Showing papers in "American Midland Naturalist in 2017"

Bison Increase the Growth and Reproduction of Forbs in Tallgrass Prairie

Abstract: Grazers may increase grassland plant species diversity through mechanisms such as selective consumption of graminoids resulting in release from competition in subordinate forb species, or the enhancement of small-scale habitat heterogeneity. This study tested the hypothesis bison on tallgrass prairie reduce local plant competition and increase the growth, reproduction, abundance, and diversity of forbs. In addition, because grazers, fire, and other drivers result in high spatio-temporal variation in limiting plant resources in tallgrass prairie, we tested the hypothesis that prairie forbs show high phenotypic plasticity in life history traits in response to large grazers. The growth, reproduction, biomass allocation, and abundances of six common perennial forb species, and estimates of local neighborhood and physical environmental factors were compared in replicate tallgrass prairie sites with and without bison. Greater light availability and percent bare ground; and lower grass canopy density, h...

Collapsing Range of an Endemic Great Plains Minnow, Peppered Chub Macrhybopsis tetranema

Abstract: The Peppered Chub Macrhybopsis tetranema was once found throughout the Arkansas River basin in portions of Texas, New Mexico, Oklahoma, Kansas, and Colorado. Range-wide declines in both abundance and distribution have occurred over the past three decades coinciding with habitat loss and fragmentation. Over the last decade or more, only two geographically isolated Peppered Chub populations persisted in the Arkansas and Ninnescah rivers in Kansas and a portion of the Canadian River in New Mexico and Texas. Intensive sampling between 2011 and 2013 documented the decline of this species from Kansas during consecutive years of region-wide drought in 2011 and 2012. Equally intensive sampling in 2015 in reaches of the Ninnescah and Arkansas rivers yielded no individuals, suggesting the potential extirpation of this population. Conversely, Peppered Chub were consistently collected in the Canadian River in New Mexico from 2012 to 2015 with increasing numbers in recent years with higher flows. Therefore, P...

Initial Movements of Re- introduced Elk in the Missouri Ozarks

Abstract: Initial movements of re- introduced wildlife populations can determine short-term restoration success. Managers need ways to encourage release site fidelity to mitigate suboptimal breeding, reduce mortality rates, and minimize human-wildlife conflicts. We studied initial movement ecology of elk (Cervus elaphus) fitted with GPS collars and re- introduced to the Missouri Ozarks in 2011 (n = 32), 2012 (n = 21), and 2013 (n = 31) for 6 mo post release. We assessed maximum displacement from the release site, range shifts, and range size across four sequential time frames (0–10 d, 11–31 d, 32–61 d, and 62–183 d). Compared to other elk restorations in eastern North America, site fidelity was high, with maximum distance from the release site 62–183 d post release ≤10 km for 94% of 2011 animals, 57% of 2012 animals, and 97% of 2013 animals. Elk range sizes were similar during the first 61 d post release but doubled in size 62–183 d post release to an average of 26.2 km2 (range: 4.0–218.8 km2). The average range overlap for individual elk in sequential time periods was between 23–26% across years, indicating elk used different areas over time. Release site had the greatest influence on initial movements; one site used in 2012 was associated with greater release site displacement and range sizes. Maternal cows also demonstrated higher site fidelity to the release site than nonmaternal cows. High site fidelity and small home ranges in elk recently restored to Missouri may be attributed to soft release, minimal human disturbance, quality habitat, and release groups of mature females.

Effects of Individual and Combined Pesticide Commercial Formulations Exposure to Egestion and Movement of Common Freshwater Snails, Physa acuta and Helisoma anceps

