Ixodes scapularis (Black-legged Tick) has expanded its range in recent decades. To establish baseline data on the abundance of the Black-legged Tick and Borrelia burgdorferi (causative agent of Lyme disease) at the edge of a putative range expansion we collected 1398 ticks from five locations along the Connecticut River in Vermont. Collection locations were approximately evenly distributed between the villages of Ascutney and Guildhall. Relative abundance and distribution by species varied across sites. Black-legged Ticks dominated our collections (n = 1348, 96%), followed by Haemaphysalis leporispalustris (Rabbit Tick, n = 45, 3%) and Dermacentor variabilis (American Dog Tick, n = 5, <1%). Black-legged Tick abundance ranged from 6198 ticks per survey hectare (all life stages combined) at the Thetford site to zero at the Guildhall site. There was little to no overlap of tick species across sites. Phenology of Black-legged Ticks matched published information from other regions of the northeastern USA. Prevalence of B. burgdorferi in adult Black-legged Ticks was 8.9% (n = 112).
To determine habitat characteristics that influence Sciurus niger (Eastern Fox Squirrel) abundance and distribution within a suburban/urban landscape in the midwestern United States, I documented the density and placement of fox squirrel leaf nests in 20 woodlots in the Indianapolis metropolitan area. Marion County, IN. The woodlots varied in size (0.94 to 19.5 ha), approximate age, shape, and degree of isolation from other woodlots and suitable squirrel habitat in the surrounding area. Only 8.0% of nests were located in a tree with another nest, and nests were randomly distributed in all but one woodlot, where they were uniformly dispersed. Nest density was not significantly related to woodlot size, approximate age, shape, or degree of isolation. Fox squirrel leaf nests were not found in greater densities along the edge of each woodlot, contrary to previous reports. My results suggest that the distribution patterns of fox squirrels within suburban/urban landscapes are similar to patterns within landscapes fragmented by agriculture. Note: Link is to the article in a subscription database available to users affiliated with Butler University. Appropriate login information will be required for access. Users not affiliated with Butler University should contact their local librarian for assistance in locating a copy of this article.
Starting from Alexander von Humboldt's always ambivalent attitude towards Potsdam, the city which made him an honorary citizen and where he conceived large parts of his Cosmos, this contribution tries to show, through a broad analysis of Humboldt's early letters and later writings, the complex relation between world image and world travel, between science and cosmopolitanism. Humboldt's innovative concept of science, at the same time transdisciplinary and intercultural, connects in its ethical dimension with ideas of Immanuel Kant, as Kant had presented them in his “Idee zu einer allgemeinen Geschichte in weltbürgerlicher Absicht.” In this respect it becomes evident that the evolution of Humboldtian science is not possible without considering his understanding of cosmopolitanism, just as it is not possible to understand the specific kind of cosmopolitics which makes the Prussian scientist, author and intellectual an important connecting link for the actual definition of cosmopolitanism and cosmopolitics. The realization of world-wide communication networks between the most different sciences and scientists should, as the material infrastructure, be the presupposition of a global thinking which can be seen as part of a project of the (European) modernity. The biographical as well as the historical background of Alexander von Humboldt's deliberations should, however, not be forgotten.
Historical accounts and descriptions of the Boston Harbor Islands were searched for references to the islands' vegetation. They indicate dramatic changes in vegetation structure and composition since 1600. Many of the islands were wooded prior to European settlement, although Native American use is evident before 1600, Forests were cleared for agriculture, building materials, and firewood. Through the centuries since European settlement, the islands have variously supported municipal and military facilities, some of which have since been abandoned. As use of the islands changed, the vegetation of the islands also changed; in some cases native trees and other species returned to abandoned areas, while in others new, exotic species became established or were planted. By the end of the 20th century the vegetation had become a mixture of woodlands (roughly 25% of the islands as a whole), shrub thickets, open lands, and manicured landscapes, all of which include a large component of non-native species.
