemical makeup of the soil on the two sites was similar 20 years following treatment but vegetation cover differed. The...