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Globally, migration phenologies of numerous avian species have shifted over the past half-century. Despite North American waterfowl being well researched, published data on shifts in waterfowl migration phenologies remain scarce. Understanding shifts in waterfowl migration phenologies along with potential drivers is critical for guiding future conservation efforts. Therefore, we utilized historical (1955–2008) nonbreeding waterfowl survey data collected at 21 National Wildlife Refuges in the mid- to lower portion of the Central Flyway to summarize changes in spring and autumn migration phenology. We examined changes in the timing of peak abundance from survey data at monthly intervals for each refuge and species (or species group; n = 22) by year and site-specific temperature for spring (Jan–Mar) and autumn (Oct–Dec) migration periods. For spring ( n = 187) and autumn ( n = 194) data sets, 13% and 9% exhibited statistically significant changes in the timing of peak migration across years, respectively, while the corresponding numbers for increasing temperatures were 4% and 9%. During spring migration, ≥80% of significant changes in the timing of spring peak indicated advancements, while 67% of significant changes in autumn peak timing indicated delays both across years and with increasing temperatures. Four refuges showed a consistent pattern across species of advancing spring migration peaks over time. Advancements in spring peak across years became proportionally less common among species with increasing latitude, while delays in autumn peak with increasing temperature became proportionally more common. Our study represents the first comprehensive summary of changes in spring and autumn migration phenology for Central Flyway waterfowl and demonstrates significant phenological changes during the latter part of the twentieth century.

Wetland stopover use by migratory shorebirds is concurrently influenced by habitat characteristics within a stopover site and characteristics related to the broader context surrounding the stopover site. To conserve wetland habitats essential for shorebird migration through the interior of North America, we need to understand how these dual scales influence stopover use. We surveyed >14,000 wetlands within 10 broad-scale landscapes in north-central Oklahoma from 2007 through 2009 to determine how characteristics within (intra) and surrounding (context) wetlands influence the density and species richness of migrating shorebirds at stopover sites. We used zero-inflated modeling and an information theoretic framework to separately examine and then compare the relative importance of intra-habitat variables and habitat context variables in explaining use of stopovers. We observed 38,288 migratory shorebirds of 29 species. Shorebirds were least likely to occur in isolated, small, steep-sided wetland habitats. Among intra-patch variables, shorebird density and richness were best explained by wetland habitat area, slope, and the cover and height of vegetation within a wetland. Shorebird density and richness were more than 2 times higher in large wetland habitats (i.e. >3.3 ha), and both decreased with increased vegetation and slope. The density of wetlands within 1.5 km of a stopover site had the greatest impact on shorebird density and richness among patch context variables. As habitat density increased from 0.07 to 1, shorebird abundance and richness increased by >200%. Shorebirds were positively related to grazing pressure but negatively related to forest/shrubland, urban/suburban development, and grassland land cover contexts. When compared to models with intra-habitat variables, models containing habitat context variables better explained migratory shorebird density and richness. We conclude that characteristics related to the broader context surrounding a wetland stopover sites strongly influence stopover use by migratory shorebirds. Conservation and management of shorebirds migrating through the continental interior should aim to provide large expanses of sparsely vegetated and shallow habitats within stopover sites and focus on open landscapes that contain high densities of stopover habitats.

Insectivores gain macronutrients and elements from consuming arthropod prey, but must also deal with indigestible components (i.e., exoskeleton) of prey. For example, avian chicks (e.g., northern bobwhites; Colinus virginianus) have limited gut space, and ingesting prey with relatively higher proportions of indigestible components may impact assimilation efficiency, growth, and survival. The ability of insectivores to choose higher quality prey would depend on prey taxa varying consistently in nutritional content. We tested whether there were consistent differences among taxonomic orders of arthropod prey in their macronutrient (protein and lipid), elemental (C and N), and exoskeleton content. We used northern bobwhite chicks as our focal insectivore and focused on their potential prey as a case study. We also tested the influence of indigestible exoskeleton on the measurement of macronutrient content and the ability of elemental content to predict macronutrients. We found large and consistent variation in macronutrient and elemental content between arthropod orders. Some orders had consistently high protein content and low exoskeleton content (i.e., Araneae) and are likely higher quality prey for insectivores. Abundant orders common in the diets of insectivores, like Hymenoptera and Coleoptera, had high exoskeleton content and low protein content. We also found support for the ability of elements to predict macronutrients and found that metabolizable (i.e., exoskeleton removed) elemental content better predicted macronutrient content. A better understanding of arthropod nutrient content is critical for elucidating the role of spatial and temporal variation in prey communities in shaping the growth and survival of insectivores. We tested whether there were consistent differences in macronutrient, elemental, and exoskeleton content among taxonomic orders of potential arthropod prey of northern bobwhite chicks. We found large and consistent variation between orders, with orders consistently low in exoskeleton content exhibiting high metabolizable protein content (i.e., Araneae). We also found that orders consistently high in exoskeleton exhibited low metabolizable protein content.

