Reexamination of Herpetofauna on Mormon Island, Hall County, Nebraska, with Notes on Natural History

The Platte River in central Nebraska, USA, was historically surrounded by mixed grass and tallgrass prairies and wet meadows, but many of those habitats were lost or altered during the last century with unknown effects on animals that reside in them. Researchers first surveyed herpetofauna on part of a large island preserve in the Platte River, Mormon Island, Hall County, Nebraska, in 1980 when the land was protected for conservation. They documented 10 species, including three species of amphibians and seven species of reptiles. We inventoried herpetofauna after 30 years of conservation management on Mormon Island and adjacent Shoemaker Island. We captured four species of amphibians and 11 species of reptiles, including five species not detected in the previous survey. New species documented on the preserve were the Bullfrog (Lithobates catesbeianus), Eastern Racer (Coluber constrictor), Smooth Green Snake (Liochlorophis vernalis), Redbelly Snake (Storeria occipitomaculata), and Lined Snake (Tropidoclonion lineatum). Smooth Green Snakes represent a new county record, and Redbelly Snakes represent the easternmost published distributional limit for this disjunct population in central Nebraska. Documentation of additional snake species likely reflects a more intensive trapping regime and possibly habitat changes since 1980. Presence of Bullfrogs on Mormon Island probably was linked to excavation of a backwater slough that created a site for overwintering tadpoles. Herein we describe the variable life-history characteristics, habitats, and seasonal activity patterns among these 15 species of herpetofauna on the large river islands. We also discuss how restoration activities and hydrologic changes may influence the presence and abundance of herpetofauna in the region. Understanding the occurrence, habitat use, and seasonality of amphibians and reptiles in this topographically unaltered (i.e., unplowed) reach of river will aid in managing the central Platte River ecosystem to protect and maintain its biological integrity for all organisms

Differences in Cottonwood Growth Between a Losing and a Gaining Reach of an Alluvial Floodplain

Interstitial flow of river (hyporheic) water influences algal productivity, benthic assemblages, and locations of fish spawning. However, little is known of the effects of hyporheic flow on the growth of riparian vegetation. By increasing water availability and nutrient delivery, regional upwelling of hyporheic water may increase the growth of terrestrial vegetation. We tested and accepted the hypothesis that cottonwood trees (Populus trichocarpa) in a gaining reach of an alluvial floodplain grow faster than trees in a losing reach by comparing basal areas and ages on an expansive floodplain in western Montana (USA). Trees in the gaining reach had basal areas twice the size of the trees in the losing reach, after correcting for tree age. In addition, the carbon-to-nitrogen ratios in leaves were 16% lower in the gaining reach. Lower cottonwood stem densities, deeper layers of fine sediments, and a higher water table occurred in the gaining compared to the losing reach. Each of these variables was significantly correlated with tree growth and likely interacted to influence the productivity of cottonwoods. We concluded that hydration and fertilization of riparian trees likely is mediated by hyporheic flow

Electronic Field Trips for Science Engagement: The Streaming Science Model

While institutions of higher education work to engage PK-12 youth in STEM (science, technology, engineering, and mathematics) concepts and careers via in-person programming, PK-12 teachers and students face many logistical and access constraints for physically traveling to sites off of school grounds during the school day. Throughout the years, electronic field trips (EFTs) have offered a digital way for schools to engage in meaningful ways with museums, parks, laboratories, and field research sites. In order for EFTs to be effective, they should be cost effective and created collaboratively with teachers, students, subject matter experts, and instructional design and communication professionals. Streaming Science is an online science communication platform that aimed to develop and implement an effective EFT model. Three Streaming Science live interactive EFTs webcasted online were piloted from various locations during 2017-2019 to test wireless internet connections, mobile technologies, STEM content, and impacts on students’ interest, attitudes, and learning. The model proved iPads and mobile applications in the field for web streaming were effective for connecting scientists with school audiences. In this professional development article, authors describe the Streaming Science EFT model, including recommendations for instructional design, the pre-production process, content development, teacher collaboration, student engagement, mobile hardware and software, and assessment

