Showing papers by "Point Blue Conservation Science published in 2005"

Global climate change and sea level rise: potential losses of intertidal habitat for shorebirds

Abstract: Global warming is expected to result in an acceleration in current rates of sea level rise, inundating many low-lying coastal and intertidal areas. This could have important implications for organisms that depend on these sites, including shorebirds that rely on them for feeding habitat during their migrations and in winter. We modeled the potential changes in the extent of intertidal foraging habitat for shorebirds at five sites in the United States that currently support internationally important numbers of migrating and wintering birds. Even assuming a conservative global warming scenario of 2°C within the next century (the most recent projections range between 1.4°C and 5.8°C), we project major intertidal habitat loss at four of the sites (Willapa Bay, Humboldt Bay, San Francisco Bay, and Delaware Bay). Projected losses range between 20% and 70% of current intertidal habitat. Such losses might jeopardize the ability of these sites to continue to support their current shorebird numbers. The mo...

Complementary areas for conserving avian diversity on Hispaniola

Abstract: Hispaniola has been identified as a global priority for avian conservation. However, little quantitative information has been available to help guide optimal strategies for conservation action on the island. Here, the first broad-scale look has been assembled of the distribution of species of conservation concern among protected areas in Haiti and the Dominican Republic and their occurrences have been analysed to determine where conservation activities might be focused to serve avian conservation interests. An iterative, heuristic complementarity approach was used, such that the most highly ranked reserve is that which protects the greatest number of species of conservation concern and subsequently ranked reserves are those that add the most species of conservation concern that are not included in the first reserve. Parks are prioritised by the presence/absence of species of concern and prioritised a second time with individual species first being weighted by species-specific extinction risks and then by uniqueness in terms of endemism at the island or regional level. Parks of highest importance are the Sierra de Bahoruco National Park and Jaragua National Park, but the importance of other protected areas to avian conservation is also documented and discussed.

Winter site fidelity and body condition of three riparian songbird species following a fire

Abstract: The effects of fire on nonbreeding songbird species in riparian habitat have not been studied. We compared body condition, within-year site fidelity, and between-year site fidelity of 3 songbird species ( Passerella iliaca , Fox Sparrow; Catharus guttatus , Hermit Thrush; and Regulus calendula , Ruby-crowned Kinglet) at 2 coastal riparian sites. Wildfire, which is rare in this habitat, had occurred at 1 of the sites before data collection. A significantly larger proportion of Passerella iliaca was recaptured in subsequent winters at the unburned site than at the burned site, but little difference was found between sites for Catharus guttatus or Regulus calendula . Body mass of all 3 species declined during winter at the burned site, but differences between sites were not significant. Similarly, body mass indices of new captures were lower at the burned site than the unburned site for all 3 species, but these differences were not significant. The within-year recapture rate for all 3 species combined declined at the burned site over the course of the study, possibly due to changes in vegetation structure caused by the fire. Overall, our data suggest that wintering songbirds were resilient to this disturbance, but that response to the post-fire environment differed among foraging guilds. Well-replicated studies that include pre-burn data are needed to evaluate the effects of this disturbance in riparian systems.