Life Sciences Commons^™

Agriculture Is Adapting To Phenological Shifts Caused By Climate Change, But Grassland Songbirds Are Not, Maeve M. Mcgowan, Noah G. Perlut, Allan M. Strong

Environmental Studies Faculty Publications

Migratory birds time their migration based on cues that signal resource availability for reproduction. However, with climate change, the timing of seasonal events may shift, potentially inhibiting the ability of some species to use them as accurate cues for migration. We studied the relationship between phenological shifts and reproduction by long- and short-distance migratory songbirds—Bobolinks (Dolichonyx oryzivorus) and Savannah Sparrows (Passerculus sandwichensis). Our study population breeds in hayfields and pastures in Vermont, USA, where farmers are also changing management activities in response to climate change. From 2002 to 2019, we monitored nest initiation dates to quantify …

Diverse Demographic Factors Influence Apparent Juvenile Survival In A Migratory Songbird, Emma M. White, Noah G. Perlut, Steven E. Travis, Allan Strong

Environmental Studies Faculty Publications

To better understand the dynamics of avian populations and their role in population trends, we require an in-depth understanding of the factors influencing the survival of adults and juveniles. How-ever, assessing survival in juveniles is often challenging, especially in small, migratory species where individuals typically disperse from the study area and are not available for recapture in subsequent years. Bobolinks (Dolichonyx oryzivorus) are a long-distance migrant that exhibits natal philopatry in at least one population, allowing for more comprehensive juvenile survival analyses than in many other long-distance avian migrants. Using a 17-yr dataset from two sites representing a …

Management Schemes, Not Philopatry Or Breeding Experience, Affect Nest Success Of Two Songbirds In Vermont Hayfields, Kylie Denny, Noah G. Perlut, Allan Strong

Environmental Studies Faculty Publications

Songbirds can benefit from natal philopatry through prior knowledge about site‐specific resources and local adaptation to environmental conditions. Likewise, breeding experience may also play a role in reproductive success. However, for birds that breed in managed habitats, management activities may overwhelm any potential benefits of philopatry or breeding experience. We examined the effect of site fidelity on reproductive success in 1,823 bobolink and Savannah sparrow nests in agricultural grasslands in Vermont, USA. From 2003–2019 we monitored the nests of 51 female Savannah sparrows and 72 female bobolinks that returned to breed on or near fields in which they hatched between …

Mixed Consequences Of Divorce On Reproductive Success Of Songbirds Nesting In Agricultural Hayfields, Kylee Dimaggio, Noah G. Perlut, Allan Strong

Environmental Studies Faculty Publications

Agricultural management, particularly haying, can cause synchronous nest failure of ground-nesting songbirds. As a consequence, these birds may subsequently renest and choose a new social mate (divorce). This study (1) quantified within-year and between-year divorce rates of grassland songbirds, and (2) determined if divorce rates differed after haying or predation-caused nest failure, and if so, whether divorce influenced reproductive success. From 2002 to 2017, we monitored 121 Bobolink (Dolichonyx oryzivorus) pairs and 436 Savannah Sparrow (Passerculus sandwichensis) pairs in an agricultural region of Vermont, USA. Within-year and between-year divorce rates were 0–84.9% for Bobolinks and 17–69.1% …

Light-Level Geolocation Reveals The Migration Route And Non-Breeding Location Of An Antillean Nighthawk (Chordeiles Gundlachii), Noah G. Perlut, Anthony Levesque

Environmental Studies Faculty Publications

The Antillean Nighthawk’s (Chordeiles gundlachii) migration routes and non-breeding location were previously unknown. We deployed a geolocator on a female Antillean Nighthawk found breeding on the Lesser Antilles island of Guadeloupe and tracked her annual movements between 2013 and 2014. Her journey included a 2-month stopover on Isla La Tortuga, Venezuela, during southward migration, and a non-breeding season in the remote forestlands of the state of Amazonas, Brazil, approximately 2,100 km south of her breeding grounds. Her migration route was geographically similar in both the fall and spring, following a north-south trajectory, but lacked a prolonged stopover in …

Migration Tactics Of A Long-Distance Migratory Songbird From Across A Continental Breeding Range, Rosalind Renfrew, Dan Kim, Noah G. Perlut, Michael D. Cadman

