Animal foraging strategies are formulated in a complex decision-making matrix that is predicated on balancing energy intake and expenditure within a landscape of predation risk. Game species encounter dynamic risks during hunting season as ephemeral predators (i.e., hunters) alter the predation risk landscape daily and seasonally. Predators and prey often concentrate around food sources during hunting season, further complicating the balance of energy intake and risk minimization for prey species. For example, many wetland managers provide energy-rich food resources, such as unharvested grain, that attract waterfowl. Hunter access to these areas varies and alters the inherent risk that wintering waterfowl face to use these resources. We hypothesized use and subsequent depletion of unharvested flooded corn fields would be influenced by proximate anthropogenic disturbance and predation risk, shifting the bioenergetic landscape for waterfowl. We first sampled 145 unharvested flooded cornfields under different hunting access regimes to estimate corn biomass in October 2019 and 2020 in western Tennessee, USA. We then returned to 30 of those fields biweekly during fall-winter 2019-2021 to estimate depletion rates in 60 fields. We modeled depletion rate as a function of hunting risk and forage accessibility by including the variables of corn ear height above water surface, field size, field ownership type, and field distance from sanctuary in our statistical model. Biomass estimates derived from initial surveys indicated private fields that were hunted provided the greatest corn biomass (7,134 +/- 448 kg/ha), followed by public fields that were hunted (5,272 +/- 320 kg/ha) and finally sanctuaries closed to hunting (3,995 +/- 371 kg/ha). Corn biomass was depleted 2-4 times faster on sanctuaries than on hunted fields during November and December but 2 times faster in hunted fields than in sanctuary fields in January. Depletion rates increased as surface water came closer to corn ears but were unaffected by field size or field distance from unhunted sanctuary. Sanctuary fields were devoid of corn by the end of January, whereas 55% of public and 50% of private hunted fields still had corn remaining on 15 March, by which time most ducks had likely initiated migration. Private lands sampled in 2020 contributed nearly 7 times more energy than assumed in the 2015 Lower Mississippi Alluvial Valley Joint Venture energetic allocation models. Despite being devoid of hunters at night, hunted lands are not perceived by foraging waterfowl to be nocturnally similar to sanctuary areas during hunting season. In turn, hunted fields were exploited by ducks later in the season when sanctuary resources were scarce, providing available biomass for migrating birds. It may be important for managers to retain water on hunted fields through early spring given the lack of energy-dense foraging resources available on sanctuary areas. Conservation planners should consider resource depletion as a multiplicative function of hunting risk and abundance when allocating foraging habitat objectives for waterfowl in the non-breeding season.

The spatiotemporal allocation of activity is fundamental to how organisms balance energetic intake and predation risk. Activity patterns fluctuate daily and seasonally, and they are proximately affected by exogenous and endogenous conditions. For birds, flight activity is often necessary for relocating between foraging patches but is energetically expensive and can increase mortality risk. Hunted species may have to adjust their behavior and activity patterns to minimize anthropogenic mortality risk. We used hourly locations from 336 GPS-marked mallards Anas platyrhynchos to examine how hunting pressure affected flight activity in response to weather conditions and habitat availability during winter in western Tennessee, USA. Mallards were more likely to fly during crepuscular times, particularly dusk, across winter months. Mallards conducted more flights after shooting hours when habitat availability increased during open hunting season; conversely, mallard flights decreased with increasing habitat availability when hunters were present on the landscape. Mallards were least active during periods open to hunting. However, indicators of approaching inclement weather (i.e. increased wind speed, precipitation, and decreasing barometric pressure) increased flights during periods open to hunting. Mallard flights decreased at lower temperatures except when hunting season was closed, wherein mallards increased nighttime flights. Flight activity was directly influenced by hunting disturbance which constrained when and how mallards reacted to environmental and habitat conditions. An understanding of the temporal shifts in waterfowl flight patterns can be used by natural resource managers to better manage stakeholder satisfaction and expectations.

