Chris S. Elphick's research while affiliated with University of Connecticut and other places

Publications (106)

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1. Conceptual models are necessary to synthesize what is known about a topic, identify gaps in knowledge, and improve understanding. The process of developing conceptual models that summarize the literature using ad hoc approaches has high potential to be incomplete due to the challenges of tracking information and hypotheses across the literature....
Article
In animal communication, signals can arise endogenously or in response to cues, such as signals by conspecifics. When one signal serves dual functions, such as in birds that use the same song for mate attraction and territorial defense, the underlying reason for a vocalization cannot be determined without direct observations, and even then, may be...
Article
Salt marsh vegetation zones shift in response to large‐scale environmental changes such as sea‐level rise (SLR) and restoration activities, but it is unclear if they are good indicators of soil nitrogen removal. Our goal was to characterize the relationship between denitrification potential and salt marsh vegetation zones in tidally restored and ti...
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Habitat loss disrupts species interactions through local extinctions, potentially orphaning species that depend on interacting partners, via mutualisms or commensalisms, and increasing secondary extinction risk. Orphaned species may become functionally or secondarily extinct, increasing the severity of the current biodiversity crisis. While habitat...
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Biodiversity is in crisis, and insects are no exception. To understand insect population and community trends globally, it is necessary to identify and synthesize diverse datasets representing different taxa, regions, and habitats. The relevant literature is, however, vast and challenging to aggregate. The Entomological Global Evidence Map (EntoGEM...
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The biogeochemistry of tidal marsh sediments facilitates the transformation of mercury (Hg) into the biologically available form methylmercury (MeHg), resulting in elevated Hg exposures to tidal marsh wildlife. Saltmarsh and Acadian Nelson’s sparrows (Ammospiza caudacutua and A. nelsoni subvirgatus, respectively) exclusively inhabit tidal marshes,...
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It is now clear that the routine embedding of experiments into conservation practice is essential for creating reasonably comprehensive evidence of the effectiveness of actions. However, an important barrier is the stage of identifying testable questions that are both useful but also realistic to carry out without a major research project. We ident...
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Saltmarsh sparrows (Ammospiza caudacuta) and seaside sparrows (A. maritima) are species of conservation concern primarily due to global sea-level rise and habitat degradation. Environmental mercury (Hg) contamination may present additional threats to their reproductive success and survival. To assess site-specific total mercury (THg) exposure and i...
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Coastal marshes are important blue carbon reservoirs, but it is unclear how vegetation shifts associated with tidal restoration and sea level rise alter soil microbial respiration rates and bacterial community composition. Within 20 Connecticut salt marshes (10 without tidal restrictions, 10 tidally restored), we sampled three vegetation zones domi...
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Seaside Sparrows (Ammospiza maritima) are tidal salt marsh endemic passerines found along the Atlantic and Gulf coasts of North America. Currently, there are 7 described subspecies, and “MacGillivray’s” Seaside Sparrow (A. m. macgillivraii) is the name given to the Atlantic coast subspecies breeding from North Carolina to northern Florida. In 2019...
Preprint
Full-text available
Saltmarsh sparrows ( Ammospiza caudacuta ) and seaside sparrows ( A. maritima ) are species of conservation concern primarily due to global sea-level rise and habitat degradation. Environmental mercury (Hg) contamination may present additional threats to their reproductive success and survival. To assess site-specific total mercury (THg) exposure a...
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Sea-level rise (SLR) is projected to increase dramatically with profound effects on tidal marshes, yet uncertainty stemming from underlying climate change scenarios, model specifications, and temporal scale is a major hurdle to conservation planning. We compared likely effects of SLR for 2030 and 2050 under static inundation and dynamic response mo...
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Denitrification removes reactive nitrogen (N) from ecosystems by transforming nitrate (NO3−) to dinitrogen (N2) gas. Incomplete denitrification produces nitrous oxide (N2O), a potent greenhouse gas. In salt marshes, denitrification, N2O production, and N2O yield (the fraction of denitrification that produces N2O) have implications for N load reduct...
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Spatial biases are a common feature of presence–absence data from citizen scientists. Spatial thinning can mitigate errors in species distribution models (SDMs) that use these data. When detections or non‐detections are rare, however, SDMs may suffer from class imbalance or low sample size of the minority (i.e. rarer) class. Poor predictions can re...
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The Saltmarsh Sparrow (Ammospiza caudacuta) is a tidal marsh bird facing rapid population decline throughout its range, largely caused by degradation and loss of breeding habitat. Thus, there is a need to preserve tidal marshes in the northeastern United States, but to do so requires an understanding of the habitat features that support robust popu...
