Conor P. McGowan

• Ph. D. Fisheries and Wildlife Sciences
• Researcher at United States Geological Survey

Decision analytic approaches have been widely recommended as well suited to solving disputed and ecologically complex natural resource management problems with multiple objectives and high uncertainty. However, the difference between theory and practice is substantial, as there are very few actual resource management programs that represent formal...

Human recreational disturbance and its effects on wildlife demographics and behavior is an increasingly important area of research. We monitored the nesting success of American Oystercatchers (Haematopus palliatus) in coastal North Carolina in 2002 and 2003. We also used video monitoring at nests to measure the response of incubating birds to human...

Understanding how events during one period of the annual cycle carry over to affect survival and other fitness components in other periods is essential to understanding migratory bird demography and conservation needs. Previous research has suggested that western Atlantic red knot (Calidris canutus rufa) populations are greatly affected by horsesho...

a b s t r a c t Incidental take is the permitted unintended or collateral killing, harassment, or habitat destruction of a protected species under endangered species law and is permissible as long as the take does not jeopar-dize the species' persistence in the wild. However, take is seldom addressed in a quantitative or popula-tion modeling contex...

Uncertainty in parameter estimates from sampling variation or expert judgment can introduce substantial uncertainty into ecological predictions based on those estimates. However, in standard population viability analyses, one of the most widely used tools for managing plant, fish and wildlife populations, parametric uncertainty is often ignored in...

Conservation and management decisions often must be made on strict timelines, based on the "best available information" regarding a species' current and expected future status. Simulation models are valuable tools for predicting a species' future status but must incorporate multiple types of uncertainty in order to provide a complete understanding...

Plateau Spot-tailed Earless Lizards Holbrookia lacerata are a species of ground lizard in central Texas that are under review for listing as endangered under the U.S. Endangered Species Act, but heretofore no predictive models of population dynamics or viability have been developed. We used limited available data and published demographic rates in...

Introduction Declining hunter populations across North America present wildlife management agencies with the prospect of declining revenues for wildlife conservation and management and the need for new tools to evaluate management strategies and predict future status of game species and hunters. Methods Here we present a modeling framework and pot...

Species status assessments are used to inform U.S. Fish and Wildlife Service (USFWS) decision making for Endangered Species Act (ESA) classification decisions, recovery planning, and more. The large number of species that require assessment and uncertainty in the data available impede the process of assigning and completing the assessments, which m...

Consideration of the full annual cycle population dynamics can provide useful insight for conservation efforts, but collecting data needed to estimate demographic parameters is often logistically difficult. For species that breed in remote areas, monitoring is often conducted during migratory stopover or at nonbreeding sites, and the recruitment ra...

Imperiled species face numerous and diverse anthropogenic threats to their persistence, and wildlife managers charged with making conservation decisions benefit from a sound understanding of how populations, species, and ecosystems will respond to future changes in threats to biodiversity. In southeastern North America, the gopher tortoise (Gopheru...

Understanding the effects of migratory stopover site conditions on both demographic rates and migratory behaviors is critical for interpreting changes in passage population sizes at stopover sites and predicting responses to future changes and conservation actions. We used a Bayesian formulation of the open robust design model to analyze mark‐resig...

Population viability analyses are useful tools to predict abundance and extinction risk for imperiled species. In southeastern North America, the federally threatened gopher tortoise (Gopherus polyphemus) is a keystone species in the diverse and imperiled longleaf pine (Pinus palustris) ecosystem, and researchers have suggested that tortoise popula...

In the U.S., 525,000 horseshoe crabs (Limulus polyphemus) per year have been captured during 2013–2017, brought to biomedical facilities, and bled to produce Limulus amebocyte lysate (LAL), then mostly released to the area of capture. The Atlantic States Marine Fisheries Commission estimates short-term bleeding-induced mortality to be 15% (4% to 30...

In the U.S., 525,000 horseshoe crabs per year have been captured during 2013-2017, brought to biomedical facilities, and bled to produce Limulus amebocyte lysate (LAL), then mostly released to the area of capture. The Atlantic States Marine Fisheries Commission estimates short-term bleeding-induced mortality to be 15% (4% to 30%), resulting in mort...

The US Fish and Wildlife Service (USFWS) has initiated a re-envisioned approach for providing decision makers with the best available science and synthesis of that information, called the Species Status Assessment (SSA), for endangered species decision making. The SSA report is a descriptive document that provides decision makers with an assessment...

Conservation planning for rare and threatened species is often made more difficult by a lack of research and monitoring data. In such cases, managers may rely on qualitative assessments of species risk that lack explicit acknowledgement of uncertainty. Snakes are a group of conservation concern that are also notoriously difficult to monitor. Here,...