This essay focuses on the historical and ecological landscape of King Philip's War (1675-1678), highlighting 2 spaces in Kwinitekw, the Western Abenaki term for the Connecticut River Valley, during the harsh winter of 1675-1676. I track the captive Mary Rowlandson's journey with the Wampanoag leader Weetamoo through the interior Nipmuc country and Kwinitekw and discuss the Penacook leader Wanalancet's winter refuge in the Kwinitekw headwaters. This paper highlights an indigenous studies methodology of place-based, experiential research in the land and waterways, in combination with more traditional historical and literary methodologies. It also demonstrates the importance of indigenous language and place names in mapping historical contexts, understanding ecological knowledge, and interpreting the movements of leaders. The paper focuses on the vast expanse of the Wabanaki country, which is often neglected or misrepresented in colonial-era histories, and especially the "extensive and varied 'winterlands'" highlighted by the scholarship of Thomas Wickman. The essay features maps of areas historically inhabitated by Native peoples created with ArcGIS by a collaborative team, and highlights contemporary on-the-ground engagement with these places, the knowledge gained from reading the archive of the land, and the possibility of understanding of these spaces as vital ecological and social communities, which have much to teach us today.
Dendronotus frondosus (Ascanius 1774) is a common inhabitant of the intertidal zone of the lower Bay of Fundy. This nudibranch experiences great daily fluctuations in physical conditions that affect all aspects of its life cycle. We examined the effect of temperature (5, 11, and 15°C) on the development time of eggs of an intertidal population of this species. Eggs developed more slowly at 5°C than at 11°C and did not develop past the second polar body stage at 15°C. The effect of this difference in development time may be to compress the settlement period to span less time than the oviposition period.
Past maps of Maine forest vegetation regions display changing perceptions of economically important resources, changing scientific knowledge, and the author's purpose in preparing them. Recent maps divide Maine into as many as 15 biophysical regions (McMahon 1993), or as few as one ecoregion (Braun 1972). A new map based on satellite imagery displays pixels indicating different forest types, dispensing with regional boundaries. This map may provide the most accurate view of Maine's complex forest vegetation.
Marstonia lustrica is a poorly understood aquatic snail, relatively rare throughout its range, and listed in the State of Massachusetts as endangered. It is the northern-most cold temperate species of its genus, with other members of the genus occurring along the southern edge of its range and in the southeastern United States. The current range of M. lustrica appears to follow the maximum extent of the Laurentide Glacier (20–25 kya), extending from Minnesota to western Massachusetts. Historically the northern Marstonia species have been identified as M. lustrica with a few historical populations of M. scalariformis and M. letsoni on the southern edge of its range. I completed a full range survey of M. lustrica in 2007 and 2008 and sampled over 60 waterbodies with populations identified in 20 lakes or rivers from Minnesota east to Massachusetts, and Ohio north to Ontario, Canada. Fifty-seven specimens from the 20 populations were sequenced for 2 mtDNA markers (COI and NDI). 14 concatenated haplotypes were documented across the range.
Based upon studies between 2001 and 2010 and the continued presence of adult shrimp including gravid females, Palaemon macrodactylus (Oriental Shrimp) is established in the estuarine waters of New York City. In summer 2010, we sampled a 1000-m² area of the East River and found that P. macrodactylus represented 4.3% of the total shrimp population, and 15.2% of the Palaemonidae (84.8% consisted of the native species Palaemonetes vulgaris [Common Grass Shrimp]). In 2001/2002, P. macrodactylus comprised 4.2% of all palaemonids, suggesting an increase in the past decade of non-native relative to native palaemonids. While not yet appearing to be "invasive" based upon population size, the feeding habits and reproductive biology of P. macrodactylus suggest that future interactions with native shrimp may occur. A key to regional shrimp is presented.
Caenestheriella gynecia, a poorly known species of the clam shrimp family Cyzicidae, is reported from New England for the first time. Two populations were monitored, along with water chemistry and vegetation features, in wooded ephemeral pools along abandoned roads in Berkshire County, Massachusetts from August through September, 2000. All animals collected alive and over 6 mm in length contained eggs. No male features were detected in any specimens. Field and laboratory observations revealed no copulation among individuals. All specimens conformed to the original description but demonstrated variability that extended across two recognized genera, Cyzicus and Caenestheriella.
