We performed short-interval mark—recapture trapping on small mammals on Bumpkin Island in Boston Harbor in 2008, 2009, and 2011 in an attempt to record patterns of species distribution, population dynamics, and habitat use. The only species captured during these intervals were native Peromyscus leucopus (White-footed Mouse) and Microtus pennsylvanicus (Meadow Vole). Both mice and voles were trapped in 2008 and 2009, while only mice were trapped in 2011. Animal densities varied by vegetation type and by year. The variation in the densities between years may be attributed to a number of factors including food availability and the sporadic presence of predators, a unique characteristic of the some of the harbor islands.

We selected 2 sites on the Saw Mill River and conducted biological assessments of water quality using macroinvertebrate composition. Assessment metrics used were: Shannon-Weiner diversity, evenness, species richness, Hilsenhoff biotic index (HBI), Ephemeroptera—Plecoptera—Trichoptera richness (EPT), and non-Chironomidae and Oligochaete (NCO) richness. Water temperature, pH, conductivity, total dissolved solids, dissolved oxygen, and water flow and velocity were not significantly different across sites. Shannon-Weiner diversity values were 2.32 (evenness = 0.20) for Chappaqua and 2.68 (evenness = 0.31) for Hawthorne. Species and NCO richness for Chappaqua were 49 and 22, respectively, and for Hawthorne were 44 and 23, respectively. HBI was 7.99 for Chappaqua and 7.69 for Hawthorne. Both sites had equal EPT values of 5. Based on macroinvertebrate assessment indices, we classified water quality at these sites as non-impacted.

The systemic insecticide imidacloprid is commonly used to protect trees against attack by the Adelges tsugae (Hemlock Woolly Adelgid [HWA]), an invasive pest that threatens Tsuga canadensis (Eastern Hemlock) and T. caroliniana (Carolina Hemlock) in eastern North America. Although there have been some studies documenting the short-term (1–3 years) impact of imidacloprid on non-target arthropods in hemlock systems, almost nothing is known about the impact over longer time scales. Here, using a set of trees which were experimentally treated 3 and 9 years prior to this study, we found that while the impact of imidacloprid on HWA may be approaching the limits of detection and efficacy on trees treated 9 years ago, there is still an intermittently detectable impact on HWA density. Similarly, 9 years after application there is a subtle but detectable increase in arthropod richness and a shift in canopy-arthropod community composition. Results from the 3-year treated trees were, however, ambiguous, but may be the result of detectable cross-contamination of insecticide among trees.

Aquatic herbicides are applied to control nuisance vegetation in lakes and ponds, and are often re-applied over many years. This study compared the abundance of 5 frog species in treated and untreated lakes in Ashburnham, MA. At each lake, I assessed the density of human housing and lake area to determine their relationship with frog abundance. I employed a standard calling index to estimate the abundance of each frog species and the sum of calling indices from all species served as a measure of total frog abundance at each survey site. The sum of calling indices declined with increasing density of human housing; herbicide treatment was not an important main effect. However, there was marginal interaction between herbicides and housing density: lakes with moderate—high housing densities seemed to have lower frog abundance with herbicide treatments. Although the data set was limited, my results suggest that frogs may benefit from permanently untreated refuge zones on lakes. When I assessed frog species individually, only Rana clamitans (Green Frog) was less common as housing density increased. None of the 5 frog species were less abundant in herbicide-treated lakes. In my study, long-term use of aquatic herbicides did not generally reduce abundance of adult frogs, but more studies may be needed to determine whether some herbicides may impair frog populations that are already stressed by housing development.

Typical efforts to monitor bat populations in North America rely on winter hibernacula counts, but this method may be ill-suited for Myotis leibii (Eastern Small-footed Bat). Timing of reproduction, migration, and hibernation in this species also are poorly understood. We piloted novel techniques to monitor Small-footed Bats during the nonhibernation period, including catching bats in mist-nets placed directly on talus slopes, visually searching for roosting bats, surveying randomly distributed quadrats to estimate population size, and using skin temperature to study thermoregulation and seasonal activity. We efficiently documented bats with mist-nets and visual searches; the animals used crevices near the surface of talus slopes from early March until the end of October. Estimates from quadrats suggested one 3-ha talus slope had a maximum population of 196–343 bats. Use of torpor varied seasonally, but was similar between sexes. In mid-March, bats exhibited a hibernation-like pattern of torpor, hinting at the possibility that they may also overwinter on talus slopes. Monitoring of Small-footed Bats on rock outcrops during summer could resolve uncertainty about population trends. Thus, techniques described herein should be tested at suitable habitats in other parts of the range of Small-footed Bats.

