Ornithology Commons^™

Interspecific Overlap In Seabird Diet Throughout The Breeding Season, Alexis V. Berkey

Student Publications

Seabirds are central-place foragers that breed in multi-species colonies, providing an opportunity to study species coexistence. I quantified interspecific competition among four seabird species (common terns Sterna hirundo, Arctic terns Sterna paradisaea, Atlantic puffins Fratercula arctica, black guillemots Cepphus grylle) breeding in the Gulf of Maine in 2022, 2024, and 2025. I hypothesized that, throughout the breeding season, 1) seabird diet would change and 2) interspecific overlap in diet would increase. I compared diets across species and time using direct observation of prey feeds and stable isotope values of seabird egg membranes and blood, which provide …

The Importance Of Body Size And Spatial Scale In Modeling Winter Bird Distributions, Carissa M. Mobley

Student Publications

Birds’ annual cycles include biologically linked breeding and non-breeding seasons, yet most research and bird atlases focus exclusively on the breeding season. There have been very few winter bird atlas projects in North America, and none have been published for the northeastern United States. Short daylight hours and harsh weather limit winter survey coverage, making species distribution models (SDMs) essential for addressing spatial gaps.

I evaluated the optimal spatial scale for SDMs across bird species differing in body size and tested whether optimal scale varies with body mass. Using 16,967 eBird checklists collected during the first winter survey period (December …

Tracking Phenological Shifts Of Black Guillemots Cepphus Grylle In The Gulf Of Maine, Jocelyn L. Little

Student Publications

Rapid warming in the Gulf of Maine has coincided with changes in phenology across trophic levels. Phenological change has yet to be studied in black guillemots (Cepphus grylle), a widely distributed benthic forager that is showing population decline in the region. Because black guillemots nest in burrows, their phenology can be challenging to study. I developed methods to track black guillemot phenology on Petit Manan Island, a seabird breeding colony in the Gulf of Maine. Specifically, I asked Q1) Can daily tower count data be used to predict black guillemot breeding phenology? Q2) How is black guillemot breeding phenology shifting …

Common Terns (Sterna Hirundo) As Bioindicators For Atlantic Herring (Clupea Harengus) Distribution In The Gulf Of Maine, Logan R. Becker

Student Publications

Effective fisheries management is increasingly challenged by climate-driven shifts in species distribution and by a lack of data on early life stages of key forage fish species. In the Gulf of Maine, Atlantic herring (Clupea harengus), a once economically dominant fishery species and a key prey species for many dependent predators, has declined due to poor early-stage recruitment and warming waters. Despite this decline, current trawl surveys do not inform early-stage Atlantic herring distribution due to mesh size limitations, leaving critical gaps in our knowledge. To address this knowledge gap, I used common terns (Sterna hirundo) …

Little Island, Leah R. Nath

Student Publications

After spending two full months living on a remote island off the coast of Maine, I had a difficult time adjusting to mainland life again; the noise, the people, the lack of birds a shock to my system after getting used to such a different way of living. In this piece, I wanted to capture the feeling of becoming part of Petit Manan island, trying to learn the language of the land and the birds, and then the feeling of loss and change once I left. I hope readers can experience the feeling of falling in love with the island …

The Effects Of Phenological Shifts On The Reproductive Success Of Common Terns (Sterna Hirundo) And Arctic Terns (Sterna Paradisaea) In The Gulf Of Maine, Jamie W. Dinella

Student Publications

Climate change is resulting in ecosystem-wide consequences, including shifts in the geographical distribution of species and the timing of biological events, or phenology. The rapidly warming Gulf of Maine hosts breeding populations of migratory common terns (Sterna hirundo) and Arctic terns (Sterna paradisaea). I used nest check data (2013-2022) and eggshell membrane stable isotope data (2022) from Petit Manan Island in the Gulf of Maine to examine the causes and consequences of variation in phenology in common and Arctic terns. I hypothesized that the timing of an individual’s breeding was impacted by their foraging behavior and that female terns that …

A Method For Estimating Songbird Abundance With Drones, Andrew M. Wilson, Darren Glass, Marisa A. Immordino, Precious S. Ozoh, Lauren Sherman, Mckenzie D. Somers

