Prior to Euro-American settlement of the Oak Openings in northwestern Ohio, the proportion of oak savanna, woodland and forest in upland sites likely varied, with open canopies developing during dry periods of higher fire frequency and denser canopies developing during wet periods of lower fire frequency. Wet prairie and oak barrens, which persisted in the landscape because of spring flooding, likely contained savanna species and, therefore, may have been sources of propagules of savanna species that colonized areas of newly opened canopy. We used regression analysis to test the hypothesis that the richness and diversity of savanna species in the herb layer of present-day savanna are related to the proximity of former wet prairie and oak barrens. Results were statistically significant for richness but generally not for diversity. This suggests that wet prairie and oak barrens may have acted as refugia and therefore as sources of propagules for savanna species during temporal shifts in the proportions of oak savanna, woodland and forest, but relative species abundances likely were determined more by local environment.

The Asiatic oak weevil [Cyrtepistomus castaneus (Roelofs 1873), Coleoptera: Curculionidae] was detected in New Jersey in 1933 and is now abundant throughout deciduous forests in the Eastern and Midwestern United States. Laboratory feeding trials had suggested a broad range of acceptable hosts for C. castaneus, but field studies were needed to corroborate these findings. We quantified host tree associations of C. castaneus by comparing its abundance among crowns of 66 trees (representing six species) in forests of Ohio and Indiana. The 1827 individuals collected during the study were not equally distributed across tree species; mean proportional abundance was significantly higher on Quercus alba (white oak), Q. rubra (northern red oak) and Acer rubrum (red maple). The high abundance of C. castaneus on Quercus spp. is consistent with laboratory studies and natural history information. However, its presence on A. rubrum and Liriodendron tulipifera (tulip poplar) – a Magnoliaceae – had not been documented in field studies. These results indicate that C. castaneus has broad host tree associations. We suggest that researchers conduct further field and experimental studies on C. castaneus to better understand its biology and potential for invading forested areas outside of its present geographic range.

We studied the pollination biology of 18 common insect-pollinated plant species on Kent Island, a boreal island in the Bay of Fundy, New Brunswick, Canada. Under natural conditions, fruit set was relatively high in most of the species studied [although it was very low (<1%) in Maianthemum canadense]. Hand-pollination increased fruit set in five of seven species examined (71%), indicating that fruit set may commonly be limited by the availability or behavior of pollinators on Kent Island. Twelve of 17 species examined (71%) were capable of substantial autonomous self-pollination (autogamy in the absence of pollinators), although fruit set averaged higher in open-pollinated flowers (65.7%) than in flowers from which insects were experimentally excluded (49.6%). The number of seeds per fruit was also less in autonomously self-pollinated flowers in two species (Rhododendron canadense and Ledum groenlandicum). In at least one species (Iris versicolor), rates of autonomous selfing were higher on Kent Island than on the mainland. Stamen-excision experiments in I. versicolor demonstrated that fruit set required pollen transfer in the absence of pollinators (i.e., agamospermy did not occur). In hand-pollination experiments, five of six species (83%) (R. canadense, L. groenlandicum, Smilacina trifolia, S. stellata and I. versicolor) showed no evidence of inbreeding depression in terms of percent fruit set, fruit size or number of seeds per fruit.

Overall, our results demonstrate that for many insect-pollinated plant species on Kent Island, pollinators are likely to be limiting, autogamy is common and inbreeding depression is negligible. Although pollinator limitation and autogamy regularly occur in mainland habitats as well, a review of the literature suggests that they may be more common on islands such as Kent Island. If such island-mainland differences are general, they may arise because genotypes and species capable of self-fertilization are more likely than obligate outcrossers to colonize and become established in isolated habitats.

