Abstract Dryland stream fishes are adapted to highly connected habitats with unpredictable hydrologic conditions, including frequent low flows and sometimes extreme drought. The flow recruitment hypothesis predicts that some spawn in main channel during when water temperatures prey densities high. However, drought periods might be disruptive even among whose life histories otherwise benefit from lower flows. We studied dynamics of six (family Cyprinidae) at 15 sites a fragmented Great Plains...

ABSTRACT Objective: Resource managers are tasked with conducting management actions to improve native communities and/or offset negative anthropogenic activities. However, measuring the effectiveness of conservation is difficult due temporal variations, time lags, and a lack control sites which examine change. Consequently, often goes unmeasured, at times can be uncertain their efforts. In Virgin River (Nevada, Arizona, Utah), have differed substantially between upper lower reaches river....

Abstract Disturbance regimes of arid regions throughout the world are changing along with global warming. Severity drought associated decreased stream discharge and increased frequency intensity wildfires increasing in many these systems. Combined, factors can have potentially devastating effects on fish communities. To quantify response communities to annual variation climate, hydrology, wildfire, we used long‐term spatially extensive datasets from Gila River drainage, NM , U.S.A ....

Abstract Reservoirs and associated river fragments are novel ecosystems not experienced by fishes in their evolutionary history, yet they now commonplace across the globe. Understanding how use these habitats is vital to conservation efforts contemporary riverscapes. Movement patterns of endangered razorback sucker ( Xyrauchen texanus ) synthesized from tagging upper Colorado River basin, USA, illustrate applications technology data sharing multiple agencies better understand spatial ecology...

Abstract The establishment of nonnative predators can have devastating consequences for native fish communities, but predation rates are often difficult to quantify due spatial and temporal variation in predator foraging behavior. Predation by Channel Catfish Ictalurus punctatus throughout the Colorado River basin potentially threatens recovery fishes. Because highly opportunistic feeders, an understanding how piscivory this species impacts prey populations should help guide management...

Abstract Increasing trends in fragmentation and dewatering of streams warrants research on how populations communities respond to varying water levels barriers movement. Although these responses are complicated by many spatial temporal processes, long‐term datasets might help reveal complex patterns processes driving variability species abundances. The objective this study was develop a predictive framework for fish community population availability across six sites two intermittent stream...

Abstract Animals contribute significantly to nutrient cycling through excretion, but most studies consider their effects under relatively benign abiotic conditions. Disturbances such as drought may alter animals’ contributions shifts in species composition and biomass. Headwater streams are particularly vulnerable extreme climate events thus might show rapid changes stream biota ecosystem effects. We tested how biomass subsequent (nutrient cycling) of an intermittent prairie community...

Abstract Objective Stocking streams with hatchery‐produced fishes is an increasingly common practice to restore native populations, but the fate of these fish uncertain due low survival or high emigration rates. Monitoring vital population rates needed assess stocking and translocation rare endangered identify approaches that maximize persistence ultimately result in established populations. Methods We quantified survival, emigration, movement directionality, long‐term (24 months) trends...

Abstract Objective The loss and degradation of aquatic habitat through fragmentation, water extraction, climate warming contribute to declining native stream fish diversity. In response these declines, a large‐scale repatriation program was established in Arizona New Mexico expand the distribution abundance fishes. This has had variable success, with imperiled populations establishing persisting some streams, while other failed establish. Methods To identify factors contributing success...

Abstract Stream habitats and disturbance regimes are rapidly changing, leading to cascading effects on native nonnative fish communities. Managers face the ongoing daunting challenge of trying maintain or recover populations as habitat is dried species invade. This reduction suitable has led distribution declines an overall lack success in many management activities. Our study aimed at exploring potential managing a heavily depleted by attempting reestablish extirpated populations. We first...

