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Year Published: 2019

Influences of spawning timing, water temperature, and climatic warming on early life history phenology in western Alaska sockeye salmon

We applied an empirical model to predict hatching and emergence timing for 25 western Alaska sockeye salmon (Oncorhynchus nerka) populations in four lake-nursery systems to explore current patterns and potential responses of early life history phenology to warming water temperatures. Given experienced temperature regimes during development, we...

Sparks, Morgan M.; Falke, Jeffrey A.; Quinn, Thomas P.; Adkison, Milo D.; Schindler, Daniel E.; Bartz, Krista K.; Young, Daniel B.; Westley, Peter A. H.

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Year Published: 2019

Using spatially‐explicit capture–recapture models to explain variation in seasonal density patterns of sympatric ursids

Understanding how environmental factors interact to determine the abundance and distribution of animals is a primary goal of ecology, and fundamental to the conservation of wildlife populations. Studies of these relationships, however, often assume static environmental conditions, and rarely consider effects of competition with ecologically...

Stetz, Jeffrey B.; Mitchell, Michael S.; Kendall, Katherine C.

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Year Published: 2019

On the relationship between conditional (CAR) and simultaneous (SAR) autoregressive models

We clarify relationships between conditional (CAR) and simultaneous (SAR) autoregressive models. We review the literature on this topic and find that it is mostly incomplete. Our main result is that a SAR model can be written as a unique CAR model, and while a CAR model can be written as a SAR model, it is not unique. In fact, we show how any...

Jay M. Ver Hoef; Ephraim M. Hanksb; Hooten, Mevin

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Year Published: 2019

Evaluation of ageing accuracy with complementary non‐lethal methods for slow‐growing, northern populations of shoal bass

In the upper Chattahoochee River basin, where some populations of shoal bass, Micropterus cataractae Williams & Burgess, are imperilled, age and growth data are lacking. Age and growth of shoal bass in this basin were assessed with non‐lethal means using scales and mark–recapture. Mark–recapture data allowed for estimation of...

Long, James M.; Holley, C. T.; Taylor, A. T.

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Year Published: 2019

Seasonal trophic variation of yellow perch exceeds spatial variation in a large lake basin

Trophic structuring of complex food webs may vary at multiple spatial and temporal scales, both in terms of direct trophic connections and underlying energy pathways that support production. In large freshwater systems, the prey and primary producers that support individual higher-order consumers may vary across seasons and habitats due to...

Hrycik, Allison R.; Collingsworth, Paris D.; Rogers, Mark W.; Guffey, Samuel C.; Hook, Tomas O.

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Year Published: 2019

Estimating abundance of an open population with an N-mixture model using auxiliary data on animal movements

Accurate assessment of abundance forms a central challenge in population ecology and wildlife management. Many statistical techniques have been developed to estimate population sizes because populations change over time and space and to correct for the bias resulting from animals that are present in a study area but not observed. The mobility of...

Ketz, Alison C.; Johnson, Therese L.; Monello, Ryan J.; Mack, John A.; George, Janet L.; Hooten, Mevin; Kraft, Benjamin R.; Wild, Margaret A.; Hobbs, N. Thompson

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Year Published: 2019

Spatial autoregressive models for statistical inference from ecological data

Ecological data often exhibit spatial pattern, which can be modeled as autocorrelation. Conditional autoregressive (CAR) and simultaneous autoregressive (SAR) models are network‐based models (also known as graphical models) specifically designed to model spatially autocorrelated data based on neighborhood relationships. We identify and discuss six...

Ver Hoef, Jay M.; Peterson, Erin E.; Hooten, Mevin; Hanks, Ephraim M.; Fortin, Marie-Josée

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Year Published: 2019

Avian predation on juvenile Salmonids: Spatial and temporal analysis based on acoustic and passive integrated transponder tags

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 a...

Evans, Allen F.; Payton, Quinn; Turecek, Aaron; Cramer, Bradley D.; Collis, Ken; Roby, Daniel D.; Loschl, Peter J.; Sullivan, Leah; Skalski; Weiland, Mark; Dotson, Curtis

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Year Published: 2018

Patch and landscape responses of bird abundance to fragmentation in agroecosystems of east-central Argentina

Forest fragmentation in agroecosystems is linked to declines of avian species worldwide. Agriculture has greatly reduced native forest cover in east-central Argentina. Assessing the influence of fragmentation on forest bird populations is vital to inform reliable conservation and management strategies for the Espinal region of Argentina. We...

Vilella, Francisco; Calamari, N.C.; Mercuri, P.A.

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Year Published: 2018

Confirmation of diving and swimming behavior in the Sora (Porzana carolina)

We first observed Sora (Porzana carolina) swimming and diving under water while capturing them with hand nets at night. Since that time, we have observed the behavior several times and documented it with photos and video. Rails are among the most elusive birds. Despite living in wetlands, water depth has often been discussed as a factor limiting...

Krementz, David G.

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Year Published: 2018

Will increased storm surge frequency impact food availability for Semipalmated Sandpipers (Calidris pusilla) at the beginning of fall migration?

Hatch-year Semipalmated Sandpipers (Calidris pusilla) use river deltas along the Beaufort Sea as their first stops during fall migration. However, these sites are subject to extreme changes in water levels that affect available foraging habitat. We examined relationships between timing of fall migration and storm surges, with respect to forage...

Churchwell, R.T.; Kendall, S.; Brown, S.C.; Powell, Abby

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Year Published: 2018

Estimates of abundance and longevity of Bridled Quail-Doves (Geotrygon mystacea) on Guana Island, British Virgin Islands

The Bridled Quail-Dove (Geotrygon mystacea) is a columbiform resident of the eastern Caribbean. It is a poorly studied species with a lack of quantitative data to assess population status, but perceived population declines have led to it being considered a species of conservation concern on many islands. I attempted to assess population size and...

Boal, Clint W.