The unintentional introduction and rapid spread of chestnut blight (caused by Cryphonectria parasitica (Murr.) Barr) in the early 20th century resulted in the demise of American chestnut (Castanea dentata (Marsh.) Borkh.; Fagaceae) as a major component of forest canopies resulting in negative impacts on eastern forest communities. Research efforts over the last century have documented the persistence of occasional trees and root crown/ stump sprouts throughout much of the species' historic range, providing the basis for ongoing breeding of blight-resistant trees and restoration efforts. Here we use environmental niche modeling to investigate whether environmentally suitable habitat remains for remnant trees throughout the southwestern historical range, and to evaluate the reintroduction potential of this relatively understudied part of the historical distribution. We also use stage-structured matrix projection models to investigate the potential demographic future of C. dentata near the historical southwestern range limit based on observations of American chestnut in these areas over the last several decades. We found suitable upland habitat with areas of high forest canopy cover occurs throughout much of the southwestern portion of the historical range and that populations of American chestnut in these areas are predicted to drastically decline over the coming decades. These results highlight the continued presence of suitable C. dentata habitat throughout the southwestern extent of its historical distribution, which should be incorporated into evaluations for future reintroduction, and emphasize the need for efforts to locate, conserve, and introduce genetic material from individuals with locally adapted genotypes into active restoration programs.

Alpine ecosystems in the arid southwestern United States are vulnerable to climate change. Many of these ecosystems are experiencing increased recreational use and introductions of nonindigenous ungulates. In the La Sal Mountains of southeastern Utah, alpine plant communities support an endemic plant species, Erigeron mancus, 11 plant and two animal species of conservation concern, and a United States Department of Agriculture (USDA) Forest Service Research Natural Area. Nonindigenous mountain goats (Oreamnos americanus) were introduced by the Utah Division of Wildlife Resources (UDWR) in 2013 and 2014, and recreational use has increased in the intervening period. To evaluate potential effects of mountain goat and recreational use, vegetation monitoring was initiated by the USDA Forest Service in 2016. We used 5 y monitoring data (2016–2020) and generalized linear mixed models to analyze the separate and interacting effects of year, recreational use, and mountain goat use on: (1) populations of plant species of conservation concern; (2) vascular and nonvascular plant cover; and (3) ground cover. Our analyses revealed decreases in proportional frequency of E. mancus at the end of the monitoring. Proportional cover of dominant plant growth forms, especially forbs, declined, while proportional cover of litter and ineffective ground cover (bare soil and pavement) increased. Recreational or goat use were a factor in several of the observed changes, although weather and climate likely also influenced the results. Management complexity arises because of the different missions of USDA Forest Service and UDWR, but adjustments in mountain goat numbers and recreational use may be needed to maintain ecologically resilient ecosystems. Continued monitoring can provide the basis for adaptive management.

Descendants of introgressive hybridization between species may have evolutionary advantages over their parental species. Prior studies have documented evidence of introgressive hybridization between coyotes, dogs, grey wolves and eastern wolves. This study attempts to attribute morphology and pelage patterns of Pennsylvania coyotes to sex, ecoregion, and the degree of coyote-wolf introgressive hybridization. A total of 192 coyotes were genotyped at 63 ancestry informative SNPS to determine the percent of coyote genome attributable to wolf origin (percent wolf). Females had higher percent wolf than males, which could be the result of lower survivorship in hybrid males. Percent wolf, sex, and ecoregion each were found to independently influence size using general linear model analysis, and the effect of sex was most pronounced. Coyotes from Northeastern and northcentral ecoregions of Pennsylvania were larger in size and possessed a higher percent wolf. Moreover, coyotes with higher percent wolf were larger, less red in some parts of their pelage, and had a different pelage patchiness composition. This correlates with previous studies that showed ecoregions with increased deer density correlated to coyotes with higher percent wolf. Size and percent wolf may be adaptively advantageous in Northeastern Pennsylvania where there is a relatively high deer population abundance. Furthermore, the degree of redness within coyotes may be used as an indicator for introgression levels for population managers, aiding in understanding the shifting ecological role of coyotes.