Abstract: Pesticides are detected in streams at concentrations that might have adverse effects on aquatic organisms. These agrochemicals typically occur in streams as combinations, yet research has focused on the effects of individual pesticides. We studied the effects of commercial formulations of atrazine, metolachlor, carbaryl, and chlorothalonil on aquatic gastropods Physa acuta and Helisoma anceps egestion and movement. We observed an eightfold reduction in P. acuta egestion rates when exposed to individual (atrazine: 200 μg/L; metolachlor, carbaryl, and chlorothalonil: 100 μg/L) and combined (atrazine x metolachlor: 200 μg/L x 100 μg/L and carbaryl x chlorothalonil: 100 μg/L x 100 μg/L) pesticide treatments relative to controls. For H. anceps individual and combined pesticide treatments had no significant effects on egestion, highlighting differential species response. Helisoma anceps movement declined when exposed to atrazine, carbaryl, and chlorothalonil individually, though responses varied with exposure time. When combined atrazine metolachlor and carbaryl chlorothalonil reduced H. anceps movement relative to the control. In addition to pesticide physicochemical characteristics, it is important to consider exposure durations to better understand the effects of pesticides on aquatic organisms. Furthermore, future risk assessments should incorporate multiple species to better represent response diversity.

Quantification of Changes in Light and Temperature Associated with Invasive Amur Honeysuckle (Lonicera maackii)

Abstract: Biological invasion by nonnative species is considered one of the major threats to the global environment. Amur honeysuckle (Lonicera maackii) is a shrub introduced from Asia which has become invasive in Eastern deciduous forests of North America. An interesting aspect of the life-history of Amur honeysuckle is its extended leaf phenology. It leafs out earlier in the spring than most native shrubs and understory trees and loses its leaves later in the fall. Thus, Amur honeysuckle has the potential to alter the natural light environment and possibly impact native species, particularly spring ephemerals which are dependent on high light levels prior to canopy leaf-out. We tested the hypothesis that light levels are lower in sites with Amur honeysuckle relative to sites with native forest understory and quantified differences between sites. We found that light levels were significantly lower under Amur honeysuckle compared to natural understory, with the greatest reduction occurring during spring. Temperature at ground level was also lower under Amur honeysuckle than under the natural understory during spring. The extended leaf phenology of Amur honeysuckle alters both temperature and light intensity, which may increase both its success as an invader and its impact on native species.

Influence of Poisoned Prey on Foraging Behavior of Ferruginous Hawks

Abstract: We recorded 19 visits by ferruginous hawks (Buteo regalis) over 6 d at two black–tailed prairie dog (Cynomys ludovicianus) subcolonies poisoned with the rodenticide Rozol® Prairie Dog Bait (0.005% chlorophacinone active ingredient) and at an adjacent untreated subcolony. Before Rozol® application ferruginous hawks foraged in the untreated and treated subcolonies but after Rozol® application predation by ferruginous hawks was only observed in the treated subcolonies. We suggest that ferruginous hawks' preference for hunting in the treated subcolonies after Rozol® application was influenced by the availability of easy-to-capture prey, presumably due to Rozol® poisoning. The energetically beneficial behavior of favoring substandard prey may increase raptor encounters with rodenticide exposed animals if prey vulnerability has resulted from poisoning.

Diets of Fishers (Pekania pennanti) and Evidence of Intraspecific Consumption in Pennsylvania

Abstract: The fisher (Pekania pennanti) is a forest-dwelling mesocarnivore native to northern North America. The species had been extirpated from many southern parts of its historic range, but several states have implemented fisher re-introduction programs over the past 40 y. While many studies have previously examined fisher diet, most occurred in northern and western portions of the species' range where mixed and coniferous forests are the dominate cover types. We examined fisher diet, in a re-introduced population in the central Appalachian Mountains where deciduous forests were the dominate cover type. We collected 91 fisher carcasses from 2002–2014 and examined their stomach contents. We detected mammalian and avian prey in 82.6% and 10.9% of stomachs, respectively. Fishers we sampled consumed a variety of plant materials (n = 11) and prey items (n = 30 spp.). Diet composition of males and females overlapped considerably (O = 0.87). Our most noteworthy and novel finding was the presence of fisher remains in 11 (12%) stomachs. We suggest here that rapid population growth of Pennsylvania fishers may have resulted in aggressive behaviors underlying our observations of interspecific consumption. Future research that examines the cause for intraspecific consumption in this central Appalachian fisher population would be a worthy endeavor.

