The Experts below are selected from a list of 807 Experts worldwide ranked by ideXlab platform
Steve Kelling - One of the best experts on this subject based on the ideXlab platform.
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modeling avian full annual cycle distribution and population trends with citizen science data
Ecological Applications, 2020Co-Authors: Daniel Fink, Tom Auer, Alison Johnston, Viviana Ruizgutierrez, Wesley M Hochachka, Steve KellingAbstract:Information on species' distributions, abundances, and how they change over time is central to the study of the ecology and conservation of animal populations. This information is challenging to obtain at landscape scales across range-wide extents for two main reasons. First, landscape-scale processes that affect populations vary throughout the year and across species' ranges, requiring high-resolution, year-round data across broad, sometimes hemispheric, spatial extents. Second, while citizen science projects can collect data at these resolutions and extents, using these data requires appropriate analysis to address known sources of bias. Here, we present an analytical framework to address these challenges and generate year-round, range-wide distributional information using citizen science data. To illustrate this approach, we apply the framework to Wood Thrush (Hylocichla mustelina), a long-distance Neotropical migrant and species of conservation concern, using data from the citizen science project eBird. We estimate occurrence and abundance across a range of spatial scales throughout the annual cycle. Additionally, we generate intra-annual estimates of the range, intra-annual estimates of the associations between species and characteristics of the landscape, and interannual trends in abundance for breeding and non-breeding seasons. The range-wide population trajectories for Wood Thrush show a close correspondence between breeding and non-breeding seasons with steep declines between 2010 and 2013 followed by shallower rates of decline from 2013 to 2016. The breeding season range-wide population trajectory based on the independently collected and analyzed North American Breeding Bird Survey data also shows this pattern. The information provided here fills important knowledge gaps for Wood Thrush, especially during the less studied migration and non-breeding periods. More generally, the modeling framework presented here can be used to accurately capture landscape scale intra- and interannual distributional dynamics for broadly distributed, highly mobile species.
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modeling avian full annual cycle distribution and population trends with citizen science data
bioRxiv, 2018Co-Authors: Daniel Fink, Tom Auer, Alison Johnston, Viviana Ruizgutierrez, Wesley M Hochachka, Frank A La Sorte, Steve KellingAbstract:Information on species9 distributions and abundances, environmental associations, and how these change over time are central to the study and conservation of wildlife populations. This information is challenging to obtain at relevant scales across range-wide extents for two main reasons. First, local and regional processes that affect populations vary throughout the year and across species9 ranges, requiring fine-scale, year-round information across broad - sometimes hemispheric - spatial extents. Second, while citizen science projects can collect data at these scales, using these data requires additional steps to address known sources of bias. Here we present an analytical framework to address these challenges and generate year-round, range-wide distributional information using citizen science data. To illustrate this approach, we apply the framework to Wood Thrush (Hylocichla mustelina), a long distance Neotropical migrant and species of conservation concern, using data from the citizen science project eBird. We estimate relative occupancy and abundance with enough spatiotemporal resolution to support inference across a range of spatial scales throughout the annual cycle. This includes intra-annual estimates of the range (quantified as the area of occupancy), intra-annual estimates of the associations between species and features of their local environment, and inter-annual season-specific trends in relative abundance. This is the first example of an analysis to capture intra- and inter-annual distributional dynamics across the entire range of a broadly distributed, highly mobile species.
Peter P. Marra - One of the best experts on this subject based on the ideXlab platform.
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environmental predictors of nestling condition postfledging movement and postfledging survival in a migratory songbird the Wood Thrush hylocichla mustelina
The Auk, 2018Co-Authors: Ben J Vernasco, Peter P. Marra, Scott T Sillett, Brandt T RyderAbstract:ABSTRACT Given that population dynamics of birds are known to be sensitive to high fledgling mortality, a comprehensive understanding of the environmental factors that drive variation in fledgling survival is essential to avian conservation. We quantified multiple aspects of the Wood Thrush postfledging period using breeding and radio-telemetry data collected over the course of 4 breeding seasons in southern Indiana, USA. First, we examined how drought, forest cover, and brood parasitism affected nestling body condition and brood size. Second, after controlling for the age-specific increase in survival, we used multimodel inference to examine how brood parasitism, drought, forest cover, nestling body condition, and nest vegetation structure influenced postfledging survival. Finally, we measured the relationship between these covariates and fledgling movements. Drought decreased cumulative survival probabilities, with the youngest age group (<4 days postfledging) being most affected; however, this relation...
