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Natal dispersal is a key demographic process for evaluating the population rate of change, especially for long‐lived, highly mobile species. This process is largely unknown for reintroduced populations of endangered avian species. We evaluated natal dispersal distances (NDD) for male and female Whooping Cranes (Grus americana) introduced into two locations in central Wisconsin (Necedah National Wildlife Refuge, or NNWR, and the Eastern Rectangle, or ER) using a series of demographic, spatial, and life history‐related covariates. Data were analyzed using gamma regression models with a log‐link function and compared using Akaike information criterion corrected for small sample sizes (AICc). Whooping Cranes released in the ER dispersed 261% further than those released into NNWR, dispersal distance increased 4% for each additional nesting pair, decreased about 24% for males as compared to females, increased by 21% for inexperienced pairs, and decreased by 3% for each additional year of age. Natal philopatry, habitat availability or suitability, and competition for breeding territories may be influencing observed patterns of NDD. Whooping Cranes released in the ER may exhibit longer NDD due to fragmented habitat or conspecific attraction to established breeding pairs at NNWR. Additionally, sex‐biased dispersal may be increasing in this population as there are more individuals from different natal sites forming breeding pairs. As the population grows and continues to disperse, the drivers of NDD patterns may change based on individual or population behavior., We evaluated natal dispersal distances for male and female Whooping Cranes (Grus americana) introduced into two locations in Wisconsin using a series of demographic, spatial, and life history‐related covariates. Whooping Cranes released in eastern Wisconsin dispersed 261% further than those released into central Wisconsin, dispersal distance increased 4% for each additional nesting pair, decreased about 24% for males as compared to females, increased by 21% for inexperienced pairs, and decreased by 3% for each additional year of age. Natal philopatry, habitat availability or suitability, and competition for breeding territories may be influencing observed patterns of natal dispersal distances.

Wet meadows are a declining and increasingly degraded ecosystem type. They contribute numerous ecosystem services, including nutrient cycling, water storage, and filtration, and provision of wildlife habitat, particularly for wetland‐dependent species such as the Whooping Crane (Grus americana). Conservation and restoration of wet meadows rely on understanding their hydrology but characterization of wet meadow hydroregimes is difficult given their hydrologic complexity, high variability, and distinct regional differences. To address this challenge, we used ground‐based time‐lapse imagery to assess inundation dynamics of an archetypal wet meadow over a six‐year period in the Central Platte River Valley, Nebraska, USA. We analyzed over 6500 images from March 2011 to May 2017 in the open‐source java‐based image processing software ImageJ. We also obtained data on groundwater, streamflow, precipitation, and evapotranspiration. We assessed the relationship between wet meadow inundation and hydrologic variables using wavelet coherence to look at fluctuations across a time–frequency spectrum and used random forest to identify seasonally specific variables of importance. We found hydroperiod, the duration surface water ponded within the wet meadow, had a mean of 141 d, on average lasting from 10 December to 1 May, but varied annually. Inundation generally peaked in the early spring, on average 10 March, but demonstrated a bimodal distribution, peaking again in late spring during wetter years. While inundation responded rapidly to precipitation events, it was highly related to streamflow, while an elevated groundwater table was necessary for sustained inundation. Overall, our study provided a comprehensive hydrological characterization of a reference wet meadow and demonstrated the utility of time‐lapse cameras for high‐resolution monitoring and assessment of highly variable wetland systems. Considering the uncertainties surrounding land‐ and water‐use changes, climate change, and the increasing demand for freshwater resources by growing human communities, understanding functional wet meadow hydroregimes and interrelated drivers is essential to inform wet meadow restoration, conservation, and management efforts.

Social organization as a topic has wide application often conserved across lineages and can lead to complex cultures, yet it is still not well understood in many taxa. We observed American bison (Bison bison) to investigate the interactions of hierarchy and behavior to elucidate patterns of social organization. Bison are highly visible animals that live in relatively accessible grasslands, and most are in semi-wild conservation herds that allows for access to low-stress observation and physiological exams. We observed behaviors in a semi-wild, reintroduced herd of 53 bison in a 140-ha prairie from April to October 2015 (165 h of observation). After establishing a linear hierarchy, we categorized individuals of each sex as high, mid-, or low ranking and then evaluated behavioral trends across rank and sex. We found that high ranking males constantly defended their linear positions and focused breeding efforts on the females with the highest productivity, consistent with disruptive sex characteristics. Intra-rank conflict focused on linear positioning likely causes the volatility in male bison hierarchy and stress of domination. Female bison, however, tend to suppress the lowest class, which likely drives their hierarchy’s stability and stress of subordination. Our results show that male and female bison are impacted differently by their social rankings and show that individual aggressive actions may provide feedback loops to their social organization.

