scispace - formally typeset
Search or ask a question

Showing papers in "American Midland Naturalist in 2011"


Journal ArticleDOI
TL;DR: In this paper, the authors evaluated land use effects on stream condition in an Iowa watershed dominated by intensive row crop agriculture and low-intensity urban development by quantifying relationships among land cover, stream invertebrate assemblages and other stream biophysical characteristics.
Abstract: Knowledge of relationships between land cover (i.e., land use) and abiotic and biotic features of headwater streams enhances our ability to predict and effectively assess conditions in a variety of aquatic ecosystems. We evaluated land use effects on stream condition in an Iowa watershed dominated by intensive row crop agriculture and low- intensity urban development by quantifying relationships among land cover, stream invertebrate assemblages and other stream biophysical characteristics (i.e., invertebrate habitat) at 29 sites. On average, 81% of subbasin land cover was agricultural and 6% of land cover was urban across study sites. High nitrate concentrations (range = 5.6–29.0 mg/L) and high relative abundance of oligochaetes and chironomid midges reflected degraded conditions at all sites. However, agriculture and urban land use appeared to have different effects on stream features. Nitrate concentrations were positively related to agricultural land cover, and turbidity and nitrate concentr...

45 citations


Journal ArticleDOI
TL;DR: It appears that these once common wallowing disturbances increase the diversity of tallgrass prairie beyond that of prairie that is grazed only (i.e., prairie with cattle), as well as local richness and diversity of plant life forms.
Abstract: Bison (Bos bison) were a keystone species in the tallgrass prairie region of the Great Plains of North America. Cattle (Bos taurus) have been described as a functional equivalent to bison and have replaced bison in most of the grassland that remains intact. However, non-grazing behaviors influence grassland dynamics and are dissimilar between bison and cattle. Wallowing behavior (a non-grazing behavior by bison, but not cattle) creates disturbances (wallows) that were a common feature (may have numbered more than 100 million) of tallgrass prairie prior to extirpation of bison and conversion of most land to row-crop agriculture. We hypothesized that wallows are a unique disturbance that significantly influence both the structure and function of tallgrass prairie. We examined the response of plants to wallowing disturbances on Konza Prairie Biological Station, Kansas, where a herd of approximately 200 bison had year-round access to 1000 ha of native tallgrass prairie. We determined the influence of...

36 citations


Journal ArticleDOI
TL;DR: This article examined both the above and belowground plant communities, along with soil organic matter, pH, texture and light in Arnot Forest located in south central New York and found plots codominated by multiple earthworm species decreased belowground seed abundance and species richness.
Abstract: Scientists are beginning to have a firm grasp on the dramatic influence invasive earthworms can have on nutrient cycling in northern hardwood forests, yet a concrete understanding of their effects on plant communities is still needed. Towards this effort, we examined both the above and belowground plant communities, along with soil organic matter, pH, texture and light in Arnot Forest located in south central New York. Two transects were aligned parallel to previously defined gradients of earthworm density and were sampled in the spring and summer of 2008. We found plots codominated by multiple earthworm species decreased belowground seed abundance and species richness. Aboveground plant cover and diversity along with soil organic matter was lower along the transect with multiple earthworm species. In addition, we found earthworm density increased with soil pH, but did not detect relationships with soil texture or light intensity. Our results were consistent with previous findings of earthworms n...

30 citations


Journal ArticleDOI
TL;DR: Two methods are used to assess the fine-scale genetic spatial structure of a dominant perennial grass and developed AFLP markers that would differentiate between genotypes, which can be applied to questions addressing how genetic diversity of dominant species affect ecosystem processes in the tallgrass prairie.
Abstract: Genotypic diversity of dominant species has been shown to have important consequences for community and ecosystem processes at a fine spatial scale. We examined the fine-scale (i.e., plant neighborhood scale, <1 m2) genotypic structure of Andropogon gerardii, a dominant species in the tallgrass prairie, which is a productive and endangered grassland ecosystem, employing the commonly used amplified fragment length polymorphism (AFLP) technique. In this paper we used two methods to assess the fine-scale genetic spatial structure of a dominant perennial grass, (1) we determined how many tillers to sample in a 1 m2 area and (2) we developed AFLP markers that would differentiate between genotypes. By determining appropriate sampling and molecular techniques, our findings can be applied to questions addressing how genetic diversity of dominant species affect ecosystem processes in the tallgrass prairie.