Electronic Field Trips for Science Engagement: The Streaming Science Model

While institutions of higher education work to engage PK-12 youth in STEM (science, technology, engineering, and mathematics) concepts and careers via in-person programming, PK-12 teachers and students face many logistical and access constraints for physically traveling to sites off of school grounds during the school day. Throughout the years, electronic field trips (EFTs) have offered a digital way for schools to engage in meaningful ways with museums, parks, laboratories, and field research sites. In order for EFTs to be effective, they should be cost effective and created collaboratively with teachers, students, subject matter experts, and instructional design and communication professionals. Streaming Science is an online science communication platform that aimed to develop and implement an effective EFT model. Three Streaming Science live interactive EFTs webcasted online were piloted from various locations during 2017-2019 to test wireless internet connections, mobile technologies, STEM content, and impacts on students’ interest, attitudes, and learning. The model proved iPads and mobile applications in the field for web streaming were effective for connecting scientists with school audiences. In this professional development article, authors describe the Streaming Science EFT model, including recommendations for instructional design, the pre-production process, content development, teacher collaboration, student engagement, mobile hardware and software, and assessment

UNUSUAL WINTERING DISTRIBUTION AND MIGRATORY BEHAVIOR OF THE WHOOPING CRANE (GRUS AMERICANA) IN 2011–2012

The last, self-sustaining population of Whooping Cranes (Grus americana), the Aransas-Wood Buffalo population, has overwintered almost exclusively along the Gulf Coast of Texas, USA, in and around the Aransas National Wildlife Refuge during recent decades. In late autumn and winter 2011–2012, Whooping Cranes were observed several hundred kilometers from coastal wintering grounds, with at least 13 Whooping Cranes in central Texas, south-central Kansas, and central Nebraska from November 2011 to early March 2012. Notably, family groups of Whooping Cranes were observed around a Texas reservoir, Granger Lake, over a 3-month period. An extreme drought, coupled with record warm temperatures in the southern and central United States, may have interacted to influence behaviors and distributions of Whooping Cranes during winter 2011–2012. Such observations suggest that Whooping Cranes may be more opportunistic in use of wintering habitat and/or more likely to re-colonize inland historical sites than previously thought. Continued documentation of Whooping Cranes overwintering in areas other than the Texas coast and/or altering timing of migration will be important for protection and management of additional winter habitat as well as for informing population estimates for the Aransas-Wood Buffalo Population of Whooping Cranes

Whooping Cranes Consume Plains Leopard Frogs at Migratory Stopover Sites in Nebraska

Whooping cranes (Grus americana) currently consist of a single, wild population that migrates annually from breeding grounds at Wood Buffalo National Park, Canada, to wintering grounds on and around the Aransas National Wildlife Refuge along the Texas coast, USA (NRC 2005). This population reached a low of less than 20 individuals in 1941 (Allen 1952) but has rebounded to over 250 individuals (Chavez-Ramirez and Wehtje 2012, Gil-Weir et al. 2012). Whooping cranes migrate approximately 4,000 km each spring and autumn, traversing much of the North American Great Plains (Lewis 1995) and periodically landing along rivers, wetlands, and other shallow bodies of water for short-duration stopovers (Austin and Richert 2001). Our observations represent some of the few published accounts of a frog species being consumed by whooping cranes along the Central Flyway

Dynamics of mycorrhizae during development of riparian forests along an unregulated river

