The Crooked Creek Barrens Preserve in the northeastern Knobs region of Kentucky contains an aggregation of species-rich grass and forb-dominated glade openings surrounded by secondary forest. Encroachment of woody species and invasion by non-native species threaten the rare forbs and sedges of the glades. The locations of these plant assemblages are commonly known to correspond to the unique properties of their underlying soils, yet few studies consider how soil factors may influence habitat conservation or restoration. This study describes vegetation and soil properties across the glade-edge-forest transition of three individual glade openings. Juniperus virginiana was the most abundant woody species within the glade openings. Juniperus virginana, Quercus stellata, Fraxinus americana and Cercis canadensis co-dominated the edge-forest boundary. Glade surface soils had dramatically higher pH (2 units) and lower extractable soil P (50% less) than forest soils. Also, total soil N content and net mineralization rates were significantly lower in glades than in forest or edge soils. The highly erodable nature of alkaline shale sediments appears to have contributed to the current location and extent of the glade openings. These findings suggest that management efforts to enhance rare plant habitat by expanding the glade openings should be accompanied by monitoring of soil changes following clearing. Further study should assess whether glade species of conservation concern are restricted to the nutrient-poor alkaline soils within extant glade openings or if they readily colonize the more nutrient-rich habitat of the cleared edge.

We investigated the processes of oak-savanna redevelopment in an abandoned sand mine site in Indiana Dunes National Lakeshore. Our Detrended Correspondence Analysis (DCA) revealed a divergence of vegetation between the prairie and the woodland portions of the study area. Eastern cottonwood (Populus deltoides) and black oak (Quercus velutina) dominated the woodland canopy. The shallow water table (0.90–1.35 m below ground surface) appeared to support the formation of tree canopy. The prairie, with deeper water table (2.09–2.62 m), was sparsely vegetated by shrubs; mostly choke cherry (Prunus virginiana), sand cherry (P. pumila) and fragrant sumac (Rhus aromatica) without apparent tree canopy. Development of woody vegetation, black oak overstory and sassafras (Sassafras albidum) understory was initiated with the colonization of cottonwoods. No evidence was found to support the ‘facilitation effect’ of cottonwoods for black oak seedling recruitment, survival or growth. The tree canopy formation, promoted by water table depth, appeared to be the major factor for divergence in herbaceous vegetation and soil characteristics. The herbaceous vegetation was dominated by C₄ and CAM species (e.g., little bluestem Schizachyrium scoparium and prickly pear cactus Opuntia humifusa) in the prairie, whereas horsetails (Equisetum arvense), asters (Aster spp.) and other C₃ forbs were the dominants in the woodland. Our curve-linear regressions revealed that the cover and diversity of herbaceous species reached their peaks at about 40% tree canopy. The regression analysis also showed strong correlations between the tree canopy and soil organic matter, cation exchange capacity, nitrogen, phosphorus and pH. The 70-y old woodland site had accumulated 1.4% organic carbon and 820 ppm of nitrogen, similar to the ‘mature’ soil of oak-savanna/woodlands near our study site. This suggests a rapid accumulation of major nutrients during the early vegetation development. Nitrogen would likely continue to accumulate beyond the ‘mature’ level. The nitrogen enrichment, particularly under the changing climate, adds uncertainty to the future trajectory of vegetation in the oak-savanna on the Lake Michigan sand dunes.

Soil properties were assessed to determine the effects of tillage agriculture on soil-quality-related parameters of former tallgrass prairie. Soil physical, chemical and biological properties were evaluated in the top 10 cm at six native grassland sites within the Grand Prairie region of east-central Arkansas and compared with adjacent tilled agricultural land in a total of 11 prairie-agriculture land-use combinations. Soil organic matter and total C and N concentrations were significantly lower and soil pH, electrical conductivity and extractable soil P, K, Ca, Mg, Fe were significantly higher under tilled agriculture than under native prairie land use. The introduction and continuance of intense mechanized agriculture and its associated practices have significantly, and for the most part negatively, impacted native soil quality in this region. These results will aid prairie restoration efforts by identifying soil properties most impacted by cultivated agriculture and those that may be desirable to restore and providing potential restoration targets based on native soil properties.