Abstract Predation by nonnative fish is often cited as a leading cause of declining native populations, but quantifying these negative interactions difficult. Bioenergetics modeling provides tool to estimate consumptive demand species and identify those that pose the greatest threats biota. We used bioenergetics Flathead Catfish Pylodictis olivaris on fishes in upper Gila River, New Mexico, across an elevational gradient. Model results were coupled with measured densities size structure well...

Abstract Observing spatial and temporal variation in aquatic communities provides insight into factors driving community structure. These observations are particularly important as ecosystems being challenged by new extremes associated with a changing climate. However, since the timing of disturbances is unpredictable, capturing their effects difficult, unless study already gathering data prior to after these events. During 2008–2016 on macroinvertebrate Gila River New Mexico, severe drought...

Most stream fish communities have changed over time in response to common anthropogenic disturbances. Impoundments are a widespread stressor that can negatively impact fishes as they alter flow regimes, block movements, and act fountainheads for the introduction spread of invasive species. Recent studies, however, reported occurrence reproduction native impoundments, suggesting might benefit some fishes. Our primary objective was evaluate whether impoundment construction has led changes...

High-severity wildfires are becoming increasingly common across the American Southwest, and knowledge of how these fires affect native organisms is essential for their conservation. We evaluated changes in fish densities habitat over 7 23 years 2 tributaries Gila River, New Mexico, that experienced large wildfires. The Miller Fire affected Little Creek 2011 was followed by moderate monsoonal flooding. Silver Black Canyon 2013 a flood. These headwater streams responded differently to...

The impacts of small impoundments on headwater streams have received little attention despite their potential to local and broad-scale ecological impacts. These might alter stream hydrology, geomorphology, facilitate the spread invasive species. Given that prairie communities adapted highly variable conditions, they resist disturbances associated with impoundments. To test resistance aquatic impoundments, we surveyed intermittent in both unimpounded impounded watersheds. We observed greater...

Quantifying movement of nonnative fish predators is needed to understand the spatial and temporal scale their impacts on native species. We used radiotelemetry document flathead catfish (Pylodictis olivaris) at hourly, daily, seasonal time scales from May 2014 June 2015 in upper Gila River basin, New Mexico. Movement varied among individuals, with a large proportion (45%) moving <100 m tagging locations, while some others moved substantial distances (7,355–42,840 m) downstream into warmer...

Ontogenetic changes in the ecological requirements of fishes are thought to influence intraspecific patterns occurrence and abundance, yet variation distribution different cohorts unknown for many species. In prairie stream headwaters with variable habitats, we predict cohort occurrences, densities, juvenile growth rates vary considerably over both space time. Specifically, differences abiotic factors across sites will likely affect age classes. To evaluate associated structure, evaluated...

Esfuerzos extensos para reducir la población de bagres canal invasores (Ictalurus punctatus) en el río San Juan, EE.UU., han aumentado abundancia relativa juveniles, con poco entendimiento sobre las posibles interacciones tróficas entre estos juveniles y peces nativos. Los contenidos del estómago (<250 mm longitud total) adultos (≥300 mm) Juan fueron colectados verano otoño 2018 2019 cuantificar cambio ontogenético dieta. consumieron principalmente insectos acuáticos plantas terrestres,...

La frecuencia cada vez mayor de incendios forestales grandes, y alta gravedad, los impactos resultantes en ecosistemas fluviales requieren la evaluación resistencia resiliencia población peces a estas perturbaciones. Nuestro objetivo fue cuantificar cómo densidad el crecimiento matalotes Sonora (Catostomus insignis) edad 0, subadultos adultos fueron influenciados por dos 2011 2012 cuenca superior del río Gila, Nuevo México, que seguidos flujos considerables ceniza mortalidad peces....

Poorly constructed road crossings block upstream movement of fish into stream reaches that provide critical habitat or connect isolated populations. Although removing these barriers is often a conservation priority, quantifying passage following removal has not been well studied, particularly in intermittent streams. In this study, we sought to understand how influence the dispersal fishes prairie We used passive integrated transponder tags and antenna stations quantify 3 prairie-stream...