30 citations


Journal ArticleDOI
TL;DR: A comprehensive list of the 75 mycorrhizal fungi isolated from P. leucophaea protocorms, seedlings and mature plants during the past 10 y from sites in Illinois and Michigan shows that Ceratorhiza appears to be an ubiquitous associate of this genus, and recommends that the fungi used in conservation should be limited to strains acquired from the same or nearby populations.
Abstract: The Federally threatened Eastern Prairie Fringed Orchid, Platanthera leucophaea (Nutt.) Lindley (Orchidaceae), has experienced long-term decline largely due to habitat loss and degradation. Although this species has been propagated from seed in the laboratory, achieving seedling survival ex vitro has been problematic, forcing conservationists to sow seeds directly into field sites in an attempt to generate seedlings. Given that the mycorrhizal fungi needed for germination in situ have sporadic distributions, sowing seeds of this threatened species indiscriminately is not a preferable option. Thus, locating fungal “hotspots” using seed baits, and amending soil with fungi may have practical merit. In anticipation of the latter possibility, we provide a comprehensive list of the 75 mycorrhizal fungi isolated from P. leucophaea protocorms, seedlings and mature plants during the past 10 y from sites in Illinois and Michigan, including newly acquired strains from five additional sites in Illinois. Coll...

29 citations


Journal ArticleDOI
TL;DR: In this article, the authors radio-marked 41 raccoons during 2008-2009 and estimated seasonal space use and habitat selection in a bottomland hardwood forest located within the Atchafalaya floodway system in Louisiana.
Abstract: Raccoon ecology is poorly understood in bottomland hardwood systems, despite the fact that bottomland forests are considered high-quality raccoon habitat. We radio-marked 41 raccoons during 2008–2009 and estimated seasonal space use and habitat selection in a bottomland hardwood forest located within the Atchafalaya floodway system in Louisiana. Space use varied seasonally, with home ranges and core areas largest during the breeding season. Forest openings were important when configuring seasonal home ranges, whereas habitat selection within home ranges varied seasonally. The composition of habitats within core use areas was similar to that of home ranges. We concluded that home range size was influenced by reproductive behaviors and seasonal food availability, whereas habitat selection was most influenced by spatio-temporal changes in seasonal food abundance. Raccoons used all available habitat types and landscape heterogeneity is likely important to raccoons when establishing home ranges in bot...

28 citations


Journal ArticleDOI
TL;DR: It is found that nearly one third of the species planted in CRP sites failed to become established and that grasses were more likely to be successful than legumes or nonleguminous forbs.
Abstract: Prairie restorations are increasingly common throughout the central United States. However, we continue to have little information about which planted species become successfully established, or about the factors potentially limiting establishment. We used a combination of site surveys, field tests and germination testing to examine these issues. We surveyed thirty 4 to 6 y old Conservation Reserve Program (CRP) plantings to quantify the likelihood that planted native species can be found 4–6 y after planting. We then selected a subset of species that had been planted in the CRP sites for use in germination tests and field tests quantifying emergence and seedling survival. We found that nearly one third of the species planted in CRP sites failed to become established and that grasses were more likely to be successful than legumes or nonleguminous forbs. We also found that species with low establishment in the CRP sites often had low emergence rates in the field experiment and low germination rate...

26 citations


Journal ArticleDOI
TL;DR: It is suggested that black cohosh is highly responsive to harvest intensity and that low to moderate harvest intensities and/or longer recovery periods will be necessary for prolonged and sustainable harvests at the study site.
Abstract: Since European colonization and subsequent commercialization of Appalachian medicinal and edible plants, millions of kilograms of plant material have been extracted from our forests, with little effort to manage these species as natural resources. Roots and rhizomes of black cohosh, a native Appalachian forest herb, are extensively harvested for treatment of menopausal symptoms. As nearly all cohosh sold commercially is collected from natural populations, the potential for harvest impacts is considerable. To better understand wild-harvest impacts and the likelihood of post-harvest recovery, we studied the effects of 2 to 4 y of experimental harvest on natural black cohosh populations in the George Washington-Jefferson National Forest in southwest Virginia. After 2 to 3 y of intense harvest (66% plant removal), we found significant reductions in foliage area, stem production, and mean and maximum plant height. The effects of moderately intense harvest (33%) were less clear, producing growth measur...

