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Clam shrimp are small, freshwater branchiopods that inhabit isolated, ephemeral pools— both natural and anthropogenic. Here we report a new locality for Cyzicus mexicanus (Mexican Clam Shrimp) in Middlesex County, NJ, that represents the first record of this species in New Jersey and a range expansion 120 km north of the nearest documented population. The only member of the genus that has previously been reported in New Jersey is Cyzicus gynecia (Mattox Clam Shrimp). The primary way that Mexican Clam Shrimp is distinguished from its congener Mattox Clam Shrimp is by the presence of individuals possessing male reproductive organs known as claspers. Since the only documented Mattox Clam Shrimp individuals are female, male specimens are indicative of Mexican Clam Shrimp.
Morone saxatilis (Striped Bass) occurs throughout the provinces of Atlantic Canada, but its full distribution in the region is undescribed. Canadian Striped Bass populations are grouped by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) into 3 geographically distinct Designatable Units: Saint Lawrence River, Southern Gulf of St. Lawrence, and Bay of Fundy. Striped Bass also occurs in many other unclassified Canadian regions, and growing evidence suggests that some of these locations may support distinct, uncharacterized populations. The recreational fisheries for Striped Bass are rapidly increasing in popularity in Canada, and thus, it has become of great importance to both recognize the species' full distribution and manage the fisheries therein. We compiled recent research, certified angling catches, historic accounts, grey literature, and anecdotal reports to identify coastal sites and rivers where Striped Bass have been reported. Our findings will help managers and researchers target rivers and coastal areas for assessment and study to encompass the entirety of the species' range in Canadian waters. Our report suggests that a fourth Designatable Unit for Eastern Cape Breton Island and Northeastern Nova Scotia is needed to both monitor and manage assemblages of Canadian Striped Bass.
Setophaga striata (Blackpoll Warbler) is a boreal forest breeder that inhabits an expansive breeding range, with its southern limit in the northeastern US. The Pennsylvania breeding population is small and isolated but has persisted since its discovery in 1993, with the nearest breeding population about 150 km northeast in the Catskill Mountains of New York. Little information is available on the structure and composition of the vegetation where Blackpoll Warblers establish territories and how these vegetative parameters compare with those present in the core of their range. In 2016, we quantified the understory and canopy structure and composition, as well as the groundcover of active Blackpoll Warbler breeding territories (n = 15). Blackpoll Warblers occupied areas that were dominated by spruce (Picea rubens [Red Spruce] and P. mariana [Black Spruce]; 75% canopy cover) with a relatively low mean canopy height (6 m) and a mean diameter at breast height of 13 cm. Overall, the structure and composition of the vegetation within territories of Blackpoll Warblers in the Pennsylvania population are similar to those found in core portions of their breeding range. While the Pennsylvania population has bred exclusively within 1 small, confined area, similar Red Spruce and Black Spruce communities can be found to the east in the Pocono Mountains of Pennsylvania, suggesting there may be an opportunity for range expansion. However, there are increasing concerns that populations of boreal species at the southern edge of their range are especially vulnerable to climate change as warming and weather extremes decrease the suitability of isolated locations.
Birds produce a variety of vocalizations ranging in function from attracting a mate to alerting others of danger. One vocalization of Tachycineta bicolor (Tree Swallow), the chatter call, is reported to serve as both a mate-attraction call and a nest-defense call. We used playback techniques to investigate the nest-defense behavior of Tree Swallows to calls of Toxostoma rufum (Brown Thrasher; control) and Sialia sialis (Eastern Bluebird; nest competitor), and Tree Swallow shriek (alarm call) and chatter calls. We measured time spent foraging, remaining in the nest box, and on nest defense. Tree Swallows spent 80% of their time on nest defense in response to the chatter call. The chatter-call and shriek-call nest-defense responses were nearly identical. Our data show that the chatter call functions as an alarm call and elicits nest-defense behavior.
We surveyed scavenger species on Nantucket Island, MA, using motion-activated wildlife cameras baited with carcasses of either a Mus musculus domesticus (House Mouse) or Colinus virginianus (Bobwhite Quail) in the summer of 2016. We aimed to identify vertebrate scavenger species, measure how long carcasses remained available, and examine differences in carrion consumption between grassland and shrubland vegetation types. This information is important for management decisions concerning a reintroduced population of a federally endangered obligate scavenger, Nicrophorus americanus (American Burying Beetle), on Nantucket Island. Carcasses were removed or consumed within 2.7 ± 1.8 d, and vertebrates removed the carcass in 74% of trials. Carcasses persisted for similar lengths of time between the 2 vegetation types, but avian scavengers were significantly more common on Bobwhite Quail carcasses in grassland, and mammalian scavengers were significantly more common on House Mouse carcasses in shrubland habitats. Avian species appear to be significant competitors for carrion appropriate for American Burying Beetle reproduction.