AbstractConservation planners use bioenergetic models to develop habitat objectives that satisfy energetic demands of waterfowl during nonbreeding periods. In turn, natural resource managers should estimate yield and availability of natural and cultivated waterfowl forage to monitor contributions to objectives and support adaptive resource management. Because bioenergetic models are particularly sensitive to unharvested flooded croplands, we developed a rapid methodology to estimate biomass of unharvested flooded corn (Zea mays) and tested our methodology in impounded corn fields planted and flooded in western Tennessee during autumn and winter of 2019–2021. We evaluated accuracy of our rapid assessment method and conducted simulations to assess variance‐bias trade‐offs relative to sample size. Rapid assessments lasted 20 min ± 10 minutes per field. Our rapid assessment method underestimated number of kernels per ear by 2.6% ± 0.5%. After adjusting for underestimation bias, corn biomass across all surveys was 5,500 kg/ha ± 250 kg/ha, which is similar yield to previous literature from waterfowl impoundment fields. Sampling 15 ears per field allowed field biomass to be estimated within acceptable accuracy (i.e., variance [SE] of mean percent error <1.8%). We recommend our rapid yield assessment method be incorporated into habitat monitoring protocols to efficiently and precisely estimate corn biomass for improved conservation planning initiatives. Additionally, our rapid assessment method allows managers to monitor field yield rapidly, enabling estimates of corn depletion and availability throughout the nonbreeding season for waterfowl to support management decisions.

Global climate change is increasing the frequency and severity of extreme climatic events (ECEs) which may be especially detrimental during late-winter when many species are surviving on scarce resources. However, monitoring animal populations relative to ECEs is logistically challenging. Crowd-sourced datasets may provide opportunity to monitor species' responses to short-term chance phenomena such as ECEs. We used 14 years of eBird-a global citizen science initiative-to examine distribution changes for seven wintering waterfowl species across North America in response to recent extreme winter polar vortex disruptions. To validate inferences from eBird, we compared eBird distribution changes against locational data from 362 GPS-tagged Mallards (Anas platyrhynchos) in the Mississippi Flyway. Distributional shifts between eBird and GPS-tagged Mallards were similar following an ECE in February 2021. In general, the ECE affected continental waterfowl population distributions; however, responses were variable across species and flyways. Waterfowl distributions tended to stay near wintering latitudes or moved north at lesser distances compared with non-ECE years, suggesting preparedness for spring migration was a stronger "pull" than extreme weather was a "push" pressure. Surprisingly, larger-bodied waterfowl with grubbing foraging strategies (i.e., geese) delayed their northward range shift during ECE years, whereas smaller-bodied ducks were less affected. Lastly, wetland obligate species shifted southward during ECE years. Collectively, these results suggest specialized foraging strategies likely related to resource limitations, but not body size, necessitate movement from extreme late-winter weather in waterfowl. Our results demonstrate eBird's potential to monitor population-level effects of weather events, especially severe ECEs. eBird and other crowd-sourced datasets can be valuable to identify species which are adaptable or vulnerable to ECEs and thus, begin to inform conservation policy and management to combat negative effects of global climate change.

Canada geese (Branta canadensis; geese) often congregate in high public use areas while molting during summer, resulting in increased nuisance complaints. We censused geese that inhabited a Cookeville city park in Tennessee, USA on a weekly basis from 2013-2014 to determine the magnitude, trends, and seasonal nature of problems caused by urban goose flocks. Fewer than 50 geese were counted in most months except during the molt, when numbers increased to >200. Most geese dispersed from the park shortly after completion of the molt. Molt site fidelity to the park was estimated to be 51.5%, indicating that permanent relocation or euthanasia would not provide long-term nuisance relief and may impact local hunting opportunities. To mitigate the nuisance aspect of high densities of molting urban geese in the park, we herded molting and flightless geese to a closed portion of the park and fenced them out of the public use area. Our temporary fencing, coupled with reduced human disturbance in the area where geese were relocated, alleviated the nuisance problems typically associated with large concentrations of geese. We recommend that other municipalities that are experiencing similar seasonal nuisance goose problems consider using nonlethal fencing options.

