Periodical cicada emergences in the eastern United States are one of the largest biomass fluctuations in the world, providing a unique opportunity to study if a root parasite can affect broad-scale patterns of forest growth and succession. We used dendrochronology to examine the direct effect of Brood X (17 y cicada) and Brood XXIII (13 y cicada) periodical cicadas on 89 individual trees from five species (Acer saccharum, Fraxinus americana, Quercus palustris, Q. velutina and Sassafras albidum) in Indiana. Standard dendrochronological techniques were used to date the tree-ring samples and our chronologies ranged from 63–98 y in age, spanning from four to eight cicada emergences. We removed the main climate variable from each species chronology by conducting a regression analysis and using the residuals for the remainder of the analysis. Significant climate models were developed for all five species. Acer saccharum growth correlated highest with Jun. temperature (r  =  −0.392), Fraxinus americana growth correlated with summer Palmer Drought Severity Index (PDSI) (r  =  0.338), Quercus palustris growth correlated with summer precipitation (r  =  0.366), Q. velutina growth correlated with Jul. PDSI (r  =  0.527) and Sassafras albidum growth correlated the highest with Jun. precipitation (r  =  0.406). A superposed epoch analysis was used to examine the effect of periodical cicadas on each tree species before, during and after multiple emergences on the stand level. No effect from root parasitism prior to emergence was evident in any of the species, but three of the species chronologies showed a significant reduction in growth the year of or the year after the emergence year. Three chronologies showed an increase in growth 5 y following the cicada emergence event.

We studied how habitat selection influences the distribution and densities of a stenotypic yellowcheek darter Etheostoma moorei (Raney and Suttkus) and eurytypic rainbow darter E. caeruleum (Storer) in a headwater stream subjected to periodic drying. We spatially sampled in habitats within riffle substrates and at four sites four to six times per year in the Middle Fork of the Little Red River. Yellowcheek darters were associated with cobble and gravel more than rainbow darters. Rainbow darters moved along the substrate surface and positioned themselves further downstream in riffles, whereas yellowcheek darters occurred further upstream in or near crevices between gravel and cobble. Neither species was found in the hyporheic zone during riffle drying. The rainbow darters used pools during riffle drying but not yellowcheek darters, which could explain recolonization of previously dry upstream sites by rainbow darters but not yellowcheek darters. Rainbow darters were at their greatest densities in upstream riffles where yellowcheek darters had not recolonized, suggesting niche partitioning. These temporal differences in microhabitat selection appear to enable the coexistence of these two sympatric and ecologically similar darters.

Habitat use by fishes in groundwater-dependent ecosystems with springs and spring-fed creeks is not widely studied or well understood. We evaluated habitat use by three disjunct populations of fish species (Phoxinus erythrogaster, Nocomis asper and Etheostoma microperca) and, a widespread species, E. spectabile in spring-fed streams draining the Arbuckle-Simpson aquifer of southern Oklahoma. Habitat preference for each species was classified based on depth, velocity, substrate and cover. Phoxinus erthyrogaster and N. asper were associated with pools with little cover, while E. microperca was found in heavily vegetated areas. Etheostoma spectabile used habitat in riffles with rapid velocity and large substrate types. We classified habitat selection and avoidance with Chesson's α and observed significant differences in habitat use among species in the study sites. Overall differences in habitat use for P. erythrogaster among the three study sites were primarily related to differences in available habitat between springs. Our study provides vital ecological information about disjunct populations of groundwater-dependent fishes in an aquifer that is experiencing development pressure for water abstraction.

Ozark pocket gophers, Geomys bursarius ozarkensis, are endemic to Izard County, Arkansas with a distribution of ∼2300 km². Limited data exists on this subspecies; thus, we collected vegetation and soil habitat data within the current range. Pocket gophers were present in 11 named soil types with loamy sand being the most common texture. No statistical significance was found between pocket gopher density and several soil parameters. We documented pocket gophers predominantly occurring in grazing land, hay fields and lawns. Twenty-one families of vegetation were recorded from samples collected from pocket gopher habitat.

The feeding habits of hoary (Lasiurus cinereus) and silver-haired (Lasionycteris noctivagans) bats have been documented for their summer grounds, but little is known about their feeding habits while en route during migration. We analyzed stomach contents of L. cinereus and L. noctivagans collected at a wind-turbine facility in southwestern Alberta to gain insight into the feeding behavior of migrating bats. We addressed four questions: (1) Do L. cinereus and L. noctivagans feed while en route? (2) On what prey types do each species feed? (3) Do diets differ between species? (4) Do diets differ between age classes within each species? We found that both species fed while migrating and that their diets were similar to those found in their summer grounds, with the exception that L. cinereus consumed a considerable number of water boatmen (Hemiptera; Corixidae). Diets differed between species and age groups within species.

