Andy Royle, Ph.D.
Biography
Andy Royle has been with Patuxent Wildlife Research Center since 2004. Before that he was a statistician (1998-2004) for the U.S. FWS in the Migratory Bird Management Office where he worked primarily on waterfowl surveys and monitoring projects. Prior to that he was a visiting scientist in the Geophysical Statistics Project at the National Center for Atmospheric Reserach, Boulder, CO. He has a PhD in Statistics (1996) from North Carolina State University and a BS in Fisheries and Wildlife (1990) from Michigan State University.
Science and Products
Enabling AI for citizen science in fish ecology
Artificial Intelligence (AI) isrevolutionizing ecologyand conservation by enabling species recognition from photos and videos. Our project evaluates the capacity to expand AI for individual fish recognition for population assessment. The success of this effort would facilitate fisheries analysis at an unprecedented scale by engaging anglers and citizen scientists in imagery collection.This...
Terrestrial wildlife and legacy oil mining on National Wildlife Refuges
Amphibian surveys are being conducted on select National Wildlife Refuges with active and/or legacy oil mining to determine species relative distribution and their risk to short- and long-term effects from exposure to crude oil and its byproducts.
Capture-recapture meets big data: integrating statistical classification with ecological models of species abundance and occurrence
Advances in new technologies such as remote cameras, noninvasive genetics and bioacoustics provide massive quantities of electronic data. Much work has been done on automated (“machine learning”) methods of classification which produce “sample class designations” (e.g., identification of species or individuals) that are regarded as observed data in ecological models. However, these “data” are...
Spatio-Temporal Statistical Models for Forecasting Climate Change Effects on Bird Distribution
Ecological indicators of climate change are needed to measure concurrent changes in ecological systems, inform management decisions, and forecast the consequences of climate change. We seek to develop robust bird-based, climate-change indicators using North American Breeding Bird Survey data.
Mammals
Our science portfolio includes the study and management of mammal populations, which can require the use of methods and analysis that incorporate the difficulty in detecting them – picture how hard it is to count and identify bats at dusk or estimate the number of mountain lions in an area.
Climate Change
The impacts of a changing climate on wildlife and associated ecosystems have yet to be fully determined but changes are clearly underway as are a variety of investigations to assess how we can best preserve key resources while effectively managing others. Using a variety of tools and a combination of studies including adaptive management, long-term monitoring, mathematical modeling, and...
Hierarchical Modeling
Hierarchical models, also known as mutl-level and mixed effects models, have advanced the field of population ecology with inferences about population dynamics at broad spatial and temporal scales. The analysis of hierarchical models has been facilitated by recent advances in Bayesian analysis, and computationally intensive techniques such as Markov Chain Monte Carlo (see Mathematical modeling...
Occupancy
Many wildlife studies seek to understand changes or differences in the proportion of sites occupied by a species of interest. These studies are hampered by imperfect detection of these species, which can result in some sites appearing to be unoccupied that are actually occupied. Occupancy models solve this problem and produce unbiased estimates of occupancy (ie, occurrence) and related...
Capture-Mark-Recapture Science
Capture-Mark-Recapture (CMR) can be viewed as an animal survey method in which the count statistic is the total number of animals caught, and the associated detection probability is the probability of capture. The method involves capturing a number of animals, marking them, releasing them back into the population, and then determining the ratio of marked to unmarked animals in the population...
Mathematical Modeling
A formal framework that revolves around the construction of a mathematical expression using equations, statements or formulas as representation of a system, behavior, or process to simulate the behavior of the system, a series of relationships, or process under study.
Population Estimation
Determining the size of animal populations is fundamental to wildlife management and how such populations change over time and space can provide insights into ecosystem function and associated processes. Patuxent scientists’ utilize a number of robust statistical techniques to generate these estimates and to improve our understanding of population dynamics.
Hierarchical Models of Animal Abundance and Occurrence
The Challenge: Research goals of this project are to develop models, statistical methods, sampling strategies and tools for inference about animal population status from survey data. Survey data are always subject to a number of observation processes that induce bias and error. In particular, inferences are based on spatial sampling – we can only ever sample a subset of locations where species...
Modeling population dynamics with multinomial count data
No abstract available.
Royle, Andy; Kery, Marc Spatial proximity moderates genotype uncertainty in genetic tagging studies
Accelerating declines of an increasing number of animal populations worldwide necessitate methods to reliably and efficiently estimate demographic parameters such as population density and trajectory. Standard methods for estimating demographic parameters from noninvasive genetic samples are inefficient because lower-quality samples cannot be used...