The peninsula on which the city of Halifax is located ends in a park that has remained mostly wooded since 1749, despite being periodically disturbed and partially cleared by military activities and storms. This first detailed study of the lichens of Point Pleasant Park is based on collections from almost 300 survey sites, which showed a remarkably diverse flora of 164 species, varying from pollution-tolerant lichens such as Lecanora conizaeoides at the northern end of the park, to members of the Lobarion community at the southern end. In 2003, Hurricane Juan felled a large number of the larger, older trees, which explains the current high proportion of crustose species established on the smaller, younger, trees. The baseline data reported in this study will be of value to follow the succession of lichens on trees as the bark surfaces change from smooth to ridged, with age, over the next few decades. The rich lichen flora of the park also reflects the fact that there are rock outcrops and vertical rock faces. These substrates support a lichen flora of 43 species, and the terricolous habitats are colonized by a further 23 species, including 18 species of Cladonia.
Cross-intertidal transects at a western Long Island Sound estuary site provided estimates of the density of the non-native Hemigrapsus sanguineus (Asian Shore Crab) from 1998 to 2017, and measurements of crab size (carapace width; CW) from 2005 to 2017. Since 2001, average intertidal density declined by ∼5% per year. This decline was driven by decreases in the density of larger crabs, with consequent reductions in average and maximum sizes of both males and females. The proportion of the largest crabs (>24 mm CW) dropped from 10.1% of the population in 2005 to 1.4% in 2017. Individual reproductive output scales with size; thus, I estimate the loss of the largest females to have reduced population reproductive output by half between 2005 and 2017. Also, the frequency of ovigerous females in the smallest reproductively mature classes (12–14 mm CW) increased. Though the density and average size of Asian Shore Crab have declined significantly, resident and native crab populations have still not recovered.
Understanding natural forest dynamics is critical for informing forest restoration and conservation efforts. However, such information is often difficult to generate for areas that have a long history of intense land use, such as the Champlain Valley of Vermont. We used dendroecological methods and assessments of forest structural conditions to describe the tree recruitment history and structural dynamics of 2 examples of valley clayplain forest, a rare natural community that has been drastically reduced in extent by agricultural land use in the Champlain Valley. Although historic selective harvesting had occurred in the areas sampled, these sites represent the best remaining examples of semi-natural valley clayplain forests in the region, thus providing an opportunity to document long-term patterns of structural and compositional conditions and tree recruitment in areas with limited land-use. Age structures in these 2 areas were strongly uneven-aged, with older cohorts composed of Quercus alba (White Oak), including an individual dating to the 1640s, and recruitment over the past 2 centuries dominated by Tsuga canadensis (Eastern Hemlock). Size distributions of live trees also reflected these patterns of recruitment, with White Oak occurring exclusively in larger diameter classes (>35 cm) and Eastern Hemlock predominating across all smaller size classes. We observed sparse regeneration of Quercus spp. (oaks) in these areas, suggesting that this historically important component of valley clayplain forests may disappear over time in the absence of large, stand-scale natural disturbances or management activities focused on the perpetuation of this species group.
We examined 318 Colinus virginianus (Northern Bobwhite) wings from 27 Kentucky counties for fault bars. Fault bars are areas in flight feathers that lack pigment due to exposure to stressors. We detected fault bars on 38 (11.9%) wings (representing individual Northern Bobwhites) from 14 Kentucky counties; fault bars were most prevalent in juveniles. Fault bars have been documented on Phasianus colchicus (Ring-Necked Pheasant) and many species of passerine and raptorial birds, but this is the first report for the Northern Bobwhite. Examination of wings for fault bars could provide a new method for assessing stress in Northern Bobwhite populations and be useful to evaluate translocations or to select donor populations for translocation.
Elliptio complanata (Eastern Elliptio) is typically an abundant species in lotic systems throughout the northeastern US; however, as with many other freshwater mussel species, some populations of Eastern Elliptio are in decline. Freshwater mussels have complex life cycles, which are important to understand for their conservation and management. The goal of this study was to determine the timing of Eastern Elliptio spawning, brooding, and glochidia release. Throughout the spawning season, we used gonad and gill extracts and drift nets to track the timing of reproduction in Otego Creek, NY, a tributary to the Susquehanna River. Females began brooding fertilized eggs by mid-May, and by early June, all females collected were brooding fertilized eggs or d-shaped glochidia. The temperature was 18 °C when all females contained glochidia. Peak glochidia-drift occurred ∼1 week after we recorded the highest levels of brooding and continued at low levels for several weeks. Phenology modeling helped us to determine that accumulated thermal units was the best predictor of reproductive activity. Our work highlights the environmental cues responsible for spawning, brooding, and glochidia release in a population of Eastern Elliptio. This empirical approach to predicting reproductive activity has great potential as a tool for timing the collection of brood stock for propagation or other important conservation measures.