Grassland Bird Productivity in Warm Season Grass Fields in Southwest Wisconsin

Abstract: Surrogate grasslands established through federal set-aside programs, such as U.S. Department of Agriculture's Conservation Reserve Program (CRP), provide important habitat for grassland birds. Warm season grass CRP fields as a group have the potential for providing a continuum of habitat structure for breeding birds, depending on how the fields are managed and their floristic composition. We studied the nesting activity of four obligate grassland bird species, Bobolink (Dolichonyx oryzivorus), Eastern Meadowlark (Sturnella magna), Grasshopper Sparrow (Ammodramus savannarum), and Henslow's Sparrow (A. henslowii), in relation to vegetative composition and fire management in warm season CRP fields in southwest Wisconsin during 2009–2011. Intraspecific variation in apparent nest density was related to the number of years since the field was burned. Apparent Grasshopper Sparrow nest density was highest in the breeding season immediately following spring burns, apparent Henslow's Sparrow nest density w...

Responses of Eastern Gray Squirrels (Sciurus carolinensis) to Predator Calls and Their Modulation by Coat Color

Abstract: In mammals, expression of certain melanocortin receptor ligands is correlated with both dark pigmentation and increased stress resistance and higher levels of aggression. Though many studies of captive and laboratory animals have explored this pleiotropic interaction, relatively few studies of animal behavior have occurred in free-living wild animals. This playback study focused on the antipredator behavior differences between melanistic and gray morphs of eastern gray squirrels (Sciurus carolinensis) in Hiram, Ohio. Vigilance, tail flagging, freezing, and escape behaviors were recorded in response to digital playback of an American robin call, a chickadee call, a car alarm, a buzzer, or one of two different red-tailed hawk calls. All squirrels exhibited increased antipredator behavior after hearing increasingly threatening stimuli. Consistent with prior findings in other species with color polymorphism, gray morphs were more likely to escape after hearing a threatening call. A growing body of ev...

Community-Level Impacts of Management and Disturbance in Western Michigan Oak Savannas

Abstract: Midwestern oak savanna systems are typically defined by their open canopy and the co-existence of scattered mature oak trees and a ground layer dominated by herbaceous vegetation. The structure of these systems is thought to be primarily maintained by disturbance such as fire. In this study we examined the plant community of 21 different oak savanna sites in western Lower Michigan, U.S.A., across a coarse disturbance gradient created by different management practices. Herbaceous community composition differed significantly across a variety of management approaches, while overall diversity remained similar. Indicator species analysis (ISA) identified several species commonly associated with mixed oak forest understories (e.g., Maianthemum canadense) as indicators for recently abandoned oak savanna sites, whereas the indicators identified for managed or heavily disturbed sites included common savanna-associates (e.g., Lupinus perennis). Variation in soil characteristics (C:N ratio and pH) and canop...

Landscape Context Affects Use of Restored Grasslands by Mammals in a Dynamic Agroecosystem

Abstract: Habitat loss from agricultural expansion is one of the leading causes of endangerment for terrestrial vertebrates. Restoration programs such as the Conservation Reserve Program (CRP) and State Acres for Wildlife Enhancement (SAFE) were initiated in part to ameliorate grassland loss. Previous assessments of grassland restoration efforts have not focused on medium and large mammals because of sampling difficulties. More generally, few assessments of restoration outcomes consider effects of landscape context. We integrated camera trapping with occupancy modeling to assess mammal responses on 30 restored grassland sites in a dynamic agroecosystem in Illinois from 2014 to 2015. We tested hypotheses about the effects of local habitat conditions and landscape context on use of restored grasslands by four focal species: raccoons (Procyon lotor), eastern cottontails (Sylvilagus floridanus), coyotes (Canis latrans), and white-tailed deer (Odocoileus virginianus). Most species showed seasonal differences in...