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Appendix C. The δ²H isoscape, feather sampling locations (bird icons) and the quadrants used in validation and to quantifying range wide migratory connectivity for Wood Thrush.
2016Co-Authors: Clark S. Rushing, Thomas B. Ryder, James F. Saracco, Peter P. MarraAbstract:The δ²H isoscape, feather sampling locations (bird icons) and the quadrants used in validation and to quantifying range wide migratory connectivity for Wood Thrush
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connectivity of Wood Thrush breeding wintering and migration sites based on range wide tracking
Conservation Biology, 2015Co-Authors: Emily A. Mckinnon, Calandra Q. Stanley, Kevin C. Fraser, Maggie Macpherson, Garth Casbourn, Lyle Friesen, Peter P. MarraAbstract:Many migratory animals are experiencing rapid population declines, but migration data with the geographic scope and resolution to quantify the complex network of movements between breeding and nonbreeding regions are often lacking. Determining the most frequently used migration routes and nonbreeding regions for a species is critical for understanding population dynamics and making effective conservation decisions. We tracked the migration of individual Wood Thrushes (Hylocichla mustelina) (n = 102) from across their range with light-level geolocators and, for the first time, quantified migration routes and wintering regions for distinct breeding populations. We identified regional and species-level migratory connectivity networks for this declining songbird by combining our tracking results with range-wide breeding abundance estimates and forest cover data. More than 50% of the species occupied the eastern wintering range (Honduras to Costa Rica), a region that includes only one-third of all wintering habitat and that is undergoing intensive deforestation. We estimated that half of all Wood Thrushes in North America migrate south through Florida in fall, whereas in spring approximately 73% funnel northward through a narrow span along the central U.S. Gulf Coast (88-93°W). Identifying migratory networks is a critical step for conservation of songbirds and we demonstrated with Wood Thrushes how it can highlight conservation hotspots for regional populations and species as a whole.
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assessing migratory connectivity for a long distance migratory bird using multiple intrinsic markers
Ecological Applications, 2014Co-Authors: Clark S. Rushing, Thomas B. Ryder, James F. Saracco, Peter P. MarraAbstract:Patterns of migratory connectivity are a vital yet poorly understood component of the ecology and evolution of migratory birds. Our ability to accurately characterize patterns of migratory connectivity is often limited by the spatial resolution of the data, but recent advances in probabilistic assignment approaches have begun pairing stable isotopes with other sources of data (e.g., genetic and mark-recapture) to improve the accuracy and precision of inferences based on a single marker. Here, we combine stable isotopes and geographic variation in morphology (wing length) to probabilistically assign Wood Thrush (Hylocichla mustilena) captured on the wintering grounds to breeding locations. In addition, we use known-origin samples to validate our model and assess potentially important impacts of isotopic and morphological covariates (age, sex, and breeding location). Our results show that despite relatively high levels of mixing across their breeding and nonbreeding ranges, moderate levels of migratory connectivity exist along an east-west gradient. In addition, combining stable isotopes with geographic variation in wing length improved the precision of breeding assignments by 10% and 37% compared to assignments based on isotopes alone or wing length alone, respectively. These results demonstrate that geographical variation in morphological traits can greatly improve estimates of migratory connectivity when combined with other intrinsic markers (e.g., stable isotopes or genetic data). The wealth of morphological data available from museum specimens across the world represents a tremendously valuable, but largely untapped, resource that is widely applicable for quantifying patterns of migratory connectivity.
Daniel Fink - One of the best experts on this subject based on the ideXlab platform.