25 citations


Journal ArticleDOI
TL;DR: The fatality rates for bats in general and little brown bats in particular were higher at the Top of Iowa Wind Resource Area than at other, comparable studies in the region.
Abstract: We examined bat collision mortality, activity and species composition at an 89-turbine wind resource area in farmland of north-central Iowa from mid-Apr. to mid-Dec., 2003 and mid-Mar. to mid-Dec., 2004. We found 30 bats beneath turbines on cleared ground and gravel access areas in 2003 and 45 bats in 2004. After adjusting for search probability, search efficiency and scavenging rate, we estimated total bat mortality at 396 ± 72 (95% ci) in 2003 and 636 ± 112 (95% ci) in 2004. Although carcasses were mostly migratory tree bats, we found a considerable proportion of little brown bats (Myotis lucifugus). We recorded 1465 bat echolocation call files at turbine sites ( = 34.88 call files/detector-night) and 1536 bat call files at adjacent non-turbine sites ( = 36.57 call files/detector-night). Bat activity did not differ significantly between turbine and non-turbine sites. A large proportion of recorded call files were made by Myotis sp. but this may be because we detected activity at ground leve...

25 citations


Journal ArticleDOI
TL;DR: In this article, the authors presented an assessment of annual survival for adult eastern box turtles that were radio-tracked over a period of 2 y. Using a known fates Kaplan-Meier estimator, the baseline annual survival estimate for adult box turtles in Indiana's south-central region is 96.2%.
Abstract: Eastern box turtles (Terrapene carolina carolina) are widespread in U.S. eastern deciduous forests, yet many populations are experiencing dramatic declines. Herein, we present an assessment of annual survival for adult eastern box turtles that were radio-tracked over a period of 2 y. Using a known fates Kaplan-Meier estimator, the baseline annual survival estimate for adult eastern box turtles in Indiana's south-central region is 96.2%. Annual survival rates varied slightly between the hibernal period (95.6%) and the active period (96.7%). These initial data provide wildlife managers with a baseline from which a recovery period can be calculated. In areas where road mortality and human interface are high, this estimate should be adjusted to ensure the time for recovery is adequate. Further research is recommended over generations and age-classes to better inform management of this protected species.

24 citations


Journal ArticleDOI
TL;DR: It is concluded that post-beetle regeneration likely will not be limited by viable seed availability in stands with serotinous cone-bearing trees, and germination rates were affected by cone age.
Abstract: Cones of lodgepole pine (Pinus contorta var. latifolia) are often serotinous, releasing their seeds from closed cones under heat from fire. Stand-replacing fires in predominantly serotinous stands can thus be expected to result in a strong regeneration response. After large-scale mortality caused by mountain pine beetle (Dendroctonus ponderosae), however, the seeds in serotinous cones may remain on the dead trees for a number of years, impacting germination and viability. We tested seeds collected from living and beetle-killed serotinous stands to determine whether they remain viable after tree death, and whether germination rates were affected by cone age. There was no significant difference in percent germination from the living stand vs. the dead stand. While there was a significant relationship between cone age and percent germination, cones that were 21–25 y still had >30% germination. We conclude that post-beetle regeneration likely will not be limited by viable seed availability in stands ...

Journal ArticleDOI
TL;DR: It is demonstrated that Microstegium has negative effects on a native species, but there is no evidence that the suppressive effects of MicroStegium invasions are mediated by plant-soil interactions in invaded areas.
Abstract: Biological invasions are associated with declining biodiversity in many ecosystems, but it is often unclear if invasions are directly responsible for such changes, or if invasions are a symptom of environmental degradation. In addition, the mechanism underlying the effects of many invasive species is unknown. To determine if invaders are driving changes in invaded communities, and to identify causal mechanisms, studies that manipulate the presence of invaders are needed. We experimentally introduced the invasive grass Microstegium vimineum into replicated field plots that had been planted with the native woodland herb Senna hebecarpa. After 3 y, we quantified Senna establishment, growth and reproduction. We then conducted a greenhouse experiment to determine if changes in Senna success were due to alteration of soil microbial communities or nutrient depletion in invaded plots. Microstegium-invaded plots had 74% fewer Senna plants and Senna growing in invaded plots were 21% shorter and weighed 64%...