I examined spatial synchrony in populations of monarch butterflies (Danaus plexippus) during the summer breeding season across North America and while overwintering along the Pacific Coast. Spatial synchrony was observed in all analyses, but was particularly great among eastern summer populations and among overwintering populations on the Pacific Coast. Thus, in a year when relatively large numbers of monarchs were found at a particular breeding or wintering site in these populations, other sites within a wide area were likely to have relatively large numbers of monarchs as well. Spatial structure, measured by the decline in synchrony with distance, was relatively strong among summer populations in eastern North America, weaker, but present, among western summering populations and virtually nonexistent among overwintering populations along the Pacific Coast. Spatial synchrony in mean temperatures during the relevant time periods was generally much greater than that observed in the monarchs, consistent with the hypothesis that environmental factors (the Moran effect) may be playing a central role in causing the observed population synchrony. However, differences in spatial structure between monarch populations and mean temperature during the summer suggest that other factors, possibly post-migratory dispersal, are also affecting synchrony. Dispersal is particularly likely to be important in determining the unusual lack of spatial structure observed in overwintering populations of monarchs, which are believed to mix over wide areas during fall migration.

We studied the life history and feeding habits of two coexisting and closely related sister species of Sialis (Sialis itasca Ross and Sialis velata Ross) from a reservoir and river in central Texas. Measurement of larval head capsules and emergence showed the two species to have 10 larval instars, and the seasonal distribution of immature and adult life stages showed synchronous, seasonal, univoltine life histories with a single cohort. Life history dynamics were somewhat faster in the river, probably due to higher temperatures during the larval growth periods. Larvae exhibited a more rapid larval development rate and earlier prepupal and adult emergence patterns relative to those reported from more northern latitudes. However, a univoltine life cycle appears to represent the norm for Sialis in geographic locations where water temperatures are not limiting to growth and suggests that evolutionary/genetic constraints play a greater role in regulating life history in these insects than environmental factors. Analysis of larval diets showed prey consumed by members of both populations consisted of ostracods, oligochaetes and chironomids.

The Barrens darter Etheostoma (Catonotus) forbesi (Teleostei: Percidae) is a rare stream fish endemic to the upper Caney Fork River system in the Barrens Plateau region of middle Tennessee. We studied the darter's population characteristics and selected aspects of its nesting biology at 10 sites surveyed during April 2004. In our survey, we caught a total of 75 Barrens darters at a rate of 21 individuals per hour of backpack-electrofishing effort. At least one male Barrens darter was present at six of the 10 sites. Females outnumbered males by a ratio of 1.4 to 1. Total lengths ranged 44–97 mm, averaging 62 mm for females and 78 mm for males. The number of Barrens darters seen in the present survey was similar to a 1994 survey. However, both surveys reveal a species in need of conservation, with low abundance at most known sites within its limited geographic range. We found 20 Barrens darter nests located on the flat undersides of cobbles with a mean length, width and thickness of 17 × 13 × 5 cm. Nests in one stream, Duke Creek, were located at a mean water depth of 22 cm, column current velocity of 15 cm/s and bottom velocity of 7 cm/s. Stream channel widths averaged 3.5 m at nest rock locations. Nests contained a mean number of 463 eggs (range 69–976) arranged in a monolayer. Male size and the number of eggs per nest were positively correlated with nest rock size for eight nests where we captured the attending guardian male; however, egg number was not correlated with rock size for all nests in the study.

Although once broadly distributed in the region, the blacknose shiner, Notropis heterolepis, has declined or has already been extirpated throughout much of the Midwest and little is known about its life history. We describe characteristics of reproductive biology and food habits for a lake population of N. heterolepis in northern Illinois to provide information for conservation and management. Gonado-somatic index scores and ovarian stage of female individuals indicated that multiple clutches of ova were produced over a prolonged period lasting from spring until mid-summer. The number of ova present in a clutch was positively related to standard length. However, this relationship weakened and less ova were present in clutches of larger individuals as the reproductive season progressed. Female individuals ≥34 mm SL were mature and the presence of tubercles on male pectoral fins suggested a similar size at maturity for males. Individuals consumed the greatest number of prey items during morning and night -time periods and consumption was less in summer and fall compared to spring. Cladocerans (Chydoridae and Bosminidae) and ostracods were principal diet contributors. Chydorid cladocerans, which are known to associate with aquatic vegetation, were increasingly selected for when ambient densities of all three principal diet contributors were relatively low. Our results indicate that N. heterolepis utilizes a reproductive strategy that should allow resilience to short term, minor disturbances, but they are likely vulnerable to chronic disturbances. In particular, chronic disturbances that reduce or eliminate aquatic vegetation, an important foraging habitat and nursery habitat, will likely have negative impacts on remaining populations.