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modeling avian full annual cycle distribution and population trends with citizen science data
Ecological Applications, 2020Co-Authors: Daniel Fink, Tom Auer, Alison Johnston, Viviana Ruizgutierrez, Wesley M Hochachka, Steve KellingAbstract:Information on species' distributions, abundances, and how they change over time is central to the study of the ecology and conservation of animal populations. This information is challenging to obtain at landscape scales across range-wide extents for two main reasons. First, landscape-scale processes that affect populations vary throughout the year and across species' ranges, requiring high-resolution, year-round data across broad, sometimes hemispheric, spatial extents. Second, while citizen science projects can collect data at these resolutions and extents, using these data requires appropriate analysis to address known sources of bias. Here, we present an analytical framework to address these challenges and generate year-round, range-wide distributional information using citizen science data. To illustrate this approach, we apply the framework to Wood Thrush (Hylocichla mustelina), a long-distance Neotropical migrant and species of conservation concern, using data from the citizen science project eBird. We estimate occurrence and abundance across a range of spatial scales throughout the annual cycle. Additionally, we generate intra-annual estimates of the range, intra-annual estimates of the associations between species and characteristics of the landscape, and interannual trends in abundance for breeding and non-breeding seasons. The range-wide population trajectories for Wood Thrush show a close correspondence between breeding and non-breeding seasons with steep declines between 2010 and 2013 followed by shallower rates of decline from 2013 to 2016. The breeding season range-wide population trajectory based on the independently collected and analyzed North American Breeding Bird Survey data also shows this pattern. The information provided here fills important knowledge gaps for Wood Thrush, especially during the less studied migration and non-breeding periods. More generally, the modeling framework presented here can be used to accurately capture landscape scale intra- and interannual distributional dynamics for broadly distributed, highly mobile species.
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modeling avian full annual cycle distribution and population trends with citizen science data
bioRxiv, 2018Co-Authors: Daniel Fink, Tom Auer, Alison Johnston, Viviana Ruizgutierrez, Wesley M Hochachka, Frank A La Sorte, Steve KellingAbstract:Information on species9 distributions and abundances, environmental associations, and how these change over time are central to the study and conservation of wildlife populations. This information is challenging to obtain at relevant scales across range-wide extents for two main reasons. First, local and regional processes that affect populations vary throughout the year and across species9 ranges, requiring fine-scale, year-round information across broad - sometimes hemispheric - spatial extents. Second, while citizen science projects can collect data at these scales, using these data requires additional steps to address known sources of bias. Here we present an analytical framework to address these challenges and generate year-round, range-wide distributional information using citizen science data. To illustrate this approach, we apply the framework to Wood Thrush (Hylocichla mustelina), a long distance Neotropical migrant and species of conservation concern, using data from the citizen science project eBird. We estimate relative occupancy and abundance with enough spatiotemporal resolution to support inference across a range of spatial scales throughout the annual cycle. This includes intra-annual estimates of the range (quantified as the area of occupancy), intra-annual estimates of the associations between species and features of their local environment, and inter-annual season-specific trends in relative abundance. This is the first example of an analysis to capture intra- and inter-annual distributional dynamics across the entire range of a broadly distributed, highly mobile species.
Bridget J M Stutchbury - One of the best experts on this subject based on the ideXlab platform.
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effects of breeding versus winter habitat loss and fragmentation on the population dynamics of a migratory songbird
Ecological Applications, 2016Co-Authors: Caz M Taylor, Bridget J M StutchburyAbstract:Many migratory species are in decline and understanding these declines is challenging because individuals occupy widely divergent and geographically distant habitats during a single year and therefore populations across the range are interconnected in complex ways. Network modeling has been used to show, theoretically, that shifts in migratory connectivity patterns can occur in response to habitat or climate changes and that habitat loss in one region can affect sub-populations in regions that are not directly connected. Here, we use a network model, parameterized by integrating long-term monitoring data with direct tracking of ~100 individuals, to explain population trends in the rapidly declining Wood Thrush (Hylocichla mustelina), and to predict future trends. Our model suggests that species-level declines in Wood Thrush are driven primarily by tropical deforestation in Central America but that protection of breeding habitat in some regions is necessary to prevent shifts in migratory connectivity and t...