Horseshoe crab harvest in the Delaware Bay on the mid-Atlantic coast of the United States was unregulated and increased substantially through the 1990s. Subsequently, shorebirds that rely on spawned horseshoe crab (HSC) eggs during spring migration, especially red knots, exhibited steep population declines, and conservationists attributed the decli...

Impacts of ecological mismatches should be most pronounced at points of the annual cycle when populations depend on a predictable, abundant, and aggregated food resource that changes in timing or distribution. The degree to which species specialize on a key prey item, therefore, should determine their sensitivity to mismatches. We evaluated the hyp...

Wildlife repatriation is an important tool to decrease extinction risk for imperiled species, but successful repatriations require significant time, resources and planning. Because repatriations can be long and expensive processes, clear release strategies and monitoring programs are essential to efficiently use resources and evaluate success. Howe...

Managers decide where to improve habitat despite substantial uncertainties about species’ ecology, management costs, and trade-offs among competing objectives. Ecological uncertainties are almost always a factor in habitat management decisions but uncertainty about management objectives and costs may also be important. Decision analyses in wildlife...

All ecological measurements are subject to error; the effects of missed detection (false negatives) are well known, but the effects of mistaken detection (false positives) are less understood. Long-term capture–recapture datasets provide valuable ecological insights and baselines for conservation and management, but where such studies rely on nonin...

As long as the funding mechanism supporting state wildlife conservation relies heavily on hunter-generated funds, declines in hunter participation are a threat to the conservation of both game and nongame species. To address options to bolster wildlife agency profit from the sale of hunting licenses, we developed a stage-based, stochastic populatio...

Extinction rates for island birds around the world have been historically high. For forest passerines, the Hawaiian archipelago has suffered some of the highest extinction rates and reintroduction is a conservation tool that can be used to prevent the extinction of some of the remaining endangered species. Population viability analyses can be used...

Decisions under the U.S. Endangered Species Act (ESA) require scientific input on the risk that the species will become extinct. A series of critiques on the role of science in ESA decisions have called for improved consistency and transparency in species risk assessments and clear distinctions between science input and policy application. To addre...

Assessment of a species’ status is a key part of management decision making for endangered and threatened species under the U.S. Endangered Species Act. Predicting the future state of the species is an essential part of species status assessment, and projection models can play an important role in developing predictions. We built a stochastic simul...

Automated cameras have become increasingly common for monitoring wildlife populations and estimating abundance. Most analytical methods, however, fail to account for incomplete and variable detection probabilities, which biases abundance estimates. Methods which do account for detection have not been thoroughly tested, and those that have been test...

At least one-third of all amphibian species face the threat of extinction, and current amphibian extinction rates are four orders of magnitude greater than background rates. Preventing extirpation often requires both ex situ (i.e., conservation breeding programs) and in situ strategies (i.e., protecting natural habitats). Flatwoods salamanders (Amb...

Although the use of camera traps in wildlife management is well established, technologies to automate image processing have been much slower in development, despite their potential to drastically reduce personnel time and cost required to review photos. We developed AnimalFinder in MATLAB® to identify animal presence in time-lapse camera trap image...

Density dependence regulates populations of many species across all taxonomic groups. Understanding density dependence is vital for predicting the effects of climate, habitat loss and/or management actions on wild populations. Migratory species likely experience seasonal changes in the relative influence of density dependence on population processe...

Many species of conservation concern are habitat limited and often a major focus of management for these species is habitat acquisition and/or restoration. Deciding the location of habitat restoration or acquisition to best benefit a protected species can be a complicated subject with competing management objectives, ecological uncertainties and st...

Understanding migratory connectivity for species of concern is of great importance if we are to implement management aimed at conserving them. New methods are improving our understanding of migration; however, banding (ringing) data is by far the most widely available and accessible movement data for researchers. Here, we use band recovery data for...

Banding Data from BDJV

Example BUGS code for analysis

American black ducks (Anas rubripes) are a harvested, international migratory waterfowl species in eastern North America. Despite an extended period of restrictive harvest regulations, the black duck population is still below the population goal identified in the North American Waterfowl Management Plan (NAWMP). It has been hypothesized that densit...

Predictive population modeling contributes to our basic scientific understanding of population dynamics, but can also inform management decisions by evaluating alternative actions in virtual environments. Quantitative models mathematically reflect scientific hypotheses about how a system functions. In Delaware Bay, mid-Atlantic Coast, USA, to more...

The horseshoe crab fishery on the US Atlantic coast represents a compelling fishery management story for many reasons, including ecological complexity, health and human safety ramifications, and socio-economic conflicts. Knowledge of stock status and assessment and monitoring capabilities for the species have increased greatly in the last 15 years...

