Publications

We studied Swainson's Hawks (Buteo swainsoni) in southeastern Arizona to assess the status of the local breeding population. Nest success (≥1 young fledged) was 44.4% in 1999 with an average of 1.43 ± 0.09 (SE) young produced per successful pair. Productivity was similar in 2000, with 58.2% nesting success and 1.83 ± 0.09 fledglings per successful pair. Mesquite (Prosopis velutina) and...

A primary research objective of the Palmer Long Term Ecological Research (LTER) program has been to identify and understand the factors that regulate the demography of Adélie penguins (Pygoscelis adeliae). In this context, our work has been focused on variability in the marine environment on which this species depends for virtually all aspects of its life history (Ainley, 2002). As we...

Investigating the potential effects of handling and marking techniques on study animals is important for correct interpretation of research results and to effect progress in data-collection methods. Few investigators have compared the reproductive output of radio-tagged and non-radio-tagged songbirds, and no one to date has examined the possible effect of radio-tagging adult songbirds on...

Anthropogenic alteration of fluvial systems can disrupt functional processes that provide valuable ecosystem services. Channelization alters fluvial parameters and the connectivity of river channels to their floodplains which is critical for productivity, nutrient cycling, flood control, and biodiversity. The effects of channelization can be exacerbated by local geology and land-use...

The bobcat (Lynx rufus) is a medium-sized spotted cat (4 - 18 kg), widely distributed in North America. Bobcats are legally harvestable in most of their range, and are currently classified as Least Concern by IUCN and listed in Appendix II of CITES, due to similarity of appearance with other spotted cat species. Bobcats in the coastal plain region of Georgia, USA, occur at densities of 0...

Host-parasite dynamics and strategies for managing infectious diseases of wildlife depend on the functional relationship between disease transmission rates and host density. However, the disease transmission function is rarely known for free-living wildlife, leading to uncertainty regarding the impacts of diseases on host populations and effective control actions. We evaluated the...

To conduct field biology requires tenacity, grit, and flexibility; to endeavor to achieve conservation success requires patience, persistence, and passion. The essence of field biology and the hope for conservation success are both reflected admirably in George B. Schaller's most recent book, Tibet Wild: A Naturalist's Journeys on the Roof of the World. I can think of no living biologist...

No abstract available.

The Cerulean Warbler (Setophaga cerulea) is a migratory songbird that breeds in mature deciduous forests of eastern North America. Cerulean Warblers (hereafter, ceruleans) require heavily forested landscapes for nesting and, within Appalachian forests, primarily occur on ridge tops and steep, upper slopes. They are generally associated with oakdominated (Quercus spp.) stands that contain...

The Mount Graham red squirrel (Tamiasciurus hudsonicus grahamensis; MGRS) is endemic to the Pinaleño Mountains of Arizona at the southernmost extent of the species’ range. The MGRS was listed as federally endangered in 1987, and is currently at high risk of extinction due to declining population size and increasing threats. Here we present a genetic assessment of the MGRS using eight...

Background. Blastomyces dermatitidis, the etiologic agent of blastomycosis, has 2 genetic groups and shows varied clinical presentation, ranging from silent infections to fulminant respiratory disease and dissemination. The objective of this study was to determine whether clinical phenotype and outcomes vary based on the infecting organism's genetic group. Methods. We used...

Diurnal activity patterns of resident Black-necked Stilts (Himantopus mexicanus) were observed on Guana Island, British Virgin Islands, during October 2010. Stilts were principally engaged in foraging and idle behaviors. The amount of time engaged in particular behaviors was relatively constant throughout the day, except during mid-afternoon when idleness increased and foraging decreased...