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Carry-Over Effects of Nonbreeding Habitat on Start-to-Finish Spring Migration Performance of a Songbird
2015Co-Authors: Emily A. Mckinnon, Calandra Q. Stanley, Bridget J M StutchburyAbstract:For migratory animals, conditions during the nonbreeding period may carry-over to influence spring migration performance. Animals in low-quality habitats are predicted to be in poorer condition, show later migration timing, and travel at slower speeds. This can result in subsequent negative effects on fitness. We tested the hypothesis that nonbreeding season body condition and habitat quality carry-over to affect spring migration performance of a long-distance migratory songbird, the Wood Thrush (Hylocichla mustelina). We tracked individual birds between multiple breeding sites in North America and nonbreeding sites in Central America. First, we compared body condition of nonbreeding birds migrating to the same general region of the breeding range with spring migration performance (timing, speed, and duration) obtained from light-level geolocators. Second, we assessed the Normalized Difference Vegetation Index (NDVI) as a proxy for nonbreeding habitat quality, and predicted that birds from wetter habitat or in wetter years (higher NDVI) would show improved migration performance relative to birds from drier sites. We found no evidence of individual-level carry-over effects of nonbreeding season body condition on spring migration performance. Lower NDVI of nonbreeding habitat resulted in delayed spring migration departure, but this effect disappeared by arrival at breeding sites. Birds occupying drier nonbreeding sites migrated faster and for fewer days, compensating for their relatively late departure. We also documented a broader pattern in NDVI and migration timing and distance, in that birds that occupied the wettest areas in the southern part of the nonbreeding range departed significantly later and migrated farther. Our results suggest that individual carry-over effects of nonbreeding habitat quality may be compensated for by a faster and shorter migration strategy. At a broad scale, consistently later spring timing and longer migration distances were associated with the wettest areas (the highest quality habitats) of the Wood Thrush non-breeding range. This supports the theory that high-quality habitats offset the costs of farther migration, resulting in a leap-frog migration pattern.
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Juvenile Wood Thrushes exhibit a significantly different migration strategy in spring than adults: A) Juveniles (solid symbols) were later than adults (hollow symbols) at winter departure, entering the U. S. along the northern Gulf of Mexico coast, and when arriving at breeding sites.
2014Co-Authors: Emily A. Mckinnon, Calandra Q. Stanley, Kevin C. Fraser, Bridget J M StutchburyAbstract:Triangles represent average for females and squares for males. Vertical bars indicate standard error. Inset map shows an example of locations where timing was measured for an individual Wood Thrush tracked from Belize. B) Spring migration speed (total distance/duration) was slower for juvenile Wood Thrushes. C) Juveniles had more stopovers during spring migration relative to adults, and D) had more stopover nights in the U. S. than adults. Note that 1 stopover night = 2 consecutive noons in the same location. Boxplots extend to 25th and 75th quartiles with dark lines showing the median value and circles indicating outliers. Sample size is n = 17 for juveniles, and n = 30 for adults, except for winter departure (n = 16, 26) migration speed (n = 15, 25), and stopovers in the U. S. (n = 16, 29).
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repeat tracking of individual songbirds reveals consistent migration timing but flexibility in route
PLOS ONE, 2012Co-Authors: Calandra Q. Stanley, Emily A. Mckinnon, Kevin C. Fraser, Maggie Macpherson, Bridget J M StutchburyAbstract:Tracking repeat migratory journeys of individual animals is required to assess phenotypic plasticity of individual migration behaviour in space and time. We used light-level geolocators to track the long-distance journeys of migratory songbirds (Wood Thrush, Hylocichla mustelina), and, for the first time, repeat journeys of individuals. We compare between- and within-individual variation in migration to examine flexibility of timing and route in spring and autumn. Date of departure from wintering sites in Central America, along with sex and age factors, explained most of the variation (71%) in arrival date at North American breeding sites. Spring migration showed high within-individual repeatability in timing, but not in route. In particular, spring departure dates of individuals were highly repeatable, with a mean difference between years of just 3 days. Autumn migration timing and routes were not repeatable. Our results provide novel evidence of low phenotypic plasticity in timing of spring migration, which may limit the ability of individuals to adjust migration schedules in response to climate change.