Wiregrass (Aristida beyrichiana) May Limit Woody Plant Encroachment in Longleaf Pine (Pinus palustris) Ecosystems

Abstract: Wiregrass (Aristida beyrichiana) is a dominant groundcover species that facilitates fire in southeastern U.S.A. pine savannas, thereby limiting woody plant cover and maintaining a herbaceous dominated understory. In December 1993 two of us planted a plot of wiregrass (Aristida beyrichiana) in the midst of fire-maintained little bluestem (Schizachyrium scoparium) longleaf pine (Pinus palustris) savanna in the outer Coastal Plain of South Carolina. The plot and the surrounding area burned three times in the following 20 y. Vegetation sampling carried out in late summer 2013 indicated wiregrass dominated the plot and the majority of little bluestem had disappeared. The wiregrass plot was comparatively open and grass dominated, whereas the surrounding formerly bluestem dominated stand had filled in with loblolly pine (Pinus taeda) saplings as well as hardwood trees and shrubs. In addition wiregrass had reproduced and established away from the original planted area, most noticeably within a soil-disturbed plow line. A subsequent prescribed fire in spring 2014 burned with higher intensity within the wiregrass plot than in the surrounding area. Our observations suggest suppression of woody plant encroachment by dense wiregrass in pine savannas even during long fire free periods, which should reduce the likelihood of transition to hardwood dominated ecosystems.

Population Status and Life History Attributes of the Texas Shiner Notropis amabilis

Abstract: Purposes of this study were to assess population status and life history attributes of the Texas Shiner Notropis amabilis, a minnow endemic to the Edwards Plateau region in Texas and the Rio Grande drainage of U.S.A. and Mexico. Despite possible extirpation from three stream reaches, populations of Texas Shiners persist with abundances categorized as occasional and frequent among multiple and independent stream reaches, streams, and drainages. Therefore, Texas Shiner population is considered stable. Quantification of life history traits suggest Texas Shiner has a protracted reproductive season (i.e., 9 mo), a life span of 2 y, and feeds on primarily aquatic invertebrates. Protracted spawning seasons are consistent with Texas Shiner's reported associations with spring systems of the Edwards Plateau. Current and future conservation of N. amabilis and other spring-associated fishes are explicitly linked to spring complexes, although exact mechanisms of association are unknown.

Conserving Large Oaks and Recruitment Potential while Restoring Midwestern Savanna and Woodland

Abstract: Restoring Midwestern oak savannas and woodlands over the long term requires balancing mortality of large oaks with recruitment of oaks into large size classes. At restoration sites in northwestern Ohio, we tracked survival of large oak trees (≥20 cm in stem diameter) and recruitment between 2002 and 2015 after initial tree thinning and prescribed burning treatments. The 24 study sites spanned a gradient of canopy cover from unrestored forests to restored woodlands and savannas. Of 141 large black oak (Quercus velutina) and white oak (Quercus alba) trees alive in 2002, 79% were alive 14 y later. Large oak survival varied among vegetation types, with restored savannas not losing a single tree, compared with 18% mortality in unrestored forests and 28% mortality in restored woodlands. At least some mortality in the woodlands was associated with a tornado that damaged two sites. Diameter distributions changed over the 14 y in all three vegetation types. Unrestored forests shifted toward proportionally greater large and fewer small diameter oaks. Meanwhile, restored woodlands, despite having the highest mortality of large oaks, still exceeded, via recruitment of new large oaks, the reconstructed pre-Euro-American-settlement tree density. Restored woodlands and savannas exhibited four-fold increases in oak recruitment potential (saplings 1 to 10 cm in diameter) between 2002 and 2015. Ecological restoration processes have been compatible with conserving large oaks and sustaining oak recruitment potential.

Resting Site Characteristics of American Marten in the Northern Lower Peninsula of Michigan

Abstract: American marten are associated with forests that are characteristically late successional, closed canopy, and diverse in structure; these attributes meet their habitat requirements and provide resting sites. However, the small populations of marten in Michigan's Northern Lower Peninsula face modern habitat conditions that are fragmented and considerably altered from presettlement environments. Resting site structures are required habitat components that are used daily and provide protection from predation and inclement weather but may be limiting and require active management to preserve. We identified resting site characteristics of American marten in the Manistee National Forest from May 2011 to December 2013. Twenty-five marten (15 male and 10 female) were monitored to identify resting sites. We identified 522 unique resting site structures; tree cavities (n = 255, 48.9%), branches (n = 162, 31%), and nests (n = 90, 17.2%) were most commonly observed. During the summer (April–September) marten...