Salvelinus fontinalis (Mitchill) (Brook Trout) abundance and distribution have declined in much of their native range in the eastern United States, with most intact habitats concentrated in the northern states. We used stream electrofishing data from the 1950s (1952 to 1960) and the 2000s (2005 to 2016) to quantify changes in the abundance and distribution of Brook Trout in Vermont over the last half century. We also investigated whether Brook Trout's co-occurrence with Salmo trutta (Brown Trout) and Oncorhynchus mykiss (Rainbow Trout) in the 1950s influenced their abundance in the 2000s and, further, whether or not the distribution or abundance of non-native trout has changed appreciably since the 1950s. Overall, Brook Trout abundance was higher in the 2000s than in the 1950s. Increased abundance was driven by increases in young of year (YOY), which was not related to the occurrence of non-native trout. Although present at fewer sites in the 2000s, non-native trout densities remained unchanged. Brook Trout distribution at the HUC-12 watershed scale was essentially identical during both time periods. This study confirms previous modeling efforts, which indicated that Brook Trout have a higher probability of persisting in higher latitude, higher elevation, and less-developed regions.
We conducted a statistical analysis of breeding census data from the first 8 years (1989-1996) of the Vermont Forest Bird Monitoring Program (FBMP). Data were collected at 17 study sites located in large tracts (=40.5 ha) of mature, forested habitats in Vermont. A route regression model was used to produce population trends for 67 species and 3 groups of species categorized by wintering range. Power analyses conducted for 4 species revealed that the FBMP adequately sampled species which occurred on at least 9 or more of the 17 study sites and that our ability to detect small (=2%) population changes will increase dramatically after 15 years of monitoring. FBMP data showed significant declines in breeding populations of black-capped chickadee, solitary vireo, and Canada warbler, but a significant increase in rose-breasted grosbeak. When species were categorized by wintering range, neotropical migrants showed a significant overall increase and year-round residents declined. The negative trend for Canada warbler, corroborated by Breeding Bird Survey (BBS) data and migration monitoring data from Long Point Bird Observatory in Ontario, suggest that this species is experiencing widespread declines over a significant portion of its breeding range. Rates of population change in FBMP data were poorly correlated to BBS trends. We found significant positive correlations between Vermont's average winter temperatures and the relative abundances of brown creeper, downy woodpecker, and for all resident species combined. We evaluated the number of brown-headed cowbird occurrences by study site and physiographic region. Most cowbirds (95.3%) occurred at FBMP sites located in the predominately agricultural Champlain Lowlands, suggesting that even relatively large forested tracts in this region may be subject to high rates of cowbird parasitism.
A recent data-recovery exercise uncovered a large amount of stomach-content data (n = 8209) from mainly demersal fishes collected seasonally in the Miramichi River Estuary, southern Gulf of St. Lawrence (sGSL), 1991–1993. Of the demersal species captured, all but Pleuronectes putnami (Smooth Flounder) represent transient species. Within the estuary, stomach samples were collected from all species (except Osmerus mordax [Rainbow Smelt]) captured by trawling and in commercial trap nets. Rainbow Smelt stomachs were collected during trawl surveys (May through October) in nearby coastal waters. The summer diet analyses were limited to Smooth Flounder (small bivalve specialist), Pseudopleuronectes americanus (Winter Flounder), and Rainbow Smelt. Many juvenile Urophycis tenuis (White Hake) entered the estuary during late September to feed and then departed during November. Numerous Gadus macrocephalus (Greenland Cod), Myoxocephalus scorpius (Shorthorn Sculpin), Winter Flounder, juvenile Clupea harengus (Atlantic Herring), Microgadus tomcod (Atlantic Tomcod), Rainbow Smelt, Morone saxatilis (Striped Bass), and Zoarces americanus (Ocean Pout) entered the estuary during autumn to overwinter, spawn, and feed. Winter Flounder, Smooth Flounder, Striped Bass, and Atlantic Herring fasted during winter. Crangon septemspinosa (Seven-spined Bay Shrimp) was the most important invertebrate prey (up to 95% of total prey mass) of all transient species. Large specimens of Greenland Cod, Shorthorn Sculpin, Ocean Pout, and White Hake also ate substantial numbers of small Rainbow Smelt, Atlantic Herring, Striped Bass, and Atlantic Tomcod. When combined with published data for the adjacent coastal zone, C. septemspinosa represents a nexus in 2 food webs and fits the description of a keystone species for the sGSL coastal zone and adjacent estuaries.
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.