The brood-rearing period in giant Canada geese (Branta canadensis maxima) is one of the least-studied areas of goose ecology. We monitored 32 broods in Putnam County, Tennessee, from the time of hatching through fledging (i.e., when the goslings gained the ability to fly) and from fledging until broods left the brood-rearing areas during the spring and summer of 2003. We conducted a fixed-kernel, home-range analysis for each brood using the Animal Movement Extension in ArcView® 3.3 GIS (ESRI, Redlands, Calif.) software and calculated 95% and 50% utilization distributions (UD) for each brood. We classified 25 broods as sedentary (8 ha 95% UD), three as shifters (84 ha 95% UD), two as wanderers (110 ha 95%UD); two were unclassified because of low sample size. We measured 5 habitat variables (i.e., percentage of water, percentage of pasture, percentage of development, number of ponds, and distance to nearest unused pond) within a 14.5-ha buffer at nesting locations. We used linear regression, using multi-model selection, information theoretic analysis, to determine which, if any, habitat variables influenced home-range size at a landscape level. The null model was the best information-theoretic model, and the global model was not significant, indicating that landscape level habitat variables selected in this study cannot be used to predict homerange size in the Upper Cumberland region goose flock. We analyzed associations among broods, using a coefficient of association of at least 0.50, and determined association areas by overlaying individual home ranges. Overall gosling survival (Ŝ) during the brood-rearing period was 0.84 (95% CL = 0.78, 0.92), using a staggered-entry Kaplan-Meier survival curve. We believe that abundance of quality forage and pond habitat, high survivorship, and a lack of movement corridors (i.e., rivers, lakes, and reservoirs) were responsible for the relatively small home ranges of geese in the Upper Cumberland region. Associations formed during brood rearing may reduce predation risks and serve as a template for lifelong social bonds with family members and unrelated geese that are reared in the same locations.

Little information is available on giant Canada goose (Branta canadensis maxima) nest-site selection on isolated nesting ponds. We monitored 46 island and 72 shoreline nests in the Upper Cumberland (UC) region of central Tennessee during 2002 and 2003. We measured 6 habitat variables at nesting ponds and randomly-selected non-nesting ponds. We used logistic regression to determine which habitat variables were important in nest-site selection. Presence of an island was the most important variable, but it was excluded from the final analysis because of quasi-separation (i.e., geese nested on all known islands in the study area). Geese that nested on shorelines generally selected larger ponds that may have offered a larger foraging base and more escape options from predators. Nest success rates were similar for island and shoreline nests. Management actions in the UC region and similar areas should be concentrated on ponds with islands because of higher goose nesting densities and ease in finding nests.

Bristle-thighed Curlews (Numenius tahitiensis, hereafter 'curlews') breed only on low Arctic tundra in the southern Nulato Hills of the Yukon Delta National Wildlife Refuge (NVVR) and on the Seward Peninsula, Alaska. Curlews use several distinct habitat types on the breeding grounds; however, quantified data of habitat use by curlews exist only for the Seward Peninsula. We investigated which available habitats on the breeding grounds were used most often by curlews in the Nulato Hills and compared availability with use to determine habitat selection using a land cover layer created in ArcGIS based on aerial photography and ground referenced locations. We also compared curlew habitat usage at our study site to habitats used on the Seward Peninsula. We used vegetation quadrats to determine plant composition within each habitat. We also determined percentage of habitat and plant composition within curlew territories. Curlews preferred shrub meadow tundra which consisted primarily of lichens (>50%), mixed with graminoid/herbaceous plants (similar to 13%) and few dwarf shrubs. Medium/tall shrub habitats, especially tall shrub thickets, were generally avoided by curlews on the ground, but the curlews were commonly observed flying and displaying over the shrubs. Low shrub tussock tundra and sedge wet meadows were occasionally used by curlews but not to the extent of shrub meadow tundra. The avoidance by curlews of areas with medium to tall shrubs was probably related to potential predation risks associated with reduced visibility in these habitats. Habitat selection was similar for both breeding populations of curlews, except curlews at our study site used shrub meadow tundra more frequently and low shrub tussock tundra and sedge wet meadow to a lesser degree than on the Seward Peninsula. Habitats differed in number of berry-producing plants. Berry-producing plants were predicted to be highest in the habitat curlews selected most (i.e., shrub meadow tundra); however, they were most abundant in habitats associated with tussocks.