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nest attendance and reproductive success in the Wood Thrush
The Condor, 2012Co-Authors: Melissa L Evans, Bridget J M StutchburyAbstract:Abstract. For most bird species, biparental care is expected to play an integral role in offspring survival. Nevertheless, relatively few studies have simultaneously examined male and female investment into nest attendance, the prevalence of nest attendance through the nesting cycle, or the relationship between nest-attendance effort and nesting success. Here, in a monogamous passerine, the Wood Thrush (Hylocichla mustelina), we use radiotracking to examine nest-attendance behaviors of males and females during the laying, incubation, and nestling stages, and the relationships between nest attendance and nesting success. Across nesting stages, males spent between 14–38% of their time <5 m and 21–58% of their time 5–25 m from the nest, and the time males spent near the nest was positively associated with nesting success. During the incubation stage, the amount of time males spent <5 m from the nest depended upon the female's presence on or off of the nest, as males appear to coordinate their nestattendance ...
Goudarz Molaei - One of the best experts on this subject based on the ideXlab platform.
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Dynamics of Vector-Host Interactions in Avian Communities in Four Eastern Equine Encephalitis Virus Foci in the Northeastern U.S.
2016Co-Authors: Goudarz Molaei, Philip M Armstrong, Michael C. Thomas, Tim Muller, Jan Medlock, John J. Shepard, Theodore G AndreadisAbstract:BackgroundEastern equine encephalitis (EEE) virus (Togaviridae, Alphavirus) is a highly pathogenic mosquito-borne zoonosis that is responsible for occasional outbreaks of severe disease in humans and equines, resulting in high mortality and neurological impairment in most survivors. In the past, human disease outbreaks in the northeastern U.S. have occurred intermittently with no apparent pattern; however, during the last decade we have witnessed recurring annual emergence where EEE virus activity had been historically rare, and expansion into northern New England where the virus had been previously unknown. In the northeastern U.S., EEE virus is maintained in an enzootic cycle involving the ornithophagic mosquito, Culiseta melanura, and wild passerine (perching) birds in freshwater hardWood swamps. However, the identity of key avian species that serve as principal virus reservoir and amplification hosts has not been established. The efficiency with which pathogen transmission occurs within an avian community is largely determined by the relative reservoir competence of each species and by ecological factors that influence contact rates between these avian hosts and mosquito vectors.Methodology and principle findingsContacts between vector mosquitoes and potential avian hosts may be directly quantified by analyzing the blood meal contents of field-collected specimens. We used PCR-based molecular methods and direct sequencing of the mitochondrial cytochrome b gene for profiling of blood meals in Cs. melanura, in an effort to quantify its feeding behavior on specific vertebrate hosts, and to infer epidemiologic implications in four historic EEE virus foci in the northeastern U.S. Avian point count surveys were conducted to determine spatiotemporal host community composition. Of 1,127 blood meals successfully identified to species level, >99% of blood meals were from 65 avian hosts in 27 families and 11 orders, and only seven were from mammalian hosts representing three species. We developed an empirically informed mathematical model for EEE virus transmission using Cs. melanura abundance and preferred and non-preferred avian hosts. To our knowledge this is the first mathematical model for EEE virus, a pathogen with many potential hosts, in the northeastern U.S. We measured strong feeding preferences for a number of avian species based on the proportion of mosquito blood meals identified from these bird species in relation to their observed frequencies. These included: American Robin, Tufted Titmouse, Common Grackle, Wood Thrush, Chipping Sparrow, Black-capped Chickadee, Northern Cardinal, and Warbling Vireo. We found that these bird species, most notably Wood Thrush, play a dominant role in supporting EEE virus amplification. It is also noteworthy that the competence of some of the aforementioned avian species for EEE virus has not been established. Our findings indicate that heterogeneity induced by mosquito host preference, is a key mediator of the epizootic transmission of vector-borne pathogens.Conclusion and significanceDetailed knowledge of the vector-host interactions of mosquito populations in nature is essential for evaluating their vectorial capacity and for assessing the role of individual vertebrates as reservoir hosts involved in the maintenance and amplification of zoonotic agents of human diseases. Our study clarifies the host associations of Cs. melanura in four EEE virus foci in the northeastern U.S., identifies vector host preferences as the most important transmission parameter, and quantifies the contribution of preference-induced contact heterogeneity to enzootic transmission. Our study identifies Wood Thrush, American Robin and a few avian species that may serve as superspreaders of EEE virus. Our study elucidates spatiotemporal host species utilization by Cs. melanura in relation to avian host community. This research provides a basis to better understand the involvement of Cs. melanura and avian hosts in the transmission and ecology of EEE virus and the risk of human infection in virus foci.
