Posters
Update (posted at 4:00 pm on August 18): The MOS Convention Committee will be updating the website with new information as it becomes available.
We will have a poster session on Saturday, Sept. 26 during our 4:00 – 6:00 pm social at the DoubleTree by Hilton in Salisbury, MD. The posters will cover avian topics by researchers or birders who are based in Maryland or nearby. We hope that this will be an opportunity for researchers and birders from our area to network, socialize and perhaps spark new projects or expand existing ones.
If you are interested in participating, please contact Robin Todd at robin.todd@mdbirds.org.
Sincerely,
Robin Todd
MOS Convention Committee
2026 Poster Summaries for the 78th Annual MOS Convention in Salisbury, MD
Impact of Age, Success, and Human Disturbance on Nest Site Fidelity in Eastern Bluebirds
Kiersten Newtoff & Kevin Omland, University of Maryland, Baltimore County
In Maryland, Eastern Bluebirds (Sialia sialis) breed twice, sometimes three times if they started earlier in the season. After a nest attempt, bluebirds are faced with a decision: to start the next attempt in the same cavity or to move to a different cavity. We color banded hundreds of Eastern Bluebirds in central Maryland that used artificial nest boxes and followed their movements and nest attempts in the 2025 and 2026 breeding season. We investigated how age, nest success, and the surrounding environment affected their movements during the season.
Non-breeding season spatial use and behavior of Eastern Bluebirds in Maryland
Alan Reich and Kevin Omland, University of Maryland, Baltimore County
I will present the results of an exploratory pilot study to track Eastern Bluebirds through the non-breeding season using radio telemetry and resight surveys. I mapped spatial use and collected behavioral observations of non-breeding season resident bluebirds in Maryland from September, 2025 to March, 2026. Most birds in our study stayed remarkably close to nest boxes they were known to have used throughout the non-breeding season. Preliminary data suggests bluebirds at our study sites may maintain year-round territories. This work exemplifies the study of full annual cycle biology in a resident cavity nesting songbird.
Defining Closure in Acoustic Bird Surveys Using Dynamic Occupancy Models
Yonah Meyers & Alice Besterman, Towson University
Occupancy modeling is an increasingly popular statistical tool for analyzing data from autonomous recording units (ARUs). However, standard occupancy models assume a site to be closed within the survey period, an assumption often violated by mobile species. Dynamic occupancy models allow occupancy to open between primary periods while detection is calculated within closed, secondary periods. Two models were fit using detection data from eight ARUs deployed at Irish Grove Sanctuary across five days, recording 30 minutes every sunrise. The standard model defined an occasion as five minutes, while the dynamic model had a primary period of days and a secondary period of five minutes. Comparing the models shows the standard model generally estimated higher occupancy and lower detection rates because it explains closure violations as imperfect detection rather than absence. It is vital that future ARU studies appropriately assign dynamic occasions to give a more accurate understanding of species’ occurrence.
Welcome to the MOS Sanctuaries
Jeremy Castle, MOS Sanctuaries Chair
An often forgotten aspect of MOS is that we own 10 sanctuaries across Maryland totally over 2,300 acres. These sanctuaries are not only great places to bird, hike, and observe nature, but members can also do overnight stays at two properties. Stop by the poster session to learn more about the conservation and research taking place at your MOS sanctuaries and how you can be more involved.
Winter Crow Roosts at North Bethesda Maryland and Shirlington Virginia
James Wilson
Winter crow roosts are a remarkable aspect of crow social behavior during the non-breeding seasons, in which thousands of crows (both American and Fish crows) gather in a dense communal group overnight. Each morning they stream out for foraging to locations that may be 10 or more miles away and return for noisy and active evening crow “happy hours” before collecting in the roost for the night. James Wilson has observed the North Bethesda, Maryland roost for decades and has studied winter crow roosts more generally over the past few years. His poster will provide images and details about the roost located at North Bethesda (estimated at 30,000 crows) and also Shirlington, Virginia (15,000 crows), including the daily crow movements as captured on weather radars back to 1992. The poster will also touch on the challenges that arise when crows choose urban areas for their roosts, as they have, increasingly, since the 1970s.
Conservation status of the world’s owls
Steven R. Sheffield (srsheffield@comcast.net)
Owls occur worldwide except for Antarctica, and are ecologically significant predators in global ecosystems. Unfortunately, many owl species are greatly declining, and more than half of owl species are without any population estimate. At least a quarter of all owl species are IUCN red listed (Critically Endangered, Endangered, Vulnerable, Neat Threatened, and Data Deficient), and at least 5 species are known to be recently extinct. The genus Otus is most represented on the IUCN red list with 23 species, followed by the genus Ninox with 14 species. More than half of the species in the Family Tytonidae (barn owls), with 20 species, are declining, and none of them are increasing. An examination of the global owl distribution through GIS digitized range maps shows diversity hotspots in W Mexico, S Brazil, W and SC Africa, and NE and SE Asia. These areas are all prone to a rapidly increasing human population on top of many other threats, including habitat destruction, illegal killing, and pesticide poisoning, among others. Insular owl species have faced the greatest threats by a wide margin. GIS was used to layer owl digital range maps with Protected Areas of the world. This analysis shows that owls vary widely in the portion of their range which was found in Protected Areas. The importance of Protected Areas in conserving the world’s owls cannot be understated – they are among the best ways of doing so and, in the process, benefitting local environments.