Ice storms are severe meteorological events that often result in damage to forested areas in the mid-latitudes. On 11 December 2008, an ice storm affected northern New York and New England and caused extensive damage to forested areas. We examined topographical and biological factors influencing the spatial distribution of forest damage due to the 2008 ice storm. We assessed 57 forest plots in 7 locations. Forest impacts from the storm were highly variable across the study area. Analysis of genera indicated that Prunus (cherry), Fraxinus (ash), Fagus (beech), and Acer (maple) were particularly susceptible to damage, while Tsuga (hemlock), Pinus (pine), and Carya (hickory) were more resistant. Elevation, latitude, and topographic exposure to post-storm winds after ice-loading were the dominant factors influencing damage levels.
The invasion of Hemigrapsus sanguineus (Asian Shore Crab) has been of concern in northeastern North America since the late 1980s. A relatively long-term record (1998-2011) of density estimates in southern New England showed displacement of resident crab species at 3 locations in Massachusetts and Rhode Island. In 2016, I visited the same locations to estimate current crab densities. The springtime Asian Shore Crab density decreased at a coastal location, but increased at an estuarine location to >300 crabs/m². Resident crabs Carcinus maenas (European Green Crab) and Mud Crabs in the family Panopeidae increased in abundance at all 3 locations.
Although the fungus Batrachochytrium dendrobatidis is a causal agent behind precipitous amphibian declines globally, little is known about its regional distribution in New York State (NYS). With an aim toward increased understanding of B. dendrobatidis prevalence locally, we collected amphibians between April through November 2012 at the Rice Creek Field Station in Oswego County, NY, and took swabs of the ventral surfaces of all individuals caught. Polymerase chain reaction on DNA extracted from swabs and comparison with B. dendrobatidis control DNA showed that 30% of amphibians sampled carried the fungus, with prevalence ranging between 20-50% for Lithobates catesbeianus (Bull Frogs), Lithobates clamitans (Green Frogs), Pseudacris crucifer (Spring Peepers), and Eurycea bislineata (Two-lined Salamanders). We detected Batrachochytrium dendrobatidis only during the months of April, May, June. August. and September of the sampling period. June and September had the highest percentage of amphibians infected with B. dendrobatidis at 32 and 48%, respectively. This study represents the first time that B. dendrobatidis has been documented in Oswego County and only the second time that the fungus has been documented in NYS. The documented prevalence levels in combination with lack of observed mass amphibian declines suggest that the fungus may be endemic in local amphibian populations, but additional research is needed to establish the relative importance of these data for the health of amphibian populations in Oswego County and NYS.
We characterized patterns of bat activity outside primary hibernacula of Myotis bats at Mammoth Cave National Park on the days preceDng, concurrent with, and following the total solar eclipse which occurred on 21 August 2017. AdDtionally, we documented nightly patterns of bat activity for hydric habitats and forest corridors across Kentucky during a 7-d period encompassing the eclipse. Our results suggest there was no Durnal bat activity occurring in response to the total solar eclipse, and there was no clear evidence of altered nightly activity patterns. However, these observations provide baseline data for future study of bat responses to eclipse events.
Environmental DNA (eDNA) analysis has become a widespread conservation tool. One promising direction is to evaluate the impacts of anthropogenic disturbances on wildlife populations. In 2016, a ruptured pipeline caused 207,000 L of gasoline to spill into a tributary of the West Branch Susquehanna River in central Pennsylvania. This tributary is known to harbor one of Pennsylvania's most prolific populations of Cryptobranchus alleganiensis alleganiensis (Eastern Hellbender), a giant salamander of special conservation concern. To evaluate the impact of the gasoline spill on Hellbender populations, we conducted spatial eDNA analysis on 9 water samples collected along a 20-km stretch of the tributary in 2018. Spatial analysis identified a notably low eDNA concentration at the site immediately downstream of the spill site, likely a result of habitat destruction caused by the flood, gasoline spill, and subsequent construction of a new bridge and stream bank. We found relatively high eDNA concentrations at several sampled sites, suggesting the gasoline spill did not completely extirpate Hellbender populations from the tributary. Finally, we make recommendations on sampling regimes, including proactive sampling, to encourage eDNA-based assessments of the impacts of future spill events on wildlife populations.
The abundance of Tachycineta bicolor (Tree Swallow) has fallen by half across North America over the past 50 years. This study presents 38 years of observations on their nesting success from coastal Maine. We document long-term declines in nest-box occupancy and fledging success. We show that nest-box occupancy was affected by proximity to other nest boxes and to buildings, and that it increased with time since mowing. The number of young fledged per nest, on the other hand, decreased in wet years and years with many cold days, and it increased with time since mowing. These local factors do not, however, explain the long-term decline in nesting success, which we tentatively attribute to anthropogenic effects on the wintering grounds or along the migration route.