Use of Buildings by Indiana Bats (Myotis sodalis) and Other Bats in South-central Iowa

Abstract: To determine whether Indiana bats (Myotis sodalis) use barns as roosts in south-central Iowa, we examined barns in six counties in 2005 and 2006. We checked barns during the day for signs of bats, and buildings with recent signs were netted at sunset. Of 232 structures checked during the day, 79.7% showed signs of use by bats. We netted 47 barns and caught 1473 bats; big brown bats (Eptesicus fuscus) and little brown bats (Myotis lucifugus) made up 98.3 % of captures. Twelve Indiana bats were captured, with most individuals captured entering buildings ≥ 1 h after sunset. Therefore it appears Indiana bats in south-central Iowa use barns primarily as night roosts. Barns represent important roosting and breeding resources in south-central Iowa for big brown and little brown bats.

Understory Vegetation Structure and Soil Characteristics of Geomys pinetis (Southeastern Pocket Gopher) Habitat in Southwestern Georgia

Abstract: Geomys pinetis (Southeastern pocket gopher) is a fossorial rodent historically associated with Pinus palustris (longleaf pine) communities. Conversion and fragmentation of longleaf pine communities have reduced quality and quantity of southeastern pocket gopher habitat. It is therefore important to determine characteristics of suitable habitat for future conservation efforts focusing on maintaining or restoring appropriate habitat conditions. We quantified understory vegetation structure (i.e., ground cover categories) and soil characteristics (i.e., soil texture, pH, nitrogen, and carbon at multiple depths) in areas with and without pocket gopher activity. We evaluated a suite of models to determine whether understory vegetation structure, soil characteristics, or a combination of vegetation and soil characteristics were better predictors of gopher presence. Soil characteristics predicted pocket gopher presence better than understory vegetation structure with the best overall model combining per...

Tree Species Preferences of Foraging Songbirds During Spring Migration in Floodplain Forests of the Upper Mississippi River

Abstract: Floodplain forest of the Upper Mississippi River is important for songbirds during spring migration. However, the altered hydrology of this system and spread of reed canary grass (Phalaris arundinacea) and emerald ash borer (Agrilus planipennis) threaten tree diversity and long-term sustainability of this forest. We estimated tree preferences of songbirds during spring migration 2010–2013 to help guide management decisions that promote tree diversity and forest sustainability and to evaluate yearly variation in tree selection. We used the point center-quarter method to assess relative availability of tree species and tallied bird foraging observations on tree species as well as recording the phenophase of used trees on five 40 ha plots of contiguous floodplain forest between La Crosse, Wisconsin and New Albin, Iowa, from 15 April through 1 June. We quantified bird preferences by comparing proportional use of tree species by each bird species to estimates of tree species availability for all 4 y and for each year separately. Species that breed locally preferred silver maple (Acer saccharinum), which is dominant in this forest. The common transient migrant species and the suite of 17 transient wood warbler species preferred hackberry (Celtis occidentalis) and oaks (Quercus spp.), which are limited to higher elevations on the floodplain. We observed earlier leaf development the warm springs of 2010 and 2012 and later leaf development the cold springs of 2011 and 2013. Yellow-rumped Warbler (Setophaga coronata), American Redstart (S. ruticilla), Warbling Vireo (Vireo gilvus) and Baltimore Oriole (Icterus galbula), and the suite of transient migrant wood warblers spread their foraging efforts among tree species in colder springs and were more selective in warmer springs. All three of the important tree species are not regenerating well on the UMR and widespread die-off of silver maple is possible in 50 y without large scale management.

