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The widespread distribution of mercury (Hg) threatens wildlife health, particularly piscivorous birds. Western North America is a diverse region that provides critical habitat to many piscivorous bird species, and also has a well-documented history of mercury contamination from legacy mining and atmospheric deposition. The diversity of landscapes in the west limits the distribution of avian piscivore species, complicating broad comparisons across the region. Mercury risk to avian piscivores was evaluated across the western United States and Canada using a suite of avian piscivore species representing a variety of foraging strategies that together occur broadly across the region. Prey fish Hg concentrations were...
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The widespread distribution of mercury (Hg) threatens wildlife health, particularly piscivorous birds. Western North America is a diverse region that provides critical habitat to many piscivorous bird species, and also has a well-documented history of mercury contamination from legacy mining and atmospheric deposition. The diversity of landscapes in the west limits the distribution of avian piscivore species, complicating broad comparisons across the region. Mercury risk to avian piscivores was evaluated across the western United States and Canada using a suite of avian piscivore species representing a variety of foraging strategies that together occur broadly across the region. Prey fish Hg concentrations were...
Categories: Publication; Types: Citation
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Understanding the dietary habits of yellow-billed loons (Gavia adamsii) can give important insights into their ecology, however, studying the diet of loons is difficult when direct observation or specimen collection is impractical. We investigate the diet of yellow-billed loons nesting on the Arctic Coastal Plain of Alaska using quantitative fatty acid signature analysis. Tissue analysis from 26 yellow-billed loons and eleven prey groups (nine fish species and two invertebrate groups) from Arctic lakes suggests that yellow-billed loons are eating high proportions of Alaska blackfish (Dallia pectoralis), broad whitefish (Coregonus nasus) and three-spined stickleback (Gasterosteus aculeatus) during late spring and...
Categories: Publication; Types: Citation; Tags: Polar Biology
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Interspecific competition is an important process structuring ecological communities, however, it is difficult to observe in nature. We used an occupancy modelling approach to evaluate evidence of competition between yellow-billed (Gavia adamsii) and Pacific (G. pacifica) loons for nesting lakes on the Arctic Coastal Plain of Alaska. With multiple years of data and survey platforms, we estimated dynamic occupancy states (e.g. rates of colonization or extinction from individual lakes) and controlled for detection differences among aircraft platforms and ground survey crews. Results indicated that yellow-billed loons were strong competitors and negatively influenced the occupancy of Pacific loons by excluding them...
Categories: Publication; Types: Citation; Tags: Journal of Avian Biology
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Yellow-billed Loons (Gavia adamsii) breed in lakes in the treeless Arctic and are globally rare. Like their sister taxa, the well-documented Common Loon (G. immer) of the boreal forest, Yellow-billed Loons exhibit strong territorial behavior during the breeding season. Little is known about what size territories are required, however, or how readily territories are retained from year to year. An understanding of territory dynamics and size is needed by management agencies as most of the U.S. breeding population of Yellow-billed Loons resides in the National Petroleum Reserve-Alaska where oil and gas development is expected to increase in the next few decades. Using locational data from a set of Yellow-billed Loons...
Categories: Publication; Types: Citation; Tags: Waterbirds
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The Red-throated Loon is the smallest of the world’s five loon species. This species typicallybreeds in low wetlands in both tundra and forested terrain (Barr et al. 2000). They nest on pondedges, sometimes along very small ponds (<1 ha), particularly in parts of their range sympatricwith Pacific Loons (Barr et al. 2000). Red-throated Loons are unique in that they regularlyforage on fish away from their nesting ponds.In Arctic Alaska this often involves flights to theArctic Ocean (Andres 1993). Like Yellow-billed Loons, the North American breedingpopulation, north of 68° latitude, appear to winter primarily in East Asia from the western KurilIslands to the Yellow Sea (J. Schmutz et al., unpublished data). In 1993,...
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Accurate estimates of breeding success are essential for understanding population dynamics and for managing populations. Unfortunately, research activities to collect these data can negatively impact the breeding success of the study species and bias estimates of breeding success. Despite the potential for negative impacts, few studies have documented the effect of capturing incubating adults on nest survival or compared nest survival following different capture methods. In this study we evaluate the impacts of investigator disturbance associated with captures and nest visits on nest survival of Yellow-billed Loons (Gavia adamsii) and Pacific Loons (Gavia pacifica) in the National Petroleum Reserve-Alaska (NPR-A),...
Categories: Publication; Types: Citation; Tags: Condor
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Species: Bobolink; Brown Pelican; Burrowing Owl; Common Loon; Common Nighthawk; Ferruginous Hawk; Franklin's Gull; Grasshopper Sparrow; Horned Lark; Loggerhead Shrike; Long-billed Curlew; Marbled Murrelet; Mountain Quail; Olive-sided Flycatcher; Purple Martin; Red-necked Grebe; Sage Sparrow; Sage Thrasher; Sharp-tailed Grouse; Upland Sandpiper; Vesper Sparrow; Western Bluebird; White-breasted Nuthatch; White-headed Woodpecker; Yellow-billed Cuckoo; Great Gray Owl; Greater Sage-Grouse Seasons: Summer; based on Breeding Bird Survey (BBS) data, and winter; based on Christmas Bird Count (CBC) data Background: In completing its climate-impacts analysis for North American birds, Audubon has generated numerous maps...
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With growing climate change concerns and energy constraints, there is an increasing need for renewable energy sources within the United States and globally. Looking forward, offshore wind-energy infrastructure (OWEI) has the potential to produce a significant proportion of the power needed to reach our Nation’s renewable energy goal. Offshore wind-energy sites can capitalize open areas within Federal waters that have persistent, high winds with large energy production potential. Although there are few locations in the California Current System (CCS) where it would be acceptable to build pile-mounted wind turbines in waters less than 50 m deep, the development of technology able to support deep-water OWEI (>200 m...
Categories: Publication; Types: Citation; Tags: Open-File Report


map background search result map search result map Red-throated Loon Pacific Northwest Climate Prioritization for Bird Species of Greatest Conservation Need Pacific Northwest Climate Prioritization for Bird Species of Greatest Conservation Need Red-throated Loon