Temporal variation in climatic conditions is a regular occurrence for most early spring flowering plants in temperate regions, often producing variation in available pollinators. Evaluating the effectiveness and importance of pollinators to a plant population provides an indication of the relative influence of each visitor on a population's reproductive success and selection on floral traits. This study examined pollinator activity and its effect on seed set in a population of Phlox divaricata L. (Polemoniaceae), investigating variation over the 24-h day and the flowering season for two consecutive years. Eleven species, representing three orders of insects, were documented visiting the study population, although lepidopterans (four species, particularly Hemaris diffinis and Megalographa biloba) accounted for 90% of all visitation. The highest visitation rates (and resulting seed set) occurred during the morning and afternoon diurnal time periods and the evening crepuscular time period. The relative frequencies of the different visitors varied over the 24-h day and between flowering seasons. Most visitors that could be evaluated were found to be effective pollinators. Thus, a pollinator's importance to reproductive success was generally dictated by its visitation frequency, H. diffinis being the most important pollinator. This study highlights the importance of considering temporal variation in effective pollinators in species experiencing variable environmental conditions.

To quantitatively compare vegetation height of original and restored prairies, and to explore the relationship between quality and vegetation height, we measured visual obstruction, the tallest nearby stem and vertical structure (density of stems at 50, 100 and 150 cm heights) in six remnant, six reconstructed tallgrass prairies and two former pastures. Reconstructed prairies in the Chicago, IL, region included two that were planted and four that were seeded. There were significant differences among sites within the four prairie types for all measures of structure. Type accounted for 39%, 41% and 40% of the variation in visual obstruction (VO), tallest nearby stem (LT) and the graminoid stem density at 1.0 m, respectively. Fields dominated by agricultural grasses had the lowest mean heights, VO = 32 cm, LT = 71 cm. Remnant original prairies had a mean VO of 44 cm and an LT of 130 cm. Planted reconstructed prairies had a mean VO of 54 cm and an LT of 125 cm, while seeded reconstructed prairies were significantly taller, VO = 86 cm and LT = 174 cm, and denser at the 1.0 m height than the other types. Original prairie had mean stem densities of 13 grasses and 4 forbs m⁻² at 1.0 m. Seeded reconstructions had 50 grass and 5 forb stems m⁻² at 1.0 m, so the seeded restorations taller, thicker and grassier than remnants of original prairie. Subjective and species richness estimates of prairie quality were highly positively correlated with one another, as were most of the height and density variables. In both original prairies and seeded reconstructions, shorter prairies have higher quality.

Surface mine lakes are common in parts of the Midwest, but little is known about the communities that inhabit them or the factors shaping them. Our objectives were to: (1) characterize littoral zone macroinvertebrate communities in surface mine lakes; (2) identify factors that influence macroinvertebrate diversity and community structure; and (3) examine the utility of some commonly used bioassessment metrics to assess habitat quality based on macroinvertebrates. Fourteen lakes on a 1133 ha parcel in southern Illinois were sampled in spring 2003 using a dip net that was swept over two (small lakes) or three (large lakes) littoral zone transects. Three hundred macroinvertebrates were randomly removed from each sample and identified. Stepwise multiple regressions were used to examine relationships between several physicochemical and biological variables and macroinvertebrates. Oligochaetes were typically the most abundant taxon, followed by Hyalella, Chironomidae, Physella and Caenis. Seventy percent of the macroinvertebrates collected from the lakes were predators, while collector-gatherers and scrapers constituted 20% and 9%, respectively. Macroinvertebrate richness was positively related to sunfish abundance and macrophyte cover (R² = 0.91, P = 0.001). Simpson diversity was positively related to lake area, percent rock and gravel substrates and simazine concentration and negatively related to bank slope and transparency (R² = 0.92, P = 0.0003). Richness and diversity metrics, % Oligochaeta, % Chironomidae, % insect taxa and % dominance varied across lakes, while a Hilsenhoff index and the EPT index appeared less useful for biological assessments in these habitats. Results indicate that macroinvertebrate communities in these lakes are typical of littoral habitats in other lentic systems and that macroinvertebrate diversity might be enhanced during creation and management of these systems by manipulating coarse mineral substrates and vegetation.