Journal ArticleDOI
TL;DR: Pistolgrip conservation efforts include sustainable flathead catfish management and habitat improvement to support expansion of remaining pistolgrip populations, according to the apparent close association between pistolsgrip and flatheadCatfish.
Abstract: We conducted a series of studies to improve our understanding of pistolgrip life history and distribution in Minnesota and Wisconsin. In the St. Croix River, where this species is relatively abundant, we studied animals biweekly from May–Nov. 1997, Apr.–Oct. 1998 and nearly biweekly during May–Jul. 2004–2007 and observed gravid females between late Apr.–Jul. at water temperatures 13–25 C. Females held mature glochidia in a large mantle magazine that was significantly more inflated at night. Fifty-seven pistolgrip glochidia measured using scanning electron microscopy had an average height and length of 119 ± 6 µm and 102 ± 4 µm (±1 sd), respectively. Of 65 fish species (18 families) exposed to pistolgrip glochidia only flathead catfish (Pylodictis olivaris) and brown (Ameiurus nebulosus) and yellow (A. natalis) bullheads were suitable hosts, with flathead catfish showing the strongest host response. Glochidia grew 422 ± 17% while attached to fish. Pistolgrip is found in central and southeastern U....

Journal ArticleDOI
TL;DR: Impacts of prescribed fire on ant nesting ecology in the Oak Openings of NW Ohio are examined, suggesting that burning did not impact frequency of nest occupation, or species composition of existing cavity-nesting ant colonies, but burning may alter colonization processes for cavity- nesting ants within savannas in theOak Openings.
Abstract: Oak savannas in the Midwestern United States are rare ecosystems heavily altered by human activity. Common land management practices, like prescribed fire can control invasive species and restore native plants, but few studies have examined the impacts of such practices on oak savanna invertebrate communities. We examined impacts of prescribed fire on ant nesting ecology in the Oak Openings of NW Ohio. We measured ant use of natural nests and colonization of artificial nests in savannas to examine ant nest-site limitation and colonization. We collected 376 potential natural nests (362 acorns, 12 twigs and 2 other hollow nuts); 161 in burned sites and 215 in unburned sites. In burned sites, seven (or 4.34%) nests were occupied by ants and in unburned sites three (or 1.4%) were occupied, but nest occupation did not differ between burned and unburned areas. Overall 6.85% of artificial nests were occupied; 5.56% in burned and 7.59% in unburned areas, but again, the difference was not significant. Two...

Journal ArticleDOI
TL;DR: Redwood may have difficulty adapting to new climatic conditions or of migrating into displaced habitats with anticipated climate change, and the southern lineage of populations is likely to be at greatest risk and is therefore of conservation priority.
Abstract: We developed a suite of tetranucleotide microsatellite loci and applied them to a study of genetic variation across the geographic range of coast redwood [Sequoia sempervirens (D. Don) Endl.]. The objectives of the study were to determine if the microsatellite loci could provide useful information on genetic diversity in this hexaploid species and to investigate earlier reports of divergent lineages within coast redwood. The microsatellite loci were highly variable, yielding a total of 142 alleles. Up to six alleles were detected in each individual consistent with the ploidy of coast redwood and suggesting that parental genomes must have been at least partially homologous. This does not rule out autoployploidy in the evolution of the redwood genome. We treated the microsatellite alleles as presence-absence data and we also estimated full genotypes assuming peak intensities varied with allele dosage. Both types of analyses revealed similar trends. Variation within the 17 watersheds sampled, explai...

