Christopher Robert Field

University of Maryland, College Park | UMD, UMCP, University of Maryland College Park · SESYNC

Salt marshes in the northeastern United States provide critical breeding habitat for tidal marsh specialist birds like the Ammospiza caudacuta (Saltmarsh Sparrow). The Ammospiza caudacuta population declined by 9% annually from 1998 to 2012, necessitating immediate conservation actions for this vulnerable species. However, estimating species vital...

Determining factors that shape a species’ population genetic structure is beneficial for identifying effective conservation practices. We assessed population structure and genetic diversity for Saltmarsh Sparrow (Ammospiza caudacuta), an imperiled tidal marsh specialist, using 13 microsatellite markers and 964 individuals sampled from 24 marshes ac...

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,...

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...

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...

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...

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...

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...

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...

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...

Significance Key questions remain about the role of social factors, especially the behavior of private landowners, in determining the outcome of strategies for conservation under climate change. We surveyed the behavioral intentions of coastal landowners in the northeast United States, where extreme sea-level rise threatens tidal marsh persistence...

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...

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...

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...

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...

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...

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 of...

Biological conservation is a crisis-driven discipline that is inextricably linked to its broader social, political, and economic context. Historically, conservation research has often been conducted within ecology disciplines and with limited links to this broader context, which has contributed to a gap between research and its real-world implement...

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...