Ecological niche models (ENMs) have increasingly been used to estimate the potential effects of climate change on species' distributions worldwide. Recently, predictions of species abundance have also been obtained with such models, though knowledge about the climatic variables affecting species abundance is often lacking. To address this, we used a well-studied guild (temperate North American quail) and the Maxent modeling algorithm to compare model performance of three variable selection approaches: correlation/variable contribution (CVC), biological (i.e., variables known to affect species abundance), and random. We then applied the best approach to forecast potential distributions, under future climatic conditions, and analyze future potential distributions in light of available abundance data and presence-only occurrence data. To estimate species' distributional shifts we generated ensemble forecasts using four global circulation models, four representative concentration pathways, and two time periods (2050 and 2070). Furthermore, we present distributional shifts where 75%, 90%, and 100% of our ensemble models agreed. The CVC variable selection approach outperformed our biological approach for four of the six species. Model projections indicated species-specific effects of climate change on future distributions of temperate North American quail. The Gambel's quail (Callipepla gambelii) was the only species predicted to gain area in climatic suitability across all three scenarios of ensemble model agreement. Conversely, the scaled quail (Callipepla squamata) was the only species predicted to lose area in climatic suitability across all three scenarios of ensemble model agreement. Our models projected future loss of areas for the northern bobwhite (Colinus virginianus) and scaled quail in portions of their distributions which are currently areas of high abundance. Climatic variables that influence local abundance may not always scale up to influence species' distributions. Special attention should be given to selecting variables for ENMs, and tests of model performance should be used to validate the choice of variables.

Recent declines in eastern wild turkeys (Meleagris gallopavo silvestris) have prompted increased interest in management and research of this important game species. However, the mechanisms underlying these declines are unclear, leaving uncertainty in how best to manage this species. Foundational to effective management of wildlife species is understanding the biotic and abiotic factors that influence demographic parameters and the contribution of vital rates to population growth. Our objectives for this study were to (1) conduct a literature review to collect all published vital rates for eastern wild turkey over the last 50 years, (2) perform a scoping review of the biotic and abiotic factors that have been studied relative to wild turkey vital rates and highlight areas that require additional research, and (3) use the published vital rates to populate a life‐stage simulation analysis (LSA) and identify the vital rates that make the greatest contribution to population growth. Based on published vital rates for eastern wild turkey, we estimated a mean asymptotic population growth rate (λ) of 0.91 (95% CI = 0.71, 1.12). Vital rates associated with after‐second‐year (ASY) females were most influential in determining population growth. Survival of ASY females had the greatest elasticity (0.53), while reproduction of ASY females had lower elasticity (0.21), but high process variance, causing it to explain a greater proportion of variance in λ. Our scoping review found that most research has focused on the effects of habitat characteristics at nest sites and the direct effects of harvest on adult survival, while research on topics such as disease, weather, predators, or anthropogenic activity on vital rates has received less attention. We recommend that future research take a more mechanistic approach to understanding variation in wild turkey vital rates as this will assist managers in determining the most appropriate management approach. Using a life‐stage simulation analysis, we show survival and reproduction of adult female wild turkeys had the greatest influence on population trajectories for this species. However, these life stages showed differing patterns in elasticity and variability, with adult survival having high elasticity but low process variance, and reproduction having lower elasticities but greater process variance. Additionally, we highlight several critical knowledge gaps regarding vital rates for different life stages and in the factors regulating or limiting wild turkeys.