We examined aspects of the ecology of Notropis sabinae, the Sabine shiner, including habitat associations, population age structure, reproduction and diet in two east Texas streams from November 2001 through October 2002. Notropis sabinae exhibited no strong seasonal habitat associations, but generally were found in relatively shallow slow flowing runs and riffles. The population consisted of three age groups (ages 0, 1, 2) with age-1 fish being the most abundant. Estimated maximum life span was 2.5 y. Reproductively mature individuals were observed from May through October. Temporal patterns in ovarian development, gonadosomatic index and ova development indicated that N. sabinae spawns multiple clutches of eggs over an extended spawning period. Stomach contents consisted primarily of aquatic insects, followed by other aquatic taxa (e.g., Collembola, Crustacea and Hydracarina) and terrestrial insects.

From April 1999 through August 2001 Etheostoma blennioides was collected from the Hocking River in south-central Ohio. Ovaries of adult females were classified by developmental stage and appropriate-stage ovaries were used to analyze clutch size, egg size and gonadosomatic index (GSI). Overall means for reproductive traits were similar to previously published estimates. No traits showed differences among years, though all traits showed significant differences across the breeding season. Clutch size was largest in the middle of the season, while egg size and GSI each declined across the season. These patterns were similar to those seen in a comparable study of E. zonale from the same stream.

Within an ongoing round-the-clock radiotracking project, a subset of adult flathead catfish Pylodictis olivaris (n = 6) was continuously radio-tracked for 24 h to determine detailed diel movement path characteristics and activity in two Missouri streams. The ongoing radiotracking revealed that only a small percentage of point-in-time relocations were recorded as moving, while the majority (greater than 90% for every hour of the day) found fish stationary. The continuously-tracked subset of catfish generally moved by making discrete directed movements from one location to another, with locations corresponding to a physical habitat feature (large woody debris, clay point, undercut bank). All fish revisited locations during the 24-h tracking efforts. Movements were less than 100 m during early afternoon and the first 2 h after sunset, with longer movements undertaken from 2100 through the night to the 0500 hour, ceasing at sunrise. Movement paths had a median distance of 641.16 m with a median activity radius of 66.55 m. Fish spent a median 23.33 h stationary and 0.67 h moving during the diel cycle. The continuous tracking effort resulted in finer resolution and detail than was evident in the larger, typical point-in-time tracking dataset which did not highlight an early afternoon activity period, perhaps due to short, quick movements made at that time.

The largest population of endangered humpback chub Gila cypha inhabits the Colorado River below Glen Canyon Dam and the lower 14 km of the Little Colorado River (LCR), Arizona. Currently, adults from both rivers spawn and their progenies grow and recruit to adulthood primarily within the LCR, where we studied G. cypha's life history using hoop net capture data. Humpback chub undergo an ontogenesis from diurnally active, vulnerable, nearshore-reliant young-of-the-year (YOY; 30–90 mm total length) into nocturnally active, large-bodied adults (≥180 mm TL). During the day, adults primarily resided in deep midchannel pools; however, at night they dispersed inshore amongst the higher densities of YOY conspecifics. Many YOY G. cypha shifted to nocturnal habitats that provided greater cover, possibly, to avoid inshore invading adults. These findings mirror predator-prey scenarios described in other freshwater assemblages, but do not refute other plausible hypotheses. Gila cypha piscivorous activity may escalate in hoop nets, which can confine fish of disparate sizes together; adults were significantly associated with YOY conspecifics and small dead fish in hoop nets at night and eight G. cypha (156–372 mm TL) regurgitated and/or defecated other fish body parts during handling following capture. Gila cypha can definitely be piscivorous given the opportunity, but the magnitude of their piscivorous activity in the wild is debatable.

