Animal Sciences Commons^™

Does Urbanization Surrounding Stopping Sites Affect Migratory Behavior In American Woodcock (Scolopax Minor)?, Zoe Pavlik

Honors College

Urban landscapes may influence bird species in complex ways, with some species exploiting urban environments, others adapting to them, and others avoiding them. Migratory birds encounter urbanization not just during breeding and overwintering, but also at stopping sites during migration. Migration routes of American Woodcock (Scolopax minor), a bird species experiencing long term population declines, follow the east coast of the United States, including the major urbanized areas of the eastern seaboard. I explored the effects of urbanization around stopping sites on Woodcock migratory behavior using the percentage of impervious surfaces within a buffer surrounding the site as a measure …

Riders On The Storm: Using Satellite Transmitters To Quantify American Woodcock Movement Behavior Following Extreme Weather Events, Katherine Trebilcock

Honors College

The American Woodcock (Scolopax minor) has experienced steady declines in abundance over the past fifty years, which has raised questions as to why (Sauer et al. 1991). Migration for many birds, woodcock included, is energetically intensive, and may be the cause for greater mortality compared to other times of the year (Newton 2007). Despite this, there remains uncertainty in how conditions encountered during migration affect their movements and survival. One obstacle that birds must face is extreme weather, which has been increasing in intensity and occurrence due to climate change. How these events impact a migrating woodcock has been speculated …

Variations In Plumage Wear In Three Closely Related Tidal Marsh Sparrow Species, Maeve Studholme

Honors College

Tidal marsh sparrow species like Saltmarsh Sparrows (Ammospiza caudacuta), Nelson’s Sparrows (Ammospiza nelsoni) and Seaside Sparrows (Ammospiza maritima) are particularly vulnerable to the environmental stressors related to climate change and human activity like sea-level rise, warming temperatures, and increased coastal development, as they nest in the grasses of tidal marsh ecosystems where the principal mode of nest mortality is flooding. With increased sea-level rise, these species may not be equipped to adapt to changing tidal cycles, and thus have reduced fitness and population sizes. Saltmarsh Sparrows are experiencing sharp declines in population, so it is more vital than ever to …

S5e11: Why Might Maine Lose Two Species Of Songbirds?, Ron Lisnet, Katherine Ruskin, Brian Olsen

The Maine Question

Maine may lose two tidal marsh songbird species in the next few decades. Saltmarsh sparrows face extinction, while Acadian Nelson’s sparrows are threatened with extirpation — localized eradication with the possibility of survival elsewhere. Their populations along the Eastern Seaboard have been declining as sea level rise destroys their habitats and, according to a new University of Maine-led study, mercury exposure inhibits their reproduction.

In the final episode of Season 5 of “The Maine Question,” Kate Ruskin, a lecturer in ecology and environmental science at UMaine who spearheaded the recent mercury exposure study, and Brian Olsen, who is now an …

Rapid: Ecological Resistance Of Multiply Stressed Populations: The Response Of Tidal Marsh Birds And Plants To Hurricane Sandy, Brian J. Olsen, Chris S. Elphick, Greg Shriver

University of Maine Office of Research Administration: Grant Reports

All animal and plant populations can weather change. However, the amount of environmental change a population can absorb is likely to depend upon other, past and ongoing stresses that the population experiences. This project will test whether the ability of populations of native plants and animals in coastal marshes to withstand the recent, extreme storm Hurricane Sandy was greater or less in marshes more subject to past stresses. Researchers will compare the abundances of marsh plants and animals before and after the storm and test whether vulnerability was greater in more specialized species or in marshes surrounded by development, invaded …

Territorial Aggression Increases Along An Urban Gradient In Resident But Not Migratory Song Sparrows, Darlene Turcotte

Honors College

During the breeding season, birds behave more aggressively toward rivals to maintain and defend territories. Resident birds are thought to be more aggressive than migratory birds because they need to maintain a territory year round. Furthermore, birds in urban environments can exhibit more aggressive behaviors than their rural counterparts because of the bolder behavioral characteristics required to colonize urban habitats. In this study, we investigated how migration strategy and landscape composition interact to affect territory defense in two subspecies of Song Sparrow (Melospiza melodia). To evoke an aggressive response, we simulated invasions by broadcasting songs from within a …

Habitat Occupancy Of Rusty Blackbirds (Euphagus Carolinus) Breeding In Northern New England, Usa, Luke L. Powell, Thomas P. Hodgman, Ian J. Fiske, William E. Glanz

Biology and Ecology Faculty Scholarship

The Rusty Blackbird (Euphagus carolinus), an uncommon songbird often associated with northern coniferous wetlands, has experienced a precipitous population decline since at least the early 20th century. Here, we provide the first analysis of breeding-habitat occupancy at the wetland scale and make recommendations for streamlined monitoring. We modeled occupancy and detectability as a function of site (i.e. habitat-based) and sampling (i.e. visit-specific) variables collected at 546 wetlands in northern New England, USA. Wetland occupancy (mean 6 SE ¼ 0.07 6 0.02 in randomly selected wetlands, and 0.12 6 0.02 in all wetlands surveyed) was best explained by variables …