Cocoons of the leech, Theromyzon tessulatum, are secreted underwater and sealed by two opercula (plugs) that are asymmetrically positioned on the upper aspect of the cocoon membrane. The opercula are protein-based, but their amino acid composition appears to differ from the surrounding cocoon membrane. Fluid deposited inside the cocoon by the parent leech contains several proteins ranging in size from ∼40–100 kDa, most of which have pI's below 6.8. While inside the cocoon, late stage embryos display peristaltic contractions that may contribute to weakening of the opercula/membrane boundary. Juveniles break through the opercula after 2–3 wk and exit the cocoon over the course of several hours. The asymmetrical position of the opercula on the upper surface of the cocoon membrane may facilitate contact between the brooding parent leech and the emerging young, which attach to the venter of the parent and are brought to their first blood meal.

Selection will favor males that can bias mating attempts towards more desirable females if the benefits of choosiness outweigh the costs of discrimination. Males that coexist with asexual and/or parasitically castrated females may benefit from discriminatory mating behavior because copulations with these females will not result in offspring that are related to the male. An example of a natural system in which these issues are relevant is Potamopyrgus antipodarum, a freshwater snail native to New Zealand. Sexual and asexual individuals coexist in some populations and the percentage of individuals sterilized by castrating trematodes can be very high. We addressed the possibility of male mate choice by conducting two laboratory experiments focused on determining whether male P. antipodarum housed with sexual, asexual and parasitically castrated P. antipodarum females biased copulatory effort towards sexual and/or healthy females. We found that male P. antipodarum readily copulated with asexual and castrated females, indicating that males do not avoid mating with females with whom they cannot father offspring. There was no evidence for strong male discrimination against any type of female. Potential explanations for this result include weak or no selection favoring discriminatory males, no heritable variation for male discrimination and no phenotypic indicators distinguishing sexual, asexual and healthy and sterilized females.

Cave invertebrate communities are dependent upon exogenous energy sources because their environment generally lacks primary producers. In small caves of central Texas, endemic terrestrial cave invertebrates often rely in part on the energy brought into caves by cave crickets (Ceuthophilus spp.), which forage above ground at night and roost in caves during the daytime. Knowledge of cave cricket foraging range is needed to effectively protect invertebrate communities that include federally endangered species. We marked approximately 2000 C. secretus emerging from Big Red Cave (Coryell County, Texas) with UV bright paint and located 291 previously marked crickets over 17 nights. Crickets foraged up to 105 m from the cave entrance and were present in relatively uniform densities out to 80 m. While 51.1% of the crickets were found within 40 m, 8.1% were found at 80 m or beyond. Relocated crickets were predominantly found in grasses (30.7%), leaf litter (22.4%) and herbaceous vegetation (20.4%) and were found close to ground level (mean = 0.49 cm). Our results show that C. secretus can forage at much greater distances than previously reported. The new data from our study should assist in the development of effective preserve design and management strategies for caves with endangered species in central Texas.

Leg autotomy in spiders is a relatively common occurrence, usually resulting from agonistic interactions with predators or conspecifics. While autotomy has immediate benefits, due to enhanced survival probability, it also potentially decreases future fitness. One possible cost of losing a leg is a reduction in burst running speed, which may affect prey capture and predator avoidance behaviors in wandering spiders. We examined sprint speed in intact and autotomized males and females of the wolf spider Pirata sedentarius from two stream banks in New York in an effort to determine if the sexes differed in either sprint speed or the potential cost of leg loss. Autotomy was fairly common in the field, with 18–22% of spiders missing at least one leg at our two sites. Males and females did not differ in frequency of leg loss. Females were larger than males (both in terms of mass and structural size) and ran significantly faster both before and after autotomy. Sprint speed was uncorrelated with body size (mass, carapace width or leg length) for males, while for females the only significant relationship was that between mass and pre-autotomy speed. Both sexes ran significantly faster when they had all legs compared to their speed after autotomy. We found no difference in speed between spiders which had lost a leg in the field and spiders from which we removed a leg in the laboratory or between intact spiders and spiders collected in the field with a leg missing. Overall, our results for P. sedentarius indicate that: (1) females are faster than males, (2) autotomy significantly reduces sprint speed in the lab for both sexes and (3) reductions in male sprint speed in the lab may result from a combination of autotomy and aging effects, while decreases in female speed are likely due primarily to autotomy.