Pair-bonding between sexes is common in vertebrate taxa, yet it has been noted far less frequently in some groups such as reptiles, and snakes in particular. Evidence to date indicates that many snake mating-systems are polyandrous, with both males and females having multiple partners in a single breeding season, and thus unlikely to exhibit lengthy pair-bonds. Wittenberger and Tilson (1980) suggested that pair-bonding exists when pairs remain intact for a consecutive period equaling at least 25% of the breeding season. Using this criterion, we present evidence of pair-bond formation in a North American pitviper, Agkistrodon contortrix (Copperhead), a species with a polyandrous mating system.

The human population and associated watershed development has risen steadily since the 1850s in Rhode Island. With these increases, human-derived wastewater has also risen dramatically, resulting in increasing nitrogen loads to estuarine systems. In this study, we examined relationships of modeled watershed nitrogen loads of 6 coastal subwatersheds of varying land development with the stable nitrogen isotope ratio (δ¹⁵N) of salt marsh fish and larvae. There was a significant positive relationship (r = 0.97, P < 0.05) between the watershed modeled percent wastewater and δ¹⁵N in Fundulus heteroclitus L. (Common Mummichog), and significantly higher (P < 0.05) δ¹⁵N in fish larvae collected from developed mainland marsh sites compared to less-developed island marsh sites. Our results support earlier published findings that fish in coastal marshes are assimilating nitrogen derived from watershed wastewater sources. Furthermore, there was an inverse relationship (P = 0.05) between the modeled percentage of human wastewater and mummichog size. The increasing loads of watershed nitrogen entering into coastal salt marshes are a concern because it is unclear how well salt marsh ecosystems can continue to assimilate high nitrogen inputs especially when also subjected to a warming climate.

Populations of grassland birds are declining in the Northeast due to habitat loss and fragmentation. Fragmentation of grasslands can contribute to lower breeding success of grassland birds by altering local predator communities. Using miniature video cameras, I estimated nest success and identified nest predators in grassland fragments at Valley Forge National Historical Park in southeastern Pennsylvania. Estimated nest-success probability for Sturnella magna (Eastern Meadowlark) at Valley Forge was 0.25 (0.04–0.65, n = 7) and similar to estimates from the Midwest, but slightly lower than other studies in the Northeast. Nest success for Spizella pusilla (Field Sparrow; 0.77 [0.31–0.98, n = 8]) and Agelaius phoeniceus (Red-winged Blackbird; 0.48 [0.18–0.80, n = 10]) was higher than estimates from other studies. The local predator community identified at Valley Forge was less diverse than documented in other studies, with only 4 species depredating 8 of 25 monitored nests. The primary predator was Odocoileus virginianus (White-tailed Deer; 38% of nest predation events) followed by Vulpes vulpes (Red Fox; 25%); Procyon lotor (Raccoon; 13%), and a probable Mustela sp. (weasel; 13%). I never detected nest predation by small mammals or snakes, which are important nest predators in the Midwest. The impact of White-tailed Deer on grassland birds at Valley Forge is uncertain, therefore further research is needed to fully understand local predator—prey community dynamics.

Population declines of cavity-nesting birds are being recorded worldwide with degraded habitat, reduced prey availability, and limited nest-site availability implicated as potential causal factors for declines. A possible aid for avian species limited by breeding-site availability is the construction of nest boxes. Although nest boxes are commonly used for Falco sparverius (American Kestrels), little is known about the survival of young from fledging to the onset of migration. Using radiotelemetry, we recorded post-fledging survival and movement of 11 juvenile American Kestrels in northeastern Connecticut from June to September 2013. We used the Kaplan-Meier procedure, adjusted for staggered entry of individuals over time, to estimate daily survival at 0.270 (95% CI 0.01, 0.53) at the onset of migration. Causes of mortality included predation (n = 4 American Kestrels), exposure (n = 2), and unknown (n = 1). During the post-fledging period, the farthest net distance that we recorded for an American Kestrel from its natal box was 16.1 km. The 3 American Kestrels that we tracked from the nest box to the onset of migration demonstrated different patterns: one made a sudden, long-distance movement to a site 8 km away from the nest box; one undertook a series of 1–5-km movements away from the nest box and eventually settled in an area 2 km from the nest box; and one made consistent movements between the nest-box area and sites 1–5 km away. Our results indicate that although many young American Kestrels die within the first month of fledging, those that survive make pre-migratory movements up to 16 km from their nest box. Extending conservation and management efforts beyond the nest-box area may be an important step towards maintaining American Kestrel populations.