From December 1998 through May 2000, seasonal use and selection of caves by salamanders were documented in 93 small caves in Crawford County, Arkansas. Caves were surveyed seasonally between winter 1998–1999 and spring 2000, and the numbers and species of all salamanders present were documented. Cave ambient temperature and relative humidity were recorded. Also, each cave entrance was georeferenced using GPS (Global Positioning System) and landscape-level variables around each entrance were quantified using ArcView GIS (Geographic Information System) data layers. Using salamander and ArcView data, relations between salamander occurrence based upon landscape-level variables (dominant overstory vegetation, geology, slope, aspect, solar radiation and distance to perennial stream) and cave characteristics (ambient temperature, relative humidity, cave length and entrance size) were examined. Six species of salamanders were found during the survey. Eurycea lucifuga (cave salamander), Plethodon albagula (western slimy salamander) and P. angusticlavius (Ozark salamander) were commonly observed. Eurycea lucifuga salamanders were active in caves during spring, summer and autumn. Plethodon albagula were most frequently encountered during the summer and P. angusticlavius were most frequently encountered during spring surveys. Few salamanders of any species were detected during winter surveys. The use of caves by the various species of salamanders was influenced by the landscape-level variables and cave characteristics. However, cave ambient temperature and relative humidity appear to have the most influences of salamander use of caves. Both E. lucifuga and P. albagula were significantly more likely to be found in caves with cooler temperatures in summer and higher relative humidities in autumn. In addition to these factors, the probability of finding E. lucifuga significantly decreased with increasing distance to permanent streams, whereas P. albagula was significantly more likely to be found in caves with south and west facing aspects, especially during summer and autumn surveys. There were no significant patterns for P. angusticlavius use of caves. Seasonal and spatial patterns of cave use by salamanders were primarily influenced by environmental (temperature and relative humidity) factors and the ecological requirements of the salamanders.

We conducted an amphibian inventory at Okefenokee National Wildlife Refuge from August 2000 to June 2002 as part of the U.S. Department of the Interior's national Amphibian Research and Monitoring Initiative. Nineteen species of amphibians (15 anurans and 4 caudates) were documented within the Refuge, including one protected species, the Gopher Frog Rana capito. We also collected 1 y of monitoring data for amphibian populations and incorporated the results into the inventory. Detection probabilities and site occupancy estimates for four species, the Pinewoods Treefrog (Hyla femoralis), Pig Frog (Rana grylio), Southern Leopard Frog (R. sphenocephala) and Carpenter Frog (R. virgatipes) are presented here. Detection probabilities observed in this study indicate that spring and summer surveys offer the best opportunity to detect these species in the Refuge. Results of the inventory suggest that substantial changes may have occurred in the amphibian fauna within and adjacent to the swamp. However, monitoring the amphibian community of Okefenokee Swamp will prove difficult because of the logistical challenges associated with a rigorous statistical assessment of status and trends.

Understanding patterns of dispersal is key to developing effective conservation plans, yet dispersal is poorly known for most species. We radio-tracked 15 adult burrowing owls (Athene cunicularia) from 13 nests within the Carrizo Plain National Monument in southern California. Our goal was to describe post-breeding movements in this extensive grassland system. Of nests that failed (n = 9 nests), 8 radio-tagged individuals from 7 nests dispersed, whereas none of the owls from successful nests (n = 4 nests) dispersed. Dispersal distances ranged from 0.2 km to 53 km (median = 3.1 km). The large dispersal distances we observed within the breeding season were greater than previously published estimates of between-year breeding dispersal based on mark-recapture methods and provide insight into the lack of genetic differentiation observed among burrowing owl populations.

