Ecosystems

Publications

Filter Total Items: 32,405
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Year Published: 2020

Standard operating procedures for wild horse and burro double-observer aerial surveys

The U.S. Geological Survey has been collaborating with the Bureau of Land Management to develop statistically reliable methods for wild horse and burro aerial survey data collection and analysis for more than a decade. In cooperation with Colorado State University, the U.S. Geological Survey tested several methods in herds with known abundance,...

Paul C. Griffin; Ekernas, L. Stefan; Schoenecker, Kathryn A.; Bruce C. Lubow
Griffin, P.C., Ekernas, L.S., Schoenecker, K.A., and Lubow, B.C., 2020, Standard operating procedures for wild horse and burro double-observer aerial surveys: U.S. Geological Survey Techniques and Methods, book 2, chap. A16, 76 p., https://doi.org/10.3133/tm2A16

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Year Published: 2020

An uncertain future for a population of desert tortoises experiencing human impacts

We evaluated the status of a population of Mojave Desert Tortoises (Gopherus agassizii), a threatened species, in the El Paso Mountains of the northwestern Mojave Desert in California, USA. The study area lies north of and adjacent to a designated critical habitat unit for the species, is adjacent to a state park, and is a short distance from the...

Berry, Kristin H.; Yee, Julie L.; Lyren, Lisa L.; Mack, Jeremy S

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Year Published: 2020

Climate change: Flowering time may be shifting in surprising ways

Climate change is known to affect regional weather patterns and phenology; however, we lack under-standing of how climate drives phenological change across local spatial gradients. This spatial variation is critical for determining whether subpopulations and metacommunities are changing in unison or diverging in phenology. Divergent responses...

Prevey, Janet

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Year Published: 2020

Wind River subbasin restoration: Annual report of US..Geological Survey activities, January 2018 through December 2018

We sampled juvenile wild Steelhead Oncorhynchus mykiss in headwater streams of the Wind River, WA, to characterize populations and investigate life-history metrics, particularly migratory patterns. We used Passive Integrated Transponder (PIT)-tagging and a series of instream PIT-tag interrogation systems (PTISs) to track juveniles. The Wind River...

Jezorek, Ian G.

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Year Published: 2020

The first occurrence of the Australian redclaw crayfish Cherax quadricarinatus (von Martens, 1868) in the contiguous United States

The Australian redclaw crayfish, Cherax quadricarinatus, is a popular aquaculture crayfish that has been introduced around the world. Here we report the first occurrence of the species in the United States in Lake Balboa, Los Angeles, California. The impacts of this species are largely unknown, and further research is needed to determine the...

Morningstar, Cayla; Daniel, Wesley; Neilson, Matthew; Yazaryan, Ara K.

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Year Published: 2020

The right trait in the right place at the right time: Matching traits to environment improves restoration outcomes

(Munson) The challenges of restoration in dryland ecosystems are growing due to a rise in anthropogenic disturbance and increasing aridity. Plant functional traits are often used to predict plant performance and can offer a window into the potential outcomes of restoration efforts across environmental gradients. We tracked 15 years of seeding...

Balazs, Kathleen R.; Kramer, Andrea T.; Munson, Seth M.; Talkington, Nora; Still, Shannon; Butterfield, Bradley J.

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Year Published: 2020

A need for speed in Bayesian population models: A practical guide to marginalizing and recovering discrete latent states

Bayesian population models can be exceedingly slow due, in part, to the choice to simulate discrete latent states. Here, we discuss an alternative approach to discrete latent states, marginalization, that forms the basis of maximum likelihood population models and is much faster. Our manuscript has two goals: 1) to introduce readers unfamiliar...

Yackulic, Charles B.; Dodrill, Michael J.; Dzul, Maria C.; Sanderlin, Jamie S.; Reid, Janice A.

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Year Published: 2020

Application of airborne LiDAR and GIS in modeling trail erosion along the Appalachian Trail, New Hampshire, USA

Recreational activities can negatively affect protected area landscapes and resources and soil erosion is frequently cited as the most significant long-term impact to recreational trails. Comprehensive modeling of soil loss on trails can identify influential factors that managers can manipulate to design and manage more sustainable trails. Field...

Eagleston, Holly; Marion, Jeffrey L.

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Year Published: 2020

Spatial epidemiological patterns suggest mechanisms of land-sea transmission for Sarcocystis neurona in a coastal marine mammal

Sarcocystis neurona was recognised as an important cause of mortality in southern sea otters (Enhydra lutris nereis) after an outbreak in April 2004 and has since been detected in many marine mammal species in the Northeast Pacific Ocean. Risk of S. neurona exposure in sea otters is associated with consumption of clams and soft-sediment prey and...

Burgess, Tristan; Tinker, TIm M; Miller, Melissa A.; Smith, Woutrina A.; Bodkin, James L.; Murray, Michael J.; Nichol, Linda M.; Saarinen, Justin A.; Larson, Shawn E.; Tomoleoni, Joseph; Conrad, Patricia A.; Johnson, Christine K.

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Year Published: 2020

Egg counts of Southern Leopard Frog, Lithobates sphenocephalus, egg masses from southern Louisiana, USA

Southern Leopard Frogs, Lithobates sphenocephalus (Cope, 1889), lay eggs year-round in their southern range, including Louisiana, but their peak breeding season is the cooler months from late fall through early spring (Mount, 1975; Caldwell, 1986; Dundee and Rossman, 1989). Double-enveloped eggs in globular masses are typically deposited in...

Glorioso, Brad M.; Muse, Lindy J.; Waddle, J. Hardin

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Year Published: 2020

Increased prespawning mortality threatens an integrated natural- and hatchery-origin sockeye salmon population in the Lake Washington Basin

The life cycle of diadromous fishes such as salmonids involves natural mortality in a series of distinct life history stages, occurring sequentially in different habitats. Decades of research have emphasized mortality at the embryo, juvenile, and sub-adult stages but it is increasingly clear that some adults that survive and return to freshwater...

Barnett, Heidy K; Quinn, Thomas P.; Bhuthimethee, Mary; Winton, James

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Year Published: 2020

Evidence for a growing population of eastern migratory monarch butterflies is currently insufficient

The eastern migratory population of monarch butterflies has experienced a multi-decadal decline, but a recent increase in abundance (to 6.05 ha in winter 2018) has led some observers to question whether the population has reversed its long-standing decline and embarked on a trajectory of increasing abundance. We examined this possibility through...

Thogmartin, Wayne E.; Szymanski, Jennifer A; Weiser, Emily L.