Augustine, Ben C.; Royle, Andy; Linden, Daniel W.; Fuller, Angela K. Migratory behavior and winter geography drive differential range shifts of eastern birds in response to recent climate change
Over the past half century, migratory birds in North America have shown divergent population trends relative to resident species, with the former declining rapidly and the latter increasing. The role that climate change has played in these observed trends is not well understood, despite significant warming over this period. We used 43 y of...
Clark Rushing; Royle, Andy; Ziolkowski, David; Pardieck, Keith L. Movement-assisted localization from acoustic telemetry data
Acoustic telemetry technologies are being increasingly deployed to study a variety of aquatic taxa including fishes, reptiles, and marine mammals. Large cooperative telemetry networks produce vast quantities of data useful in the study of movement, resource selection and species distribution. Efficient use of acoustic telemetry data requires...
Hostetter, Nathan J.; Royle, Andy Consequences of ignoring group association in spatial capture-recapture analysis
Many models in population ecology, including spatial capture–recapture (SCR) models, assume that individuals are distributed and detected independently of one another. In reality, this is rarely the case – both antagonistic and gregarious relationships lead to non-independent spatial configurations, with territorial exclusion at one end of the...
Bischof, Richard; Dupont, Pierre; Milleret, Cyril; Chipperfield, Joseph; Royle, J. Andrew Acoustic space occupancy: Combining ecoacoustics and lidar to model biodiversity variation and detection bias across heterogeneous landscapes
There is global interest in quantifying changing biodiversity in human-modified landscapes. Ecoacoustics may offer a promising pathway for supporting multi-taxa monitoring, but its scalability has been hampered by the sonic complexity of biodiverse ecosystems and the imperfect detectability of animal-generated sounds. The acoustic signature of a...
Rappaport, Danielle I.; Royle, J. Andrew; Morton, Douglas C. Integrating side-scan sonar and acoustic telemetry to estimate the annual spawning run size of Atlantic sturgeon in the Hudson River
There is considerable interest in evaluating the status and trends of sturgeon populations, yet many traditional approaches to estimating the abundance of fishes are intractable due to their biology and rarity. Side-scan sonar has recently emerged as an effective tool for censusing sturgeon in rivers, yet challenges remain for censusing open...
Kazyak, David; Flowers, Amy M; Hostetter, Nathan J.; Madsen, John A; Breece, Matthew W.; Higgs, Amanda; Brown, Lori M.; Royle, Andy; Fox, Dewayne A. Estimating abundance from capture-recapture data
No abstract available.
Sandercock, Brett K.; Murray, Dennis L. ; Converse, Sarah J.; Royle, J. Andrew Occupancy Patterns of Breeding American Black Ducks
Occupancy patterns can assist with the determination of habitat limitation during breeding or wintering periods and can help guide population and habitat management efforts. American black ducks (Anas rubripes; black ducks) are thought to be limited by habitat and food availability during the winter, but breeding sites may also limit the size or...
Roberts, Anthony J.; Royle, J. Andrew; Padding, Paul I.; Devers, Patrick K.; Lepage, Christine; Bordage, Daniel Estimating spatially and temporally complex range dynamics when detection is imperfect
Species distributions are determined by the interaction of multiple biotic and abiotic factors, which produces complex spatial and temporal patterns of occurrence. As habitats and climate change due to anthropogenic activities, there is a need to develop species distribution models that can quantify these complex range dynamics. In this paper, we...
Rushing, Clark S.; Royle, J. Andrew; Ziolkowski, David; Pardieck, Keith L. Incorporating citizen science data in spatially explicit integrated population models
Information about population abundance, distribution, and demographic rates is critical for understanding a species’ ecology and for effective conservation and management. To collect data over large spatial and temporal extents for such inferences, especially for species with low densities or wide distributions, citizen science can be an efficient...
Sun, Catherine C.; Royle, Andy; Fuller, Angela K. Genetic tagging in the Anthropocene: Scaling ecology from alleles to ecosystems
The Anthropocene is an era of marked human impact on the world. Quantifying these impacts 51 has become central to understanding the dynamics of coupled human-natural systems, resource52 dependent livelihoods, and biodiversity conservation. Ecologists are facing growing pressure to 53 quantify the size, distribution, and trajectory of wild...
Clayton T Lamb; Adam T Ford; Michael Proctor; Royle, Andy; Garth Mowat
PROGRAM SPACECAP
A Program to Estimate Animal Abundance and Density using Spatially-Explicit Capture-Recapture