Faithann Vanderwalker

Co-author: Stacy McNulty

Snapping Turtle Nesting Trends Over Fifty Years in the Adirondack Park

Abstract - Timing of oviposition is critical for many endothermic reptiles with long egg-incubation periods and temperature-sensitive sex determination. In response to increasingly warm spring temperatures, some species may lay eggs earlier in the season. We conducted longitudinal research on nesting timing of Chelydra serpentina (Common Snapping Turtle) at ESF’s Huntington Wildlife Forest in the Upper Hudson River Watershed. Using observations beginning in 1968 and intensive population trapping and observation in summer of 2022, we tracked changes in annual mean, minimum, and median nesting Julian Day (n = 1017 observations in 54 years). In years with ≥20 observations (n = 18), mean Julian day decreased by 0.24 days ± 0.25 (SD)/year (R2 = 0.24). In years with >10 observations (n = 30), median date of nesting decreased by 2.26 ± 0.27 days per decade (R2 = 0.81). Removing 2022 data resulted in a decreased nest date of 1.55 days per decade (R2 = 0.74). Average minimum nest date increased by 2.06 ± 2.5 days per decade (R2 = 0.30). Variance of all 3 statistics decreased with time. Most notably by 2.5 days per decade (R2 = 0.98) for the minimum nesting day. A decrease in variance may indicate a shortening of the nesting window. We also analyzed the minimum and maximum nest temperatures for days that turtles were observed nesting from 1968 to 2022 (n = 883).  Mean maximum (23.30 °C ± 6.20 SD) and minimum (11.30 °C ± 4.12 SD) temperatures did not vary significantly over time. As climate continues to shift, nesting seasons may continue to shift along with it, which may lead to changes in incubation periods, and importantly the nest conditions during the incubation period experienced by Snapping Turtle embryos. A more complete study with standardized observation effort each year would minimize variability due to human observation effort and increase the sample size each year.

George NIi

Co-authors: Nicholas Gotelli and Jian Duan

Using Machine-Learning Models to Identify Crown Class Condition of EAB-Infested Forests

Abstract - As an increasing number of invasive insect pests are introduced to landscapes due to global trade transport and geographic range shifts, there is a greater need for research and study on alternative methods of control beyond insecticides and pesticides. A classical biocontrol program was developed and implemented by the US Department of Agriculture against the invasive beetle Agrilus planipennis (Emerald Ash Borer [EAB]) after first detection in the US in 2002. The EAB biocontrol program has released several introduced parasitoid wasps as biocontrol agents across 32 EAB-infested states. While recent field studies have observed the successful establishment of these agents and significant EAB suppression in release sites, the contribution of this EAB biocontrol program to ash recovery and regrowth is currently not known. This project assesses the ecological impacts of the current EAB biocontrol program on ash tree survival and crown class recovery in North America. This study will establish whether machine learning (ML) models and drone photography can serve as a new fieldwork methodology to identify crown class conditions and forest canopy cover in EAB-infested forests, and whether the crown class conditions of EAB-infested forests are recovering over time given biocontrol deployment. We have trained a suite of machine-learning models on drone imagery of EAB-infested natural areas collected in the summer of 2022 in the New England Region and will ground truth the sites by field transect surveys collected at the same time. Current benchmarks show that the models can adjust their weights and predictions for crown class to result in 75% validation dataset accuracy. These results support the hypothesis that machine learning models are able to learn structural components of forest crown class conditions and can learn to predict them. This study suggests that ML models can be compared to current field methodologies used to detect EAB damage in native ash forests, and with increased data and high-resolution imagery, ML can assess both the impact that the EAB has on native ash trees as well as the impact biocontrol agents have on both the EAB and native ash forests after deployment. 

Zach Hart

Co-authors: Madelyn Lehman, Linh Le, Michael Hurban, and Mark Lesser

Put a Ring on it: Effects of Climate Change on Growth of Pinus banksiana and Pinus rigida at Opposing Range Margins

Abstract - Species range margins may indicate climatic (i.e., temperature and precipitation) niche limits that species cannot grow beyond. Ongoing climate change is shifting climate spaces, potentially creating conditions unfavorable to a species at a given location—particularly at or near a current range margin. Further, the response to changing climate may be dramatically different depending on the geographic position of the range limit (i.e., polar vs. equatorial). To study how species are dealing with climate change at their range margins, we assessed annual growth trends in 2 long-lived tree species, Pinus banksiana (Jack Pine) and Pinus rigida (Pitch Pine) at the Altona Flat Rock in northern New York. At this site, Jack Pine is near its southernmost limit, while Pitch Pine is near its northernmost limit. We hypothesized that with warming climate, conditions may be becoming unsuitable for Jack Pine while Pitch Pine will potentially thrive with warming temperatures. We collected cores from ~200 Jack Pine and ~100 Pitch Pine. All cores were measured and crossdated using standard dendrochronological techniques. We modeled annual ring-width against a suite of regional temperature and precipitation variables to determine what factors each species was responding to over time. Preliminary results showed that Jack Pine growth has remained relatively stable over the past century, while Pitch Pine showed an increasing trend in growth since the 1960s. However, over the past ~10 years, both Jack Pine and Pitch Pine showed decreasing growth trends. Jack Pine showed a low correlation with both temperature and precipitation, suggesting that climate is not a determining factor for growth at this site, and its southern range limit may be set by other factors. Pitch Pine showed a stronger correlation to climate, with fall temperature and annual precipitation having the largest influence on growth. This study will increase our knowledge of how tree species are responding to ongoing climate change and inform management decisions in regard to species vulnerability and forest biodiversity along range margins.