We investigated the influence of hoop-net trap size on number and size of captures for comparatively large (Chelydra serpentina [Snapping Turtle]) and small (Chrysemys picta [Painted Turtle]) freshwater turtle species. We trapped turtles at 32 ponds throughout West Virginia in the summers of 2016 and 2017, with each pond sampled for 5 consecutive days using five 0.91-m–diameter and five 0.76-m–diameter baited hoop-net traps. We captured a total of 98 and 283 unique Snapping Turtles and Painted Turtles, respectively. Larger-diameter traps captured more Snapping Turtles and smallerdiameter traps captured more Painted Turtles. Mean carapace length was greater for both species in larger-diameter traps, but this result was possibly influenced by the ability of the smallest Painted Turtles to escape through the mesh of the larger traps. Our results indicate that hoop-net–trap diameter can substantially influence both number and size distribution of captures, and thus, trap size is an important sampling design consideration for freshwater turtle research and monitoring using hoop-net traps.
Ixodes scapularis (Blacklegged Tick), vector of Lyme disease, has a broad distribution in eastern North America, but is relatively rare in Missouri. In this study, we report the change in abundance of this species in Adair County, MO, from 2006 to 2015. We collected data from 85 small-mammal trapping sessions beginning in 2006, and from 175 off-host sampling sessions using both drag and bait sampling beginning in 2007. The total number of Blacklegged Ticks collected in this study was 182; we collected <10 Blacklegged Ticks in most years. However, we collected 61.5% of specimens in 2014 and 86% in the last 3 years. Systematic, long-term monitoring has provided information about the dynamics of a tick species with low abundance.
Cordulegaster erronea (Tiger Spiketail) is of conservation concern throughout much of its range; yet only a single study on the nymphs has been conducted, and many aspects of the species’ life-history are poorly understood. The present study evaluated the size, age structure, and density of Tiger Spiketail nymphs at a stream on the Schiff Reservation Natural Lands Trust (Schiff) in Mendham Township, Morris County, NJ. We investigated the habitat and surrounding landscape characteristics of this stream and a second stream containing Tiger Spiketails at Schiff. We collected and measured 137 Tiger Spiketail nymphs during this study—82 in the spring and 55 in the fall—representing pre- and postadult emergence. We found 24 exuviae along both study streams and an additional 8 exuviae along 3 other streams in New Jersey, Connecticut, and Delaware. We are aware of only 1 other published report of Tiger Spiketail exuvia, which documented a single specimen. Our data and habitat assessment indicate that the Tiger Spiketail has a long nymphal stage and may be dependent upon high quality, fish-free, perennial headwater streams flowing through extensive forests. This information may assist resource managers in developing conservation strategies and habitat-protection measures for this species.
North American crayfishes are hosts for 2 major groups of obligate ectosymbionts, namely annelids of the order Branchiobdellida and ostracods of the family Entocytheridae. These symbionts are widely distributed across the continent, coincident with their typical hosts; however, the diversity and distribution of both groups are poorly known in much of the northeastern US. We examined 93 crayfishes collected from 30 sites across New England for the presence of branchiobdellidans and entocytherids. We recovered 4 branchiobdellidan and 3 entocytherid species, with both groups displaying curiously dissimilar distributions. We present here the first published records of the branchiobdellidan Cambarincola vitreus in New England, the first record of the Procambarus acutus (White River Crayfish) from New Hampshire, and begin to fill substantial gaps in the known distribution of 2 major groups of obligate crayfish ectosymbionts.
Since 2004, my students and I have caught and examined 1441 individual bats representing 7 species from mist-net surveys in Grant County, WI. Across all years and sites, Myotis lucifugus (Little Brown Bat) was the most frequently captured bat (59.6% of all captures). We captured over 78% (n = 1106) of bats within the first 120 min after sunset. Based on the capture of lactating females, the following species raise young in southwest Wisconsin: Eptesicus fuscus (Big Brown Bat), Perimyotis subflavus (Tri-colored Bat), Little Brown Bat, M. septentrionalis (Northern Long-eared Bat), Lasiurus borealis (Eastern Red Bat), and L. cinereus (Hoary Bat). Secondary sexual dimorphism was most evident in Big Brown Bats and Eastern Red Bats. Trends at 1 primary research site for the 3 most commonly captured species showed that, from 2007 to 2017, there was no significant change in number of bats captured per mist-net-meter-hour for Big Brown Bats and Eastern Red Bats. In contrast, and coincident with the occurrence of white-nose syndrome in Wisconsin, there was a signicant decline in the number of Little Brown Bats captured per mist-net-meter-hour over that same time period. Monitoring of bat populations in southwest Wisconsin should continue.