Introduced American bullfrogs (Rana catesbeiana) come in contact with native amphibians on four continents and are well established in lowlands of western North America. To date, research on the effects of introduced bullfrogs on native frogs has focused on competition and predation, and is based largely on larval interactions. We present observations of interspecific amplexus between bullfrogs and two native ranid frogs (R. aurora and R. pretiosa) from six sites across the Pacific Northwest that imply that this interaction is more widespread than currently recognized. Our observations indicate that R. catesbeiana juveniles and subadults in this region are of appropriate size to elicit marked amplectic responses from males of both native species. Our literature review suggests that greater opportunity may exist for pairings between R. catesbeiana and native R. aurora or R. pretiosa than among syntopic native ranids in western North America. We hypothesize that interspecific amplexus with introduced R. catesbeiana could result in reproductive interference with negative demographic consequences in native ranid populations that have been reduced or altered by other stressors.

Though locally abundant throughout the high mountains of West Virginia, intensive studies on the natural history and population structure of the hellbender, Cryptobranchus alleganiensis, have not been conducted in the state. From 1998–2000 we conducted a mark-recapture study within a 216 × 18 m stream section in east-central West Virginia using diurnal and nocturnal survey methods. Ninety-nine captures of 44 individuals were recorded. Density estimates ranged from 0.8–1.2 individuals/100 m². The sex ratio was 1.2:1. Sexual dimorphism was apparent, as females were longer and heavier than males. However, the longest males were underweight compared to their predicted mass. This population was highly skewed toward large adults, and larvae and juveniles were not encountered. The mean inter-capture distance was 35.8 m and 95% MCP home range estimates averaged 198 m². Water depth where hellbenders were captured ranged from 16–56 cm and individuals were never captured in heavily silted areas. Hellbender size was not correlated to rock size and not more than one individual was found beneath a single rock. We suggest that more thorough searches focusing on larval and juvenile habitat are needed before accurate assessments of population health can be made in this and other streams in West Virginia.

This study documents the ingestion of leaves and seeds by gopher tortoises (Gopherus polyphemus) in a relatively intact pine savanna habitat. Fifty-three species of seeds were identified. Species richness of seeds ingested was highest during spring and fall and was lowest during summer. Grass seed and foliage were consumed consistently by tortoises throughout the year. Despite being found in only 12% of all scats, Rubus seed comprised half of all seeds recovered. Based on seeds in scats, tortoises ingested the fruits of plants in the same proportions in which the plants occurred immediately around active burrows. Although some kinds of leaves were less prevalent in scats than predicted by their availability near active tortoise burrows, this may have occurred because these leaves were digested and, therefore unrecognizable in scats. The role of the gopher tortoise as a generalist herbivore and an opportunistic frugivore was confirmed.

