Buehler, David A.

Bulluck, Lesley P.

Canterbury, Ronald A.

Confer, John L.

Rosenberg, Kenneth V.

Roth, Amber M.

Swarthout, Sara Barker

Vallender, Rachel

Will, Tom C.

The Auk

Ithaca College

Status and conservation priorities of Golden-winged Warbler (Vermivora chrysoptera) in North America

Conklin, J. R.

Colwell, Mark A.

University of Groningen

Diurnal and nocturnal rroost site fidelity of Dunlin (<i>Calidris alpina pacifica</i>) at Humboldt Bay, California

Shorebird roosts are often considered traditional, on the basis of predictable occupancy by large numbers of birds over long periods. However, fidelity of individuals to roosts at fine spatial and temporal scales, particularly at night, has rarely been described. We compared diurnal and nocturnal use of high-tide roosts by radiotagged Dunlin (Calidris alpina pacifica) wintering (November-March) at Humboldt Bay, California. Despite high fidelity to the study area, fidelity to particular roosts was relatively low and highly variable. At night, Dunlin used fewer roosts, were more faithful to primary roosts, and moved shorter distances between successive roosts than during the day. Day and night roosts differed in location, habitat, and distance from tidal flats. At night, Dunlin made greater use of pasture, and less use of islands and manmade structures. Day and night strategies of high-tide space use by Dunlin may be related to differences in food availability or predation danger. Our results illustrate that notions of tradition and site fidelity are scale-dependent and that knowledge of space use across the full range of environmental conditions is necessary for appropriate management of shorebird habitat

ARTS repository - University of Groningen

Inferences based on counts adjusted for delectability represent a marked improvement over unadjusted counts, which provide no information about true population density and rely on untestable and unrealistic assumptions about constant delectability for inferring differences in density over time or space. Distance sampling is a widely used method to estimate delectability and therefore density. In the standard method, we model the probability of detecting a bird as a function of distance alone. Here, we describe methods that allow us to model probability of detection as a function of additional covariates-an approach available in DISTANCE, version 5.0 (Thomas et al. 2005) but still not widely applied. The main use of these methods is to increase the reliability of density estimates made on subsets of the whole data (e.g., estimates for different habitats, treatments, periods, or species), to increase precision of density estimates or to allow inferences about the covariates themselves. We present a case study of the use of multiple covariates in an analysis of a point-transect survey of Hawaii Amakihi (Hemignathus virens).</p

Marques, Tiago Andre

Thomas, Len

Fancy, S G

Buckland, Stephen Terrence

University of St. Andrews - Pure

Improving estimates of bird density using multiple covariate distance sampling

University of Groningen Research Database

Diurnal and Nocturnal Roost Site Fidelity of Dunlin (<i>Calidris alpina pacifica</i>) at Humboldt Bay, California

Kristina L. Paxton

Charles Van Riper

Tad C. Theimer

Eben H. Paxton

Crossref

English

SPATIAL AND TEMPORAL MIGRATION PATTERNS OF WILSON’S WARBLER (WILSONIA PUSILLA) IN THE SOUTHWEST AS REVEALED BY STABLE ISOTOPES

Dyke, Gareth J.

Nudds, R.L.

Benton, M.

Southampton (e-Prints Soton)

Modern avian radiation across the Cretaceous-Paleogene boundaryno access

We used stable hydrogen isotopes (δD) to identify the breeding locations of Wilson's Warbler (Wilsonia pusilla) migrating through five sites spanning a cross-section of the species' southwestern migration route during the springs of 2003 and 2004. Determining the temporal and spatial patterns of migration and degree of population segregation during migration is critical to understanding long-term population trends of migrant birds. At all five migration sites, we found a significant negative relationship between the date Wilson's Warblers passed through the sampling station and δD values of their feathers. These data were consistent with a pattern of "leap-frog" migration, in which individuals that bred the previous season at southern latitudes migrated through migration stations earlier than individuals that had previously bred at more northern latitudes. We documented that this pattern was consistent across sites and in multiple years. This finding corroborates previous research conducted on Wilson's Warbler during the fall migration. In addition, mean δD values became more negative across sampling stations from west to east, with the mean δD values at each station corresponding to different geographic regions of the Wilson's Warblers' western breeding range. These data indicate that Wilson's Warblers passing through each station represented a specific regional subset of the entire Wilson's Warbler western breeding range. As a result, habitat alterations at specific areas across the east--west expanse of the bird's migratory route in the southwestern United States could differentially affect Wilson's Warblers at different breeding areas. This migration information is critical for management of Neotropical migrants, especially in light of the rapid changes presently occurring over the southwestern landscape

Paxton, Kristina L.

Van Riper III, Charles

Theimer, Tad C.

Paxton, Eben H.

OpenKnowledge@NAU

Spatial and temporal migration patterns of Wilson's Warbler (wilsonia Pusilla) in the southwest as revealed by stable isotopes

Modern avian radiation across the Cretaceous-Paleogene boundaryno access

Abstract

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