Journal ArticleDOI
TL;DR: The first study to demonstrate the negative impact of R. ficaria on a native species and the possible role of allelopathy in its success is demonstrated, calling into question previous widespread assumptions about R.ficaria exerting effects primarily on other ephemeral species.
Abstract: Information about invasive species is often based primarily on anecdotal evidence, indicating the need for further information Ranunculus ficaria is an ephemeral riparian plant species that is presumed invasive in the United States, despite the lack of any published information on its impacts Mechanisms by which R ficaria may affect native plant species include competition and allelopathy We examined if R ficaria negatively affected the growth and reproduction of the native Impatiens capensis and, if so, whether it is by allelopathy, nutrient competition or some combination thereof We performed a fully-factorial field experiment, manipulating the presence of R ficaria, nutrients and allelopathy (with the use of activated carbon) The presence of R ficaria tended to negatively affect life span of I capensis In the absence of carbon, R ficaria significantly decreased seed production, illustrating the negative impact of R ficaria In the presence of carbon, there was no effect of R ficaria, suggesting that carbon may have ameliorated the negative allelopathic effect of R ficaria Nutrient competition did not show strong effects Despite its widespread identification as an invasive species, this is the first study to demonstrate the negative impact of R ficaria on a native species and the possible role of allelopathy in its success Further, the negative impacts of this ephemeral species persist well beyond its early growing season, which calls into question previous widespread assumptions about R ficaria exerting effects primarily on other ephemeral species

Journal ArticleDOI
TL;DR: In this paper, the authors conducted river otter sign surveys from Jan. to Apr. 2008 and 2009 in eastern Kansas to assess how local and landscape-scale habitat factors affect river otters' occupancy.
Abstract: The North American river otter (Lontra canadensis) is recovering from near extirpation throughout much of its range. Although reintroductions, trapping regulations and habitat improvements have led to the reestablishment of river otters in the Midwest, little is known about how their distribution is influenced by local- and landscape-scale habitat. We conducted river otter sign surveys from Jan. to Apr. in 2008 and 2009 in eastern Kansas to assess how local- and landscape-scale habitat factors affect river otter occupancy. We surveyed three to nine 400-m stretches of stream and reservoir shorelines for 110 sites and measured local-scale variables (e.g., stream order, land cover types) within a 100 m buffer of the survey site and landscape-scale variables (e.g., road density, land cover types) for Hydrological Unit Code 14 watersheds. We then used occupancy models that account for the probability of detection to estimate occupancy as a function of these covariates using Program PRESENCE. The best-fitting model indicated river otter occupancy increased with the proportion of woodland cover and decreased with the proportion of cropland and grassland cover at the local scale. Occupancy also increased with decreased shoreline diversity, waterbody density and stream density at the landscape scale. Occupancy was not affected by land cover or human disturbance at the landscape scale. Understanding the factors and scale important to river otter occurrence will be useful in identifying areas for management and continued restoration.

Journal ArticleDOI
TL;DR: Deer management in four distinct ecoregions relies on hunter harvest to maintain deer populations within state management goals and had the lowest AICc value suggesting that survival differed only between seasons where winter and summer survival was equal and differed with fall season.
Abstract: Survival and cause-specific mortality of female white-tailed deer (Odocoileus virginianus) have been well documented in forested and agricultural landscapes, but limited information has been collected in grassland habitats typical of the Northern Great Plains. Our objectives were to document and compare survival and cause-specific mortality of adult female white-tailed deer in four distinct ecoregions. We captured and radiocollared 190 (159 adult, 31 yearling) female white-tailed deer and monitored (including deer from a previous study) a total of 246 (215 adult, 31 yearling) deer from Jan. 2000 to Dec. 2007. We documented 113 mortalities; hunting (including wounding loss) accounted for 69.9% of all mortalities and vehicle collisions accounted for an additional 15.0%. Natural causes (e.g., disease, predation) of mortality were minor compared to human-related causes (e.g., hunting, vehicle collisions). We used known fate modeling in program MARK to estimate survival rates and compare ecoregions an...

