Population Estimates of Nearctic Shorebirds

Morrison, R. I. G.; Gill, Robert E.; Harrington, Brian; Skagen, Susan K.; Page, Gary W.; Gratto‐Trevor, Cheri L.; Haig, Susan M.

doi:10.2307/1522172

Cited by 68 publications

(86 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Most migratory shorebird species are entirely dependent on wetlands for food and rest during long-distance journeys in the spring and fall (Brown et al, 2001); many face dual threats of habitat loss and climate change (Davidson, 2014;Morrison et al, 2006). Under ongoing climate change, inland nontidal wetlands are at increased risk from future drought severity, and they will increase in importance for migratory shorebirds when sea level rise reduces access to coastal wetlands (Galbraith et al, 2002;Werner et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Three decades of Landsat-derived spring surface water dynamics in an agricultural wetland mosaic; Implications for migratory shorebirds

Schaffer‐Smith

Swenson

Barbaree

et al. 2017

Remote Sensing of Environment

View full text Add to dashboard Cite

Satellite measurements of surface water offer promise for understanding wetland habitat availability at broad spatial and temporal scales; reliable habitat is crucial for the persistence of migratory shorebirds that depend on wetland networks. We analyzed water extent dynamics within wetland habitats at a globally important shorebird stopover site for a 1983-2015 Landsat time series, and evaluated the effect of climate on water extent. A range of methods can detect open water from imagery, including supervised classification approaches and thresholds for spectral bands and indices. Thresholds provide a time advantage; however, there is no universally superior index, nor single best threshold for all instances. We used random forest to model the presence or absence of water from >6200 reference pixels, and derived an optimal water probability threshold for our study area using receiver operating characteristic curves. An optimized mid-infrared (1.5-1.7 μm) threshold identified open water in the Sacramento Valley of California at 30-m resolution with an average of 90% producer's accuracy, comparable to approaches that require more intensive user input. SLC-off Landsat 7 imagery was integrated by applying a customized interpolation that mapped water in missing data gaps with 99% user's accuracy. On average we detected open water on ~26000 ha (~3% of the study area) in early April at the peak of shorebird migration, while water extent increased five-fold after the migration rush. Over the last three decades, late March water extent declined by ~1300 ha per year, primarily due to changes in the extent and timing of agricultural flood-irrigation. Water within shorebird habitats was significantly associated with an index of water availability at the peak of migration. Our approach can be used to optimize thresholds for time series analysis and near-real-time mapping in other regions, and requires only marginally more time than generating a confusion matrix.

show abstract

Section: Introductionmentioning

confidence: 99%

Three decades of Landsat-derived spring surface water dynamics in an agricultural wetland mosaic; Implications for migratory shorebirds

Schaffer‐Smith

Swenson

Barbaree

et al. 2017

Remote Sensing of Environment

View full text Add to dashboard Cite

show abstract

“…Shorebirds dominate, both in terms of abundance and diversity, the avian fauna of the ACP of Alaska Herter 1989, Bart et al 2012), with many species exhibiting restricted breeding ranges solely within the Arctic (Poole 2005), making them ideal species to investigate potential impacts from development and climate change within this region. Moreover, numerous shorebird species, including those that nest within the ACP of Alaska have declined in recent years (Brown et al 2001, Morrison et al 2001, Morrison et al 2006, with nine species considered species of high conservation concern or highly imperiled on a global or national scale (U.S. Shorebird Conservation Plan 2004). Additionally, due to their unique life history characteristics (e.g., specialized feeding, long-distance migrations, and diverse habitat associations), shorebirds have been identified as potential indicator species of environmental change (International Wader Study Group 2003, Piersma andLindströ m 2004).…”