Local-scale Habitat Associations of Grassland Birds in Southwestern Minnesota

Abstract: Conservation of obligate grassland species requires not only the protection of a sufficiently large area of habitat but also the availability of necessary vegetation characteristics for particular species. As a result land managers must understand which habitat characteristics are important for their target species. To identify the habitat associations of eight species of grassland birds, we conducted bird and vegetation surveys on 66 grassland habitat patches in southwestern Minnesota in 2013 and 2014. Species of interest included sedge wren (Cistothorus platensis), Savannah sparrow (Passerculus sandwichensis), grasshopper sparrow (Ammodramus savannarum), Henslow's sparrow (Ammodramus henslowii), dickcissel (Spiza americana), bobolink (Dolichonyx oryzivorus), and western meadowlark (Sturnella neglecta). We calculated correlation coefficients between vegetation variables and species density as measures of linear association. We assessed curvilinear relationships with loess plots. We found grassla...

The Reproductive Ecology of Diploid and Tetraploid Galax urceolata

Abstract: Polyploidy is common in nature, particularly among plants, and is often associated with significant morphological, ecological, and evolutionary change. These changes may contribute to prezygotic and postzygotic isolation between cytotypes; therefore, polyploidy is commonly thought to lead to speciation. Recent work suggests prezygotic mechanisms may be more important in determining isolation than postzygotic mechanisms. We compared the reproductive ecology of populations of diploid and tetraploid Galax to assess the potential for gene flow between the cytotypes. Galax urceolata is native to the southern Appalachian Mountains and is a natural polyploid series with diploid, triploid, and autotetraploid individuals occurring in uniform and mixed-cytotype populations. We found the temporal peak of flower production in tetraploids slightly preceded that of diploids; however, the overall distributions of flowering phenologies were similar. Hymenoptera and Diptera were the most common floral visitors and diploids were visited slightly more often than tetraploids; however, there were no differences between cytotypes in terms of the taxonomic composition of their floral visitors. Seed production is likely pollen limited, but again this does not differ between cytotypes. While tetraploids produced more flowers than diploids, there was no difference in fruit production. Finally, our data suggest that Galax urceolata is self-incompatible. In sum we found few differences in the reproductive ecology of diploid and tetraploid Galax, which when combined with obligate outcrossing increases the potential for gene flow between cytotypes and reduces the likelihood of differentiation.

Life History Attributes of Arizona Grasshopper Sparrow (Ammodramus savannarum ammolegus) and Comparisons with Other North American Subspecies

Abstract: Ammodramus savannarum ammolegus—commonly referred to as the Arizona Grasshopper Sparrow—occurs in the desert and plains grasslands of southeastern Arizona, southwestern New Mexico, and northern Sonora, Mexico. Although a subspecies of conservation concern, this is the first intensive study of its life history and breeding ecology, providing baseline data and facilitating comparisons with other North American Grasshopper Sparrow subspecies. Specifically, I found A. s. ammolegus males generally weighed less than other subspecies (16.0 ± 0.8 g) but with intermediate exposed culmen length (11.6 ± 0.5 mm) and wing chord length similar to the other two migratory subspecies (62.7 ± 1.5 mm). Territory size for A. s. ammolegus was 0.72 ± 0.37 ha, with some variation between sites and among years, possibly indicating variation in habitat quality across spatial and temporal scales. The return rate for A. s. ammolegus males was 39.2%. Nest initiation for A. s. ammolegus was early to mid-July after the monsoons had begun. Domed nests were constructed on the ground, primarily under native bunch grasses, and frequently with a tunnel extending beyond the nest rim, with nest openings oriented north. Clutch size was 3.97 ± 0.68, with no evidence of Brown-headed Cowbird (Molothrus ater) nest parasitism. Extreme climate factors in the arid Southwest may have affected the life history and morphology of A. s. ammolegus as compared to other subspecies, influencing body size and mass, culmen length, breeding phenology, and nest orientation. Other geographic variation occurred in return rates, clutch size, and nest parasitism rates. The baseline data for A. s. ammolegus obtained in this study will inform future taxonomic and ecological studies as well as conservation planning. Comparisons of A. s. ammolegus morphometrics with those of other subspecies will assist field biologists in distinguishing among subspecies where they overlap, especially on wintering grounds.

