Recent climatic warming is widely expected to cause changes in the geographic distributions of plant and animal species. Potential evidence of such changes includes expansion of populations at the cool range margin and contraction of populations at the warm range margin. We made use of town-level occurrence data from herbaria and state natural heritage programs to assess evidence of potential range contraction in a group of rare (state-listed) northern plant species in southern New England based on differences between historical and current records. For comparison, we examined samples of rare southern species and rare species that were neither northern nor southern (central). The mean annual temperature of towns with current occurrences was significantly lower than in towns with only historical occurrences in the northern and central samples, but not in the southern sample. A potentially confounding variable was human alteration of natural habitats, for which we used human population density as a proxy. Towns with historical occurrences had significantly higher population densities than current towns in the southern and central samples but not in the northern sample, representing a greater overall loss in towns with greater human presence. To separate the potential effects of human habitat alterations and temperature, we analyzed residuals from a regression of town temperature on human population density. When compared between historical and current towns, these residuals were significantly lower in current towns for both the northern and central samples, indicating an effect of climate beyond what could be accounted for by human habitat alterations. For rare southern species, in contrast, the residuals were greater for current than historical towns, indicating that these species were not being disproportionately lost from warmer towns. This is one of a small number of studies that show warm-edge range contractions in a group of plant species, and apparently the only one to consider the potentially confounding effects of human habitat alteration. Our results highlight the value of herbarium specimens in conjunction with recent surveys to document such changes and point to the importance of considering potentially confounding factors in any such analysis.

The Bronx River is an urban waterway with a long history of anthropogenic disturbance. We conducted a longitudinal assessment of the Bronx River's water quality by measuring benthic macroinvertebrate diversity at 6 sites along the river. We integrated long-term water-quality data collected by the New York State Department of Environmental Conservation. We found that the overall water quality of the river has remained moderately impacted over different timepoints throughout the past 22 years. The study site upstream of combined sewage overflows and municipal separate stormwater systems exhibited healthier biological profiles, whereas the most-downstream sites exhibited slight declines in water quality. The most recent survey of the Bronx River (2020) revealed that high invasive species dominance was associated with benthic macroinvertebrate communities that were less healthy. Notably, one invasive species not documented in historical surveys, Corbicula fluminea (Asian Clam), was sampled in 5 of 6 study sites during the 2020 surveys. Moreover, no species were sampled from the order Ephemeroptera (mayflies) in 2020 despite being present in previous surveys. These results can be used to guide the management of urban rivers.

There is a long history of recording bird observation in Acadia National Park, ME. These studies and resulting long-term data sets provide evidence of changes happening within and around the park, as well as an opportunity to compare local dynamics with trends detected in regional to continental-scale studies. Over 51 years (1971–2021), community volunteers in and around Acadia National Park engaged in annual Christmas bird counts (CBC), collecting valuable information to assess winter bird-population dynamics and species trends. We analyzed the cumulative data from 2 CBC circles that encompass Acadia and the surrounding lands and waters to generate a combined summary of early winter population-trend estimates for 162 species. We found a 43% reduction in the total number of birds over the 51-year study, with 42 species exhibiting declines, and 33 species showing increasing abundance. The annual number of species observed has declined by over 7%; however, the cumulative species in the full dataset continues to increase as newly observed species are added in most years. Our study complements many other studies from Acadia documenting ongoing changes in the physical environment and coastal biota. Conservation and management actions take place at the local level (e.g., Acadia National Park), and local resource data and trends are critical to synthesize and share for effective decision making.

High-throughput DNA sequencing can generate large genetic datasets in a cost-effective manner. Although the diet of Eptesicus fuscus (Big Brown Bat) has been studied widely in natural and rural systems using visual identification of prey items in feces, our aim was to more completely assess diet using a metabarcoding approach across a wide urban–natural landscape gradient in the mid-Atlantic region. Concordant with our expectations and previous Big Brown Bat diet studies from visual identification, we observed a high abundance of Coleoptera (beetles) relative to other insect orders. Although a possible improvement over visual techniques for studying food habits, we suggest caution in interpreting metabarcoding results in diet studies. We noted observations of environmental or contaminant taxa within these data, and designed a stringent filtering method that we used to eliminate these taxa, but that also removed previously documented prey taxa from our dataset.

Here we present the first description of nest architecture, immature stages, and brood-parasitism of Andrena (Callandrena s. l.) asteris (Aster Miner Bee) and the first description of the nesting biology of any Callandrena in eastern North America. Brood cells varied from 50 to 91 cm in depth, making this the deepest solitary bee nest recorded in northeastern North America. Additionally, we assembled data on soil texture, phenology, geographic distribution, and host-plant preferences. By modeling publicly available observation data, we find that areas of peak habitat suitability for A. asteris are in proximity to coastal and inland shorelines and major water courses. Our results corroborate a recent assessment of the conservation status of New York pollinators, which ranked A. asteris as “vulnerable”.

Pylodictis olivaris (Flathead Catfish) is a large piscivorous ictalurid catfish that has been introduced widely outside of its native range. Introduced Flathead Catfish are recognized as invasive in many locations and have contributed to declines in native fishes. Flathead Catfish were first documented in the mainstem Delaware River in 2001 and now occupy at least 200 km of tidal and non-tidal habitats. This paper describes the movements of 2 Flathead Catfish opportunistically tagged with acoustic transmitters in the tidal Delaware River. The first Flathead Catfish, tagged in November 2005 and tracked for 1055 days, occupied a 26-km reach of the upper tidal river and evidenced 3 cycles of seasonal movement between the same areas of the river. The second Flathead Catfish, tagged in January 2020 and tracked for 340 days, occupied a 49-km reach of the lower tidal Delaware River and was detected for an extended period in the lower Christina River. This catfish also demonstrated seasonal downriver and upriver movements, but exhibited weaker site fidelity than the other individual. Both Flathead Catfish tended to move at night or in the morning, which is typical for the species, although daylight movements were also observed. The annual ranges of river occupied by the Flathead Catfish in this study were larger than previously described for introduced populations, and suggest that any program of management or control would have to be at a watershed scale. This study is the first to describe seasonal movements of Flathead Catfish in the Delaware River, documents a 17-km downriver expansion of the species' range, and provides the first record of Flathead Catfish in the Christina River.

Larids are well known for their kleptoparasitic habits, but mostly they steal from conspecifics or other birds. Here we describe Larus delawarensis (Ring-billed Gull) stealing cicadas from Sphecius speciosus (Eastern Cicada Killer) in flight over the Susquehanna River in southern Pennsylvania.