Section: Introductionmentioning

confidence: 99%

Predicting breeding shorebird distributions on the Arctic Coastal Plain of Alaska

et al. 2013

View full text Add to dashboard Cite

Abstract. The Arctic Coastal Plain (ACP) of Alaska is an important region for millions of migrating and nesting shorebirds. However, this region is threatened by climate change and increased human development (e.g., oil and gas production) that have the potential to greatly impact shorebird populations and breeding habitat in the near future. Because historic data on shorebird distributions in the ACP are very coarse and incomplete, we sought to develop detailed, contemporary distribution maps so that the potential impacts of climate-mediated changes and development could be ascertained. that commonly breed within the ACP of Alaska. These habitat suitability models were based on 767 plots surveyed during nine years between 1998 and 2008 (surveys were not conducted in 2003 and 2005), using single-visit rapid area searches during territory establishment and incubation (8 June-1 July). Speciesspecific habitat suitability indices were developed and mapped using presence-only modeling techniques (partitioned Mahalanobis distance) and landscape environmental variables. For most species, habitat suitability increased at lower elevations (i.e., near the coast and river deltas) and decreased within upland habitats. Accuracy of models was high for all species, ranging from 65-98%. Our models predicted that the largest fraction of suitable habitat for the majority of species occurred within the National Petroleum Reserve-Alaska, with highly suitable habitat also occurring within coastal areas of the Arctic National Wildlife Refuge west to Prudhoe Bay.

show abstract

“…Population pressures on migratory shorebirds have shifted over the past century from a population bottleneck due to market hunting to more gradual declines due to loss or alteration of suitable habitat, exposure to environmental contaminants, climate change, and other anthropogenic disturbances (Butler et al 2004;Morrison et al 2006;Andres et al 2012;Sutherland et al 2012). Population losses and the concomitant loss of genetic variation associated with these slow but sustained pressures over multiple generations have been linked to inbreeding depression and negative impacts on adaptability and fitness.…”

Section: Introductionmentioning

confidence: 99%

Museum collections reveal that Buff-breasted Sandpipers (Calidris subruficollis) maintained mtDNA variability despite large population declines during the past 135 years

et al. 2014

View full text Add to dashboard Cite

A principal goal of conservation efforts for threatened and endangered taxa is maintenance of genetic diversity. Modern and historic processes that limit population size can contribute to a loss of genetic variation that can reduce future adaptability of a species. Buff-breasted Sandpipers (Calidris subruficollis) are a Neotropical migratory shorebird that experienced rapid, large-scale declines in population numbers (population bottleneck) due to intensive market hunting at the turn of the 20th century. Market hunting ended shortly after the passage of the Migratory Bird Treaty Act in 1918, but subsequent population losses have occurred due to continued anthropogenic disturbances throughout the species' migratory range. To assess the impact of population declines on the genetic variation of Buff-breasted Sandpipers, we surveyed two mitochondrial DNA (mtDNA) markers, the control region and cytochrome b, from 209 museum specimens collected between 1874 and 1983 and 460 modern samples collected between 1993 and 2009. Measures of mtDNA variation did not change significantly among individuals sampled before and after the ban on market hunting, nor among four temporal groups (Pre-Act, Early Post-Act, Late Post-Act, and Modern; trend analysis: v 2 = 0.171, P = 0.679). Similarly, we did not observe loss of common haplotypes, implying that there was no substantial reduction in unique matrilineal units during our 135-year study period. Using Bayesian Skyline reconstruction of temporal changes in effective population size of females (N ef ), we concluded that N ef has been stable for the past century. Results of resampling suggest that diversity estimators can be imprecise and we emphasize the importance of a wellrounded analytical approach to addressing conservation genetic hypotheses. Considering all of the evidence it appears that genetic variation and N ef were stable despite the pressures of market hunting early in the 20th century and habitat loss and degradation in the latter half of the 20th century. Conservation efforts should continue to focus on maintaining the population size of Buff-breasted Sandpipers to avoid reaching a threshold where genetic variability is lost.

show abstract

Population Estimates of Nearctic Shorebirds

Cited by 68 publications

References 12 publications

Three decades of Landsat-derived spring surface water dynamics in an agricultural wetland mosaic; Implications for migratory shorebirds

Three decades of Landsat-derived spring surface water dynamics in an agricultural wetland mosaic; Implications for migratory shorebirds

Predicting breeding shorebird distributions on the Arctic Coastal Plain of Alaska

Museum collections reveal that Buff-breasted Sandpipers (Calidris subruficollis) maintained mtDNA variability despite large population declines during the past 135 years

Contact Info

Product

Resources

About