Long-term data on wildlife populations are needed to elucidate the relative importance of extrinsic factors on population dynamics; however, such data are rare for most species such as medium-sized mammals. We present long-term population indices for Virginia opossums (Didelphis virginiana) and striped skunks (Mephitis mephitis) in Illinois from 1975 to 1998. Annual road-kill indices (RKI) and spotlight indices were correlated for opossums, but not for skunks. Opossum indices exhibited an overall increase (P < 0.01) during the study, but there was no trend since 1983. Skunk RKI exhibited a negative slope (P < 0.01), but this was influenced by a fluctuation in RKI during the late 1970s and there has been no overall trend since. Mean winter temperatures (t − 1) were positively correlated with opossum RKI, but were not correlated with skunk RKI. Estimated harvest (t = 0) was positively related to skunk RKI, and effective harvest was positively correlated with opossum RKI. Annual rabies cases in skunks were positively (P < 0.001) correlated with skunk RKI. These results suggest there are interspecific differences in long-term population dynamics, and associated limiting factors, between these species at large spatial scales.

Extensive effort has been directed at the roosting ecology of the federally endangered Indiana bat (Myotis sodalis) during the maternity season; however, spring roosting ecology has received much less attention. In April 2002, radio transmitters were attached to the back of 19 female Indiana bats as they emerged from a hibernaculum in northeastern New York. Thirty-nine roost trees were found in the vicinity of the Lake Champlain Valley of New York and Vermont over the span of 224 bat days (i.e., 1 bat located for 1 d equals 1 bat day). Distances from hibernaculum to roost trees ranged from 14.6 to 40.0 km (mean = 26.9 km). Shagbark hickory (Carya ovata) was the most common (33.3% of all trees, 39.7% of all bat days) of 11 tree species used. Roost trees had a mean diameter of 45.6 cm, were 18.9 m tall and were similar in structure to those used during summer by Indiana bats elsewhere in their range. This study provides the first large-scale examination of trees used by female Indiana bats after spring emergence, supplying critical life history information useful for the conservation of this species.

The Southern flying squirrel (Glaucomys volans) is a species designated at risk in Canada where its range is restricted to parts of Ontario, Quebec and Nova Scotia. Before this study, its distribution in Nova Scotia was poorly documented, with only seven site records. Based on live-trapping and intact and partial specimens provided by the public, we present data for 28 additional locations; these combined with historic records delineate a disjunct range that is more extensive than previously believed, but limited to southwest Nova Scotia. To identify specimens that were not fully intact, simple morphological and molecular techniques were employed. The latter, which consisted of PCR amplification and then restriction enzyme digestion of the cytochrome-b gene, allowed reliable species identification of tree squirrels from Nova Scotia by use of partial specimens.

Over the last two decades, declines in trap success, stick-nest density and population density estimates have fueled concerns that the federally endangered Key Largo woodrat (KLWR, Neotoma floridana smalli) population is declining. Information on the current population status and habitat selection of KLWR is needed in the recovery of this population. We trapped on 60 (1-ha) randomly-placed grids (20 grids in each of three hardwood hammock age-classes). Grids were trapped from March–September 2002 and April–August 2004. Population estimates for the two trapping periods were 106 (95% ci 30–182) and 40 (95% ci 5–104) individuals, respectively. Greater than 80% of all KLWRs captures occurred in the young hammock age-classes (disturbed after 1971). Young hammocks were characterized by a more open canopy, smaller overstory trees, fewer logs, greater dispersion of overstory trees and a different species composition than old and medium age hammocks (P < 0.024). Contrary to previous research, KLWRs were found to nest in rock piles and garbage piles more than other materials. Results from this study suggest the KLWR population is critically low and management efforts should focus on the creation and restoration of young hammock habitats.

