Publications

We describe a simple and robust method for estimating trends in population size. The method may be used with Breeding Bird Survey data, aerial surveys, point counts, or any other program of repeated surveys at permanent locations. Surveys need not be made at each location during each survey period. The method differs from most existing methods in being design based, rather than model...

Information on amphibian responses to fire and fuel reduction practices is critically needed due to potential declines of species and the prevalence of new, more intensive fire management practices in North American forests. The goals of this review are to summarize the known and potential effects of fire and fuels management on amphibians and their aquatic habitats, and to identify...

Predation by brown tree snakes (Boiga irregularis ) devastated the avifauna of Guam in the Mariana Islands during the last half of the twentieth century, causing the extirpation or serious reduction of most of the island's 25 resident bird species. Past studies have provided qualitative descriptions of the decline of native forest birds but have not considered all species or presented...

Conservation of native fishes and changing patterns in wildfire and fuels are defining challenges for managers of forested landscapes in the western United States. Many species and populations of native fishes have declined in recorded history and some now occur as isolated remnants of what once were larger more complex systems. Land management activities have been viewed as one cause of...

Ambystoma gracile (Baird) and Ambystoma macrodactylum Baird are common salamander species occupying key trophic positions in mountain ponds and lakes of Mount Rainier National Park (MORA). Based on amphibian surveys conducted in ponds and lakes in the northeast quadrant of MORA during the summers of 1993a??1995, 20 sites were resampled in 1996 to document and evaluate distributions of...

Before agricultural expansion in the 19th century, river valleys of North America supported expanses of wetland habitat. In restoring these landscapes, it is important to understand their historical condition and biological function. Synthesizing historical primary accounts (from explorers, travelers, settlers, and farmers) with contemporary knowledge of these wetland systems, we...

An examination of boundary-layer meteorological and avian aerodynamic theories suggests that soaring birds can be used to measure the magnitude of vertical air motions within the boundary layer. These theories are applied to obtain mixed-layer normalized thermal updraft intensity over both flat and complex terrain from the climb rates of soaring American white pelicans and from...

We studied gyrfalcon (Falco rusticolus) food delivery and feeding behavior during the nestling period in central West Greenland during the 2000 and 2001 field seasons. We used time-lapse video cameras installed at three nests to record 2677.25 hours of nestling video. Ptarmigan delivered to nests were usually plucked prior to delivery and included the breast and superior thoracic...

We used solar-powered time-lapse video photography to document nesting Gyrfalcon (Falco rusticolus) food habits in central West Greenland from May to July in 2000 and 2001. We collected 2677.25 h of videotape from three nests, representing 94, 87, and 49% of the nestling period at each nest. The video recorded 921 deliveries of 832 prey items. We placed 95% of the items into prey...

The decline and range reduction of sage grouse populations are primarily due to permanent loss and degradation of sagebrush–grassland habitat. Several studies have shown that sage grouse productivity may be limited by the availability of certain preferred highly nutritious forb species that have also declined within sagebrush ecosystems of the Intermountain West, U.S.A. The purpose of...

We examined the use of agricultural habitats by Swainson's Hawks (Buteo swainsoni)in La Pampa and Santa Fe provinces, Argentina. We found an association of foraging Swainson's Hawks with permanent pastures such as fallow, natural, and alfalfa fields. The hawks also used plowed fields for sunning, resting, and preening. Fields planted with annual crops and pastures were used very little...

Background Humans have dramatically altered wildlands in the western United States over the past 100 years by using these lands and the resources they provide. Anthropogenic changes to the landscape, such as urban expansion and development of rural areas, influence the number and kinds of plants and wildlife that remain. In addition, western ecosystems are also affected by roads...