Environmental Studies Faculty Publications

Migration strategies in the avian world are often compared at the species level and evaluated relative to general ecology and constraints such as molting and breeding timetables. The advancement of tracking technology provides an opportunity to explore variation in more specific migration tactics within species and their populations as it relates to demographic and environmental factors throughout the annual cycle. We compare migration timing among 4 populations of Bobolink (Dolichonyx oryzivorus) from across the breeding range using data from light-level geolocators. The date of departure from the breeding grounds and the duration of southbound migration differed among breeding …

Heritability And Evolvability Of Morphological Traits Of Savannah Sparrows (Passerculus Sandwichensis) Breeding In Agricultural Grasslands, Jenna A. Cava, Noah G. Perlut, Steven E. Travis

Environmental Studies Faculty Publications

No abstract provided.

Weak Effects Of Geolocators On Small Birds: A Meta-Analysis Controlled For Phylogeny And Publication Bias, Vojtěch Brlík, Noah G. Perlut

Environmental Studies Faculty Publications

Currently, the deployment of tracking devices is one of the most frequently used approaches to study movement ecology of birds. Recent miniaturization of light-level geolocators enabled studying small bird species whose migratory patterns were widely unknown. However, geolocators may reduce vital rates in tagged birds and may bias obtained movement data. There is a need for a thorough assessment of the potential tag effects on small birds, as previous meta-analyses did not evaluate unpublished data and impact of multiple life-history traits, focused mainly on large species and the number of published studies tagging small birds has increased substantially. We quantitatively …

Latest Documented Fall Record Of Oporornis Agilis (Connecticut Warbler) In North America, Noah G. Perlut

Environmental Studies Faculty Publications

On 11 November 2017, a male hatch-year Oporornis agilis (Connecticut Warbler) was killed by a Felis catus (Domestic Cat) in Scarborough, Cumberland County, ME. This specimen, housed in the University of New England ornithological collection, is the latest documented fall record of this species in North America.

Prevalent Transoceanic Fall Migration By A 30-Gram Songbird, The Bobolink, Noah G. Perlut

Environmental Studies Faculty Publications

Three North American passerines are known to perform transoceanic flights during their fall migration, with open-water flights ranging in length from 1,700 to 3,400 km. However, little is known about within-population variation of these flights. From 2013 to 2017, I used geolocators to study variation in the fall migratory track of the Bobolink (Dolichonyx oryzivorus) from a population that bred in agricultural grasslands of Vermont, USA. Thirteen of seventeen birds took transoceanic flights during fall migration, ranging in length from 1,098 to 3,536 km (mean ± SD = 1,969 ± 640); five of these flights were nonstop from …

Age-Specific Differences In Fat Reserves And Migratory Passage Of Setophaga Striata (Blackpoll Warbler), Emily N. Filiberti, Noah G. Perlut

Environmental Studies Faculty Publications

Adequate fat reserves are vital for long non-stop transatlantic avian-migration movements, such as those made by Setophaga striata (Blackpoll Warbler). Over a 5-y period, we studied differences in preparedness (determined by presence of fat content and arrival time at stopover locations) between hatch-year (HY) and after hatch-year (AHY) Blackpoll Warblers at 3 stopover sites (Hancock and York counties in Maine, and Plymouth County in Massachusetts) covering 2.65° latitude along the Gulf of Maine. Migration timing varied across a latitudinal gradient and between age classes. In September, AHY Blackpoll Warblers were more abundant in the northern and central counties, but HY …

Haemosporidian Parasite Community In Migrating Bobolinks On The Galapagos Islands, Noah G. Perlut, Patricia G. Parker, Rosalind B. Renfrew, Maricruz Jaramillo

Environmental Studies Faculty Publications

Bobolinks (Dolichonyx oryzivorus) migrate from their breeding grounds in North America to their wintering grounds in South America during the fall each year. A small number of Bobolinks stop temporarily in Galapagos, and potentially carry parasites. On the North American breeding grounds, Bobolinks carry a least two of the four Plasmodium lineages recently detected in resident Galapagos birds. We hypothesized that Bobolinks carried these parasites to Galapagos, where they were bitten by mosquitoes that then transmitted the parasites to resident birds. The haemosporidian parasite community in 44% of the Bobolinks we captured was consistent with those on their …

