Registered users receive a variety of benefits including the ability to customize email alerts, create favorite journals list, and save searches.
Please note that a BioOne web account does not automatically grant access to full-text content. An institutional or society member subscription is required to view non-Open Access content.
Contact firstname.lastname@example.org with any questions.
Documenting the impacts of white-nose syndrome (WNS) on demographic patterns, such as annual survivorship and recruitment, is important to understanding the extirpation or possible stabilization and recovery of species over time. To document demographic impacts of WNS on Myotis septentrionalis (Northern Long-eared Bat), we mistnetted at sites in western Virginia where Northern Long-eared Bats were captured in summer before (1990–2009) and after (2011–2013) the onset of WNS. Our mean capture rates per hour, adjusted for area of net and sampling duration, declined significantly from 0.102 bats/ m2/h before WNS to 0.005 bats/m2/h (-95.1%) by 2013. We noted a time lag in the rate of decline between published data based on bats captured during the swarming season and our summer mist-netting captures from the same geographic area. Although proportions of pregnant or lactating females did not vary statistically in samples obtained before and after the onset of WNS, the proportion of juvenile bats declined significantly (-76.7%), indicating that the viability of Northern Long-eared Bats in western Virginia is tenuous.
Calidris maritima (Purple Sandpiper) is a shorebird found along northern coasts of Europe and eastern North America during the winter. While its winter diet is well known in Europe, the only North American study examining diet included 5 individuals and suggested a narrow diet focused on Littorina spp. (periwinkles). We examined the diet of Purple Sandpipers wintering at several sites in Nova Scotia, Canada, during 2013, and found that the birds consumed a broad variety of items, though principally marine invertebrates, dominated by periwinkles and Mytilus edulis (Blue Mussel), but also many arthropods. Our study confirms the importance of mollusks in the diet of this species and also indicates that Purple Sandpipers in North America have a similar winter diet to those studied in Europe.
In recent years, a small insect was discovered predating seeds of Crocanthemumcanadense (Canada Frostweed or Rockrose), which is an endangered plant with small, localized populations in Nova Scotia. This insect targets primarily chasmogamous flowers (insect-pollinated, open flowers) but not cleistogamous flowers (self-pollinated, closed) of Canada Frostweed. This behavior is of concern because a decrease in the number of seeds produced by outcrossing could cause a decrease in genetic variance within populations at affected sites (e.g., Canadian Forces Base Greenwood, NS). We extracted DNA from larvae collected from chasmogamous flowers and used the mitochondrial cytochrome oxidase subunit I (COI) gene to barcode the DNA. Results from queries showed a 91% match to Mompha (Lepidoptera: Momphidae) species on GenBank, indicating that this insect was a member of the genus Mompha, but that this particular species was not in the database. To further characterize this lepidopteran, we collected and incubated chasmogamous flowers to rear the larvae to adulthood. We identified the reared adults as Mompha capella, a species of Momphidae not previously documented in the Maritime provinces, Canada.
Plethodon cinereus (Eastern Red-backed Salamander) exhibits 3 distinct color morphs across eastern North America. The ecology of the least-common phenotype (i.e., erythristic morph) is largely unknown and no study has tested for ecological differences between sympatric erythristic and striped morphs. In this study, we compared dietary contents of striped and erythristic P. cinereus. We identified 553 prey items from 12 prey groups. Mean number and volume of prey per stomach did not differ between the 2 morphs. Important prey types were similar for both morphs and included Acari, formicids, Collembola, Diptera larvae, and adult Coleoptera. Additional studies regarding erythristic P. cinereus ecology will provide a better understanding of the role of this morph in natural populations.
In Pennsylvania, Lepus americanus (Snowshoe Hare) is near the southern limits of its range and at risk of range contraction because of loss of early-successional forest and impacts of climate change. We used hunter-harvest data to investigate changes in the distribution of Snowshoe Hare in Pennsylvania (1983–2011), forest inventory and land-use data to assess changes in amount and distribution of early-successional forest (1988–2011), and occupancy modeling (2004) to identify habitat and climate variables that explain the current distribution of Snowshoe Hare. We determined presence of Snowshoe Hare based on visual sightings, observations of tracks, and DNA analysis of fecal pellets, and used repeated visits to sampling sites and occupancy models to estimate occupancy rates (Ψ). Hunter-harvest data indicated the range of Snowshoe Hare in Pennsylvania contracted towards northwestern and northeastern portions of the state. Based on occupancy modeling, Snowshoe Hare were most likely to occupy early-successional and mixed deciduous—coniferous forest types and areas with colder winter temperatures, which coincided with the distribution of hunter harvests. Among the 4 forest types, we estimated Ψ = 0.52–0.79 and Ψ = 0.10–0.32 where winter temperatures were coldest and warmest, respectively. Total forest loss was <1% during 1988–2011, and the loss of early-successional forest in the current and former range of Snowshoe Hares was similar as were mean patch size and a fragmentation metric of early-successional habitat. Thus, changes in forest characteristics did not explain the range contraction we observed. We used climate-model predictions and our occupancy model to predict that average occupancy probability across northern Pennsylvania may decline from 0.27 in 2004 to 0.10–0.18 by 2050–2059, depending on the climate model. The range of Snowshoe Hare in Pennsylvania has contracted to regions of Pennsylvania with the coldest winter temperatures and most persistent snowpack, and based on projected climate change, our results suggest further range contraction of Snowshoe Hare in Pennsylvania.