Exotic tree diseases have direct impacts on their host and may have indirect effects on native fauna that rely on host tree species. This paper reports on relative preference for European beech [Fagus sylvatica (L.)] and sugar maple [Acer saccharum (Marsh.)] seed to small mammals, the direct impacts of beech bark disease (BBD) on seed production of American beech [F. grandifolia (Ehrh.)], and indirect impacts of this disease complex on native small mammal fauna in the Upper Peninsula of Michigan. We expected these indirect effects to result from altered seed production in American beech, both in the short and long term. If present, a preference for beech could suggest a mechanism for an indirect impact of BBD on native small mammals. Seed production of infected American beech declined throughout the 3 y of the study, while production of trees in healthy stands varied annually. We found that the abundance of Peromyscus spp. were related to seed crop in the previous autumn but that the presence of the disease complex had no detectable effect on mouse populations. Variation in eastern chipmunk [Tamias striatus (L.)] population sizes were not explained by variation in seed production, although this species tended to be more abundant where beech was present. Finally, southern red-backed voles [Clethrionomys gapperi (Vigors)] were present in forests that did not contain American beech, apparently absent from forests with healthy beech, and present in low numbers in BBD-infected forests. We found that granivorous small mammals consistently preferred European beech seed over sugar maple seed. In general, our studies were indicative of limited short term impacts of BBD on small mammals but suggest the possibility of greater impacts in the future.

Spatial analysis that aims to identify site-specific hotspots of collision mortality from birds or bats striking wind turbines can potentially lead to mitigating measures that reduce mortality rates. During May–Jul. 2004 and 2005, we studied bird and bat mortality from collisions with wind turbines at a 102 megawatt, 68-turbine wind farm in the southern Great Plains, Oklahoma, USA. Standardized searches around turbine bases yielded 122 total carcasses of which 92 (75%) were found within 20 m of the turbine bases. We identified 111 carcasses of seven species of bats and 11 carcasses of 6 species of birds. Brazilian free-tailed bats (Tadarida brasiliensis) comprised 85% of bat carcasses collected. We corrected turbine collision estimates using searcher efficiency trials and a range of removal (i.e., “scavenging”) rates reported in the literature. Estimated bat turbine collisions ranged from 1.19–1.71 fatalities/turbine (1.03–1.37/megawatt). These data provide some of the first evidence for a steady rate of collision mortality of Brazilian free-tailed bats at a North American wind farm, most likely due to the site's proximity (∼15 km) to a maternity colony. Spatial analyses indicated no consistent pattern in mortality estimates relative to ground cover or topographic position; but collision mortality was higher at several individual turbines, all of which were located near the heads of eroded ravines.

We quantified changes in capture rates and sex ratios from May to Sept. for eight species of bats, derived from 8 y of extensive mist netting in forests of the Ouachita Mountains, Arkansas. Our primary goal was to determine patterns of relative abundance for each species of bat captured over forest streams and to determine if these patterns were similar to patterns of abundance found in other types of studies, including studies of bat mortality at wind turbines. We also wanted to discern regional patterns in sex ratios that have implications for seasonal distributions and migration. Capture rates for eastern red bats (Lasiurus borealis) were up to 25 times greater in Aug. and Sept. than in spring or early summer. Although not significant (P  =  0.063), capture rates of hoary bats (L. cinereus) peaked in both late spring and late summer. Silver-haired bats (Lasionycteris noctivagans) were abundant in late spring and late summer but were absent during mid summer, suggesting they migrated from the area. Sex ratios of red bats were predominately male in late spring and late summer but were dominated by females in mid summer, possibly because of increased activity of lactating females during mid summer. Female Seminole bats (L. seminolus) were only captured after Aug. 1, suggesting a seasonal geographic separation of sexes. Our results suggest that patterns of bat abundance derived from mist netting over forest streams may be similar to patterns of bat fatalities at wind turbines, communication towers, aircraft strikes, roads and patterns derived from trapping at cave entrances for many species, but it is unclear why this pattern appears ubiquitous.

We quantified the habitat characteristics associated with capture sites (2003–2006) of the state endangered northern flying squirrel (Glaucomys sabrinus) in Pennsylvania to develop management recommendations that help ensure its continued persistence in the Appalachians. In addition, we used this refined understanding of northern flying squirrel habitat to update the Pennsylvania Gap analysis model for this species. We examined habitat at both the landscape and local level and determined that northern flying squirrels preferred sites that contained mature (>95 y old) mixed coniferous forests and were adjacent to a permanent water source. In addition, sites where northern flying squirrels were captured contained significantly more overstory trees (all species), saplings and rock cover. After using these data to refine the Pennsylvania Gap model for northern flying squirrels, we reduced the primary or core habitat predicted for this species in the state by 90%. Our findings further support the reliance of this species on specialized habitat in the Appalachians and help reinforce the need to conserve and manage mature mixed-coniferous forest stands, which are threatened by exotic pests and human development throughout the region.