Dissertation Research: The Role Of Breeding Hormones In Seasonal Interactions: How Do Birds Meet The Conflicting Demands Of Breeding Preparation And Migration?, Rebecca L. Holberton, Christopher Tonra

University of Maine Office of Research Administration: Grant Reports

Migratory birds complete different stages of their life cycle in locations that can be thousands of miles apart. Conditions during one stage can impose carry-over effects on subsequent stages. It is critical that researchers examine how environmental factors act as carry-over effects across different annual stages in order to fully understand how migratory bird populations are regulated. In the American redstart (Setophaga ruticilla), males wintering in superior quality habitats arrive earlier at the breeding grounds and have greater breeding success than those wintering in poor habitats. While these seasonal interactions are well documented, the underlying mechanisms are not …

The Effects Of White Noise Disturbance On Zebra Finch Behavior; Does Disturbance Predictability Matter?, Kathryn Chenard

Honors College

It is undeniable that the progress of human civilization has altered the natural landscape of the world in ways that range from the merely aesthetic to the irreparably destructive. Some impacts are patently obvious. Others may not be as obvious to the casual observer, and yet they can be just as important in terms of truly understanding not only our impact on the world around us, but how we can mitigate this impact.

One of the most far-reaching of these latter impacts is the increased and altered levels of background noise upon the natural acoustic landscape. These changes have the …

The Physiological Ecology Of Seasonal Interactions: How Do Wintering Ground Events Constrain Breeding Success In Neotropical Migrants?, Rebecca L. Holberton

University of Maine Office of Research Administration: Grant Reports

Migratory birds breed throughout the temperate regions of North America but winter in very different habitats further south. Although 1000 km or more may separate wintering from breeding areas, recent research has revealed that ecological conditions during winter can influence subsequent reproductive success. The major objective of this research is to investigate the underlying physiological factors linking winter events with an individual's ability to breed. The American redstart (Setophaga ruticilla) is an excellent study animal: its ecology and behavior during the wintering and breeding periods have been intensively studied. The degree to which redstarts prepare for breeding, and …

Home Ranges Of Rusty Blackbirds Breeding In Wetlands: How Much Would Buffers From Timber Harvest Protect Habitat?, Luke L. Powell, Thomas P. Hodgman, William E. Glanz

Biology and Ecology Faculty Scholarship

We calculated the home ranges and core areas of 13 adult Rusty Blackbirds (Euphagus carolinus) in Maine to determine (1) the area requirements of breeding adults, (2) whether area requirements of the sexes and of colonial and noncolonial individuals differ, and (3) the proportion of the home range and core area that would be protected by a buffer of no logging of 50–100 m around occupied wetlands. Mean home ranges (37.5 ± 12.6 ha) and core areas (11.1 ± 2.8 ha) were large in comparison to those of other breeding icterids, and adults often foraged in multiple unconnected wetlands. Rusty …

Nest-Site Selection And Nest Survival Of The Rusty Blackbird: Does Timber Management Adjacent To Wetlands Create Ecological Traps?, Luke L. Powell, Thomas P. Hodgman, William E. Glanz, James D. Osenton, Caleb M. Fisher

Biology and Ecology Faculty Scholarship

Animals are subject to ecological traps when anthropogenic changes create habitat that appears suitable but when selected results in decreased fitness. The Rusty Blackbird (Euphagus carolinus) breeds in boreal wetlands and has declined by 85–95% over the last half century. We studied nest-site selection and daily nest survival rate (DSR) of 43 Rusty Blackbird nests in northern New England and evaluated whether regenerating logged areas adjacent to wetlands created ecological traps. Although nesting adults avoided high-canopied forests and selected areas with dense balsam fir (Abies balasmea) 1 to 3 m high, those characteristics were not associated …

Behavioral And Physiological Differences In Migratory Strategies Of A Long-Distance Migrant, The Blackpoll Warbler, And A Facultative Short-Distance Migrant, The Yellow-Rumped Warbler, Rebecca L. Holberton

University of Maine Office of Research Administration: Grant Reports

The primary focus of these studies has been to investigate the functional role of corticosterone in the development of migratory condition (i.e. hyperphagia, lipogenesis, and migratory restlessness) and to investigate the underlying endocrine mechanisms of migratory condition in two species that differ dramatically in their strategies for reaching their wintering grounds. The main approach has been to measure and to manipulate the peripheral signal molecule, corticosterone, and look at the resulting patterns of feeding behavior, body mass and fat reserves, migratory activity, and metabolites of energy use (fat deposition and protein use). In the comparative component, the Blackpoll warbler (Dendroica …

Assessment And Choice: An Operant Simulation Of Foraging In Patches, John P. Roche, D. Alan Stubbs, William E. Glanz

Biology and Ecology Faculty Scholarship

Pigeons were presented with an operant simulation of two prey patches using concurrent random ratio schedules of reinforcement. An unstable patch offered a higher initial reinforcement probability, which then declined unpredictably to a zero reinforcement probability in each session. A stable patch offered a low but unvarying reinforcement probability. When the reinforcement probability declined to zero in a single step, the birds displayed shorter giving-up times in the unstable patch when the ratio between the initial reinforcement probabilities in the unstable and stable patches was greater and when the combined magnitude of the reinforcement probabilities in the two patches was …