The habitat selection choices that individuals make in response to thermal environments influence both survival and reproduction. Importantly, the way that organisms behaviorally respond to thermal environments depends on the availability and juxtaposition of sites affording tolerable or preferred microclimates. Although, ground nesting birds are especially susceptible to heat extremes across many reproductive stages (i.e., breeding, nesting, brood rearing), the mechanistic drivers of nest site selection for these species are not well established from a thermal perspective. Our goal was to assess nest site selection relative to the configuration of the thermal landscape by quantifying thermal environments available to a ground-nesting bird species inhabiting a climatically stressful environment. Using northern bobwhite (Colinus virginanus) as a model species, we measured black bulb temperature (Tbb) and vegetation parameters at 87 nests, 87 paired sites and 205 random landscape sites in Western Oklahoma during spring and summer 2013 and 2014. We found that thermal space within the study area exhibited differences in Tbb of up to 40°C during peak diurnal heating, resulting in a diverse thermal landscape available to ground-nesting birds. Within this thermally heterogeneous landscape, nest sites moderated Tbb by more than 12°C compared to random landscape sites. Furthermore, successful nests remained on average 6°C cooler than unsuccessful nests on days experiencing ambient temperatures ≥ 39°C. Models of future Tbb associated with 2080 climate change projections indicate that nesting bobwhites will face substantially greater Tbb throughout the landscape for longer durations, placing an even greater importance on thermal choices for nest sites in the future. These results highlight the capacity of landscape features to act as moderators of thermal extremes and demonstrate how thermal complexity at organism-specific scales can dictate habitat selection.

Global climate change is causing increased climate extremes threatening biodiversity and altering ecosystems. Climate is comprised of many variables including air temperature, barometric pressure, solar radiation, wind, relative humidity, and precipitation that interact with each other. As movement connects various aspects of an animal's life, understanding how climate influences movement at a fine‐temporal scale will be critical to the long‐term conservation of species impacted by climate change. The sedentary nature of non‐migratory species could increase some species risk of extirpation caused by climate change. We used Northern Bobwhite (Colinus virginianus; hereafter bobwhite) as a model to better understand the relationship between climate and the movement ecology of a non‐migratory species at a fine‐temporal scale. We collected movement data on bobwhite from across western Oklahoma during 2019–2020 and paired these data with meteorological data. We analyzed movement in three different ways (probability of movement, hourly distance moved, and sinuosity) using two calculated movement metrics: hourly movement (displacement between two consecutive fixes an hour apart) and sinuosity (a form of tortuosity that determines the amount of curvature of a random search path). We used generalized linear‐mixed models to analyze probability of movement and hourly distance moved, and used linear‐mixed models to analyze sinuosity. The interaction between air temperature and solar radiation affected probability of movement and hourly distance moved. Bobwhite movement increased as air temperature increased beyond 10°C during low solar radiation. During medium and high solar radiation, bobwhite moved farther as air temperature increased until 25–30°C when hourly distance moved plateaued. Bobwhite sinuosity increased as solar radiation increased. Our results show that specific climate variables alter the fine‐scale movement of a non‐migratory species. Understanding the link between climate and movement is important to determining how climate change may impact a species’ space use and fitness now and in the future. Because movement connects various aspects of an animal's life, research is needed to understand how climate influences movement to inform conservation efforts aimed at conserving species impacted by climate change. This study sought to understand how changes within specific climate variables alter the movement ecology of a non‐migratory animal. We conclude increased climate variability associated with climate change has the potential to alter the movement of many species, which may reduce survival and limit population connectivity in the future.

Temperature is highly variable across space and time at multiple scales, shapes landscape pattern, and dictates ecological processes. While our knowledge of ecological phenomena is vast relative to many landscape metrics, thermal patterns which shape landscape mosaics are largely unknown. To address this disconnect, we investigated the thermal landscape by measuring black bulb temperature (Tbb) at intervals as small as 15 min across 3 yr in a mixed‐grass shrub vegetation community. We found that the thermal landscape was highly heterogeneous displaying a prevalence for thermal extremes (i.e., Tbb > 50°C) and that Tbb was driven by the synergism of environmental, terrain, and vegetation factors. Specifically, variation of Tbb on the landscape was best predicted by the inclusion of ambient temperature (Tair), solar radiation (Srad), low woody cover, and tall woody cover as variables. Moreover, models of single vegetation parameters (i.e., bare ground, low woody, or tall woody cover) each had greater relative importance than those containing a single terrain variable (i.e., slope or aspect) based on AIC, providing evidence that vegetation is a key driver of Tbb on the landscape. Within the thermally heterogeneous landscape, tall woody cover moderated Tbb by 10°C more than bare ground, herbaceous, or low woody cover during peak diurnal heating (14:00), and was the only cover type that remained <50°C on average. Given that tall woody cover comprises only about 7% of the landscape in our study, these findings have direct conservation implications for species inhabiting shrub communities, specifically that the distribution of tall woody cover is a spatially limited but key predictor of potential thermal refugia on the landscape. Our findings also demonstrate that local interactions between vegetation and temperature can create thermal patterns that shape dynamic landscape mosaics across space and time. Furthermore, we show that structural heterogeneity can maximize thermal complexity across landscapes which can provide greater potential thermal options for organisms. However, our modeled climate projections suggest that far greater thermal extremes will be possible across increasingly larger swaths of the landscape in the future, making assessments and quantifications of thermal landscapes increasingly critical.