Throughout the Midwestern U.S., grassland birds have been declining faster than any other group of birds, with the main cause for these declines being the extensive loss of native prairies. During the last 25 y, surrogate grasslands, such as Conservation Reserve Program (CRP) lands, have become increasingly important as an alternative habitat for grassland birds. However, many CRP grasslands that once provided excellent habitat are now dominated by monculture stands of grass, resulting in a less diverse habitat that has reduced wildlife benefits. In summer 2002, the Nebraska Game and Parks Commission and Pheasants Forever partnered with the United States Department of Agriculture's Farm Service Agency and Natural Resource Conservation Service to initiate a program that promotes disking and interseeding legumes as a mid-contract management practice in CRP fields. The objectives of this study were to determine grassland bird abundance and nest-productivity in disked and interseeded CRP fields and evaluate vegetative responses to disking and interseeding. We conducted our study on 16 CRP fields in Stanton County, Nebraska where we used fixed transects to determine avian species richness and abundance and nest-searched twelve 4-ha plots to determine nest productivity in treatment (managed by disking and interseeding) and reference (unmanaged) CRP fields. We also recorded vegetation characteristics along each transect and at each nest. Overall abundance in treatment fields was 4.49 ± 0.25 (se) birds/transect compared to 2.93 ± 0.21 birds/transect in reference fields. Species richness and diversity were also higher in treatment fields. There was no difference in nest density or nest success between treatment and reference fields. Treatment field vegetation had higher percentages of forbs and bare ground than reference sites. Maximum vegetation height and horizontal visual obstruction were also higher in treatment sites. To accommodate the most grassland bird species in CRP fields, management of CRP fields should include establishing an annual rotation of disking/interseeding, while leaving portions of fields in mature grass stands. Future research should focus on methods that will increase the longevity of the vegetation effects of disking/interseeding legumes.

We examined changes in plant species composition at Faville Prairie in southeastern Wisconsin, based on surveys in permanently-marked, 2 × 2 m quadrats in 1946–1948, 1976–1978 and 2005. Permanent quadrats were distributed across a wide soil moisture gradient. During settlement the site was never cultivated but was mowed for hay for several decades prior to 1946, and burned most years during the dormant season after 1946. Total species richness increased 47% between 1946–1948 and 2005, while species density per quadrat doubled. Only nine non-native species were present in 2005 and most were uncommon. Species density of habitat generalists increased nearly fourfold; moderate specialists increased 43%; and remnant specialists increased nearly twofold. Species density of endangered, threatened and special concern species (collectively conservation-dependent species) increased ninefold. Species density of C3 graminoids, C4 grasses, legumes, woody plants and forbs all increased through time. The majority of species density increases were attained by the 1976–1978 sampling period and remained high since. Elsewhere in Wisconsin, prairie habitat specialists have been declining. Our findings run counter to general trends throughout the state. It is likely that the change from annual mowing to annual prescribed burns accounts for the increases in species density.

Evaluating the progress of ecological restoration projects is critical to improving our understanding of degraded ecosystems and their rehabilitation. In a remnant tallgrass prairie in southeast Michigan that is being managed by periodic dormant-season burns to reduce exotic species and increase native diversity, we tracked plant community changes in seven management units over a period of 16 y to evaluate ecological trajectory in the context of restoration goals. Factors that influenced compositional change from year to year were also assessed. We found that fire frequency, growing season temperature and growing season precipitation were correlated with the magnitude of year-to-year compositional change. Over the 16 y period, most management units decreased sharply in exotic species richness and abundance but did not increase appreciably in native species richness. Also, species evenness and native species abundance increased while total species richness decreased in most units. Over both spatial and temporal scales, the native C₄ grass Andropogon gerardii (big bluestem) was negatively correlated with species richness, likely because of competitive pressure from A. gerardii. Moreover, the direction of ecological trajectory, which diverged among management units over time, was related to differences in the abundance of A. gerardii across the prairie. Ultimately, we concluded that although frequent fire was effective at maintaining prairie species and reducing exotic species, using fire as the only restoration tool was not effective at achieving a species-diverse prairie community.

We investigated pollinator response to a pair of sympatric sister taxa, Antirrhinum subcordatum and A. vexillo-calyculatum (Plantaginaceae). These two taxa, native to northern California, have overlapping geographic distributions, show specialization to different soil types and are morphologically similar except that they differ in flower color (white and purple respectively). We observed and identified floral visitors and performed array experiments. Our results show that similar suites of pollinators visit both plant taxa, which implies no fixed preference on the part of the pollinator species. However, when individual insects visit mixed arrays, they tend to restrict their visits to either the white or purple flowered taxon, likely resulting in assortative pollen transfer even in areas of fine-scale sympatry. The assortative visitation observed is noteworthy given that A. subcordatum and A. vexillo-calyculatum are best interpreted as incipient species. Thus, assortative mating caused by the specialization of individual pollinators towards a single flower color may be crucial for allowing the continued divergence of these lineages. These data contribute to our understanding of the relationship between angiosperm species and their animal pollinators and how these interactions may contribute to the diversification of flowering plants.