Amphibians are a highly vulnerable taxonomic group that have suffered population declines worldwide. As amphibians serve critical links between trophic levels and facilitate nutrient recycling, it is critical to understand how their species richness, abundance, and phenology shift over time. Because amphibian populations naturally fluctuate, short-term monitoring can provide insight into how amphibian communities respond to proximate changes in weather conditions, which is helpful for predicting long-term responses to climate change. We used pitfall traps to examine interannual variation of the amphibian community at Powdermill Nature Reserve (PNR) in Pennsylvania during 2020–2021 to provide critical details for future long-term monitoring. Mean monthly temperature and precipitation did not vary significantly between years, but monthly captures per sampling effort declined and monthly biomass per sampling effort increased from 2020 to 2021. Despite a lack of significant relationships between total amphibian captures and temperature and precipitation, peak abundance shifted earlier, and individuals were larger in 2021 compared to 2020. Interestingly, individual species biomass was predicted by an interaction between temperature and precipitation, suggesting individual species will vary in vulnerability to climate change, but the amphibian community as a whole at PNR is resilient to minor fluctuations in temperature and precipitation.

Lakes and reservoirs are frequently monitored by researchers for elevated mercury concentrations in sportfish. Rivers and streams, especially those of smaller orders, are less frequently monitored for mercury contamination and nonsport fishes and invertebrates, although important components of the food web, are rarely examined. We addressed this gap by surveying mercury levels in a stream community in the Kiamichi River in southeastern Oklahoma, U.S., by sampling fish and macroinvertebrates at ten sites in the river. We found elevated levels of mercury across taxa within the river including individuals of smallmouth bass populations 10–25 cm in length having concentrations (2986 ± 1053 ng/g dry weight) above the U.S. Environmental Protection Agency human limit. Furthermore, we observed high concentrations in darters and logperch (1133 ± 464 ng/g dry weight), nonsport fishes found predominantly in rivers and streams. Our results indicate mercury contamination can reach elevated concentrations in rivers and stream food webs, posing risks to both humans and wildlife.

Despite their visibility, abundance, and widespread distribution, the movements of Isabella moth larvae (a.k.a “woolly worms:” Pyrrharctia isabella (J.E. Smith); Lepidoptera: Erebidae: Arctiinae) have been poorly studied. We observed these larvae to assess the relationship between their movement and local environmental conditions. Twice each day for 83 d, nearly 52 km of highway were observed in northwest Missouri. A total of 264 larvae were encountered during 664 total visits to four road sections, peaking in the first week of October. Analyses revealed increased larva abundance (n ≥ 159 road-section visits) associated with temperature, wind speed, pale pavement tint, and afternoon time-of-day. The best overall model to explain larval movement patterns, based on 163 visits and all measured conditions, incorporated temperature, north wind speed, west wind speed, and humidity (P = 0.015), but no other factors. In addition, larvae showed a significant tendency to travel in the same direction as the wind, and to travel eastward in the afternoons. These observations provide insights into the fall movements of a common larva, and provide directions for future research.

Based on daily collections of final instar exuviae, the widespread annual cicada adult emergence of Neotibicen canicularis (Harris) (Hemiptera: Cicadidae) was studied in southeastern Wisconsin in a combined plot containing 15 mature trees and suburban lawns for seven successive years and in a separate plot of two trees for four years. The daily numbers of males and females were recorded. Over the entire seven years of the 15-tree plot, total female and male exuviae were equal, a summative 50:50 ratio. However, there was considerable deviation from this ratio three of the seven years. More females than males eclosed in the first two years and more males eclosed in the final year, yet the overall trend was for females to eclose later than males for the entire seven-year study of the 15-tree plot, with many more females emerging in the last twenty plus days. Although ambient temperatures varied over the study (cooler in the first two years and warmer later), they did not have any discernible effect on the timing of female and male eclosions. The overall annual emergence period was 56.7 (se 4.48) d for a seven-year total of 2967 exuviae, with the annual average emergence being 437.6 (se 34.6) per year. The average density of exuviae, an estimate of the emerging adult population, was 1.3 ± 0.09 (se) per m². In the separate two-tree plot, a greater number of males emerged than females for all four years.

ARISTOTLE ADVISES: “Male cicadas are tastier when young, but the females are preferable later when they are full of eggs.”