Arthropod consumption provides amino acids to invertebrates and vertebrates alike, but not all amino acids in arthropods may be digestible as some are bound in the exoskeleton. Consumers may not be able to digest exoskeleton in significant amounts or avoid it entirely (e.g., extraoral digestion). Hence, measures that do not separate digestible amino acids from those in exoskeleton may not accurately represent the amino acids available to consumers. Additionally, arthropods are taxonomically diverse, and it remains unclear if taxonomic differences also reflect differences in amino acid availability. Thus, we tested: (1) if there were consistent differences in the content and balance of amino acids between the digestible tissue and exoskeleton of arthropods and (2) if arthropod Orders differ in amino acid content and balance. We measured the amino acid content (mg/100 mg dry mass) and balance (mg/100 mg protein) of whole bodies and exoskeleton of a variety of arthropods using acid hydrolysis. Overall, there was higher amino acid content in digestible tissue. There were also significant differences in the amino acid balance of proteins in digestible tissue and exoskeleton. Amino acid content and balance also varied among Orders; digestible tissues of Hemiptera contained more of some essential amino acids than other Orders. These results demonstrate that arthropod taxa vary in amino acid content, which could have implications for prey choice by insectivores. In addition, exoskeleton and digestible tissue content differ in arthropods, which means that whole body amino acid content of an arthropod is not necessarily a predictor of amino acid intake of a predator that feeds on that arthropod. Exoskeleton is a ubiquitous component of arthropods, which many consumers cannot digest. Arthropod exoskeleton differs from digestible tissue in amino acid balance and content. Amino acid balance and content also vary considerably among arthropod taxa.

Camera traps are an important noninvasive tool used by scientists to monitor wildlife efficiently and at reduced costs. New camera trap features improve performance and encourage increased use by researchers and the public. Cellular transmission of image data, which provides users the ability to digitally receive images instead of retrieving or downloading images in the field is a useful new feature. Cellular data transmission has 2 key benefits for wildlife research in that it reduces travel time required for downloading image data and the uncertainty involving storage capacity of SD cards and battery life, and cellular transmission allows for near real-time analysis of images, which could redistribute the time usually devoted to processing a large data set when the memory card is retrieved. Despite potential benefits, cellular transmission technology in camera traps is still new and questions remain about its reliability. Our objective was to determine the efficacy of cellular transmission technology in wildlife research by designing a camera trap study as part of a senior-level class (Wildlife Management Applications and Planning; NREM 4522) project at Oklahoma State University. We used ArcGIS to generate a stratified random sample of trap locations, deploying five cellular transmission camera traps in open grassland and five in closed canopy forest areas from 5 September to 5 October 2021. We monitored the number of transmitted images each day online, and after camera trap retrieval, we compared the number of transmitted images to those stored on the memory card to determine transmission efficiency. Our data indicated the majority of the images taken each day were transmitted successfully; however, transmission efficiency (i.e., number transmitted divided by total number taken by the camera trap) tended to be lower in forested areas (47%) compared to open grassland (86%). Though cellular transmission technology shows promise, the combination of cellular signal, landscape features, and transmitted data quality may limit the effectiveness of cellular transmission technology for near real-time data analysis. Based on our results, we recommend that researchers consider advantages and disadvantages of cellular transmission when designing studies and note that researchers may need to adopt an adaptive approach or conduct pilot testing that includes quantifying the transmission functionality.