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Southern flounder are an iconic coastal finfish through the Southeast U.S. Atlantic and Gulf of Mexico. Southern flounder spend the early part of their lives in coastal and estuarine habitats, later moving offshore to spawn. Several decades of research have provided much clarity to the biology, life history, and aquaculture aspects of southern flounder—this information is summarized and reviewed in this study. Despite substantial improvement in understanding the species, major questions remain about their recruitment, offshore behaviors, captive rearing, and management. Recently, southern flounder have also been in focus because of substantial synchronous population declines throughout their range with specific concerns that recruitment failure and possibly climate change may be implicated. Management of southern flounder has thus far taken place within individual states, but coming into focus is the possibility that larger coastwide management approaches may need to be considered due to both the migratory nature of the species and the possibility of population stressors acting at regional scales. Many states have already begun aquaculture and enhancement efforts, with an eye toward supplementing wild populations. Large group efforts, like the symposium that led to this study, will likely be needed to tackle the complex challenges confronting southern flounder. [ABSTRACT FROM AUTHOR]

As global temperatures and precipitation become more extreme, habitat specialists are at particular risk of being pushed past their environmental tolerance limits. Flammulated Owls (Psiloscops flammeolus) are small migratory owls that breed in temperate conifer forests of western North America. Their highly specialized nesting and foraging requirements make them indicators of ecosystem health. Using 17 years of nest observations, we investigated how annual weather patterns affected Flammulated Owl nesting and foraging behaviors during the breeding season. We used generalized linear models with a changepoint parameter to evaluate nest provisioning and nestling growth rates in years of extreme temperature and precipitation. We also evaluated how adult mass, division of labor, and productivity varied based on precipitation and temperature. Compared to wet and warm years, adults made more frequent prey deliveries to nestlings in dry and cold years, particularly early in the night and early in the season, and they experienced earlier changepoints in these years. We found a significant effect of temperature on the number of fledglings in broods, but weather did not affect other variables including productivity, nestling growth rates, adult masses, and division of labor. Our findings suggest that extreme annual weather patterns influence insect prey availability during the Flammulated Owl breeding season, forcing adults to work harder to provision for nests during dry and cold years. While productivity and nestling growth did not vary between years, these may incur a long‐term tradeoff in adult survival. [ABSTRACT FROM AUTHOR]

Southern flounder (Paralichthys lethostigma) are a coastal flatfish species that supports recreational and commercial fisheries but are currently experiencing range‐wide declines. To quantify the range‐wide declines and investigate the role of climate in these declines, fishery‐independent sampling data of age‐0 flounder were obtained from 34 estuaries representing four states in the Gulf of Mexico (TX, LA, AL, and FL) and three states in the Southeastern United States Atlantic Ocean (FL, SC, and NC) spanning from 1976 to 2019. Generalized additive models (GAM) were used to estimate age‐0 recruitment trends. Spatial and temporal synchrony analyses were then conducted using annual GAM‐predicted values to determine if trends were similar between estuaries in close proximity, and if declines occurred at the same time. Because the species is dependent on physical transport (i.e., winds and tides) for recruitment, hourly wind speed, wind direction, water temperature, and air temperature were obtained for estuaries with non‐zero sampling totals and long‐term data sets. Only six estuaries showed significant relationships between age‐0 flounder indices and growing degree days. However, all estuaries with wind data showed significant relationships between age‐0 flounder indices and hourly summed wind speed. Southern flounder also have environmental sex determination, meaning warming estuaries could also account for population changes and declines. We document that water temperatures in the same space and time where southern flounder sexually determine are warmer now than even a decade ago, which could masculinize populations and substantially change population demographics. These results illustrate the vulnerability of estuarine finfish populations to climate change and increased climate variability. Understanding how climate acts on southern flounder biology may help managers respond to and prevent fishery collapses. [ABSTRACT FROM AUTHOR]