In this study, we explore two mycorrhizal groups during development of riparian soils along a freely‐flowing river. We provide the first documentation of a shift in abundance between arbuscular mycorrhizae and ectomycorrhizae during floodplain succession. We used a chronosequence spanning 0–70 yr along a river in northwestern Montana, USA, to test the hypothesis that abundance of arbuscular mycorrhizal fungi (AMF) is greatest in early stages of soil development, and abundance of ectomycorrhizal fungi (ECMF) is greatest later in floodplain succession. We also measured the AMF‐mediated process of formation of soil aggregates during site development. AMF colonization of the dominant tree (black cottonwood, Populus trichocarpa) remained low (<5%), while AMF colonization of understory species was high (45–90%), across the chronosequence. Mycorrhizal inoculum potential (MIP) and hyphal length of AMF in soil peaked within the first 13 yr of succession and then declined. No single variable significantly correlated with AMF abundance, but AMF tended to decline as litter and soil organic matter increased. Density of ectomycorrhizal root tips in soil increased linearly throughout the chronosequence, and ectomycorrhizal colonization of cottonwood roots increased rapidly in early stages of succession. These patterns suggest that ECMF are not limited by dispersal, but rather influenced by abundance of host plants. Formation of water stable aggregates increased rapidly during the first third of the chronosequence, which was the period of greatest AMF abundance in the soil. The peak in AMF infectivity and hyphal length during early succession suggests that regular flooding and establishment of new sites promotes AMF abundance in this ecosystem. Regulation of rivers that eliminates creation of new sites may reduce contributions of AMF to riparian areas

Spatial analysis of borrow pits along the Platte River in south-central Nebraska, USA, in 1957 and 2016

The Central Platte River Valley (CPRV) of Nebraska provides critical habitat for wildlife, while serving agricultural, indus­trial, and other human uses. Mining of sand and gravel from the floodplain of the Platte River has supported construction of roads and other uses, and this extraction has created many borrow-pit ponds, lakes, and other small bodies of standing water (hereafter borrow-pits), further transforming riparian and prairie habitats. The objective of this study was to compare the abundance, size, and distribution of borrow pits before construction of Interstate 80 (1957) and at present (2016) from Lexington to Chapman, Nebraska, a length of river spanning about 146 km (90 mi) and sometimes referred to as the Big Bend Reach. Orthorectified aerial imagery of the Platte River was obtained for years 1957 and 2016, and we digitized the standing bodies of water within the floodplain in Arc­GIS. Total numbers of borrow pits and measures of pit shape were calculated and compared between floodplain regions where im­agery overlapped. From 1957 to 2016, the number of borrow pits increased from 300 to 786, total area occupied by pits expanded by 538%, and total shoreline of pits increased by 261%. In 2016, aerial imagery was available for a larger extent of the floodplain and contained a total of 1,062 borrow pits covering 16 km2 (6 mi2), with a total shoreline of 581 km (361 mi). For context, the Platte River channels’ approximate area was 45 km2 (17 mi2) and shoreline 1,582 km (983 mi) between Lexington and Chapman, Nebraska, in 2016. Results provide insight into historical and current presence, distribution, and shape of borrow pits along the Platte River, as well as serve as a reference point for future studies investigating regional landscape change and ecological effects of creating hun­dreds of borrow pits on the floodplain

Climate, Hydrologic Disturbance, and Succession: Drivers of Floodplain Pattern

Floodplains are among the world\u27s most threatened ecosystems due to the pervasiveness of dams, levee systems, and other modi. cations to rivers. Few unaltered floodplains remain where we may examine their dynamics over decadal time scales. Our study provides a detailed examination of landscape change over a 60-year period ( 1945 - 2004) on the Nyack floodplain of the Middle Fork of the Flathead River, a free-flowing, gravel-bed river in northwest Montana, USA. We used historical aerial photographs and airborne and satellite imagery to delineate habitats ( i.e., mature forest, regenerative forest, water, cobble) within the. oodplain. We related changes in the distribution and size of these habitats to hydrologic disturbance and regional climate. Results show a relationship between changes in. oodplain habitats and annual flood magnitude, as well as between hydrology and the cooling and warming phases of the Pacific Decadal Oscillation (PDO). Large magnitude floods and greater frequency of moderate floods were associated with the cooling phases of the PDO, resulting in a floodplain environment dominated by extensive restructuring and regeneration of floodplain habitats. Conversely, warming phases of the PDO corresponded with decreases in magnitude, duration, and frequency of critical flows, creating a floodplain environment dominated by late successional vegetation and low levels of physical restructuring. Over the 60-year time series, habitat change was widespread throughout the floodplain, though the relative abundances of the habitats did not change greatly. We conclude that the long- and short-term interactions of climate, floods, and plant succession produce a shifting habitat mosaic that is a fundamental attribute of natural. oodplain ecosystems