Continuous Acoustic Monitoring Reveals Previously Undetected American Barn Owl at a Maryland Piedmont Restoration Site
Samar Mathur & Michael Greer – Mallorn Labs
The American Barn Owl (Tyto furcata) is a Maryland Species of Greatest Conservation Need and a focal species of the Farmland Raptor Program. The species is difficult to detect through conventional surveys: it vocalizes primarily at night, ranges widely, and calls infrequently, making it largely invisible to diurnal point counts.
We deployed autonomous recording units (ARUs) at an actively managed early-successional restoration site in the Maryland Piedmont, primarily to monitor shrubland obligate songbirds against the site’s spring count record. Units recorded continuously through the 2026 breeding season, generating thousands of recording-hours. Confirmation was provided through the Audubon Society of Central Maryland and the Maryland Bird Conservation Partnership’s Farmland Raptor Program.
To make this volume of audio tractable, we used Durin (Mallorn Labs), a passive acoustic monitoring platform that enables continuous 24-hour recording by processing raw audio through automated data reduction and detection. The pipeline produces species-level detections with audio and spectrograms for manual verification, reducing thousands of recording-hours to a reviewable set of candidate vocalizations.
The pipeline produced over 200 confirmed American Barn Owl detections, the first documented occurrence in the site’s monitoring history. Vocalizations are consistent with an advertising male maintaining territorial presence. The finding demonstrates how automated, continuous acoustic monitoring can reveal species of conservation concern that are difficult to detect. Site-specific location is withheld per sensitive species protocol.
Investigating Changes in Nest Success and Habitat Quality of Two Marsh Sparrows Across a Fragmenting Salt Marsh
Evan Powers & Dr. Alice Besterman, Towson University
Avian marsh specialists, such as the Saltmarsh Sparrow (Ammospiza caudacuta, SALS) or Seaside Sparrow (Ammospiza maritima, SESP), are experiencing rapid population declines associated with increasing rates of high-tide nest flooding. SALS are obligate tidal-marsh specialists that nest in specific grasses such as Spartina patens, whereas SESP are less specialized but may also be vulnerable to increased nest-flooding. While tidal flooding plays a direct role in sparrow nest failure, ultimate nest fate may be indirectly impacted by microhabitat quality and nest placement. Accelerating relative sea-level rise (RSLR) has been shown to degrade marsh vegetation through prolonged inundation and expanding interior marsh pools, which may result in lower “quality” habitat or decreased available habitat. To investigate the effects of interior marsh fragmentation on sparrow nest success and to quantify nest-habitat quality, we conducted avian demographic and vegetation surveys at Irish Grove Sanctuary in Somerset County, MD. We classified microhabitat “quality” at nest sites, at random points, and along transects adjacent to pools. During our first field season, 43% (n = 6) of SALS nests were successful, and 21% (n = 3) failed due to flooding. In contrast, 70% (n = 16) of SESP nests were successful, and 4% (n = 1) failed due to flooding. Despite higher nest success and fewer flooding-related failures in SESP, nest heights did not differ significantly between species. Next steps of our analysis include investigating specific nest characteristics such as Leaf Area Index (LAI) or thatch integrity.
Runnels as a marsh restoration strategy at Irish Grove Sanctuary – Marshes for Tomorrow
David Curson, Bri Panos, Henrietta Bellman, Jesse Baird, (Audubon Mid-Atlantic) Sophia Seufert (US Fish and Wildlife Service)
Climate-driven sea level rise is contributing to the deterioration of salt marshes on Maryland’s Lower Eastern Shore. The Maryland Ornithological Society’s Irish Grove Sanctuary, in Somerset County, is experiencing marsh vegetation die-off and increasing ponding and is the site of a marsh restoration project, co-led by Audubon and the U.S. Fish and Wildlife Service. In Fall 2026, runnels will be excavated by hand at Irish Grove to relieve excessive waterlogging and allow marsh plants to recover. Irish Grove is ideal for restoration due to the extent of high-quality high marsh habitat that is key for breeding salt marsh specialist birds like the Saltmarsh Sparrow (Ammospiza caudacuta). This is the first implementation project of the Marshes for Tomorrow initiative led by Audubon Mid-Atlantic.
Creating Natural and Artificial Islands are necessary for Species Recovery
Kim Abplanalp, Bird Habitat Coordinator, Maryland Coastal Bays Program
Six years ago, DNR’S Heritage Service, Audubon Mid-Atlantic and Maryland Coastal Bays Program embarked on an effort to save three, State-listed Endangered Species: the Common Tern, Royal Tern and Black Skimmer, by creating the Bird Habitat Program at its host, Maryland Coastal Bays.
The first initiative was building an artificial island as a stop-gap measure while island restoration was being designed, permitted and installed. The “tern raft,” in it’s sixth year, has been a success story, having over 350 nesting pairs consistently after it’s third year. Just completing its sixth year, it hosted 376 pairs, its largest number yet and reaching its carrying capacity.
Two new natural breeding locations have been installed in the last two years, Reedy Beach and West Reedy. It has a new colony of Common Terns which hosted 88 nests in its second year. We have recovered the coastal COTE breeding population to ~475 pairs; this is where we were back in the early 2000s, and half the amount of 40 years ago. It is the result of the combination of the tern raft and restoration work at Reedy Island.
Our continued focus on building small islands for the recovery of these species is our highest priority to keep these iconic species in the coastal bays of Maryland.