The Barrens Darter (Etheostoma forbesi) is a rare darter in subgenus Catonotus endemic to the Caney Fork River system in middle Tennessee. Hybridization with the closely related Fringed Darter (E. crossopterum) has been assumed as a risk to E. forbesi. To assess chronology and similarity of nesting habitat between these species, nests of both egg-clustering darters were observed through the spring nesting seasons in four streams during 2008 and 2009. Microhabitat variables associated with nests exhibited evidence of headwater specialization by E. forbesi that may isolate spawning populations from E. crossopterum. Etheostoma forbesi used nest rocks of smaller average dimensions and bottom surface area, and nested at shallower depths where water velocities were higher than nesting individuals of E. crossopterum. Nesting chronology and clutch sizes were similar between species, with spawning periods similar to those reported for other darter species in subgenus Catonotus and with clutch sizes up to 2,000 eggs/nest. Nests were present from March through early June at Duke, Lewis, and Meadow Branch creeks, but spawning was delayed by approximately two weeks at West Fork Hickory Creek, the largest and only spring-fed stream in the study. Etheostoma forbesi displayed peak egg production from mid-April to early May in Duke and Lewis creeks. Etheostoma crossopterum in a similar-sized stream also followed this chronological pattern, but spawning of E. crossopterum was delayed and the active nesting period was protracted into mid-June in the largest and spring-fed stream. Under contempory streamflow conditions, the observed differences in spawning microhabitat suggest a low likelihood of interspecific hybridization, despite the similarities in timing of the two species' spawning activities.

Giant Canada Geese (Anser canadensis maxima) are generally con- sidered to be non-migratory residents throughout the southeastern United States, although biologists have known for some time that Canada Geese in the south- east move long distances (e.g., from north Alabama to Akimiski Island in Canada). To better understand movements of Canada Geese in east Tennessee, we devel- oped a database to track first- and last-known dates and locations of geese that were banded near the Department of Energy's Oak Ridge Reservation. Legband recovery data were also obtained from the U.S. Geological Survey's Bird Banding Laboratory in Laurel, Maryland. Approximately 1% of the nearly 3,000 geese that we tracked are known to have moved outside the State of Tennessee. We estimate that ~5% of Giant Canada Geese in central east Tennessee actually move outside the state and the other 95% are probably permanent residents. The known hunter harvest rate for geese in this study is ~18%, with the actual harvest estimated at 32%. Twenty-eight geese that we documented traveling outside of Tennessee were found in 11 other states and four Canadian provinces.

Species diversity and richness, relative abundance, and community structure were compared between simultaneous single-pass electrofishing and depletion sampling. Additionally, the number of fish displaced from sample reaches when not using block nets was estimated at. each sample site. A total of 40 depletion samples was obtained during the spring and summer of 1999 and 2000 in small first- and second-order warmwater streams of central Tennessee; first passes were used as single-pass samples. Shannon-Wiener diversity values obtained with the single-pass approach were strongly correlated to those obtained with depletion sampling(r(2) = 0.95). The same number of species was captured using both approaches in 15 of 40 streams; depletion sampling richness values exceeded single-pass values by more than two species in only one stream. Using bootstrap analyses, relative abundance values from single-pass samples differed from those of depletion samples in 21 of 40 streams. However, community structure comparisons using similarity indices (SIMI) indicated that the single-pass approach effectively sampled fish abundance. SIMI values were above 0.90 in 32 of 40 streams and above 0.75 in the other eight. Fish were displaced from sample reaches when not using block nets in 32 of 40 streams, but displaced fish species represented less than 10% of the total number of species in 29 of these streams. Fish movement from sampled reaches did not negatively affect estimates of diversity, richness, or relative abundance; the single-pass approach effectively 4:1 sampled fish communities in these streams.

Effects of vegetation, wastewater drawdown, hydraulic retention time (HRT), and media depth on removal of nitrogen, phosphorous, and organic carbon in microcosms were investigated. Synthetic wastewater was added daily to 28 microcosms, and effluent was sampled every 12 days for 132 days. Effluent was analyzed for ammonium (NH(4)(+)-N), nitrate (NO(3)(-)-N), orthophosphate (PO(4)(3-)-P), and total organic carbon (TOC). Average percent removal of NH(4)(+)-N was significantly greater in microcosms containing plants (67%) than in those without plants (29%). Percent removal of PO(4)(3-)-P was also significantly greater in microcosms with plants (42%) than in microcosms without plants (20%), but no significant difference was found for TOC removal between microcosms with plants (67%) and those without plants (74%). Average removal was significantly lower in microcosms with wastewater drawdown than in those without wastewater fluctuation for both NH(4)(+)-N (51% versus 83%) and PO(4)(3-)-P (14% versus 71%). Percent NH(4)(+)-N removal was significantly greater in microcosms with a 6-day retention time (80%) than in those with a 2-day retention (53%), and PO(4)(3-)-P removal was also significantly greater with a 6-day retention time (55%) than a 2-day retention (29%). No differences were seen in TOC removal due to any of the treatments but HRT, where removal was greater microcosms with a 2-day HRT (76%) than in those with a 6-day HRT (60%). Media depth did not have a significant effect on nutrient removal. Results of this study demonstrate that required design parameters are different depending on the nutrient being removed in systems simulated by these microcosms.

