TWEL Current Research

TWEL Current Research


Eastern Massasauga Rattlesnake: Ohio Population Survey and Survey Technique Development

Evan Amber, M.S. Candidate

Advisor:  William Peterman  


Evan's thesis, supported by The Ohio Department of Transportation, is to modify and test the Adapted-Hunt Drift Fence Technique as a non-invasive and cost-effective alternative survey method for the endangered eastern Massasauga rattlesnake in northeastern Ohio. With our adaptation of this method, developed by Martin et al. in 2017, snakes will be guided along a Y-shaped drift fence to inverted buckets containing a camera trap.

TWEL Evan Amber

Funded by: The Ohio Department of Transportation


Filling in the Gaps for Full Annual Cycle Conservation of the Prothonotary Warbler: Phenology, Post-Fledging Survival, and Links to the Winter Grounds

Elizabeth M. Ames, M.S. Candidate

Advisor:  Christopher Tonra  

Summary: Every year thousands of birds migrate between the breeding grounds, in temperate North America, and the wintering grounds in tropical Central America. Many of these Neotropical migrants complete the various stages of their annual cycle thousands of kilometers apart, and events in one of these stages can effect events in a subsequent stage. Understanding these “carry-over effects” is fundamental to understanding changes in migratory populations and the conservation of those populations, as many are in enigmatic decline. The objective of my research is to explore carry-over effects between wintering and breeding events, and elucidate an unexamined life-cycle stage in a migratory bird of conservation concern, the Prothonotary Warbler (Protonotaria citrea). My research will take place across the Hoover Nature Preserve which hosts the largest breeding population in Ohio. There, I will examine three important aspects of their ecology to test the hypothesis that carry-over effects from winter habitat limits post-fledging survival through impacts on arrival and breeding timing. First, I will determine if arrival timing to breeding grounds is winter habitat dependent using stable isotopes in bird claws to estimate winter habitat wetness and thereby quality. Second, I will track breeding timing and fledging success relative to arrival time and winter habitat quality. Lastly, I will use radio telemetry to estimate post-fledging survival as a function of phenology and winter habitat quality. My research will fill important gaps in the ornithological knowledge of the Prothonotary Warbler’s full annual cycle and guide forested wetland bird conservation across the Americas.

Funded by: The Ohio State University, OARDC SEEDS Grant, Columbus Audubon, Explorer's Club, Association of Field Ornithologists, Ohio Avian Project Initiative, USFWS.


The Impact of Amur Honeysuckle (Lonicera maackii) Removal on Avian Assemblage Composition

Leanna DeJong, M.S. Candidate


Advisor: Stephen N. Matthews


Since its introduction to North America in the late 1880s, Amur honeysuckle (Lonicera maackii) has become highly invasive in the midwestern and northeastern regions of the United States. This shrub is highly adaptable, outcompeting native vegetation to create monoculture thickets. Besides negatively impacting plant communities, Amur honeysuckle can represent an ecological trap: lowering songbird reproductive success by falsely appearing to be a productive nest site. The shrub can also impact avian species composition. Generalists and understory (e.g. shrub-nestors) species seem to prefer Amur honeysuckle-abundant areas while canopy species and others do not. Due to its detrimental effects on ecosystems, many managers have invested substantial effort towards removing Amur honeysuckle. Albeit studies have explored the impact that this shrub has on avian species, few have investigated how birds might be influenced by its removal, especially in rural areas. The objective of my research is to explore how recent removal of Amur honeysuckle affects the composition of avian assemblages in rural riparian forests, areas that provide vital refuges in homogeneous landscapes dominated by agriculture. A better understanding of how Amur honeysuckle removal alters avian assemblage composition will help inform managers and optimize management strategies.

TWEL Current, DeJong


Population Ecology, Habitat Relationships, and Survey Methodology of Sora and Virginia Rails in Northwestern Ohio 

James Hansen, M.S. Candidate

Advisor: Robert Gates  
Summary: The amount of wetland habitat across North America has declined heavily over the last century. The Virginia rail and sora are two species of wetland-dependent birds that are part of a guild of birds known as secretive marsh birds that inhabit wetlands across the United States and Canada. Populations of secretive marsh birds are thought to have been declining and negatively impacted by the monumental wetland loss across the North American continent. However, the populations status of many secretive marsh bird species is not well understood due to their cryptic behavior and the densely vegetated habitats they occupy. In 2011,  the North American Marsh Bird Monitoring Protocol was established to survey and monitor secretive marsh birds across the continent, however, concerns over the limitations of this survey have arisen due to these birds’ low detectability, variable calling rates, intra-seasonal movements, and a number of other factors.  I aim to test this survey and investigate the relationship between rail population ecology and bird movements, calling behavior, and fluctuations in environmental variable.  This research will provide modifications for the marsh bird survey in an Ohio context and help inform wildlife managers on the implications of harvest regulations and wetland habitat management for the Virginia rail and sora.
Funding Source: Funding  provided by the Federal Aid in Wildlife Restoration Program (W-134-P, Wildlife Management in Ohio), and administered jointly by the U.S. Fish & Wildlife Service and the Ohio Division of Wildlife.  


Demographics and distribution of the Northern bobwhite and other birds of early-successional habitat

Connor J. Rosenblatt, M.S. Candidate

Advisors: Stephen N. Matthews and Robert Gates  

Birds of early-successional habitat are one of the most rapidly declining groups of birds across North America. This is primarily due to the loss of young-forest and shrubland habitat. In eastern North America, habitat loss has been primarily due to processes such as regeneration of mature forests, altered disturbance regimes, and agricultural intensification. One particular shrubland bird of conservation interest is the Northern bobwhite (Colinus virginianus). Across their range, bobwhites have been declining at an alarming rate for the past several decades. Declines in Ohio have been particularly acute, and research has found that these populations suffer high winter mortality during periods of extreme snowfall. Given the social and economic importance of the bobwhite as a gamebird species, much effort and support has been given towards bobwhite conservation, yet despite this, populations in Ohio continue to decline. My project is focused into two components. First, in order to help inform managers on the most effective way to manage bobwhite populations, I seek to employ a novel population modeling technique known as integrative population modeling. Utilizing existing data on abundance and life-history demographics, I seek to model bobwhite population dynamics and relate this to weather and habitat covariates. Doing so will allow me to predict the future population growth rate and understand which aspects of the bobwhite’s annual life cycle have the greatest influence on the population growth rate. Given projected future climate change, understanding the relationship between demographic parameters, weather, and population growth will be crucial for effective bobwhite management in a changing future. The second part of my project is focused on examining the relationship between landscape characteristics and the distribution of other early-successional birds in areas where bobwhites persist. Previous work has suggested that, because of their need for a heterogenous landscape, managing land for bobwhites may benefit other non-target shrubland bird species with similar habitat requirements. Because of their broad habitat requirements and the amount of conservation attention they receive, bobwhites have potential to serve as an umbrella species for a whole suite of early-successional birds. Thus, in order to assess the potential for this, I will be seeking to model the relationship between bird distributions and various components of landscape composition and configuration. I will be focusing on landscapes in southern Ohio where bobwhites are present, and examining whether the presence of bobwhites is a predictor for the presence of other bird species, and how both of these measures are related to landscape characteristics. Ultimately, I hope the findings from my project can help inform managers across the state as to how to better manage early-successional habitat for multiple species of conservation concern.

TWEL Current, Rosenblatt

View completed projects here.