Winter Habitat Associations for Spotted Skunks (Spilogale spp) in South-Central Wyoming

Abstract: Long-term trends suggest the eastern spotted skunk (Spilogale putorius) experienced a significant decrease in populations throughout the distribution of the species, necessitating development of range-wide management and conservation strategies. However, information on the basic ecology for both S. putorius and the western spotted skunk (S. gracilis) is lacking especially in regions where the distribution of these two species is predicted to converge. We evaluated habitat associations for spotted skunks in an occupancy modeling framework within the foothill transitional habitat of south-central Wyoming during–December 2014. We found occurrence of spotted skunks was positively associated with rocky outcroppings (β = 2.51, se = 1.11, 95% ci = 0.34–4.68, P-value = 0.02). During late-fall and winter, rocky outcropping may represent an important habitat requirement of spotted skunks in this region.

Using Randomized Sampling Methods to Determine Distribution and Habitat Use of Barbicambarus simmonsi, a Rare, Narrowly Endemic Crayfish

Abstract: Habitat requirements are essential knowledge for the conservation of narrowly endemic species. Basic ecological information is unavailable for most crayfish species, including the Tennessee bottlebrush crayfish, Barbicambarus simmonsi. To obtain ecological data, we conducted surveys for B. simmonsi within the Shoal Creek drainage in Lawrence County, Tennessee and Lauderdale County, Alabama from Summer 2013–Spring 2014. The objectives of our study were to determine distribution and habitat use of Barbicambarus simmonsi. Our work increased the number of known sites for the species from three to 14 across Shoal Creek, showing that they occupy a 38.6 km stretch of the creek. Habitat use modeling did not yield significant results, but observations show that crayfish use large flat boulders as habitat, with over 96% of crayfish found under such habitat. We conclude that while habitat modeling is an effective tool we should not overlook the importance of field observations as a contributor to natural hi...

Microhabitat Factors Associated with Occupancy of Songbirds in Suburban Forest Fragments in the Eastern United States

Abstract: Forests in the eastern United States have become fragmented by urban development and agriculture, creating a landscape of remnant forest patches. Many bird species rely on these fragments for breeding habitat, but habitat selection in these patches is not well-understood. Our objective was to examine the effects of forest structure, native plants, and invertebrate biomass on the occupancy of an assemblage of common Eastern songbird species in suburban forest fragments. We collected data at 98 plots in remnant forest patches in Delaware and Maryland. Avian point counts were conducted three times per season between 15 May–7 August 2009–2010. We estimated occupancy probability, while accounting for imperfect detection, for nine common songbird species in order to understand how they are influenced by invertebrate biomass and vegetation characteristics. We ranked competing models using Akaike Information Criteria (AIC). Occupancy of six of our 10 candidate species was affected by forest structure, na...

Spawning Observations of Clinch Dace: Comparison of Chrosomus Spawning Behavior

Abstract: Clinch Dace (Chrosomus sp. cf. saylori), discovered in 1998, is a species of fine-scaled dace confined to northern tributaries of the Upper Clinch River watershed. Only one previous study has documented spawning behavior of Clinch Dace. On June 4–6, 2014, we observed Clinch Dace exhibiting staging and possibly spawning behavior over a gravel nest constructed by either Campostoma or Semotilus. We recorded five video clips totaling over 1 h of spawning behavior. We quantified various behaviors, including: long duration chases, short duration chases, Clinch Dace chasing other species, other species chasing Clinch Dace, Clinch Dace benthic feeding, other species benthic feeding, and nest construction. Analysis revealed an increase in all recorded behaviors between 4 June and 6 June. We speculate 4 June was territorial prespawn behavior and 6 June represented mid spawn/post spawn behaviors. Comparison of spawning observations of all southern Chrosomus species indicates the Clinch Dace is similar to other Chrosomus species in that they seem to prefer pit style nests and exhibit similar spawning aggregation behavior. However, other Chrosomus species in some cases spawn without hosts and seem to spawn within a more specific temperature range than Clinch Dace.