Little is known about composition of bat communities and their acoustic activity in the northern boreal forests. Acoustic and capture surveys were conducted in the Mecatina River Ecoregion (MRE) in south central Labrador. We acoustically surveyed forest edges, streams, and ponds and netted and trapped bats near streams and along forest edges. The acoustic survey showed greater bat activity at streams and ponds. The capture survey confirmed the presence of Myotis lucifugus (Little Brown Bat) and M. septentrionalis (Northern Long-eared Bat) in the MRE, the latter showing signs of reproduction. Together these results support the idea that riparian areas in the boreal forest are important landscape features for bats in the genus Myotis.

Intensive forest management may influence the availability of suitable den sites for large den-seeking species, such as Procyon lotor (Raccoon). As part of a Raccoon ecology study on an industrial forest in the Allegheny Mountains of central West Virginia, we radio-tracked 32 Raccoons to 175 diurnal den sites to determine relative use of dens that included cavity trees, rock dens, log piles, slash piles, and exposed limbs. Patterns of den use significantly differed between sexes and among seasons. Overall, we recorded 58 cavity dens in 12 tree species with 7 maternal dens found in 5 tree species. Raccoons selected larger-diameter den trees than available cavity trees and non-cavity trees. Because the abundance of suitable tree cavities is known to influence Raccoon densities and recruitment at fine spatial scales and female Raccoons in this study used tree cavities as maternal den sites, the continued harvest of large-diameter trees (i.e., those capable of developing den cavities) without replacement may impact Raccoon recruitment within intensively managed forests throughout the central Appalachians.

We evaluated the spatial variation in the supply of Anguilla rostrata (American Eel) glass eels and elvers to a Mid-Atlantic Bight estuary (Barnegat Bay, NJ) by sampling over two years at multiple inlets, thoroughfares to adjacent estuaries and tributaries. Both inlets and all three thoroughfares provided sources of glass eels to Barnegat Bay. However, the level of supply to individual tributaries was markedly different, although size and pigmentation stage was consistent. The difference between tributaries might reflect distance from inlet supply and local human disturbance (a large lagoon-front housing development in one tributary). These pronounced differences imply that glass eel and elver supply to tributaries should be taken into consideration before mitigation or restoration is attempted in response to the decline of this species in North America.

We studied the distribution and food sources of larval Petromyzon marinus (Sea Lamprey) in the Hudson River basin, NY, and found ammocoetes of Sea Lampreys in four tributaries of the Hudson River: 1) Cedar Pond Brook, 2) Catskill Creek, 3) Roeliff Jansen Kill, and 4) Rondout Creek. The largest numbers of Sea Lampreys in the Hudson River basin appears to come from Catskill Creek. Sea Lampreys could increase their range in the Hudson River basin in the near future as barriers to migration are removed. Isotopic analysis demonstrated that Sea Lamprey larvae depended on both terrestrial plant material (i.e., allochthonous) and aquatic primary production (i.e., autochthonous), but that site characteristics influenced the importance of each to nutrition. Larval lampreys from the Kaaterskill Creek depended on allochthonous sources for about half of their nutrition, while those at Cedar Pond Brook obtained only ∼1% of their nutrition from these same sources. Gut contents of larval Sea Lampreys were isotopically distinct from filter-feeding macroinvertebrates, suggesting that they exploit food resources differently.

Building collisions are a significant threat to birds in North America, and urban areas can be particularly hazardous to birds using city parks as stopover habitat. We examined the effects of light and glass on bird—building collisions in an urban park using New York City Audubon's collision-monitoring data from fall migration 2013 and photographic analysis of building facades. We found a significant positive relationship between the number of collisions and interior building light (rho = 1); however, the amount of light was strongly correlated with the amount of glass in building facades (r² = 0.82). Carcass persistence at the site was examined using tagged, dead birds. Only 37 percent of carcasses were found by our monitors, suggesting that our estimate of bird mortality due to collisions has been too conservative. The amount of glass on a building facade may have an equal or greater effect on bird— building collisions than the amount of light emitted from the facade. Mitigation of both light and glass are needed to reduce bird—building collisions in urban areas.