Journal ArticleDOI
TL;DR: In this article, the authors conducted surveys to detect latrines (locations where scats are deposited in riparian areas) from reintroduced populations of river otters at 26 bridge-suites in northern Pennsylvania.
Abstract: Riparian sign surveys near bridge crossings are commonly used to detect the presence of river otters. However, the efficacy of using such surveys for determining river otter presence has not been evaluated relative to habitat conditions. We conducted surveys to detect latrines (locations where scats are deposited in riparian areas) from reintroduced populations of river otters at 26 bridge-suites in northern Pennsylvania. A bridge-suite consisted of a bridge site, a random site and a selected site (i.e., high quality site based on several habitat variables), <2.5 km upstream or downstream from the bridge. Sites consisted of both shorelines along a 200-m section of stream or river. Site quality was determined by applying a modified Pattern Recognition model (PATREC) previously developed to provide a probabilistic assessment for predicting the occurrence of river otter latrines based on the presence or absence of certain riparian and riverine habitat features. Sites were surveyed in fall 2003 and s...

Journal ArticleDOI
TL;DR: In this paper, the authors sampled five linear segments of urban forest along bike trails in Lincoln, Nebraska to assess the invasion of woody non-native species relative to corridors and assess the composition of these urban forests.
Abstract: Corridors such as roads and trails can facilitate invasions by non-native plant species. The open, disturbed habitat associated with corridors provides favorable growing conditions for many non-native plant species. Bike trails are a corridor system common to many urban areas that have not been studied for their potential role in plant invasions. We sampled five linear segments of urban forest along bike trails in Lincoln, Nebraska to assess the invasion of woody non-native species relative to corridors and to assess the composition of these urban forests. The most abundant plant species were generally native species, but five non-native species were also present: white mulberry (Morus alba), common buckthorn (Rhamnus cathartica), tree-of-heaven (Ailanthus altissima), honeysuckle (Lonicera spp.) and elm (Ulmus spp.). The distribution of two of the woody species sampled, common buckthorn and honeysuckle, significantly decreased with increasing distance from a source patch of vegetation (P = 0.03...

Journal ArticleDOI
TL;DR: Understanding the breeding biology of A. filipes will be necessary for reliable and consistent commercial seed production with this species, which is weakly self compatible and visited most commonly by Osmia bee species plus several bee species each of Eucera, Anthidium, Bombus and sometimes Hoplitis.
Abstract: Astragalus L. (Fabaceae) is an enormous and diverse plant genus with a cosmopolitan distribution, but relatively few breeding biologies are known for its member species. Threadstalk (or basalt) milkvetch, Astragalus filipes Torrey ex. A. Gray, is common and widespread throughout the U.S. Intermountain West, including the Great Basin. It is being studied and ultimately propagated for extensive rangeland restoration projects throughout the sagebrush steppe. Understanding the breeding biology of A. filipes will be necessary for reliable and consistent commercial seed production with this species. We examined reproductive output from four manual pollination treatments (autogamy, geitonogamy, xenogamy and distant xenogamy) in a common garden. As measures of fitness, we counted fruit and seed set, then germinated viable seeds, to assess reproductive output. This species is weakly self compatible; xenogamous pollen transfer results in nine times more seed per pollination. Pollen transfer between geograp...

Journal ArticleDOI
TL;DR: In this article, the impacts of recent fire suppression in pine and oak stands on the Menominee Indian Reservation in northeast Wisconsin were studied and a total of 93 fire events with a fire-return interval (FRI) of 5.9-17.7 were recorded across all stands before fire suppression activities in 1935.
Abstract: Due to the paucity of long-term fire chronologies in the upper Midwest, we studied basal cross-sections dating back to 1822 and the impacts of recent fire suppression in pine and oak stands on the Menominee Indian Reservation in northeast Wisconsin. A total of 93 fire events with a fire-return interval (FRI) of 5.9–17.7 y were recorded across all stands before fire suppression activities in 1935. After 1935, we recorded 29 fires. Most stands have only burned 0–3 times since 1935, and only four of 16 stands yielded enough fire years to calculate FRIs. Superposed Epoch Analysis (SEA) determined significantly lower Palmer Drought Severity Index (PDSI) values 1 y before individual fire years. Fire wounding occurred primarily in the dormant season and average tree diameter at time of wounding ranged from 7–30 cm. Current forest composition was dominated by white pine (Pinus strobus L.) and red maple (Acer rubrum L.) overstories, whereas seedlings and saplings were predominantly eastern hemlock (Tsuga ...