Environmental Studies Faculty Publications

Using drones to conduct airborne bioacoustics surveys is a potentially useful new way to estimate the abundance of vocal bird species. Here we show that by using two audio recorders suspended from a quadcopter drone it is possible to estimate distances to birds with precision. In an experimental test, the mean error of our estimated distances to a broadcast song across 11 points between 0 and 100 m away was just 3.47 m. In field tests, we compared 1 min airborne counts with 5 min terrestrial counts at 34 count locations. We found that the airborne counts yielded similar data …

Leveraging Land Easements For Grassland Bird Habitat Conservation, Amy N. Marigliano, Hayden E. Dubniczki, Sarah W. Westrick

Student Publications

In addressing the decline of North American grassland bird populations, it is important to consider the various interdisciplinary approaches that can be employed in their conservation. OECMs, or “other effective area-based conservation measures” encompass a wide array of strategies which can be leveraged to conserve natural landscapes and species. Land easements implemented by the Land Conservancy of Adams County (LCAC) are an example of one such strategy. The LCAC seeks primarily to preserve the rural character of Adams County but has more recently turned their focus toward environmental conservation. In partnering with the Land Conservancy, this case study aimed to …

Spatial Models To Account For Variation In Observer Effort In Bird Atlases, Andrew M. Wilson, Daniel W. Brauning, Caitlin Carey, Robert S. Mulvihill

Environmental Studies Faculty Publications

To assess the importance of variation in observer effort between and within bird atlas projects and demonstrate the use of relatively simple conditional autoregressive (CAR) models for analyzing grid-based atlas data with varying effort. Pennsylvania and West Virginia, United States of America. We used varying proportions of randomly selected training data to assess whether variations in observer effort can be accounted for using CAR models and whether such models would still be useful for atlases with incomplete data. We then evaluated whether the application of these models influenced our assessment of distribution change between two atlas projects separated by twenty …

Changes In The Breeding Range Of The Broad-Winged Hawk (Buteo Platypterus) Due To Habitat Fragmentation In The Northern Appalachian Region, Rachael M. Pruitt

Student Publications

The Broad-winged Hawk (BWHA), Buteo platypterus, a small, secretive hawk with distinguishing broad black tail bands, breeds in northeastern North America. The hawks nest in deciduous or mixed forest, often near water, and close to clearings or forest edges. Land conversion and fragmentation alters the landscape and reduces the area of contiguous forest used by BWHA. This study seeks to determine the habitat metrics that may be influencing the apparent breeding range declines of the BWHA at the landscape scale. Landscape characteristics and BWHA presence data from 18,684 Breeding Bird Atlas blocks (each about 25km2) from Ohio, West Virginia, Maryland, …

The Feasibility Of Counting Songbirds Using Unmanned Aerial Vehicles, Andrew M. Wilson, Janine M. Barr, Megan E. Zagorski

Environmental Studies Faculty Publications

Obtaining unbiased survey data for vocal bird species is inherently challenging due to observer biases, habitat coverage biases, and logistical constraints. We propose that combining bioacoustic monitoring with unmanned aerial vehicle (UAV) technology could reduce some of these biases and allow bird surveys to be conducted in less accessible areas. We tested the feasibility of the UAV approach to songbird surveys using a low-cost quadcopter with a simple, lightweight recorder suspended 8 m below the vehicle. In a field experiment using playback of bird recordings, we found that small variations in UAV altitude (it hovered at 28, 48, and 68 …

The Feasibility Of Using Drones To Count Songbirds, Andrew M. Wilson, Janine M. Barr, Megan E. Zagorski

Environmental Studies Student Conference Presentations

Point and transect counts are the most common bird survey methods, but are subject to biases and accessibility issues. To eliminate some of these biases, we propose attaching a recorder to a consumer-grade quadcopter (Unmanned Aerial Vehicle, or UAV) to estimate songbird populations from audio recordings. We conducted a blind experiment using broadcast recordings to estimate the detection radius of a compact recorder attached to a UAV, and found that the detection radius did not vary significantly when the UAV was flown at elevations of 20, 40 and 60m. We field tested our system by comparing UAV-based bird counts with …