Wooded draws comprise about 1% of the landscape in the Northern Great Plains but provide various mammalian and avian species, including some listed as species of conservation priority, with food, cover, and protection. However, understanding the status of wooded draw health is lacking. Therefore, our objectives were to identify if wooded draws were regenerating by assessing long-term trends of sampled wooded draws while using predictive equations to assign the seral stage of each sampled wooded draw as an indicator of wooded draw health in North Dakota, USA. We found decreasing numbers of green ash (Fraxinus pennslyvanicus) and American elm (Ulmus americanus) stems temporally while percent cover of Prunus spp and Symphoricarpos spp increased temporally. However, we found a general trend for percent shrubby cover to decrease within our microplots. Using predictive equations, we classified 61% of wooded draws as late seral stage, 7% as late intermediate, 8% as early intermediate, and 24% as early successional by their last year of data collection. Our results indicate most wooded draws in North Dakota are aging and not regenerating. Given the importance of this rare cover type, management strategies aimed at regenerating wooded draws are discussed.
Studies on the effectiveness of fish passage structures to allow for upstream movements through dams have mostly focused on recreationally important fishes. A Denil fishway fitted with a passive integrated transponder (PIT) tag array was constructed on the Cedar River near Spalding, Nebraska, in 2015. We evaluated whether this passage structure would allow for upstream movement of five non-game species. Individuals were captured, implanted with PIT tags, and released during 2016–2018. An attempt at passage was noted if an individual passed the antenna placed at the bottom of the fish passage structure and successful passage was defined as crossing the antenna at the top of the fish passage structure. The number of attempts and successful passages by date and species were monitored. Passage attempts and successful passage occurred between April and September for all five species, but peaked in May in 2017 and 2018 and later in the year in 2016. The rates of attempts varied from 15% for Platygobio gracilis (Flathead Chub) to 67% for Carpiodes carpio (River Carpsucker). The rates of successful passage varied from 66% for Cyprinus carpio (Common Carp) to 100% for Flathead Chub. Results of this study indicate that non-game fish use and successfully move upstream through a Denil fish passage structure on the Cedar River in Nebraska. Similar structures might be useful to facilitate movement of non-game fishes through dams in Great Plains rivers.
Exposure of a dam to pathogens may potentially affect her fawns positively or negatively. Mammalian females transfer immunologic protection to their offspring via colostrum obtained while nursing. Conversely, chronic diseases in dams may potentially result in small and weak neonates, reduced milk production or quality, or infection. Little is known about how pathogen exposure in adult female white-tailed deer (Odocoileus virginianus) affects offspring survival. Our objective was to assess pathogen exposure for female white-tailed deer and subsequent survival rates of fawns in Dunn and Grant counties, North Dakota, and Perkins County, South Dakota, USA. We collected blood serum from 150 adult female deer during 2014. We compared survival of 49 fawns to maternal exposure to 10 pathogens from 37 of 150 adult females. There was no difference in fawn mass between dams based on antibody status and no difference in fawn survival for nine pathogens. The 12-wk survival for fawns born to mothers with antibodies against bovine herpesvirus 1 (BoHV-1, causing infectious bovine rhinotracheitis) was lower than for fawns born from mothers without antibodies against BoHV-1; however, the indirect or direct impacts of BoHV-1 exposure in mothers on fawn survival are unclear. Although our findings suggest that the cost of exposure to previous diseases may have minimal impact on short-term fawn survival for most pathogens, additional research with increased sample sizes is needed to confirm our findings.
The relict plains cottonwood (Populus deltoides subsp. monilifera) forest along the Missouri River between Lakes Sakakawea and Oahe includes trees as large as two meters in diameter. We cored 24 of these trees to determine their age and suitability for flow reconstruction. Because most of the trees were rotten in the center, we developed a method to estimate the date of the center ring that accounts for the increase in ring width toward the center. Estimated center ring dates were as early as 1806. Cottonwood growth at a dry site was correlated with April–August flow prior to construction of Lake Sakakawea (1929–1953; r = 0.50, P = 0.011) and to Palmer Drought Severity Index following construction (1954–2014; r = 0.38, P = 0.003). We conclude that cottonwood rings can be used to improve reconstructions of Missouri River flows before the beginning of stream-gage records.