Fish assemblages of small temperate streams are strongly influenced by harsh winter conditions, which are tolerated by year-round resident species and avoided by seasonal migrants. We tested effects of season and longitudinal position on total biomass, species abundances and body condition of fish in two neighboring streams (Plum Run, Brintons Run) in southeast Pennsylvania, USA. In each stream we sampled four pools in a downstream reach in close proximity to a larger (6^th order) stream and four pools in a more isolated upstream reach during fall, winter and spring. Total biomass depended strongly on pool volume, with which other habitat variables (area, maximum depth, extent of undercut bank) were also correlated. Downstream pools of Plum Run (mean volume 18.1 m³, link magnitude 5) had 21 fish species, including 6 species of Centrarchidae that largely vacated the pools in winter. The assemblage in upstream pools of Plum Run and in both upstream and downstream pools of Brintons Run (mean volumes 5.6 m³, 5.7 m³ and 4.4 m³, respectively; all link magnitude 2), consisted of 7 to 11 species. These pools were dominated by Cyprinidae, generally lacked centrarchids and showed little seasonal variation. Three year-round resident cyprinids [Semotilus atromaculatus (Creek chub), Rhinichthys atratulus (Blacknose dace) and Clinostomus funduloides (Rosyside dace)] and the winter emigrant Catastomus commersonii (White sucker) were the most abundant species in the two streams. Body condition of all four species declined substantially in winter; effects of longitudinal position (upstream vs. downstream) on body condition were less pronounced and varied among species. Abundances of the three resident cyprinids were all negatively correlated with the abundances of large, potentially predatory, centrarchids. Occupation of downstream pools in the larger stream by the centrarchids during fall and spring, but emigration from the study area during winter, further modified the effects of winter on the fish assemblage.

Etheostoma zonale, the banded darter, was introduced to the Susquehanna River basin of Pennsylvania through an interbasin transfer, or transplantation of native fishes outside their natural range. We examined the habitat use of a darter native to the Susquehanna River drainage E. olmstedi, the tessellated darter, in sympatry and allopatry with E. zonale to determine if its habitat use was different. In the presence of E. zonale, E. olmstedi occupied significantly (P < 0.05) shallower habitats (mean depth < 27 cm) with smaller substrates (mean substrate index < 32) and slower water velocities (mean water velocity < 0.13 m s⁻¹) than in sites without E. zonale. The habitat shift of E. olmstedi was accompanied by a compression of niche breadth. The results are consistent with the hypothesis that E. zonale excludes E. olmstedi from riffle and run habitats, restricting E. olmstedi to shallow pools and stream margins.

Rural mail carrier surveys (RMCS) have been used to track populations of game animals in the United States for many years, but few states employ RMCS data to track populations of wild turkeys (Meleagris gallopavo). Fourteen years (1987–2000) of RMCS data and hunter harvest data were examined for trends in wild turkey population dynamics in Kansas. Exponential expansion was seen in five of the six regions of the state, the only exception being the southwest, where the population dynamics did not differ significantly from a zero-growth model. Although no population estimates exist for comparison with the relative indices generated from the RMCS data, the residuals from respective exponential models, which represent stochastic fluctuations in turkey abundance, were correlated among adjacent regions of the RMCS, suggesting that the RMCS is internally consistent. Comparisons of RMCS indices with hunter harvest survey data are suggestive of a Type-I functional response curve in the fall hunting season and a Type-II functional response curve in the spring hunting season. Changes in current management strategies are proposed to increase harvest in response to the observed growth of wild turkey populations in Kansas.

Shorebirds use stopover sites throughout the Lower Mississippi Alluvial Valley (LMAV) to fuel their southern migration. At these stopover sites shorebirds exploit macroinvertebrates as their primary foraging material during migration. Studies from coastal areas suggest that shorebirds can significantly deplete macroinvertebrate abundance and biomass at stopover sites. Whether these results are true for the LMAV remains to be evaluated. An exclosure experiment was conducted on five National Wildlife Refuges (NWRs) stretching 400 km throughout the LMAV to see if shorebird foraging impacted macroinvertebrate community composition, abundance and standing stock biomass. Macroinvertebrates were sampled in the late summer of 2001 and 2002 from exclosure areas and open areas and compared using 2-sample paired t-tests. Community composition was relatively similar between the five refuges sampled. Macroinvertebrate abundances ranged from 300 to 433,000 individuals/m² with a mean of 66,500 (±6000) individuals/m².

Shorebird foraging had no significant impact on abundance. Macroinvertebrate biomass ranged from less than 0.1 to greater than 24.4 g ash free dry mass (AFDM)/m² with a mean of 3.43 (±0.35) g AFDM/m². With the exception of one sampling date, 21 August 2001 at Bald Knob NWR, shorebird foraging did not significantly impact macroinvertebrate biomass. On the exceptional date, the difference was due to a reduction of Chironomidae larvae, which was neither the most abundant macroinvertebrate present nor the macroinvertebrate comprising the highest biomass. Results of this study suggest that, at present, shorebirds do not have a significant impact on foraging material in the LMAV flyway during their southern migration. However, with continued degradation to other interior regions and increased promotion of shorebird management in the LMAV, the potential exists for shorebirds to increase in numbers high enough to cause significant impacts in the future.