Article
Despite the importance of reviews and syntheses in advancing our understanding of the natural world and informing conservation policy, they frequently are not conducted with the same careful methods as primary studies. This discrepancy can lead to controversy over review conclusions because the methods employed to gather evidence supporting the con...
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The interdisciplinary nature of conservation problems is increasingly being incorporated into research, raising fundamental questions about the relative importance of the different types of knowledge and data. Although there has been extensive research on the development of methods and tools for conservation planning, especially spatial planning, c...
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Changes in the frequency and severity of extreme weather may introduce new threats to species that are already under stress from gradual habitat loss and climate change. We provide a probabilistic framework that quantifies potential threats by applying concepts from ecological resilience to single populations. Our approach uses computation to compa...
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Aim Citizen science data are increasingly used for modelling species distributions because they offer broad spatiotemporal coverage of local observations. However, such data are often collected without experimental design or set survey methods, raising the risk that bias and noise will compromise modelled predictions. We tested the ability of speci...
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A body of research by Russell Greenberg, Glenn Tattersall, and their colleagues has proposed a corollary of Allen's Rule: that in freshwater‐limited environments, bill surface area increases with temperature. Increases in both population density and sexual dimorphism, however, could also explain increases in bill surface area. After controlling for...
Article
1.Systematic review, meta‐analysis, and other forms of evidence synthesis are critical to strengthen the evidence base concerning conservation issues and to answer ecological and evolutionary questions. Synthesis lags behind the pace of scientific publishing, however, due to time and resource costs which partial automation of evidence synthesis tas...
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Theory suggests that different taxa having colonized a similar, challenging environment will show parallel or lineage‐specific adaptations to shared selection pressures, but empirical examples of parallel evolution in independent taxa are exceedingly rare. We employed comparative genomics to identify parallel and lineage‐specific responses to selec...
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In eastern North America, the invasive hemlock woolly adelgid (Adelges tsugae Annand), has expanded northward at a pace that exceeds predictions from mechanistic models, suggesting successful long-distance dispersal despite the only viable dispersive phase being a flightless nymph, or “crawler.” We hypothesize that migrating birds may contribute to...
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Globally limited to 45,000 km2, salt marshes and their endemic species are threatened by numerous anthropogenic influences, including sea-level rise and predator pressure on survival and nesting success. Along the Atlantic coast of North America, Seaside (Ammospiza maritima) and Saltmarsh (A. caudacuta) sparrows are endemic to salt marshes, with Sa...
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Coastal ecosystems are at risk across the globe due to combined effects of sea-level rise and human development. This threat is prevalent in the northeastern USA, where sea levels increase 2-6 mm annually. Much of this coastline is buffered by tidal marsh, directly linking monitoring of this ecosystem to effective coastal management into the future...
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Insufficient time and funding remain obstacles to collecting data across broad spatial scales on the fine-scale distribution of multiple species, their life histories, and interactions with other species and the environment. This often necessitates the use of focal species to inform conservation and management decisions. We used the systematic cons...
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Reduced ecological specialization is an emerging, general pattern of ecological networks in fragmented landscapes. In plant–herbivore interactions, reductions in dietary specialization of herbivore communities are consistently associated with fragmented landscapes, but the causes remain poorly understood. We propose several hypothetical bottom–up a...
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Salt marshes of the northeastern United States are dynamic landscapes where the tidal flooding regime creates patterns of plant zonation based on differences in elevation, salinity, and local hydrology. These patterns of zonation can change quickly due to both natural and anthropogenic stressors, making tidal marshes vulnerable to degradation and l...
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An individual’s body condition and probability of survival can change throughout the annual cycle, based on the combined effects of many factors, including reproductive investment during breeding, colder temperatures during winter, and elevated risks during migration. We evaluated body condition and survival during breeding and non-breeding periods...
Article
Hurricane Sandy made landfall in the USA on October 29, 2012 and had devastating impacts on human-dominated landscapes in the mid-Atlantic and New England states, but its effects on tidal marsh habitats remain largely undescribed. We evaluated the short-term resilience (a resistance to change or a rapid return to pre-storm conditions) of tidal mars...
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The balance of abiotic and biotic stressors experienced by a species likely varies across its range, resulting in spatially heterogeneous limitations on the species' demographic rates. Support for spatial variation in stressors (often latitudinal gradients) has been found in many species, usually with physiological or correlative occupancy data, bu...