Geolocator Data Reveal The Migration Route And Wintering Location Of A Caribbean Martin (Progne Dominicensis), Noah G. Perlut, Thomas C. Klak, Eldar Rakhimberdiev

Environmental Studies Faculty Publications

Caribbean Martins (Progne dominicensis) are common breeders on most Caribbean islands, where they regularly roost and nest in urban areas from February through August. However, from September through January, the basic ecology of this species--its migration and wintering locations--are largely unknown. In 2012, we deployed seven geolocators, and in 2014, we recovered one geolocator from a female Caribbean Martin on the Commonwealth of Dominica, a small eastern Caribbean island. Her wintering location was the western portion of the State of Bahia, Brazil, ~3550 km southeast of Dominica. Although the location of the non-breeding grounds changed minimally, the fall …

Winter Diet Of Bobolink, A Long-Distance Migratory Grassland Bird, Inferred From Feather Isotopes, Rosalind B. Renfrew, Jason M. Hill, Daniel H. Kim, Christopher Romanek, Noah G. Perlut

Environmental Studies Faculty Publications

Effective conservation of migratory bird populations depends on advancements in our understanding of processes throughout the life cycle. Fundamental information about wintering ecology (e.g., habitat use and diet composition) remains limited, which limits assessment of threats to populations during winter. Bobolink (Dolichonyx oryzivorus) is a year-round grassland obligate and Nearctic-Neotropical migrant that undergoes 2 complete molts each year, including a complete prealternate molt on the South American wintering grounds. This unusual winter molt provides a rare opportunity to examine, using stable isotope analysis, the timing and contribution of foraging resources in the Bobolink diet prior to northbound migration …

A Multicriteria Decision Analysis For Identifying Priority Conservation Areas For Grassland Birds, Flavio Sutti, Allan Strong, Noah G. Perlut

Environmental Studies Faculty Publications

Biodiversity conservation frequently competes with the needs of society for agricultural production and development. However, properly designed and efficiently implemented conservation programs can be used to integrate wildlife and human needs. We tested the efficacy of multicriteria decision analysis as a tool to select priority areas for conservation in human-dominated landscapes using grassland birds in the northeastern US as a test case. We created detailed GIS layers including landscape- (forest, grassland, development, and roads within a 3000-m buffer around each grassland patch) and patch-level (size, management, and conservation status) criteria important in grassland bird habitat selection and conservation. We developed …

Stopover On Galapagos During Autumn Migration Of Bobolinks (Dolichonyx Oryzivorus), Noah G. Perlut, Rosalind Renfrew

Environmental Studies Faculty Publications

The Bobolink (Dolichonyx oryzivorus) is the only landbird species that is known to stop every year in Galapagos while migrating; however, its stopover ecology while on the islands is unknown. In October 2015, we searched for and captured Bobolinks in the highlands of San Cristóbal. We found Bobolinks in two fields, separated by 9.15 km, at ∼425 m elevation. Average daily counts of Bobolinks on these two fields were 3.2 ± 1.8 and 4.8 ± 2.3 individuals. We caught nine individuals; body mass and fat reserves varied from 22.5–40.0 g and no fat reserves to 50–100% reserves, respectively. …

Why Come Back Home? Investigating The Proximate Factors That Influence Natal Philopatry In Migratory Passerines, Jenna A. Cava, Noah G. Perlut, Steven E. Travis

Environmental Studies Faculty Publications

Knowledge of which cues attract birds back to natal areas is important for conservation because the cues could be manipulated to attract breeders to source habitat or discourage breeders from settling in sink habitat. We examined the influence of intrinsic and extrinsic variables on natal philopatry using two metrics, short-distance natal dispersal and the probability of philopatry to the natal field, in two obligate-grassland bird species breeding in an agricultural landscape: the bobolink, Dolichonyx oryzivorus, and the Savannah sparrow, Passerculus sandwichensis. During 2002–2014, we detected 90 locally hatched Savannah sparrows and 129 locally hatched bobolinks breeding as adults …

Comparative Analysis Of Factors Associated With First‐Year Survival In Two Species Of Migratory Songbirds, Noah G. Perlut, Allan M. Strong