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molecular identification of blood meal sources in culiseta melanura and culiseta morsitans from an endemic focus of eastern equine encephalitis virus in new york
American Journal of Tropical Medicine and Hygiene, 2006Co-Authors: Goudarz Molaei, Philip M Armstrong, Theodore G Andreadis, Joanne Oliver, John J. HowardAbstract:Eastern equine encephalitis (EEE) virus perpetuates in an enzootic cycle involving ornithophilic mosquito vectors, principally Culiseta melanura (Coquillett) and avian amplification hosts. To better understand the role of Cs. melanura and Culiseta morsitans (Theobald) in the epizootiology of EEE virus, we collected blood-fed mosquitoes between 31 May and 15 October 2004 at two sites associated with an EEE virus focus in central New York and identified the source of vertebrate blood by nucleotide sequencing of polymerase chain reaction (PCR) products of the cytochrome b gene. Analysis of 484 Cs. melanura and 122 Cs. morsitans revealed that 94.2% and 86.9%, respectively, acquired blood solely from avian hosts. Blood meals derived exclusively from mammals were detected in 0.8% of Cs. melanura and 1.6% of Cs. morsitans. Individual mosquitoes containing mixed-blood meals from both avian and mammalian hosts were also detected in 5.0% of Cs. melanura and 11.5% of Cs. morsitans. Wood Thrush constituted the most common vertebrate host for Cs. melanura (23.6%) and Cs. morsitans (30.9%), followed by American robin, song sparrow, ovenbird, red-eyed vireo, and common yellowthroat. Mammalian-derived blood meals were identified as white-tailed deer, horse, domestic cat, and eastern pipistrelle bat. There were three isolations of EEE virus from Cs. melanura and one from Cs. morsitans. These results suggest that Wood Thrush and a few other passerine birds may play key roles in supporting EEE virus transmission in the northeast and possibly throughout the geographic range of EEE in North America. The frequency of mammalian feedings also suggests that Cs. melanura and Cs. morsitans may play a role in the transmission of EEE virus to equines, in addition to maintaining enzootic transmission among avian hosts. We report the first isolation of arboviruses from mosquito vectors concomitant with the identifications of their blood meal sources.
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Molecular identification of blood meal sources in Culiseta melanura and Culiseta morsitans from an endemic focus of eastern equine encephalitis (EEE) virus in New York
2006Co-Authors: Goudarz Molaei, Philip M Armstrong, Theodore G Andreadis, Joanne Oliver, John J. HowardAbstract:Abstract. Eastern equine encephalitis (EEE) virus perpetuates in an enzootic cycle involving ornithophilic mosquito vectors, principally Culiseta melanura (Coquillett) and avian amplification hosts. To better understand the role of Cs. melanura and Culiseta morsitans (Theobald) in the epizootiology of EEE virus, we collected blood-fed mosquitoes between 31 May and 15 October 2004 at two sites associated with an EEE virus focus in central New York and identified the source of vertebrate blood by nucleotide sequencing of polymerase chain reaction (PCR) products of the cytochrome b gene. Analysis of 484 Cs. melanura and 122 Cs. morsitans revealed that 94.2 % and 86.9%, respectively, acquired blood solely from avian hosts. Blood meals derived exclusively from mammals were detected in 0.8 % of Cs. melanura and 1.6% of Cs. morsitans. Individual mosquitoes containing mixed-blood meals from both avian and mammalian hosts were also detected in 5.0 % of Cs. melanura and 11.5 % of Cs. morsitans. Wood Thrush constituted the most common vertebrate host for Cs. melanura (23.6%) and Cs. morsitans (30.9%), followed by American robin, song sparrow, ovenbird, red-eyed vireo, and common yellowthroat. Mammalian-derived blood meals were identified as white-tailed deer, horse, domestic cat, and eastern pipistrelle bat. There were three isolations of EEE virus from Cs. melanura and one from Cs. morsitans. These results suggest that Wood Thrush and a few other passerine birds may play key roles in supporting EEE virus transmission in the northeast and possibly throughout the geographic range of EEE in North America. The frequency of mammalian feedings also suggests that Cs. melanura and Cs. morsitans may play a role in the transmission of EE