Automated recording devices and call-recognition software are technologies available to survey vocal fauna. We evaluated the Song Scope® call-recognition software designed by Wildlife Acoustics to automatically identify vocalizations of 3 North American winter bird species. We used a Wildlife Acoustics SM-2 automated recorder to record winter avian vocalizations and then screened these field recordings using the Wildlife Acoustics Song Scope software programmed with recognition models, or recognizers, we created. Song Scope correctly identified an average 39% of target vocalizations to species using featured recognizers, with some recognizers performing better than others (accuracy range = 20–59%). Screening a 10-h field recording with Song Scope took an average of 7 minutes per recognizer. Call-recognition software can be used to survey vocal species; however, when biologists use this software to determine species presence or density, they need to be aware of potential bias in survey results because some species-recognizer models perform better than others.
White-nose syndrome (WNS) and wind-turbine facilities on the Delmarva Peninsula are emerging threats to the peninsula's current bat fauna. However, until our study, there had been no assessment of bat populations or their habitats in that region. The purpose of our research was to fill this gap by using 28 road-based transects and 24 passive-monitoring sites to acoustically monitor bats across the peninsula. In total, we recorded 4432 bat-call sequences and documented the presence of at least 6 species: Lasiurus borealis (Eastern Red Bat), Eptesicus fuscus (Big Brown Bat), Nycticeius humeralis (Evening Bat), L. cinereus (Hoary Bat), Perimyotis subflavus (Tri-colored Bat), 1 or more species in the genus Myotis, and potentially Lasionycteris noctivagans (Silver-haired Bat). Given the similarity in call structure between Silver-haired and Big Brown Bats, we cannot say with certainty the former were present. Eastern Red Bats, Evening Bats, and Hoary Bats were relatively widespread and abundant; Tri-colored Bat and Myotis were not. Of the species for which adequate sample sizes were available, all but the Hoary Bat (and possibly the Silver-haired Bat) showed strong preferences for forest edges, demonstrating the importance of these landscape features for maintaining healthy bat populations. Point-counts along road transects and stationary-monitoring sites yielded similar results, suggesting that road-based transects are a valuable tool for surveying bat populations across large geographic areas.
The apparent stability of urbanized portions of the coast of the northeastern US belies a much longer history of intertwined geomorphological and ecological change. Herein, I compare and contrast a set of 100 maps and charts from 1501 to 1844 of Jamaica Bay, a coastal lagoon located on the southeastern side of New York City. These documents, while requiring careful interpretation and appreciation for historical context, appear to suggest in series that Jamaica Bay was formerly much more open, without the marsh islands that are today the subject of intense scrutiny and restoration. I present a hypothesis regarding the east-to-west progression of the Rockaway Peninsula that in turn led to salt marsh formation in the interior of the bay approximately 200–230 years ago. This cartographic-driven hypothesis is supported by discussion of independent observations from soil cores taken in Jamaica Bay marsh islands. The paper concludes with brief remarks on the relevance of a long-term historical perspective for contemporary restoration and resilience efforts.
Habitat conservation is performed in North America to support populations of managed and wild pollinators. The current recommended plant selections for northeastern pollinator habitats primarily provide resources for common or generalist pollinators. However, such plants may not benefit uncommon or rare northeastern specialist pollinators, whose populations are susceptible to harm from anthropogenic threats. This manuscript presents the first catalog of native specialist bees and associated host plants for the Northeast. Approximately 15% of northeastern native bee species are pollen specialists, represented by 6 families, 15 genera, and 61 species of bees that restrict pollen foraging to 23 families, 33 genera, and 201 possible species of native host plants. Specialist bees are associated with non-graminoid forbs and non-coniferous woody plants in nearly all major northeastern terrestrial and wetland habitats. Herein, I identify and discuss vulnerable bee—plant associations and suggest greater emphasis on research and restoration efforts. I recommend that northeastern pollinator-conservation practice specifically target specialist bees.
Three types of macroinvertebrate collecting devices, Gerking box traps, D-shaped sweep nets, and activity traps, have commonly been used to sample macroinvertebrates when conducting rapid biological assessments of North American wetlands. We compared collections of macroinvertebrates identified to the family level made with these devices in 6 constructed and 2 natural wetlands on the Delmarva Peninsula of Maryland. We also assessed their potential efficacy in comparisons among wetlands using several proportional and richness attributes. Differences in median diversity among samples from the 3 devices were significant; the sweep-net samples had the greatest diversity and the activity-trap samples had the least diversity. Differences in median abundance were not significant between the Gerking box-trap samples and sweep-net samples, but median abundance among activity-trap samples was significantly lower than among samples of the other 2 devices. Within samples, the proportions of median diversity composed of major class and order groupings were similar among the 3 devices. However the proportions of median abundance composed of the major class and order groupings within activity-trap samples were not similar to those of the other 2 devices. There was a slight but significant increase in the total number of families captured when we combined activity-trap samples with Gerking box-trap samples or with sweep-net samples, and the per-sample median numbers of families of the combined activity-trap and sweep-net samples was significantly higher than that of the combined activity-trap and Gerking box-trap samples. We detected significant differences among wetlands for 4 macroinvertebrate attributes with the Gerking box-trap data, 6 attributes with sweep-net data, and 5 attributes with the activity-trap data. A small, but significant increase in the number of attributes showing differences among wetlands occurred when we combined activity-trap samples with those of the Gerking boxtrap or sweep net.