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The human aspects of conservation are often overlooked but will be critical for identifying strategies for biological conservation in the face of climate change. We surveyed the behavioral intentions of coastal landowners with respect to various conservation strategies aimed at facilitating ecosystem migration for tidal marshes. We found that sever...
Article
Demographic rates are rarely estimated over an entire species range, limiting empirical tests of ecological patterns and theories, and raising questions about the representativeness of studies that use data from a small part of a range. The uncertainty that results from using demographic rates from just a few sites is especially pervasive in popula...
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There is growing evidence to support that paleo-timescale events are important determinants in the present-day distribution of organisms. We explored the relationship between community composition of tidal marsh birds in the northeastern United States and potential drivers of biodiversity patterns across timescales to explore the relevance of histo...
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As saltmarsh habitat continues to disappear, understanding the factors that influence the population dynamics of saltmarsh breeding birds is an important step in the conservation of these declining species. Using 5 yrs (2011–2015) of demographic data, we evaluated and compared apparent adult survival and nest survival of Seaside (Ammodramus maritim...
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Breeding strategies can shape the timing of other events and processes, including arrival on the breeding grounds, prebasic molt, and departure for fall migration. We studied these relationships in sympatric Saltmarsh Sparrows (Ammodramus caudacutus) and Seaside Sparrows (A. maritimus), 2 closely related species with notably different breeding stra...
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Conservation of threatened or endangered species in a hybrid zone requires a comprehensive understanding of interspecific dynamics over time and space. We evaluated changes in location and composition of a hybrid zone over a 15-year period (with replicated sampling in 1997–2000 and 2011–2013) for saltmarsh (Ammodramus caudacutus) and Nelson’s (A. n...
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The detrimental effects of nest ectoparasites on breeding birds have been well documented, but interactions between birds' parasites and their environment are less well understood. The Saltmarsh Sparrow, Ammodramus caudacutus is a ground-nesting bird endemic to tidal wetlands in the eastern USA, where the majority of nests are lost to tidal floodin...
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Understanding the processes that drive divergence within and among species is a long-standing goal in evolutionary biology. Traditional approaches to assessing differentiation rely on phenotypes to identify intra- and interspecific variation, but many species express subtle morphological gradients in which boundaries among forms are unclear. This i...
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The range of a species is determined by the balance of its demographic rates across space. Population growth rates are widely hypothesized to be greatest at the geographic center of the species range, but indirect empirical support for this pattern using abundance as a proxy has been mixed, and demographic rates are rarely quantified on a large spa...
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Habitat specialists are declining at alarming rates worldwide, driving biodiversity loss of the earth's next mass extinction. Specialist organisms maintain smaller functional niches than their generalist counterparts, and tradeoffs exist between these contrasting life history strategies, creating conservation challenges for specialist taxa. There i...
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Sea-level rise will affect coastal species worldwide, but models that aim to predict these effects are typically based on simple measures of sea level that do not capture its inherent complexity, especially variation over timescales shorter than one year. Coastal species might be most affected, however, by floods that exceed a critical threshold. T...
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Little is known about how biotic interactions will influence the distributions of vegetation types under climate change, but these interactions could determine the effectiveness of conservation actions aimed at encouraging ecosystem migration. Tidal marshes are threatened by sea-level rise worldwide unless losses are offset by landward migration. W...
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Coastal marshes are one of the world's most productive ecosystem's. Consequently, they have been heavily used by humans for centuries, resulting in ecosystem loss. Direct human modifications such as road crossings and ditches and climatic stressors such as sea-level rise and extreme storm events have the potential to further degrade the quantity an...
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1.There is ongoing debate in ecology about the value of the increasing complexity of analytical methods, especially as it relates to models that correct occupancy or abundance estimates for imperfect detection. While both arguments for and against increasing complexity have merit, there is a need for greater clarity on how to determine what level o...
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Tidal marsh loss to anthropogenic environmental impacts and climate change, particularly sea level rise, has and will continue to cause declines in tidal marsh bird populations. Distribution patterns of tidal marsh birds are generally known, yet we lack detailed knowledge of local abundance and regional population sizes, which limits our ability to...
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As species become rare and approach extinction, purported sightings can be controversial, especially when scarce management resources are at stake. We consider the probability that each individual sighting of a series is valid. Obtaining these probabilities requires a strict framework to ensure that they are as accurately representative as possible...
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As species become rare and approach extinction, purported sightings can be controversial, especially when scarce management resources are at stake. We report a Bayesian model where we consider the probability that each individual sighting is valid. Obtaining these probabilities clearly requires a strict framework to ensure that they are as represen...