Managers have assumed that migratory geese regularly interchange among wintering refuges, providing a potential to manage them as a complex. The primary purpose of our study was to determine population affiliation and magnitude of goose movements among 4 national wildlife refuges (NWR) in Tennessee and northern Alabama, thereby assessing the feasibility of this approach. Interchange and population affiliation were examined using neck collar observations from 1977-1998. Population affiliation varied among refuges, with Southern James Bay geese being most common at Wheeler NWR, and Mississippi Valley geese being most common at Reelfoot NWR. Only 5.1% of 11,039 different blue-and orange-collared geese observed at the 4 refuges were observed at more than 1 refuge during the entire study period. Less interchange occurred within individual years of the study; only 1.5% of 13,680 collared geese was observed at more than I refuge during a single season, and none were observed on 3 or more refuges. Most interchange occurred between the 2 closest Tennessee refuges, about 50 km apart. However, even this interchange was negligible, not exceeding 2% in any given year and was less than 3.5% throughout the 20-year period. Our findings suggest that Canada geese wintering at these refuges exhibit high site fidelity, and this fidelity should be considered when developing management strategies and setting harvest regulations.

Factors affecting growth of softstem bulrush (Scirpus validus), an obligate wetland plant frequently used in subsurface-flow constructed wetlands in North America, were studied in a controlled environmental chamber. Effects of media depth (30-and 46-cm), hydraulic retention time (HRT) (2- and 6-day), and water-level drawdown (drawdown vs. no drawdown) on plant growth in 24 microcosms were investigated. Weekly root and stem growth was measured and stem health assessed to determine effects of treatments on plant vigor. Water-level drawdown was detrimental to plant growth, increasing the percentage of dead stems. Stem production was higher in microcosms with a 46-cm media depth than those with a 30-cm depth and also higher in microcosms that were permanently flooded than in those with fluctuating water levels. Root production was greater in microcosms with a 30-cm media depth than in those with a 46-cm depth, and root production was also greater in microcosms that were constantly flooded than in those drawn down. Scirpus validus is a robust plant that grows well in gravel media microcosms; however, problems are experienced when rhizomes and roots dry out during water drainage.

ABSTRACT Effects of bridge and culvert construction or replacement were studied on 41 streams in Tennessee. One 100-m stream reach above and two 100-m reaches below were sampled at each bridge or culvert with a 50-m buffer zone separating each reach. Fish communities were sampled bi-annually for two years following single pass depletion techniques using a backpack electrofishing unit. Sediment depth and silt-clay percentages were measured during the spring at the upper end of each 100-m sampling reach. Sediment depth and percent silt-clay were greater at streams with culverts than at streams with bridges. Sediment depth and silt-clay percentages did not differ between structure and downstream transects for either bridges or culverts; but they were greater at structure transects than at upstream transects only on streams with culverts. Fish diversity, abundance, and richness did not differ between streams with bridges and streams with culverts, nor among sample reaches. Sediment characteristics and fish metrics were not correlated with bridge age in months. This study indicated that culverts, but not bridges, caused sediment accumulation. However, this accumulation was not sufficient to impact fish communities

Habitat use of eastern wild turkey (Meleagris gallopavo silvestris) broods (1993: N = 7; 1994: N = 9) in western Tennessee were monitored for up to 2 months following hatching to determine preferred habitats during this critical period. Based on availability within their home ranges, hens and their broods selected bottomland hardwoods over other habitat types during weeks 1-4 (P < 0.001). Older broods (4-6 weeks) selected upland hardwood, upland pine, bottomland hardwood, and open habitats in that order over other habitat types (P < 0.001). Intensive monitoring of 6 broods in 1995 verified that telemetry data accurately reflected habitat use. Invertebrate biomass was lower in bottomland forests than in open habitats (P = 0.02), but apparently was adequate to meet the needs of developing poults.