Ammocrypta pellucida (Eastern Sand Darter) has a broad and sporadic distribution in eastern North America. Once common, the species has experienced a sharp decline in its range during the last 50 years primarily because of habitat destruction. Populations now persist only in isolated localities which contain clean, sandy substrates. In this paper, we document the presence of the Eastern Sand Darter in Racoon Creek in southeastern Ohio, where it had not been reported in over 57 years, and briefly review its historical and contemporary distribution throughout the state. This new distributional observation suggests stabilization and perhaps gradual recovery of an ecologically sensitive species recently considered for federal listing.
We examined macroinvertebrate drift at 4 sites downstream of Abanakee Dam on the Indian River, NY, on separate days at base-flow conditions and following days during recreational releases (rapid releases supporting white-water rafting enterprises). Macroinvertebrate drift rates were highest near the dam due to high numbers of drifting Simuliidae at both base flow and during a release. At the other 3 sites, Simuliidae were less abundant in the drift, and Chironomidae and Sphaeriidae had especially high drift densities during a release, suggesting a greater vulnerability to catastrophic drift. Macroinvertebrate drift was not affected by differences in stream gradients or shear forces that did differ between sites. Our drift densities during the recreational releases were higher than observations from other studies during natural floods, suggesting greater drift vulnerability to rapid increases (∼15 min) in discharge when flood gates are opened.
Prior to arrival of white-nose syndrome, we found bats hibernating in 82 of 119 abandoned mines in northern Michigan. Unoccupied sites typically were short (19 ± 17 m SD) and/or experienced chimney-effect airflow, which led to temperatures near or below freezing (-0.8 ± 2.9 ºC). Overall, occupied sites were more structurally complex, longer (307 ± 865 m), and warmer (5.7 ± 3.0 ºC) than unoccupied mines. Number of bats varied from 1 to > 55,000, although the median was 115. Perimyotis subflavus (Eastern Pipistrelle) and Eptesicus fuscus (Big Brown Bat) accounted for only 0.5% of the total of 244,341 bats that were observed. Ninety percent of hibernating animals were Myotis lucifugus (Little Brown Bat), and almost 10% were M. septentrionalis (Northern Bat). Relative to Little Brown Bats, Northern Bats were more common in the mines of the Upper Peninsula than in hibernacula in the East and Ohio River Valley. Maximum ambient temperature, presence of standing water, and water vapor pressure deficit were potential predictors of the number of Myotis that was present. Seventy-five percent of Northern Bats and 22% of Little Brown Bats roosted alone, rather than cluster with other bats. Little Brown Bats in Michigan were solitary much more often than in the East.
There are few undisturbed freshwater habitats remaining in the populated areas of the United States. Aquatic organisms, such as dragonflies (Odonata), have therefore either had to adapt to disturbed and modified secondary habitats, such as farm, golf course, storm-water remediation, and community-park ponds, or risk extirpation. The species that readily adapt to these habitats are usually widespread common species. However, other aquatic habitats inadvertently created at abandoned work sites often evolve distinctive characteristics over time that provide refuge for species rarely or never found at deliberately created pond habitats. For 17 years, we have monitored the diverse Odonata fauna at several floristically distinct ponds formed in depressions left from the dredging of the Chesapeake and Delaware Canal in the 1960s. Among the species found are ones not known elsewhere locally or ones found in unusual abundance at one or more of the ponds, though infrequently encountered regionally. These dredge spoil ponds are important for conserving regional Odonata biodiversity by providing unique habitats in an increasingly urbanized environment.
Quercus (oak) regeneration failure threatens many forest and savanna communities worldwide, where preservation of vegetation structure and composition depends on acorns germinating and surviving into adulthood. However, predation on the acorns and browsing of seedlings limits oak regeneration. To better understand the effects of these 2 mechanisms on oak recruitment in the endangered Bluegrass savanna-woodland of Kentucky, we compared seed predation and herbivory on Quercus muehlenbergii (Chinquapin Oak) with Carya laciniosa (Shellbark Hickory), a successfully regenerating tree species. Compared to hickory nuts, acorns were predated more, cached less, and dispersed shorter distances. Neither the distribution of the seedlings under the parent canopy nor browse damage differed between the 2 species. Our results suggest that seed-predation prevents regeneration of oaks in this endangered community.