Journal ArticleDOI
TL;DR: The effects of fire on prairie carabid assemblages and detrimental effects on individual species appeared to be short-lived and nonmetric multidimensional scaling and analysis of similarity supported the findings of MRPP.
Abstract: The diversity of ground beetles in relation to habitat type was investigated in west-central Illinois from May to Oct. 2005 and 2006 using pitfall traps in six habitats: (1) prairie burned in 2004, (2) prairie burned in 2005, (3) early successional forest, (4) oak-hickory forest burned in 2004, (5) oak-hickory forest burned in 2005 and (6) oak-hickory forest burned in 2006. A total of 2712 ground beetles representing 28 genera and 54 species were collected. A multi-response permutation procedure showed significant differences in ground beetle assemblages among habitat types. Nonmetric multidimensional scaling and analysis of similarity supported the findings of MRPP. Indicator species analysis found significant habitat associations for seven species of carabids in 2005 and eight species in 2006. Forest habitats generally had lower species richness than expected based on rarefaction. The effects of fire on prairie carabid assemblages and detrimental effects on individual species appeared to be sho...

Journal ArticleDOI
TL;DR: The results suggest that dispersal among plants by strawberry aphid apterae is affected by plant characteristics associated with genotype and quality of the host plant for the herbivore.
Abstract: Herbivore movement behavior is a key mediator of how host-plant populations affect herbivore populations. We examined the effects of host-plant genotype and variance among host-plant genotypes on movement rates of apterous strawberry aphids, Chaetosiphon fragaefolii (Cockerell) (Homoptera: Aphididae), on Fragaria chiloensis (L.) P. Mill. In the field we estimated aphid movement rates over several years on experimental populations of five different plant genotypes. In the greenhouse, we followed the movement of individual aphids in plant arrays of a single genotype or three different genotypes. In both cases, aphid apterae movement differed among host plant genotypes, with more movement on higher quality genotypes. Movement rate in the field was also influenced by aphid population size. In the greenhouse, aphids showed no taxis toward particular plant genotypes but left different plant genotypes at different rates. Aphids also tended to move more often among plants in three genotype arrays (with a...

Journal ArticleDOI
TL;DR: In this article, the authors examined breeding bird species composition and vegetation community composition on three glade sites undergoing restoration with prescribed fire and compared them to three unburned glades sites and three un-burned forest sites.
Abstract: Due to fire suppression and land use changes, Missouri glade habitats have undergone long-term declines in area and function leading to consequent declines in many bird species that rely on these habitats. We examined breeding bird species composition and vegetation community composition on three glade sites undergoing restoration with prescribed fire and compared them to three unburned glade sites and three unburned forest sites. Although we documented subtle changes in vegetation characteristics in response to prescribed fire, important structural characteristics, such as canopy cover (>55% at all study sites) and grass cover (<10% at all study sites) remain outside ranges used to characterize glades. Despite this, bird community structure shifted towards grass-shrubland (glade) birds (e.g., prairie warbler (Dendroica discolor), blue-winged warbler (Vermivora pinus), yellow-breasted chat (Icteria virens)) in glades that had been managed with prescribed fire. Using canonical correspondence analy...

Journal ArticleDOI
TL;DR: The importance of considering local adaptation in butterfly conservation is addressed and investigations of regional specialization that may enhance the effectiveness of conservation strategies such as captive rearing, habitat restoration and the introduction of populations into new localities are encouraged.
Abstract: Butterflies are among the most charismatic and alluring of invertebrate organisms. Their complex life histories and diverse habitat affiliations often produce regional variation and local adaptation among different populations. Unfortunately, numerous lepidopteran species are facing extinction. In this paper we address the importance of considering local adaptation in butterfly conservation and encourage investigations of regional specialization that may enhance the effectiveness of conservation strategies such as captive rearing, habitat restoration and the introduction of populations into new localities. We also give suggestions for dealing with problems arising from local adaptation in particular instances.