We surveyed the vegetation growing on the surface of tall boulders (>1.5 m), on the surface of short boulders (<0.5 m) and in areas adjacent to these boulders on the soil surface in the Allegheny National Forest, Pennsylvania. Our purpose was to test the hypothesis that tall boulders serve as refugia from deer browsing for both woody plant species as well as understory herbs. We conducted our surveys during spring when many of these herbs reproduce sexually and their inflorescences are vulnerable to browsing. Deer cannot gain access and browse on these tall boulders, whereas they can easily browse plant species on shorter boulders and on the forest floor. We predicted that the tall boulders would have the highest plant diversity, woody species density and the density of reproductive individuals of understory herbs. We found a total of more than 1300 reproductive individuals of flowering herbs of more than 10 species growing on tall boulders and only 6 reproductive individuals of only a few species growing on the soil surface. Overall, there was a much greater density and diversity of woody species and sexually reproducing herbs on tall boulders or Rock Refugia Gardens than either on short boulders or the soil surface. Because the diversity and abundance of vegetation on the short boulders was nearly identical to that on the forest floor, our findings are unlikely to be explained by tall boulders providing a superior edaphic or abiotic habitat relative to habitats on the forest floor. Species accumulation curves showed that plant species continued to accrue with area on tall boulders, but did not increase with area on the forest floor or on the short boulders. These Rock Refugia Gardens demonstrate the pervasive and deleterious impact that deer are having on plant species diversity and forest regeneration in the Allegheny National Forest and likely elsewhere in the eastern US where these vertebrates are abundant.

Spatial patterns of sexual dimorphism in minks (Mustela vison) from 35 localities in North America were examined using 25 cranial characters to test predictions of the resource partitioning hypothesis of sexual dimorphism. Specific hypotheses evaluated were that trophic structures would be among the most dimorphic and would not be strongly correlated to body size characters. Twenty of 25 characters were significantly larger in males. Predictions of the resource partitioning hypothesis were not supported as canine diameter, a widely used indicator of resource partitioning, was not sexually dimorphic and there was a relatively large correlation between body size traits and trophic traits. Significant spatial variation in degree of dimorphism was found. The patterns of sexual dimorphism from principal components analysis indicated that largest degrees of sexual dimorphism were found in minks from Pennsylvania and Florida and least degrees of dimorphism were in minks from Alaska and Quebec. Sexual dimorphism may have an important temporal component which should be investigated in further studies.

We used radiotelemetry to estimate natal dispersal patterns and survival rates of 13 yearling and 19 subadult beavers (Castor canadensis) at two geomorphologically different sites in southern Illinois. Overall, we observed a 55% dispersal rate for yearlings and a 73% dispersal rate for subadults. Normally, juveniles (yearlings subadults) initiated dispersal around 16 February (range = 28 Jan.–20 Mar.) and settled around 18 April, with juveniles remaining transient from late January through late June. Nine subadult beavers dispersed significantly earlier at one site (x̄ = 25 Nov., range = 31 Oct.–16 Dec.), presumably due to intra-colony strife brought on by management-induced autumn flooding of wetlands for waterfowl. Dispersal occurred earlier than documented in northern regions. Beavers dispersed farther from natal colonies with free-flowing water access (x̄ = 5.9 km) than those landlocked (x̄ = 1.7 km). Males moved more frequently and traveled greater distances per individual move than did females, but overall dispersal distances were similar between sexes. Dispersal distances of beavers with access to free-flowing waterways generally were similar to other studies. Survival during dispersal was greater for beavers emigrating from lodges on the land-locked, less densely populated site (0.80), than for those dispersing in an area of higher population densities (0.43), but did not differ between dispersers and non-dispersers at either site.