Understanding relationships between insects and invasive plant species in their introduced range is important for management of a new invader and prioritization of its control. This study investigates the insect communities associated with Oplismenus undulatifolius (Wavyleaf Basketgrass), an invasive grass in the mid-Atlantic US, and looks at the effect of herbivory on the species’ growth and reproduction. We surveyed aerial and ground-dwelling insect communities in areas with and without Wavyleaf Basketgrass and examined leaf samples from caged and uncaged patches of Wavyleaf Basketgrass for type and amount of insect damage. Insect richness, evenness, and diversity were similar between invaded and uninvaded areas. At the plot level, there was no difference in abundance of insects caught in pitfall traps, but there were more insects captured in sticky traps at the uninvaded area. Orthoptera in general and Rhaphidophoridae specifically, were indicators of uninvaded plots, along with Sciaridae in the Diptera and Scarabaeidae in the Coleoptera. Indicators of the invaded plots included Blattidae within the Blattodea and Staphylinidae and Carabidae within the Coleoptera. Leaf damage was minor; the 6 most heavily damaged leaves lost between 15% and 21% of their leaf area. Punctures, stippling, and mining were the most common types of leaf damage observed, and most leaves had fewer than 25 incidences of damage per leaf. There was no significant difference in leaf damage, plant biomass, or inflorescence production between caged and uncaged plots. Differences in insect community composition in invaded and uninvaded areas may be due to Wavyleaf Basketgrass itself or concomitant increases in plant cover and changes in microclimate. At least some insect groups are using Wavyleaf Basketgrass as habitat, which may be important in areas where excessive deer browse has removed most of the herbaceous layer.
Stable-isotope analysis can address fundamental questions about the ecology and life history of mobile organisms. The hydrogen isotope, deuterium (δ2H), follows distinct and predictable patterns along environmental gradients, enabling migratory-origin assignments in vagile animals such as bats. However, it is unclear to what degree deuterium levels vary within non-migratory bat populations in fixed areas. To understand this, we compared deuterium signatures among adult female bats in maternity colonies of non-migratory Mid-Atlantic Eptesicus fuscus (Big Brown Bat). We sampled from 5 different locations along the Delmarva Peninsula. We also compared differences in signatures between males and females within colonies. Despite relative proximity to each other, deuterium signatures of females among colony locations differed significantly. Deuterium signatures did not differ among males and females or between 2010 and 2011. We suggest that variation in foraging and roosting behavior, as well as changes in water sources along the peninsula influence deuterium levels on a small geographic scale. These and other factors should be considered when interpreting sampled deuterium levels.
Past studies have demonstrated successions of epiphyte communities on trees of progressively larger diameters, suggesting the existence of temporal resource-gradients associated with aging/growing phorophyte hosts. The objective of this study was to identify possible resource gradients associated with the diameter/age of Acer saccharum (Sugar Maple) in northern New York. We determined epiphytic bryophyte cover by species on 102 Sugar Maples (min–max = 11–84 cm diameter at breast height) from 12 Adirondack northern hardwood forest stands. We extracted a 12.6-cm2 bark sample from each tree to analyze in the laboratory for moisture-holding capacity, surface-moisture availability, drying rates, and leachate cation and nitrogen concentrations. We collected throughfall and stemflow from 15 trees (19–79 cm dbh) at a separate site over the course of a growing season and analyzed samples for cation and nitrogen concentrations. Bark mass per unit surface area (g cm-2) was positively correlated with tree diameter, reflecting increasing bark thickness with age. Bark moisture-holding capacity (H2O as % dry mass) was independent of tree diameter, but bark surface-moisture availability (g H2O cm-2 bark) increased with diameter as a result of thickening bark. Bark drying rates were negatively correlated with bark mass (thickness). Cation (Ca2+, Mg2+, K+) concentrations in bark leachate were all positively correlated with tree diameter, but NH4+ and DON concentrations varied independently of tree diameter, and NO3- concentrations were typically below detection limits. Stemflow became enriched 10- to 20-fold with dissolved cations but not with dissolved nitrogen. Percent cover of several mesophytic and calciphilic epiphytes (e.g., Anomodon rugelii, Brachythecium laetum, Neckera pennata, and Porella platyphylla) were positively correlated with cation concentration in bark leachate, bark thickness, and moisture availability, and negatively correlated with bark drying rate. The results of this study are consistent with hypotheses that increased moisture and nutrient availability and slower drying rates of bark on large-diameter trees may account for increasing total cover and species richness of bryophtyes and increasing dominance of mesophytic and calciphilic bryophytes on larger trees. We extend McCune's similar gradient hypothesis with an analogous set of nutrient-based gradients, and offer an alternative mechanism for McCune's original time-based moisture gradient.