On 21 August 2017, a total solar eclipse crossed the continental United States, providing a unique natural experiment to observe how wildlife and plants respond to rapid and drastic changes in photic conditions using a multi-modal suite of tools. We installed passive time-lapse and infrared cameras, sound recorders, and data loggers in the Central Platte River Valley of Nebraska to study this phenomenon. The eclipse lasted about three hours, and complete obscuration of the sun (totality) lasted for about 2 min and 30 sec. Light values, measured with time-lapse camera systems, decreased 67% on average during totality relative to the daily mean light value. Ambient temperatures decreased by 6.7 °C on average (12% of the daily mean) approximately 11–16 min after totality; concurrently, humidity increased by an average of 12% of the daily mean. We found evidence for altered acoustic activity in response to the eclipse, including site and species-specific changes in the call activities of late season breeding birds and insects in the orders orthoptera and hemiptera. In addition, acoustic indices were differentially correlated with changes in photic and thermal conditions. However, we did not observe changes in flowering plants nor detect bat activity at known night roost and foraging areas. Historically, observations during rare occurrences, such as a total solar eclipse, were anecdotal or limited in scope, and thus, how they changed the light, sound, and meteorological conditions on the landscape were difficult to validate and measure. In comparison, anthropogenic disturbances, including impacts from light pollution and climate change, often take place slowly over long periods, and therefore, can be complex and challenging to assess. Documentation of this stochastic occurrence, with an immediate change in environmental conditions, highlights the utility of passive multimedia technologies to increase our capacity to monitor ecosystem dynamics and chronicle the variations of abiotic properties of a landscape and concomitant responses of organisms with varying sensory abilities.

From late February to early April the Central Platte River Valley in Nebraska is home to the largest gathering of Sandhill Cranes (Antigone canadensis) in the world and increasingly serves as a foraging ground for migrating Bald Eagles (Haliaeetus leucocephalus). On 7 March 2017, we documented a subadult Bald Eagle depredating an adult Sandhill Crane. Though evidence suggests that Bald Eagles depredate Sandhill Cranes on rare occasion, the process of that depredation has not been described in the scientific literature. The Sandhill Crane effectively defended itself several times against hovering attacks from the Bald Eagle by utilizing wing-spread displays and “bill stab” attacks. However, the Bald Eagle was eventually able to land on the Sandhill Crane's neck and back with its talons, push the crane's head under water, and drown its prey. Following submersion, the Sandhill Crane was only momentarily responsive before floating on its back down the river. We also documented 5 subadult Bald Eagles competing for access to a second Sandhill Crane carcass. As Bald Eagle populations continue to recover, Sandhill Cranes may become more frequently depredated by Bald Eagles during the spring migration-staging period in the Central Platte River Valley.

Anthropogenic climate change and habitat loss pose major threats to grassland breeding birds, the most rapidly declining group of birds in continental North America. Although previous studies have investigated grassland breeding bird responses to land management, few empirical studies explore their responses to climatic variation or its interactions with land management, which warrant urgent conservation attention. We evaluated the effects of climate and land management parameters on an indicator species for grassland breeding birds, the Grasshopper Sparrow (Ammodramus savannarum), a Neotropical migrant of conservation concern whose global population has declined by more than two thirds since 1970. We quantified Grasshopper Sparrow responses to climate variation, land management actions, and their interactions in the Platte River Valley, Nebraska, in the North American Great Plains, using six years of mark-recapture data collected via the Monitoring Avian Productivity and Survivorship (MAPS) protocol. We implemented generalized linear mixed models to estimate avian population trends (adult abundance and productivity) in response to changes in precipitation and temperature as well as cattle grazing, haying, and prescribed burning. Our models showed that climatic variation, especially spring precipitation, was the most important driver of avian population trends. Grasshopper Sparrow abundance declined with increasing spring precipitation, but prescribed burns helped mitigate this effect and were positively related to productivity, especially during years of lower spring temperatures. Our findings demonstrate the vulnerability of grassland bird population trends to ongoing and predicted climate change as well as the potential of land management actions to mitigate some negative effects of climate change on grassland breeding birds.

Although anuran reproductive behavior follows a phenological pattern, environmental factors may influence the timing of anuran activity. To characterize the spring calling phenology of Pseudacris maculata (boreal chorus frog) we installed acoustic recorders during three spring breeding seasons (2015–2017) within wet meadow and forested slough habitats in central Nebraska near the Platte River. The recorders were paired with time-lapse camera systems that were used to measure vegetation change and wet meadow inundation. We examined the relationship between environmental variables, including temperature, precipitation, and hydropattern, and P. maculata calling activity using random forest models. Calling activity exhibited diel and seasonal variation with differences observed between habitats. Hourly call activity was highest between 20:00 and 01:00, with diurnal and sometimes near-continuous calling observed at the wet meadow but not at the forested slough. Random forest models explained 73% of calling activity variance at the wet meadow and 45% at the forested slough, suggesting additional factors, such as predation, may be influential at the forested slough, as it exhibited near permanent hydrology. P. maculata was predicted to increase chorusing at the 70th day of the year at the wet meadow but not until the 100th at the forested slough. When average air temperatures exceeded 5 °C, calling activity was predicted to increase at both wetlands, and calling declined below this temperature. Hydropattern and weekly precipitation accumulation were important predictors of P. maculata calling activity. Our findings highlight the importance of climatic factors such as temperature and precipitation regimes, in addition to habitat conditions such as water-availability, on P. maculata calling activity. Furthermore, this study demonstrates the utility of multimodal passive monitoring technologies, including both visual and auditory tools, for understanding the environmental factors that influence biological activity. Multimodal approaches can be especially useful for documenting and measuring vocal-taxa diversity, activity, and drivers of change.