Journal ArticleDOI
TL;DR: These noxious larval anurans also showed ontogenetic shifts in palatability to one or more predators by becoming more palatable throughout development, and Predator tolerance to noxiousness also played a key role in predation trials.
Abstract: We tested the palatability of 12 species of anuran larvae that occur in eastern Texas using four common predators. Palatability was determined by offering larvae to predators and recording the behavior of the predator. We also tested for ontogenetic shifts in palatability in twelve species of anuran larvae. Incilius nebulifer, Anaxyrus woodhousii, Lithobates catesbeianus, L. clamitans and L. sphenocephalus all showed evidence of unpalatability in laboratory experiments. These noxious larval anurans also showed ontogenetic shifts in palatability to one or more predators by becoming more palatable throughout development. Predator tolerance to noxiousness also played a key role in predation trials. Bluegills were the least tolerant, followed by green sunfish and dragonfly larvae. Crayfish had the highest tolerance to noxiousness.

Journal ArticleDOI
TL;DR: The diet of river otters changed seasonally, including a decline in the frequency of fish in the summer diet, and a corresponding increase in the occurrence of crayfish.
Abstract: The food habits of river otters (Lontra canadensis) on three rivers in the Red River of the North drainage of eastern North Dakota were evaluated using an analysis of 569 scats collected between 4 Oct. 2006 and 26 Nov. 2007. Fish and crayfish were the primary prey items, occurring in 83.0% and 51.1% of scats, respectively. Other prey included insects (26.7%), birds (7.9%), amphibians (6.7%), mammals (6.0%) and freshwater mussels (0.2%). Fish of Cyprinidae (carp and minnows) were the most prominent fish in the diet, occurring in 64.7% of scats. Other relatively common fish in the diet included Ictaluridae (catfish, 17.4% frequency of occurrence), Catostomidae (suckers, 13.0%), and Centrarchidae (sunfish, 11.2%). The diet of river otters changed seasonally, including a decline in the frequency of fish in the summer diet, and a corresponding increase in the occurrence of crayfish. Consumed fish ranged from 3.5 to 71.0 cm total length, with a mean of 20.7 cm (se ± 0.5, n = 658). Fish 10.1–20.0 cm w...

Journal ArticleDOI
TL;DR: A list compiled by the New York State Department of Environmental Conservation (NYSDEC) of observations of lake sturgeon from 1800 to 2005 was combined with recent observations through 2008 and formatted (Geographic Information System) as mentioned in this paper.
Abstract: Lake sturgeon (Acipenser fulvescens) are native within the Lake Ontario drainage basin and listed as threatened by New York State. In 1995 the New York State Department of Environmental Conservation (NYSDEC) initiated restoration management of lake sturgeon. This management included both protection of extant populations and stocking of uninhabited historic waters with juvenile sturgeon. A list compiled by NYSDEC of observations of lake sturgeon from New York State waters for the period encompassing 1800–2005 was combined with recent observations through 2008 and formatted (Geographic Information System) to allow mapping of sturgeon geographical distribution. Distributions of pre- and post-restoration sturgeon were examined by occurrence and type of observation. Distribution patterns indicated lakes and rivers with current sturgeon presence have increased from five to eight, which was the first-phase goal of the New York Lake Sturgeon Recovery Plan. Lake sturgeon have started to expand into joinin...

Journal ArticleDOI
TL;DR: An 18 mo survey of the seasonal activity and species composition of dung beetles from a cattle pasture on Crowley's Ridge, Arkansas and of 17 additional surveys, at various localities and habitats across Arkansas finds 64 species that are now known to occur in Arkansas.
Abstract: We present the results of an 18 mo survey of the seasonal activity and species composition of dung beetles (Scarabaeidae: Scarabaeinae and Aphodiinae and Geotrupidae: Geotrupes) from a cattle pasture on Crowley's Ridge, Arkansas, and of 17 additional surveys, at various localities and habitats across Arkansas. Collections at the cattle pasture comprised 236,880 beetles, representing 22 species. Labarrus pseudolividus Balthasar comprised 97.7% of the total trap catch, with the majority being collected in Jun., Jul. and Aug. 2007 which involved two separate mass occurrences during that time. From all surveys, we documented 22 state records, of which Colobopterus erraticus (Linnaeus) and Onthophagus taurus (Schreber) represented subtle range extensions to their known distributions, while the remaining 20 species were projected to occur in Arkansas. A checklist, distributional record and bibliography of the 64 species of dung beetles that are now known to occur in Arkansas are presented.