Twenty-one swift fox (Vulpes velox) den sites were examined in northeastern New Mexico and compared to 50 random sites across public and private land, and to 50 random sites on public land only, to determine landscape level habitat characteristics in 1997–1998. Den sites were located by monitoring of radio-collared foxes and by systematic field surveys. We used Geographic Information System coverages to describe den site characteristics, including distances to nearest road, prairie dog town, residential structure and agricultural land; road density, residential density and percent agricultural land within 1 and 2 km of the den site or random site; and soil series, United States Department of Agriculture texture class, unified texture class, slope and elevational index at the den site or random site. Den sites had higher values than both types of random sites for road density within 1 km, road density within 2 km and elevation index; and lower values for distance to prairie dog town, residential density within 1 km and residential density within 2 km. Den sites were found more frequently in heavier-textured soils than would be expected if dens were distributed randomly with respect to soil texture. Furthermore, den sites were closer to prairie dog towns and residential structures than random sites on public land. Characteristics of swift fox den sites identified in this study might be helpful for large-scale habitat assessments and for development of conservation strategies.

We conducted a mark-recapture experiment to examine population dynamics of the fulvous harvest mouse (Reithrodontomys fulvescens) and plains harvest mouse (R. montanus) in response to low-level nitrogen amendments (16.4 kg N/ha/y) in an old-field grassland. The experimental design consisted of 16, 0.16-ha plots with four replicates of each treatment combination (fenced, nitrogen amendment; unfenced, nitrogen amendment; fenced, control; unfenced, control). We predicted that densities, survival, and transition probabilities would be greater for both species on nitrogen-amended plots because of greater aboveground biomass (i.e., enhanced concealment from predators). We observed no distinct patterns in survival or transition probabilities of R. fulvescens or R. montanus with regard to treatments. Although population densities of R. fulvescens did not exhibit any distinct patterns with regard to treatments, densities of R. montanus tended to be highest on nitrogen plots, but lowest on nitrogen-fenced plots during winter 1999–2000. As low-level nitrogen amendments continue to be applied, we predict survival and densities of R. montanus and R. fulvescens on control plots, especially fenced plots with no nitrogen amendment, will eventually exceed those on nitrogen-amended plots as a result of higher plant species diversity, food availability and better quality cover.

Wolves (Canis lupus) have recolonized many areas of the Midwestern United States, prompting concern over the possible risk wolves may pose to livestock producers. To better understand the risks wolves may pose to livestock, we initiated a 3-y study examining the food habits of wolves in an agricultural area of northwestern Minnesota and their relation to depredation records of livestock losses in the same area. We collected 533 wolf feces during the non-winter seasons from 1997–1999. White-tailed deer (Odocoileus virginianus) was the most abundant food item (39.2%) of all prey items for all 3 y combined. The deer component comprised both adult deer (26.9%) and fawns (12.3%). Muskrats (Ondatra zibethicus) were the second highest food item at 16.6%. Moose (Alces alces), both adults (13.0%) and calves (0.6%), comprised 13.6% of the diet of wolves, followed by cattle (10.3%), domestic pig (4.4%), lagomorphs (3.6%) and beaver (Castor canadensis; 2.1%). During our 3-y study, eight head of livestock were officially reported as wolf depredations in the agricultural lands within the study area. The confirmed losses included one sheep, one injured cow, one blind cow and five calves. Even with very low deer and moose densities in the study area and a high preponderance of cattle in the area (>1000 head), the wolves in the area preyed mostly on native prey species.

Before 2004, there were no records of evening bats (Nycticeius humeralis) from northern Indiana and northern Ohio and, although three records existed for Michigan, these bats were believed to be vagrants or lost migrants. In August 2004, however, we discovered a maternity colony consisting of at least 68 evening bats in Lenawee County, Michigan. The colony is located over 300 km from the nearest extant colony in Hendricks County, Indiana, and it is the northernmost on the continent. The lack of a large continuous riparian corridor, lined with suitable bottomland forest and connecting the Ohio River with the southern Great Lakes area, probably contributes to the rarity of evening bats across northern Indiana, northern Ohio and southern Michigan.