Environmental Studies Faculty Publications

Our understanding of the full life cycle of most migratory birds remains limited. Estimates of survival rates, particularly for first‐year birds are notably lacking. This knowledge gap results in imprecise parameters in population models and limits our ability to fully understand life history trade‐offs. We used eleven years of field data to estimate first‐year apparent survival (φ_1st) for two species of migratory grassland songbirds that breed in the same managed habitats but have substantially different migration distances. We used a suite of life‐history, habitat and individually‐based covariates to explore causes of variation in φ_1st. The interaction …

Roof-Top Nesting In A Declining Population Of Herring Gulls (Larus Argentatus) In Portland, Maine, Usa, Noah G. Perlut, David N. Bonter, Julie C. Ellis, Margaret S. Friar

Environmental Studies Faculty Publications

A number of colonial waterbird species have been documented nesting on roof-tops throughout Europe and North America. The most common hypothesis explaining why gulls (Laridae) select roof-tops for nesting has been that population growth rates are higher than territory vacancy rates in traditional (island) habitat, suggesting that roof-tops are a non-preferred habitat. Roof-top habitat may actually be equal to or higher quality than island habitat as anthropogenic food is abundant and lower nest density may lead to lower intraspecific aggression and predation. During 2011–2012, reproductive effort and success was monitored in a regionally declining population of Herring Gulls (Larus …

Morphological Variation Among Herring Gulls (Larus Argentatus) And Great Black-Backed Gulls (Larus Marinus) In Eastern North America, Gregory J. Robertson, Sheena Roul, Karel A. Allard, Cynthia Pekarik, Raphael A. Lavoie, Julie C. Ellis, Noah G. Perlut, Antony W. Diamond, Nikki Benjamin, Robert A. Ronconi, Scott G. Gilliland, Brian G. Veitch

Environmental Studies Faculty Publications

Herring Gull (Larus argentatus) and Great Black-backed Gull (L. marinus) morphometric data from various eastern North American locations was collected to examine the sources of variation in body size within and among geographic regions. For Herring Gulls, significant differences in all commonly taken measurements at local and regional scales were found. However, most of the variation in measurements was due to sex differences and the natural variance seen within local populations. Herring Gulls breeding in the Arctic did not show any evidence of being morphologically different from other groups. A discriminant function derived from a Newfoundland, …

Bobolink (Dolichonyx Oryzivorus), Stephen G. Martin, Thomas A. Gavin, Rosalind Renfrew, Allan M. Strong, Noah G. Perlut

Environmental Studies Faculty Publications

Bobolink (Dolichonyx oryzivorus)
Order:PASSERIFORMES
Family: ICTERIDAE

Includes the following information: Introduction, Appearance, Systematics, Distribution, Migration and Habitat, Diet and Foraging, Sounds and Vocal Behavior, Behavior, Breeding, Demography and Populations, Conservation and Management, Priorities for Future Research, Acknowledgments, About the Author(s), Multimedia, Tables and Appendices, References

Sustaining The Saco Estuary: Final Report 2015, Christine B. Feurt Ph D, Pamela A. Morgan, Mark D. O. Adams, Anna L. Bass, Carrie J. Byron, Michael C. Daley, Michael O. Esty, Noah G. Perlut, Kayla Smith, Tyler Spillane, Michelle M. Steen-Adams, James Sulikowski, Stephan I. Zeeman, Jacob Aman, Michele Dionne, Jeremy Miller, Kristin Wilson

Environmental Studies Faculty Publications

This study focuses on the Saco estuary, the tidal portion of the Saco River, which drains the largest watershed in southern Maine. With headwaters in the White Mountains of New Hampshire, the watershed encompasses more than 4,400 km², and provides clean healthy drinking water to over 100,000 people living and working in communities in southern Maine.