Structured decision making (SDM) is an increasingly utilized approach and set of tools for addressing complex decisions in environmental management. SDM is a value-focused thinking approach that places paramount importance on first establishing clear management objectives that reflect core values of stakeholders. To be useful for management, object...

Application of adaptive management to complex natural resource systems requires careful evaluation to ensure that the process leads to improved decision-making. As part of that evaluation, adaptive policies can be compared with alternative nonadaptive management scenarios. Also, the value of reducing structural (ecological) uncertainty to achieving...

Distal border fragments of the navicular bone are increasingly being detected due to the improved capabilities of magnetic resonance imaging (MRI), but their clinical significance remains unclear. The purpose of this retrospective study was to describe the location, size, and frequency of fragments in a cohort of horses presented for MRI of the foo...

Estimating productivity for precocial species can be difficult because young birds leave their nest within hours or days of hatching and detectability thereafter can be very low. Recently, a method for using a modified catch-curve to estimate precocial chick daily survival for age based count data was presented using Piping Plover (Charadrius melod...

Decision making related to incidental take of endangered species under U.S. law lends itself well to a structured decision making approach. Incidental take is the permitted killing, harming, or harassing of a protected species under the law as long as that harm is incidental to an otherwise lawful activity and does not "reduce appreciably the proba...

Background/Question/Methods The Atlantic Horseshoe crab, Limulus polyphemus,is a valuable resource along the Mid-Atlantic coast which has, in recent years, experienced new management paradigms due to increased concern about this species role in the environment. While current management actions are underway, many acknowledge the need for improved...

The Atlantic horseshoe crab fishery is managed by the Atlantic States Marine Fisheries Commission. A traditional single-species assessment is not sufficient for managing harvest of the Delaware Bay horseshoe crab population given their ecological connection with migratory shorebirds which feed on horseshoe crab eggs. In response, a multi-species ma...

P>Adaptive management requires that predictive models be explicit and transparent to improve decisions by comparing management actions, directing further research and monitoring, and facilitating learning. The rufa subspecies of red knots (Calidris canutus rufa), which has recently exhibited steep population declines, relies on horseshoe crab (Limu...

Population models can be useful tools for evaluating management strategies and risks for a given species. A major, but often overlooked, component of endangered or threatened species management and recovery is the incidental take allowance of many endangered species laws. In the United States population models are seldom applied to address specific...

Each spring millions of horseshoe crabs spawn on the beaches of Delaware Bay, which is the epicenter of the American horseshoe crab distribution. Density-dependent quantities of eggs are brought to the beach surface and consumed by migrating shorebirds. Until recently management of Delaware Bay horseshoe crabs and migrant shorebirds had followed tr...

Available at http://ncep.amnh.org/index.php?globalnav=resources&sectionnav=modules&sectionsubnav=module_files&module_id=245

Since 2000, we have been banding American Oystercatcher (Haematopus palliatus) chicks at Cape Lookout and Cape Hatteras national seashores as part of a long-term demographic study. Between 2000 and 2002, we banded 23 chicks. We report on resightings of eight chicks that returned to the Outer Banks of North Carolina in the summers of 2003 and 2004....

Estimating reproductive success for birds with precocial young can be difficult because chicks leave nests soon after hatching and individuals or broods can be difficult to track. Researchers often turn to estimating survival during the prefledging period and, though effective, mark-recapture based approaches are not always feasible due to cost, ti...

Piping Plovers (Charadrius melodus) typically nest on unvegetated sand or gravel substrates throughout their breeding range. We report on the atypical habitat characteristics of four Piping Plover nests that we found amongst young cottonwood (Populus deltoides) saplings on a sandbar island in the Missouri River along the South Dakota-Nebraska borde...

We used a stochastic Leslie matrix model parameterized with demographic data from Wind Cave National Park to evaluate effects of four culling strategies on population growth rates and age and sex structure of bison (Bison bison Linnaeus). The four culling scenarios we modeled included removal of: (1) yearlings only; (2) calf/cow combination; (3) a...

We present an efficient and effective method for trapping adult, breeding American Oystercatchers (Haematopus palliatus) that minimizes disturbance to nesting birds and the risk of trapping injuries. We used a remote controlled mechanical decoy to lure territorial adults to a leg-hold noose-mat trap. We trapped 25 birds over two seasons and were su...

American Oystercatcher (Haematopus palliatus) numbers along the east coast of the United States are declining in some areas and expanding in others. Researchers have suggested that movement from traditional barrier beach habitats to novel inland habitats and coastal marshes may explain some of these changes, but few studies have documented oysterca...