Emily Schmidt

Co-author: Mike Rubbo

Are Human Perceptions of the Environment Consistent with Ecological Data? A Study of User’s Opinions and Water Quality in the Pocantico River, Westchester County, NY

Abstract - It is critical for human perceptions of the environment to accurately represent ecological conditions, as conservation efforts can be affected by public opinion. This influence is especially prevalent at the local-level where municipalities play a major role in land-use decisions. To determine if human opinions are consistent with environmental data, we performed a study to document user’s opinions of stream health and water quality in the Pocantico River, Westchester County, NY. We split the 14.5-km (9-mi) Pocantico into 15 zones for social assessments and conducted interviews with users during the day, evenings, and on weekends.  We performed rapid ecological assessments every 200 m along the entire length of the river with water-quality sampling conducted at strategic locations. Preliminary review of the social data show that compared to the perceptions of non-local users, local users believed the river was of poorer condition. Ecological and water-quality data showed the river to be in moderate condition; however, there were high levels of fecal bacteria found throughout testing sites. Currently, we are examining the social and ecological data to document any further relationships among these variables.

Kristen Pareti

Co-author: Allyson Jackson

Insect Biodiversity Amongst Native and Nonnative Plants in Teatown Lake Reservation, Ossining, NY

Abstract -Through human development, global trade, and travel, plant species have been distributed to novel environments. Some of these species can outcompete native plants and aggressively take over ecosystems. Vegetation acts as an important foundational ecosystem service to the higher trophic levels through habitat and food resources. It is important to understand how changes in plant species can reverberate throughout the food chain. This study assesses possible differences in biodiversity in the invertebrate insect populations found on native and nonnative plants. We studied 2 locations on Teatown Lake Reservation in Westchester County, NY. We collected insect samples from 10 transects per site via sweep net collection in July, August, and September (total n = 60). We identified the insect species and calculated Shannon diversity and family level richness. We identified plants to species level at every meter of the transect, from 0 to 5 m. We categorized transects based on the overall percentage of native species present. There were minimal differences between insect biodiversity of native plants versus nonnative plants. These preliminary results could shed light on insect population's ability to adapt to nonnative plants.

Lauren Berkley

Co-authors: Ellen Martinsen, Nathan Bieber, Josh Blouin, Jacob DeBow, Therese Donovan, Caitlin Drasher, Martin Feehan, Dylan Ferreira, Nick Fortin, Rebecca Furda, Henry Jones, Pauline Kamath, Lee Kantar, Andrew Labonte, James Murdoch, Elias Rosenblatt, Inga Sidor, and Alaina Woods

Emerging Vector-borne Pathogens in Northeastern US Cervids

Abstract -Emerging infectious diseases pose an increasingly severe threat to wildlife populations around the world. Vector-borne diseases are of particular concern as arthropod vectors rapidly move northward with climate change, thus exposing northerly restricted and immunology-naïve species to novel pathogens. The understudied blood parasites Babesia odocoilei, Theileria cervi, and Plasmodium odocoilei pose a threat to northern cervid populations such as Alces alces (Moose) and Rangifer tarandus (Caribou). In this study, we sampled cervids including Odocoileus virginianus (White-tailed Deer), Moose, and captive Caribou across the northeastern US for the tick-borne pathogens B. odocoilei and T. cervi, and the mosquito-borne malaria parasite P. odocoilei. We sought to establish foundational knowledge on the prevalence and geographic distribution of B. odocoilei, T. cervi, and P. odocoilei in northeastern US cervids. By forging collaborations with every state fish and wildlife agency in New England, as well as veterinarians, we obtained hundreds of tissue samples from Deer, Moose, and Caribou. By PCR, we found positive samples for B. odocoilei and T. cervi,including B. odocoilei in captive Caribou and T. cervi in free-ranging White-tailed Deer. This study aims to uncover the demographic and ecological drivers of cervid pathogen prevalence and distribution. The ultimate goal is to inform the decisions of wildlife managers, conservation biologists, veterinarians, and livestock owners to mitigate the impact of emerging infectious diseases in northern wildlife populations and livestock.