We studied the impact of a small, residential wind turbine on birds on Appledore Island, ME, to augment the limited published data on avian fatalities due to residential turbines. We conducted mortality and behavioral surveys of birds flying in the vicinity of the turbine. We did not detect any turbine-related fatalities during twice-daily surveys from fall 2007 to spring 2012, and we have only two anecdotal reports of collision events. Behavioral observations showed that the majority of birds flew below the turbine propeller (95.5%) vertically and near the turbine (53.4%) horizontally. Our behavioral surveys indicated that birds were often seen close to the monopole, but were less likely to be detected near the turbine blades compared to areas more distant from the blades. Furthermore, birds perching on and around the monopole structure provided additional anecdotal evidence of birds not avoiding the vicinity of the wind turbine. Our findings suggest a limited impact of this residential wind turbine on birds. However, we advise carefully choosing the location of a wind turbine so as to minimize potential impacts to avian populations; the turbine on Appledore Island was constructed only after extensive consideration of the possible impacts on birds at this site.

Riparian landscapes are dynamic systems and exhibit considerable spatio-temporal variation in stream flow and physical composition of stream substrates that provide habitats for many species. We investigated genetic diversity and population genetic structure of Harperella nodosa (Harperalla; Apiaceae), a federally endangered semi-aquatic plant. We employed a unique study design that involved sampling at regional, stream, and fine scales in 3 riverine systems in Maryland and West Virginia. Using intersimple sequence repeats (ISSRs), we found high levels of genetic diversity at all scales and pronounced fine-scale genetic structure. Pairwise correlation between geographic and genetic distance was scale-dependent. This study illustrates that temporal monitoring and multiple-scale plans are essential for conservation management programs for Harperella.

In the Sheepscot River, ME, we measured percent saturations of dissolved methane (CH₄) and carbon dioxide (CO₂) and concentrations of nitrate (NO₃^-) four times in the main stem and once in the West Branch. River water was super-saturated with CH₄ at all sites throughout the study, and measurements were generally higher at lower-gradient sites (1000–5000% saturation) than higher-gradient sites (generally <1000%). Percent saturations of CO₂ in the main stem varied in both time and space and were under-saturated at some sites. CO₂ percent saturations and NO₃^- concentrations in the more-developed West Branch were significantly higher than the main stem, likely because of the position of mainstem sites downstream of Sheepscot Pond where primary production and degassing could occur. We also measured CH₄ and CO₂ fluxes from wetland soil adjacent to the main stem, which averaged 710 (± 59) µmolCH₄/m²/h and -51 (± 6.4) mmolCO₂/m²/h. Our findings suggest that rivers and fringing wetlands in the formerly glaciated northeastern US contribute to the production of greenhouse gasses, and that dissolved methane shows spatial variations with channel morphology.

The arrival of a novel predator in an ecosystem necessitates many wildlife-management decisions that should be based on sound demographic data. Canis latrans (Coyote) has experienced a dramatic range expansion across North America since the early 19^th century, completing its colonization of the continental US in the mid-Atlantic region over the past 20 years. Their arrival in the suburbs of Washington, DC, has generated much public attention, and demonstrated a need for demographic information about this species. To address the challenges of surveying an elusive animal, we used fecal DNA to describe the population genetics and demographics of a newly colonized Coyote population at Marine Corps Base Quantico (MCBQ) in northern Virginia. We collected 331 scats over a period of 2 years at MCBQ, resulting in identification of 23 unique individual Coyotes and 41 total Coyote captures that were analyzed using spatial capture—recapture models. We found evidence of colonization by multiple genetic lineages and a low population density of 0.047 individuals/km². Importantly, this study incorporates a new class of models on individual animals identified by genotype data derived from fecal DNA and demonstrates the utility of these models in surveying elusive animals.

Small mammals have been proposed as important dispersers of the spores of arbuscular mycorrhizal fungi (AMF), yet few data exist to support this hypothesis. We experimentally tested 2 models of small-mammal dispersal of AMF spores by quantifying their impact on the mycorrhizal inoculum potential of sterile soil flats in a northeast mesophytic forest in Maryland. Epizoochory did not provide a mechanism for spore dispersal in our study. However, our data demonstrated that endozoochory by several small-mammal species can be an effective dispersal mode for AMF. In the field experiment, inoculum potential of soil from plots that were accessible to Peromyscus leucopus (White-footed Mouse) was significantly higher than in control plots, which excluded small mammals. This study provides experimental evidence that White-footed Mice disperse AMF spores.