When the study began in 2009, very little was known about the ecology of the Saco estuary. Researchers at the University of New England and the Wells National Estuarine Research Reserve employed the process of collaborative learning to bring together people who …

Brood Provisioning And Nest Survival Of Ardea Herodias (Great Blue Heron) In Maine, Margaret M. Meserve Auclair, Kathryn A. Ono, Noah G. Perlut

Marine Sciences Student Publications

From 1983–2009, the number of coastal breeding pairs of Ardea herodias (Great Blue Heron [GBHE]) in Maine declined by 64%, and the number of occupied islands on which these birds bred declined by 40%. The Maine Department of Inland Fisheries and Wildlife listed the GBHE as a species of special concern in 2007, and expanded its annual monitoring to include inland colonies in 2009. To assess regional demographic differences, we compared the relationship between brood provisioning and nest survival of GBHEs in 1 coastal and 1 inland colony. In terms of brood-provisioning within the 2 colonies, the inland colony had …

Male Savannah Sparrows Provide Less Parental Care With Increasing Paternity Loss, Noah G. Perlut, Lindsay M. Kelly, Nathan J. Zalik, Allan M. Strong

Environmental Studies Faculty Publications

Male parental care can significantly affect fledging success and, therefore, is a strong target of both natural and sexual selection. However, for songbird species that exhibit extra-pair paternity, males may reduce parental care based on how much paternity they have lost in a brood. We studied Passerculus sandwichensis (Savannah Sparrow) male parental care relative to the proportion of extra-pair young in the nest, to see if males adjusted care in response to increasing loss of paternity. Males brought less food (mass) with increasing rates of extra-pair paternity, although male provisioning did not influence fledging success. These results contrast with a …

Aggressive Response Of Adult Bobolinks To Neck Ligatures On Nestlings, Lynn P. Little, Allan M. Strong, Noah G. Perlut

Environmental Studies Faculty Publications

We monitored provisioning behavior at 18 Bobolink (Dolichonyx oryzivorus) nests during 240.5 min of videotape data from June to July 2006, and observed 64 nest visits by adults while nestlings were fitted with neck ligatures. Adults pecked or pulled at the ligatures, often aggressively, at 72% of nests (n = 18) and 52% of visits (n = 64). These behavioral responses by adults indicate the neck ligature technique is more invasive than previously believed. We documented no mortality as a result of ligature placement, but researchers should minimize the time that ligatures are in place to reduce stress …

The Potential Of Uncut Patches To Increase The Nesting Success Of Grassland Songbirds In Intensively Managed Hayfields: A Preliminary Study From The Champlain Valley Of Vermont, Roger J. Masse, Allan M. Strong, Noah G. Perlut

Environmental Studies Faculty Publications

Changes in land use and intensification of agricultural practices are associated with declines of grassland songbird populations in North America. Hay harvests in the northeastern United States are occurring earlier and more frequently today than 30 years ago, resulting in substantially decreased nesting success of grassland songbirds on early-hayed fields. Few studies have examined whether uncut patches within fields cut during the breeding season can increase the nesting success of grassland songbirds. Twenty-nine artificial nests were placed in 17 uncut patches (mean = 0.337 ha, median = 0.103 ha) on four early-hayed fields in Shelburne, VT. Only one of the …

Simultaneous Incubation By Two Females And Nestling Provisioning By Four Adults At A Savannah Sparrow Nest, Nathan J. Zalik, Noah G. Perlut

Environmental Studies Faculty Publications

We present the first observations of misdirected parental care by Savannah Sparrows (Passerculus sandwichensis) including a rare occurrence of simultaneous incubation. Two females simultaneously incubated eggs, brooded, and fed nestlings, and two males fed nestlings in one nest. These behaviors may have been prompted by strong parental instincts in combination with a stressful breeding environment mediated by hayfield management, as any genetic benefits were unlikely.

Distribution Of Foraging Shearwaters Relative To Inner Front Of Se Bering Sea, J. Jahncke, K. O. Coyle, Stephan I. Zeeman, N. B. Kachel, G. L. Hunt Jr.

Marine Sciences Faculty Publications

We examined the hypothesis that short-tailed shearwaters Puffinus tenuirostris aggregate to forage at the inner front of the SE Bering Sea because of enhanced production there. We tested this hypothesis by comparing primary production, the distribution of euphausiids and the distribution of shearwaters relative to the front during late spring and late summer/early fall of 1997, 1998 and 1999. We found enhanced primary production at the front and offshore of the front during summer but not during spring. Primary production varied between seasons and years. Major differences were related to anomalous conditions in 1997 and 1998. The density of euphausiids …