We radio-tracked 13 evening bats (Nycticeius humeralis) to 34 trees during the summer of 2003 and 10 evening bats to 29 trees during the winters of 2003 and 2004. We captured males in every month of the year and provide evidence suggesting that females are also year-round residents of southwestern Missouri. These captures extend the known winter range of N. humeralis at least 110 km northeast. Evening bats selected trees in late stages of decay during the summer, but during the winter they selected a higher proportion of live trees. Comparisons of summer and winter trees suggest that habitat characteristics are more important than tree characteristics in explaining variation between roosts used in the two seasons. Winter roost trees were located in areas with lower average tree height and higher densities of trees. Those attributes would likely cause problems with clutter when leaves are on the trees during summer.

We used intensive live trapping over a 1-y period to investigate the general ecology of a population of Norway rats (Rattus norvegicus) inhabiting a barn in east-central Illinois. At the start of our study in April 1986, the population contained 10 adult females and three adult males. The population increased and exhibited two peaks of about 100 individuals, one peak in late June and the other in late October 1986. Reproduction ceased during the late autumn and winter, and the population declined to only one adult male and one adult female by spring 1987. Increases in the number of rats represented young born at the barn, not adult rats moving into the population; decreases in population size likely resulted from predation rather than dispersal. Females first captured as adults persisted longer at the barn than did males and females first captured as juveniles or subadults; the few males first captured as adults persisted the shortest time of all age and sex classes. Young males gained body mass more rapidly than did young females. Wounding and parasitism by botflies occurred at relatively low levels. Our data indicate that a rat population with negligible immigration and seasonal breeding can exhibit dramatic changes in numbers, and that live-trapping at weekly intervals can yield high recapture rates useful for examining growth rates, survival and other basic life history characteristics.

It is commonly assumed that population estimates derived from trapping small mammals are accurate and unbiased or that estimates derived from different capture methods are comparable. We captured southern flying squirrels (Glaucomys volans) using two methods to study their effect on red-cockaded woodpecker (Picoides borealis) reproductive success. Southern flying squirrels were captured at and removed from 30 red-cockaded woodpecker cluster sites during March to July 1994 and 1995 using Sherman traps placed in a grid encompassing a red-cockaded woodpecker nest tree and by hand from red-cockaded woodpecker cavities. Totals of 195 (1994) and 190 (1995) red-cockaded woodpecker cavities were examined at least three times each year. Trappability of southern flying squirrels in Sherman traps was significantly greater in 1995 (1.18%; 22,384 trap nights) than in 1994 (0.42%; 20,384 trap nights), and capture rate of southern flying squirrels in cavities was significantly greater in 1994 (22.7%; 502 cavity inspections) than in 1995 (10.8%; 555 cavity inspections). However, more southern flying squirrels were captured per cavity inspection than per Sherman trap night in both years. Male southern flying squirrels were more likely to be captured from cavities than in Sherman traps in 1994, but not in 1995. Both male and female juveniles were more likely to be captured in cavities than in traps in both years. In 1994 males in reproductive condition were more likely to be captured in cavities than in traps and in 1995 we captured significantly more reproductive females in cavities than in traps. Our data suggest that population estimates based solely on one trapping method may not represent true population size or structure of southern flying squirrels.

We investigated the diets of insectivorous bats (Chiroptera: Vespertilionidae) in forests with high densities of western spruce budworm (Choristoneura occidentalis, Lepidoptera: Tortricidae), in southern interior British Columbia, Canada. Caterpillars as potential prey were more common and widespread than previously reported. Caterpillar consumption by bats was more frequent where C. occidentalis larvae were more abundant, suggesting that the caterpillars being eaten were C. occidentalis. The frequency of caterpillar consumption was similar for Myotis evotis, which gleans prey from vegetation, and for other bat species that forage primarily by aerial-hawking. We suggest that caterpillars hanging by silk threads were captured by bats that foraged aerially.