Wetland research has described changes in plant communities along environmental gradients, however, little is known about the relationship between fine-scale hydrologic and abiotic factors and the relative abundances of individual, co-occurring species. Larix laricina (Eastern Larch) and Picea mariana (Black Spruce) are the 2 dominant tree species in open boreal peatlands in the northeastern US. In order to describe abiotic gradients that correlate with species abundances at local spatial scales, we collected data on Eastern Larch and Black Spruce stem abundances, groundwater pH, conductivity, depth to water table, water temperature, dissolved oxygen, and canopy closure from 42 plots along 6 transects in an Adirondack wetland. We correlated stem abundances with each of the abiotic variables and then used regression to explain variation in stem abundances of the 2 species along those abiotic gradients. Percent canopy closure explained 56% of the variability in Eastern Larch stem abundance, and depth to groundwater was also positively correlated with number of Eastern Larch stems. These 2 abiotic conditions covaried; thus, the best model to explain variability in Eastern Larch stem abundance included only canopy closure. Black Spruce stem abundance was significantly lower in plots with higher water temperatures (R² = 0.31). In a multiple-regression model, depth to the water table explained an additional 6% of the variance and substantially reduced Mallows' Cp . Eastern Larch and Black Spruce appear to establish along different abiotic gradients at the scale of tens of meters within this study wetland. Although light levels, as mediated by canopy closure, would be predicted to influence the establishment of Eastern Larch based on its silvics, the strong negative relationship between Black Spruce stem abundance and water temperature has not been previously reported. Sampling other peatlands will allow us to determine the universality of these patterns and to better understand which environmental gradients operate at local spatial scales to structure patterns of tree distribution within peatlands.
During summer 2001 I consistently observed a group of 6 adult coyotes (the breeding female was radiocollared) raising 1 pup in a suburban area on Cape Cod, Massachusetts. In this note I describe the activities of this group and possible reasons for the large pack size.
Lake acidification is a major problem in northeastern US lakes that can control fish presence or absence. We examined the history of fish populations in Lake Minnewaska, in eastern New York. We examined historical documents and found that Lake Minnewaska was fishless from 1922-2008 because of high lake-acidity. Following 30 years of recovery from acidic conditions, Notemigonus crysoleucas (Golden Shiner), a small minnow species, was introduced in 2008 and quickly proliferated, peaking at ∼15,000 individuals in 2013. In 2012, the piscivorous species Micropterus salmoides (Largemouth Bass) was introduced, and the minnow population was effectively removed by 2014. We present a conceptual model of the history of fish in Lake Minnewaska as fish disappeared and reappeared over 100 years as a consequence of acid rain and human introductions.
Grassland breeding bird abundances in New York State mirror a national downward trajectory as land-use changes degrade, destroy, and fragment suitable habitat. We quantified and compared bird abundances on pastures that were subject to continuous grazing, minimal rotation, or holistic resource management. We hypothesized that grassland bird abundance varied systematically with pasture management approaches. We measured grassland bird abundances using 40-m radius point counts performed on 27 pastures. Further, we assessed vegetation and environmental parameters to characterize the available habitat on each pasture. Holistic resource managed pastures had 1.5 and 4.5 times higher average abundances of obligate grassland birds than minimally rotated or continuously grazed pastures, respectively. Overall, our results indicate that farms can employ strategies that promote grassland bird habitat and may therefore have a positive influence on grassland bird metapopulations in New York State.
Global wildlife populations are in decline, in part, due to habitat loss resulting from urbanization. Urban green roofs may mitigate such habitat loss by providing supplemental habitat for wildlife, including bats, which are more active over urban green roofs than nearby traditional roofs. To better understand bat activity over urban green roofs, we surveyed bats and arthropods on a 27,316-m² green roof planted with Sedum spp. in New York City from June to August 2017. We found that Lasiurus borealis (Eastern Red Bat), a species with a diet consisting mainly of moths, accounted for 88% of identified bat calls. We collected over 15,000 arthropods of 16 taxa and found that moth abundance, while a relatively small proportion of green roof arthropods, correlated positively with bat activity. Our findings suggest that urban green roofs provide useable habitat for moths and other arthropods and, consequently, bats may forage on green roofs when prey are available.
