We evaluated the impact of predation on juvenile steelhead Oncorhynchus mykiss and yearling and subyearling Chinook Salmon O. tshawytscha by piscivorous waterbirds from 11 different breeding colonies in the Columbia River basin during 2012 and 2014. Fish were tagged with both acoustic tags and PIT tags and were tracked via...
Water scarcity in semiarid environments provides a model system to evaluate the role of mesic resources in structuring the distribution and abundance of wildlife. We used remote sensing and point process analyses to evaluate spatio–temporal variability in limited mesic resources in relation to greater sage-grouse (Centrocercus urophasianus) distributions in Oregon,...
Coastal wetland plants are adapted to varying degrees of inundation. However, functional relationships between inundation and productivity are poorly characterized for most species. Determining species-specific tolerances to inundation is necessary to evaluate sea-level rise (SLR) effects on future marsh plant community composition, quantify organic matter inputs to marsh accretion, and...
Following a four-year period of writing, member comment, and multiple revisions, the AFS Position Paper and Policy on Mining and Fossil Fuel Extraction was approved unanimously by the membership at the Society's annual business meeting August 19, 2015, in Portland, Oregon. The entire document can be read at fisheries.org/policy_statements; a...
Ampelisca eschrichtii are among the most important prey of the Western North Pacific gray whales, Eschrichtius robustus. The largest and densest known populations of this amphipod occur in the gray whale’s Offshore feeding area on the Northeastern Sakhalin Island Shelf. The remote location, ice cover and stormy weather at the...
Landscape characteristics can strongly influence demographic and genetic processes in wildlife populations. Climate change and human land use are causing many landscapes to change rapidly, and the effects on wildlife populations must be understood to properly manage these threats and design effective conservation strategies. In this dissertation, I explored the...
Reproductively and geographically isolated populations of predators may be synchronized by a phenomenon known as the Moran effect—specifically if they exhibit common responses to external processes, such as climate, density dependence (parasites, disease), or prey. Prey has the ability to synchronize predators if geographically isolated predator populations target the same...
Identifying habitat and spatial requirements of wildlife species across multiple spatial scales is a challenging, yet crucial component of wildlife management. Habitat use of bats is particularly difficult to study, and managing habitat to conserve bats is especially challenging because bats are highly vagile organisms that exploit several different types...
Marine bivalves are globally recognized as ecologically and commercially valuable species and, for over a century, researchers have been studying their feeding, digestion and other related physiological processes. These studies have shown that marine bivalves have complex feeding and particle processing behaviors to maximize growth in dynamic environmental conditions. Additionally,...
Loss of lowland estuarine and freshwater off-channel habitats along the Pacific Northwest coast has contributed to the decline of salmonid populations. These habitats serve as nursery grounds for juvenile salmonids providing them with food, winter shelter, and a transition zone between freshwater and saltwater. Lowland areas have undergone anthropogenic alterations...
Since the decimation of the southern right
whale Eubalaena australis population in New Zealand by
whaling, research on its recovery has focused on the wintering
ground at the Auckland Islands, neglecting potentially
important wintering habitat at Campbell Island. For
the first time in 20 years we conducted an expedition to...
Over the last 50 years, riparian zones in the semi-arid West have gained recognition as disproportionately important habitats for both breeding bird communities and agricultural operations. Despite growing interest in exploring avian-habitat relationships in these systems to better inform land management, few studies have attempted to describe temporal changes in...
This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes.
Grassland and shrubland birds are declining globally due in part to anthropogenic habitat modification. Because population performance of these species is also influenced by non-anthropogenic factors, it is important to incorporate all relevant ecological drivers into demographic models. We used design-based sampling and occupancy models to test relationships of environmental...
Reintroduction programs are used to re-establish species back into their historical habitat. Most reintroduction programs have failed and few papers have evaluated factors that may be important to Pacific salmon. The 158 meter tall Cougar Dam has blocked Chinook salmon (Oncorhynchus tshawytscha) from accessing 40 kilometers of historical spawning and...
Time can be a limiting constraint for consumers, particularly when resource phenology mediates foraging opportunity. Though a large body of research has explored how resource phenology influences trophic interactions, this work has focused on the topics of trophic mismatch or predator swamping, which typically occur over short periods, at small...
This dissertation addresses gaps of knowledge associated with how ecosystem carbon stocks and greenhouse gas emissions are affected by land use land cover change in tropical peatlands. This was the first study that paired peat swamp forests with oil palm plantations and analyzed site scale variation on greenhouse gas emissions....
Mercury (Hg) is a bioaccumulative metal that can threaten the health of wild birds. Feathers are commonly used biomonitoring tools for non-lethally estimating Hg exposure in birds because they contain stable Hg concentrations upon completion of feather growth, when blood flow to the feather has stopped. Despite the common use...
All animals that interact with fishing gear are not necessarily captured, and all animals that are captured are not necessarily retained. Fishing practices and gear configuration, management regulations, and markets dictate which animals ultimately are retained or discarded. The impact of a fishery and the efficacy of management regulations can...
Rapid adaptation and evolution based on standing genetic variation and novel mutations is likely to be one of the primary ways that species survive the widespread anthropogenic environmental changes expected of the next century. Three-spined stickleback (Gasterosteus aculeatus) are known to be capable of extremely quick, dramatic adaptation in response...