Consumption of Native Green Ash and Nonnative Common Buckthorn Leaves by the Amphipod Gammarus pseudolimnaeus

Abstract: Decomposition of allochthonous organic matter that enters shaded headwater streams during a short autumn leaf fall period provides much of the energy the streams receive throughout the year. As such, alterations of riparian communities, including those resulting from invasive species, should have a significant impact on these energy inputs and potentially alter microbial communities and the behavior of shredders that process leaf litter. We compared consumption of leaves of an abundant native species (green ash Fraxinus pennsylvanica) and nonnative species (common buckthorn Rhamnus cathartica) by the northern spring amphipod Gammarus pseudolimnaeus, with and without periods of stream conditioning. Amphipods consumed a very small proportion of the unconditioned leaves of common buckthorn and green ash and demonstrated no significant preference for the unconditioned leaves of either species. When leaves were stream-conditioned, there was a significant interaction between the effects of leaf species...

Temporal Activity Levels of Mammals in Patches of Early Successional and Mature Forest Habitat in Eastern Connecticut

Abstract: Combining our knowledge of how wildlife species behave across space and time broadens our understanding of patterns of resource use. Temporal patterns of activity may be shaped by species morphology and physiology, major disturbances in an ecosystem, seasonal shifts in abundances of resources, or habitat preferences. Camera traps and univariate kernel density estimates can now be used to quantify temporal activity patterns throughout the day in wildlife. Our goals were to quantify how daily activity patterns of mammals common to southern New England differ between two focal habitat types [i.e., early successional (ES) and mature hardwood (MH) forest patches] and to quantify how temporal activity patterns change seasonally. For all species with sufficient observations, temporal activity patterns did not differ significantly between adjacent ES and MH habitat patches. Daily temporal activity was greatest in the fall and winter for cottontail (Sylvilagus spp.), but we did not detect shifts in activi...

Effects of Woody Biomass Harvests on a Population of Plethodontid Salamanders in Southeast Indiana

Abstract: Biomass harvesting removes unmarketable vegetative material from timber harvests for use as cellulosic bioenergy, leaving only leaf litter. To test whether biomass harvests negatively affect red-backed salamander (Plethodon cinereus) populations, we set up coverboard arrays at 10 sites (mean 3.29 ha, range 2.35–4.61 ha) with varying degrees of biomass harvesting at the Southeast Purdue Agricultural Center (SEPAC) in Jennings County, Indiana. We monitored salamander artificial cover object (ACO) arrays within each site from spring 2012 to fall 2015 and marked all salamanders with visible implant elastomers, generating capture histories for all individuals. Using Program MARK and Pollock's robust design we developed 10 a priori candidate models to test salamander population parameters, with variations on capture probability, recapture probability, survival, emigration, and immigration, as well as a set of models comparing preharvest and postharvest data. To incorporate precipitation events, we clas...

Factors Influencing Detection of the Federally Endangered Diamond Darter Crystallaria Cincotta: Implications for Long-Term Monitoring Strategies

Abstract: Population monitoring is an essential component of endangered species recovery programs. The federally endangered Diamond Darter Crystallaria cincotta is in need of an effective monitoring design to improve our understanding of its distribution and track population trends. Because of their small size, cryptic coloration, and nocturnal behavior, along with limitations associated with current sampling methods, individuals are difficult to detect at known occupied sites. Therefore, research is needed to determine if survey efforts can be improved by increasing probability of individual detection. The primary objective of this study was to determine if there are seasonal and diel patterns in Diamond Darter detectability during population surveys. In addition to temporal factors, we also assessed five habitat variables that might influence individual detection. We used N-mixture models to estimate site abundances and relationships between covariates and individual detectability and ranked models using...

Use of Laguna de Bustillos, Chihuahua, by Waterbirds during the 2011–2012 Wintering Season

Abstract: The importance of Laguna de Bustillos, Chihuahua, Mexico for waterbirds was evaluated during the 2011–2012 nonbreeding season. Thirty-seven percent of all birds were light geese (Chen caerulescens and C. rossii) and 44% consisted of three other species (Anas clypeata, Grus Canadensis, and Anser albifrons). Our data contrast with the historical counts of birds by the U.S. Fish and Wildlife Service using aerial surveys and may reflect recent land-use changes. Given the fact we observed some species in numbers that were far greater than previously recorded, our results provide evidence of the increasing importance of Laguna de Bustillos for wintering waterfowl.