Winter is typically considered a dormant period in northern forests, but important ecological processes continue during this season in these ecosystems. At the Hubbard Brook Experimental Forest, located in the White Mountains of New Hampshire, we used an elevational climate gradient to investigate how changes in winter climate affect the litter and soil invertebrate community and related decomposition rates of Acer saccharum (Sugar Maple) litter over a 2-year period. The overall abundance and richness of litter invertebrates declined with increasing elevation, while the diversity and abundance of soil invertebrates was similar across the gradient. Snow depth and soil temperature were correlated to the abundance and distribution of the litter invertebrate community, whereas soil organic matter, soil moisture, and soil frost were correlated with the distribution and abundance of the soil invertebrate community. Decomposition rates were initially faster at lower-elevation sites following 1 year of decomposition, then stabilized at the end of 2 years with no difference between higher- and lower-elevation sites. This pattern may be explained by the distribution and abundance of the litter and soil invertebrates. Higher abundances of litter invertebrates, especially Collembola, at lower-elevation sites contribute to faster initial breakdown of litter, while greater abundances of Acari in soils at higher elevation contribute to the later stages of decay. The interaction between decomposition and the associated invertebrate community responded to changes in climatic conditions, with both soil temperature and soil moisture being important determinants.
Weekly collections, from May to September over 3 years from one 2-tier box trap in Addison, VT, totaled more than 29,000 tabanids representing 44 species and included 417 Tabanus calens. Seasonal succession was evident, with T. calens most numerous in the upper trap in August. This very large horse fly was easily collected around a bait horse with an aerial net. Other abundant horse fly species were Hybomitra lasiophthalma, T. quinquevittatus, T. lineola, and T. sackeni. The most abundant deer flies were Chrysops univittatus and C. vittatus. Most deer flies showed a preference for the upper trap, whereas horse flies showed a mixed preference. Tabanus quinquevittatus made up 60% of the collected horseflies in the trap. The trap collected 41% less horse flies (73% less T. calens) and 24% less deer flies with the trap in 2013 to compared to in 2015. Both the presence of T. calens and the use of the 2-tier box trap in Vermont at one site for 3 whole seasons were new events. Tabanus calens was not listed in the 1990 checklist of Vermont tabanids. These results are presented in the context of trap modifications, range extension, and polarized light.
Sampling in several habitat types (sand/mud, eelgrass, sand, gravel, macroalgae/mud) during all seasons with a variety of gears in Nauset Marsh, Massachusetts during 1985-1987 found a fauna consisting of 35 fish and 10 decapod crustacean species. Although most of the abundant species were found in several habitat types, species richness and habitat use appeared to be highest for vegetated habitats (eelgrass, macroalgae). The fishes and decapods were numerically dominated by cold-water taxa; however, numerous fish species, represented by rare individuals of predominantly southern forms, enriched the fauna. Species composition of Nauset Marsh could be distinguished from estuaries south of Cape Cod and even from the south shore of the cape. Both fishes and decapods were most abundant during the summer, apparently due to the contributions from spring and summer spawning in the estuary and the adjacent Atlantic Ocean. The location of Nauset Marsh and other estuaries on Cape Cod provide a unique opportunity to evaluate the importance of this region as a faunal boundary to estuarine species.
Bombus spp. (Bumble bees) face population declines, in part due to habitat loss. Roadside rights-of-way (ROWs) are potential habitats; however, they are highly disturbed due to roadside mowing and on-road traffic. We investigated whether these factors are associated with variation in abundance of bumble bees in highway roadside ROWs across New York State. We used sweep netting and photography along 30 highways with different mowing pattern (control, reduced) and traffic level (low, medium, high) treatments in 2019 and 2020. Very few bumble bees were observed (98% of n = 916 observations found 0). This result was potentially due to insufficient foraging plants or nesting areas. Further investigation is needed to understand how highway roadside ROWs can be high quality habitat for bumble bees.