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Full-text available
As species become rare and approach extinction, purported sightings can be controversial, especially when scarce management resources are at stake. We report a Bayesian model where we consider the probability that each individual sighting is valid. Obtaining these probabilities clearly requires a strict framework to ensure that they are as represen...
Article
Birds have been studied in rice fields for over a century. Early studies focused on species directly linked to crop production, either because they were considered to be crop pests or because they preyed upon undesirable species found in fields. Prior to 1970, most studies focused on waterfowl, with a majority coming from North America. This taxono...
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Tidal marshes are among the most threatened habitats on Earth because of their limited natural extent, a long history of human drainage and modification, and anticipated future sea-level rise. Tidal marshes also provide services to humans and support species of high conservation interest. Consequently, millions of dollars have been spent on tidal m...
Chapter
Many compelling management issues in Long Island Sound (LIS) focus on how organisms respond to stresses such as commercial and recreational harvesting, eutrophication, hypoxia, habitat degradation, invasion of non-native species, ocean acidification, and climate change. In order to address these complex problems, we must first understand the factor...
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Applied ecologists routinely use demographic models to predict population trajectories. Survival rates throughout the life cycle, which are required for these models, are often difficult to obtain, especially for long-lived or mobile species. Detailed information for pre-adult age classes in particular is often lacking. Using a 20-year dataset from...
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Correlations between transequatorial migratory bird routes and bipolar biogeographic disjunctions in bryophytes suggest that disjunctions between northern and southern high latitude regions may result from bird-mediated dispersal; supporting evidence is, however, exclusively circumstantial. Birds disperse plant units (diaspores) internally via inge...
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Many compelling management issues in Long Island Sound (LIS) focus on how organisms respond to stresses such as commercial and recreational harvesting, eutrophication, hypoxia, habitat degradation, invasion of non-native species, ocean acidification, and climate change. In order to address these complex problems, we must first understand the fac...
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Sex ratios of adult birds are frequently skewed, but in few species is the sex ratio of offspring also skewed. Adult females, however, should modify their offspring's sex ratio and invest more in the sex with the greatest future reproductive potential. We investigated the relationship between nestlings' morphology, timing of reproduction, and sex r...
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Habitat models that associate organisms with features of their environment can help identify areas for planning conservation strategies. These models, however, should be tested with new data before their conclusions are widely accepted. The Saltmarsh Sparrow (Ammodramus caudacutus) is a species of growing conservation concern along the Atlantic coa...
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Remote sensing data can represent various habitat characteristics, and thus can substitute for detailed ground sampling when constructing habitat models. To predict saltmarsh sparrow (Ammodramus caudacutus) distribution and nesting activity, we compared Bayesian hierarchical models in which variables were generated from field or remote sensing data...
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Understanding mechanisms that promote colonization by target species is critical to advancing the success of coastal wetland restoration. Recent work in avian behavioral ecology suggests that social cues might influence settlement decisions in a range of species, however little is known about the extent to which social mechanisms might influence se...
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Assessing the impacts of manipulative research can be hard when few animals are affected in any one study. Collating information across studies, however, can identify vulnerable organisms and allow researchers to tailor research to reduce, and possibly eliminate, adverse effects. Relatively few studies have documented radiotransmitter impacts on pa...
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We analyzed long-term winter survey data (1956–2007) for three endangered waterbirds endemic to the Hawaiian Islands, the Hawaiian moorhen (Gallinula chloropus sandvicensis), Hawaiian coot (Fulica alai), and Hawaiian stilt (Himantopus mexicanus knudseni). Time series were analyzed by species–island combinations using generalized additive models, wi...
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Considerable work has been done to investigate linkages between the production of rice (Oiyza sativa) and bird ecology and conservation. Rice is an extremely important crop globally and affects waterbirds in diverse ways. Rice fields are not substitutes for natural wetlands but are used by many species and can help mitigate the loss of natural habi...
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Literature is reviewed to determine the effects of landscape features on waterbird use of fields in regions where rice (Oryza sativa) is grown. Rice-growing landscapes often consist of diverse land uses and land cover, including rice fields, irrigation ditches, other agricultural fields, grasslands, forests and natural wetlands. Numerous studies in...
Article
Rice (Oryza sativa) is one of the world's most important crops. The crop is grown in at least 114 countries, occupies over 156 million ha of land annually, is a primary source of nutrition for over half the world's human population and constitutes over a fifth of the global grain supply. Rice is generally grown under flooded conditions and, if mana...