How are rainforest birds faring in the Anthropocene? We use bird captures spanning > 35 years from 55 sites within a vast area of intact Amazonian rainforest to reveal reduced abundance of terrestrial and near‐ground insectivores in the absence of deforestation, edge effects or other direct anthropogenic landscape change. Because undisturbed forest includes far fewer terrestrial and near‐ground insectivores than it did historically, today's fragments and second growth are more impoverished than shown by comparisons with modern 'control' sites. Any goals for bird community recovery in Amazonian second growth should recognise that a modern bird community will inevitably differ from a baseline from > 35 years ago. Abundance patterns driven by landscape change may be the most conspicuous manifestation of human activity, but biodiversity declines in undisturbed forest represent hidden losses, possibly driven by climate change, that may be pervasive in intact Amazonian forests and other systems considered to be undisturbed. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) in fresh-water environments is poorly understood, yet in marine environments CO2 can affect fish behaviour, including predator-prey relationships. To examine changes in predator success in elevated CO2, we experimented with predatory Micropterus salmoides and Pimephales promelas prey. We used a two-factor fully crossed experimental design; one factor was 4-day (acclimation) CO2 concentration and the second factor CO2 concentration during 20-min predation experiments. Both factors had three treatment levels, including ambient partial pressure of CO2 (pCO2; 0-1000 matm), low pCO2 (4000-5000 matm) and high pCO2 (8000-10 000 matm). Micropterus salmoides was exposed to both factors, whereas P. promelas was not exposed to the acclimation factor. In total, 83 of the 96 P. promelas were consumed (n = 96 trials) and we saw no discernible effect of CO2 on predator success or time to predation. Failed strikes and time between failed strikes were too infrequent to model. Compared with marine systems, our findings are unique in that we not only saw no changes in prey capture success with increasing CO2, but we also used CO2 treatments that were substantially higher than those in past experiments. Our work demonstrated a pronounced resiliency of freshwater predators to elevated CO2 exposure, and a starting point for future work in this area. [ABSTRACT FROM AUTHOR]

Studies with marine fishes indicate that exposure to elevated partial pressures of CO2 ( pCO2) related to climate change have negative consequences for fish behaviour. Freshwater fishes may experience similar increases in pCO2 due to a number of different mechanisms, but there is a paucity of information on how freshwater fishes may respond to exposure to elevated pCO2., To define the effects of elevated pCO2 on a free-swimming freshwater fish, 19 adult largemouth bass ( Micropterus salmoides) were tagged with acoustic transmitters, held in water with pCO2 levels of either ˜10 000 μatm or ambient pCO2 (<100 μatm) for 5 days and released into a naturalised, earthen-bottom pond outfitted with an acoustic telemetry array., Findings indicate that largemouth bass not exposed to elevated levels of pCO2 decreased movement over 35% during the daylight periods; however, fish exposed to elevated levels of pCO2 did not exhibit this pattern. This difference in diel movement patterns between fish exposed to elevated pCO2 and fish not exposed was not detectable after 11 days., Changes in home range size and daily distance travelled were not observed. However, based on an assessment of position estimates after the completion of the telemetry monitoring portion of the study, space use differed for fish exposed to elevated pCO2., Exposure to elevated pCO2 therefore can have consequences for some movement behaviours of freshwater fish and this may influence a variety of ecological processes including energetics, foraging and predator-prey dynamics. CO2-induced alterations to behaviour should recover upon a return to ambient water. [ABSTRACT FROM AUTHOR]

Estuarine ectothermic vertebrates, such as diamondback terrapins ( Malaclemys terrapin , Schwartz 1955), inhabit a dynamic environment, and many aspects of their biology reflect their ability to withstand and respond to these environmental challenges. The physiological adjustments necessary to maintain water and salt balance and the metabolic adjustments that accompany seasonal changes in activity and behavior have not been well-characterized for overwintering terrapins under field conditions. To investigate terrapin osmotic and metabolic physiology during winter when activity levels are depressed, we obtained repeat blood samples from 10 radio-tagged female terrapins maintained in a semi-natural, open-air salt marsh enclosure in southeastern North Carolina, USA. From November 2011 to April 2012, we measured monthly plasma osmolality, plasma concentrations of inorganic osmolytes (Na + , K + , Cl − ), and protein catabolic indices (urea and uric acid), as well as monthly plasma concentrations of total Ca 2 + , lactate, and glucose as metabolic indices. We used linear mixed models to determine the best predictors of blood chemistry, where time (i.e., day) and environmental variables were fixed factors and individual terrapins were random factors. Day was a poor predictor of blood chemistry concentrations, indicating that the progression of winter did not elicit corresponding changes in biochemical indices as documented in other semi-aquatic turtles exposed to more severe winter and/or laboratory conditions. Carapace temperature was the most common predictor of blood chemistry concentrations in all models, underscoring its relative influence on physiology. In contrast to previous laboratory-based studies on the overwinter physiology of terrapins, our study demonstrates that terrapins in their natural environment are able to maintain biochemical homeostasis throughout winter. The use of evasive behavioral strategies may be an important factor for terrapins to reduce the passive exchange of water and salts with the estuarine environment. [ABSTRACT FROM AUTHOR]