The goal of this study was to obtain information on diversity, abundance, and distribution of non-volant small mammals in 4 major habitat types in each of 5 regions of Ohio. We trapped in 31 study areas, representing 39 counties, for 3 consecutive nights for a total of 38,400 trap nights. We established eight 100-m transects (each with 10 live traps, 20 snap traps, and 20 pitfall traps) per study area in woodland, oldfield, grassland-pasture, or restored prairie-wetland habitats. We captured fourteen species of small mammals (shrews and rodents <100 g in body mass), but 97% of the 2150 captured consisted of just 4 species: Microtus pennsylvanicus (Meadow Vole; 31%), Peromyscus leucopus (White-footed Mouse; 29%), Blarina brevicauda (Short-tailed Shrew; 21%), and Sorex cinereus (Masked Shrew; 16%). Regional differences in abundance of small mammals (captures/100 trap nights) and species diversity (H') were not significant (P > 0.05). Seven species of interest were captured in low numbers (<10) and 2 others, Reithrodontomys humulis (Eastern Harvest Mouse) and Myodes gapperi (Red-backed Vole), were not captured in the course of the 2-year study.
Surveys of Odonata were carried out at Mass Audubon wildlife sanctuaries in all regions of the state and in multiple habitats. Our goals were to provide a comprehensive look at patterns of species distribution and relative species richness across Massachusetts and compare surveys where effort was and was not controlled. Observers encountered a total of 146 species, 11 of which were very widespread, having been recorded at more than 40 of the 54 properties examined. Thirty-five species were relatively rare, occurring at only 1 or 2 sanctuaries. A few sanctuaries were particularly notable for supporting somewhat uncommon species. These sites were not located in any particular ecoregion, but reflected local conditions. In surveys where effort was not controlled, a regression analysis indicated that about two thirds of the variation in species richness among sanctuaries could be explained by the amount of observer effort, the size of the sanctuary, and the extent of wetland habitat. Quantitative surveys that used transects or point counts to control for sampling effort resulted in observation of fewer species, including state-listed taxa, compared to the non-quantitative surveys. Despite producing fewer species, data from these quantitative surveys can be used to make statistical comparisons with data from future studies and detect changes over time in species richness, abundance, and frequency of occurrence.
Vermivora chrysoptera (Golden-winged Warbler) and Scolopax minor (American Woodcock, hereafter, Woodcock) are 2 young-forest-dependent species of eastern North America that are experiencing population declines due to loss of breeding habitat. The goals of our study were to compare avian abundance and habitat similarities and differences in sites used by the 2 species. A portion of our survey plots were manipulated under Woodcock or Golden-winged Warbler habitat prescriptions in managed shrublands, and others were on regenerating timber-harvest sites. In north-central PA, we compared Woodcock abundance in 10-ha experimental plots assigned to one of 3 habitat prescriptions: uncut controls, Woodcock strip plots, and Golden-winged Warbler mosaic plots. We also quantified vegetation characteristics in each 10-ha study plot. Woodcock density was higher in the strip (4.8 males/10 ha) and mosaic (5.1 males/10 ha) plots compared to the uncut reference plots (3.3 males/10 ha). Woodcock density was negatively correlated with sapling cover in the north-central PA study plots. In regenerating timber harvests in northeastern PA, we demonstrated that vegetation characteristics overlap regardless of whether we detected only Woodcock or both species. Mean basal area of harvested stands with only Woodcock (i.e., 11.5 m2/ha) was greater than the mean basal area in stands used by Golden-winged Warbler (8.4 m2/ha). Our results suggest that creation of young forests at the stand level using either the Woodcock or Golden-winged Warbler habitat guidelines has benefits for both species. However, the Golden-winged Warbler is less flexible in the density of herbaceous cover and residual trees it requires. We recommend that in areas where the 2 species coexist, the Golden-winged Warbler guidelines be implemented to benefit both species.
Chemical treatments are used to protect Tsuga canadensis (Eastern Hemlock) from Adelges tsugae (Hemlock Woolly Adelgid), yet little is known about how avian communities respond. We tested the efficacy of imidacloprid soil drenches on hemlocks and its impact on avian indicator species in the Appalachian Mountains of Kentucky at 65 sites (37 treated) in 2009 and 2018. Percent dead hemlock increased 11%, regardless of chemical treatment. Hemlock had higher vigor in treated sites, but a hemlock-decline index did not differ by treatment. None of 6 indicator bird species showed a significant population response to chemical treatments. Setophaga virens (Black-throated Green Warbler) declined between years across treated and untreated sites, whereas Contopus virens (Eastern Wood-Pewee) increased between years. Treatments positively affected individual hemlocks, but this did not carry over to influence avian species. Hemlock health may need to decline below some threshold before avian species respond.