Invasive species can cause dramatic changes in the structure of intertidal communities. In some systems, however, abundance or impacts of invaders may peak 10–20 years after invasion and decline thereafter. Hemigrapsus sanguineus (Asian Shore Crab) has been established at Sandwich, MA, on the north side of Cape Cod, since the mid-1990s. This study documented population dynamics of the Asian Shore Crab and 3 species of prey or competitors (Carcinus maenas [Green Crab], Mytilus edulis [Blue Mussel], and Littorina littorea [Common Periwinkle]) over 10 years. An additional goal of the study was to determine whether population growth of the Asian Shore Crab has slowed since its initial establishment. Density of the Asian Shore Crab increased over time, with no evidence of a density-dependent decrease in per capita growth rates. Concurrently, density of the Green Crab and the Blue Mussel declined, but there was no significant temporal trend in density of the Common Periwinkle. If observations at Sandwich are representative of sites north of Cape Cod, populations of the Asian Shore Crab are growing rapidly, and dramatic changes in community structure may be widespread.

We assessed the validity of the reported regional decline of Cicindela marginata (Salt Marsh Tiger Beetle) in the northeastern US by examining data from 3 sources: potential habitat availability maps, author inquiries, and historical and current state records. While the species has apparently experienced decline at a few sites, we contend that existing data do not support the assertion of decline throughout the Northeast. The paucity of systematic surveys, a disproportionate number of northeastern states with comparatively short tidal shorelines, and over-reliance on C. hirticollis (Hairy-necked Tiger Beetle) as a proxy species for C. marginata, have all contributed to the perception of regional decline. Our findings indicate the need for a better understanding of this species' distribution and abundance. Concerted statewide surveys are needed to assess the current status of decline and to establish a baseline for assessing emerging threats such as sea-level rise due to climate change.

Extensive vegetation growth has decreased potential basking sites for an endangered population of Sistrurus catenatus (Eastern Massasauga Rattlesnake [EMR]), and habitat management is needed to restore these sites. Practices that decrease canopy cover can unintentionally impact snakes by increasing exposure, thereby raising predation rates. Basking behavior of slow-moving EMRs often involves remaining cryptic or retreating to avoid detection. We observed several aspects of EMR basking behavior—location, exposure, and defensiveness—relative to distance from habitat edge within 100-m² square plots of cut shrubs to determine whether the habitat alterations modified EMRs use of the landscape as it related to predator avoidance. EMRs basked throughout the entirety of plots and did not vary their level of exposure or defensiveness based on their distance from the edge of plots. Our results suggest that shrub-cutting in up to 10 m × 10 m areas does not alter predator-avoidance behavior in EMRs.

Currently there is limited information on blood-parasite distribution and diversity in wildlife in North America, particularly for some groups such as reptiles, despite their potential impact on their hosts. Snakes and small mammals were surveyed in the Huyck Preserve, NY, during September 2013. No snakes were infected, but a Peromyscus leucopus (White-footed Mouse) was positive. Similarity of the 18S rRNA gene with data from Gen-Bank indicates that Hepatozoon spp. from snakes and small mammals are related, further highlighting a possible role for trophic transmission.

A rich fish assemblage that once thrived in the bays of western Lake Erie, and Ohio's glacial pothole lakes, wetlands, and clear prairie streams has changed over the past century. Three species have been extirpated from many of their historic localities, with surviving members reduced to relict populations. Recognizing that conservation efforts for these sensitive species rely on accurate occurrence records, we present results from 2011–2012 surveys of Ohio’s glacial lakes and associated habitats for 2 native members of this fish assemblage, Etheostoma exile (Iowa Darter) and Erimyzon sucetta (Lake Chubsucker). We found previously undocumented populations of Lake Chubsuckers in 4 glacial lakes and a previously undocumented population of Iowa Darters; however, comparing our results to surveys completed in the 1980s indicates that both species have been extirpated from many localities. A variety of factors including intensive agricultural practices, urban development, and exotic species are likely the cause of their decline.

Over the past 25 years, unionid mussels in the Laurentian Great Lakes of North America have been adversely impacted by invasive dreissenid mussels, which directly (e.g., by attachment to unionid shells) and indirectly (e.g., by competing for food) cause mortality. Despite the invasion, unionids have survived in several areas in the presence of dreissenid mussels. We investigated current spatial patterns in these native mussel refuges based on surveys for unionid mussels across 48 sampling locations (141 sites) in 2011 and 2012, and documented species abundance and diversity in coastal areas of lakes St. Clair and Erie. The highest-quality assemblages of native mussels (densities, richness, and diversity) appear to be concentrated in the St. Clair delta, where abundance continues to decline, as well as in in Thompson Bay of Presque Isle in Lake Erie and in just a few coastal wetlands and drowned river-mouths in the western basin of Lake Erie. The discovery of several new refuge areas suggests that unionids have a broader distribution within the region than previously thought.