Maria develops models to estimate abundance and assess environmental drivers of fish population dynamics in the Grand Canyon ecosystem.
Maria’s research interests include: 1) evaluating links between floods, temperature, and life history of fishes, 2) developing approaches for integrating detections from autonomous PIT antennas into mark-recapture models to improve estimation of survival, movement, and abundance, 3) using population models to guide decision making, and 4) alternative life history strategies and partial migration in fishes.
Education and Certifications
2003 – B.S., Biology, University of Michigan
2011 – M.S., Wildlife Ecology, Iowa State University
2021 – PhD, Fish, Wildlife, and Conservation Biology, Colorado State University
Science and Products
Humpback chub (Gila cypha) capture history data (2009-2020), Grand Canyon, Arizona
These tabular data were compiled to estimate abundance from paired physical capture and antenna detection data in closed, open, and robust design mark-recapture models. These data represent humpback chub capture histories in the Little Colorado River (LCR) and in the juvenile chub monitoring (JCM) reach of the Colorado River in the Grand Canyon, Arizona. The dataset includes multistate capture his
Humpback Chub (Gila cypha) capture history data (2009-2017), and code for mark-recapture analysis and stochastic matrix projections, Colorado River and Little Colorado River, Arizona
These data represent capture histories for humpback chub (Gila cypha) that spawn in the Little Colorado River (LCR) from 2009-2017. Capture histories pertain to size class (<150mm total length [TL], 150-199mm TL, 200-249mm TL, and >250mm TL) and spatial location (the juvenile chub monitoring [JCM] reach in the Colorado River [63.4-65.0 river miles downstream of Lees Ferry],
Humpback chub spring and fall capture histories in the Little Colorado River, 2009-2019
These data were compiled to examine rates of skipped migration in adult humpback chub that spawn in the Little Colorado River (LCR). These data include mark-recapture information from the lower 13.56 kilometers of the LCR and from the Colorado River, from river kilometer 105.5-145.7 downstream of Glen Canyon Dam. Data also include detections from a multiplexer array (MUX) that is located in the LC
Marginalizing Bayesian population models - data for examples in the Grand Canyon region, southeastern Arizona, western Oregon USA - 1990-2015
These data were compiled here to fit various versions of Bayesian population models and compare their performance, primarily the time required to make inferences using different softwares and versions of code. The humpback chub data were collected by US Geological Survey and US Fish and Wildlife service in the Colorado and Little Colorado Rivers from April 2009 to October 2017. Adult fish were cap
Continuous Detection PIT Array Data & Model
These data represent a set of capture histories of rainbow trout (Oncorhynchus mykiss or RBT) captured in the Colorado River (CR) and(or) detected on the multiplexer array in the Little Colorado River (LCR). Capture trips to the Colorado River occurred in April 2012, July 2012, September 2012, January 2013, April 2013, July 2013, September 2013, January 2014, April 2014, July 2014, and September 2
Incorporating antenna detections into abundance estimates of fish
Autonomous passive integrated transponder (PIT) tag antennas are commonly used to detect fish marked with PIT tags but cannot detect unmarked fish, creating challenges for abundance estimation. Here we describe an approach to estimate abundance from paired physical capture and antenna detection data in closed and open mark-recapture models. Additionally, for open models, we develop an approach tha
Assessing the population impacts and cost‐effectiveness of a conservation translocation
Managers often move, or translocate, organisms into habitats that are assumed to be suitable, however the consequences of these translocations are usually not rigorously assessed. Robust assessment of these management experiments should consider impacts to both donor and recipient populations and compare the cost‐effectiveness of translocations to other actions.Here we evaluate translocations of a
Partial migration and spawning movements of humpback chub in the Little Colorado River are better understood using data from autonomous PIT tag antennas
Choosing whether or not to migrate is an important life history decision for many fishes. Here we combine data from physical captures and detections on autonomous passive integrated transponder (PIT) tag antennas to study migration in an endangered fish, the humpback chub (Gila cypha). We develop hidden Markov mark-recapture models with and without antenna detections and find that the model fit wi
Changes in prey, turbidity, and competition reduce somatic growth and cause the collapse of a fish population
Somatic growth exerts strong control on patterns in the abundance of animal populations via effects on maturation, fecundity, and survival rates of juveniles and adults. In this paper, we quantify abiotic and biotic drivers of rainbow trout growth in the Colorado River, AZ, and the resulting impact on spatial and temporal variation in abundance. Inferences are based on approximately 10,000 observa
A need for speed in Bayesian population models: A practical guide to marginalizing and recovering discrete latent states
Bayesian population models can be exceedingly slow due, in part, to the choice to simulate discrete latent states. Here, we discuss an alternative approach to discrete latent states, marginalization, that forms the basis of maximum likelihood population models and is much faster. Our manuscript has two goals: 1) to introduce readers unfamiliar with marginalization to the concept and provide worked
Inferring species interactions through joint mark–recapture analysis
Introduced species are frequently implicated in declines of native species. In many cases, however, evidence linking introduced species to native declines is weak. Failure to make strong inferences regarding the role of introduced species can hamper attempts to predict population viability and delay effective management responses. For many species, mark–recapture analysis is the more rigorous form
Estimating disperser abundance using open population models that incorporate data from continuous detection PIT arrays
Autonomous passive integrated transponder (PIT) tag antenna systems continuously detect individually marked organisms at one or more fixed points over long time periods. Estimating abundance using data from autonomous antennae can be challenging, because these systems do not detect unmarked individuals. Here we pair PIT antennae data from a tributary with mark-recapture sampling data in a mainstem
Incorporating temporal heterogeneity in environmental conditions into a somatic growth model
Evaluating environmental effects on fish growth can be challenging because environmental conditions may vary at relatively fine temporal scales compared to sampling occasions. Here we develop a Bayesian state-space growth model to evaluate effects of monthly environmental data on growth of fish that are observed less frequently (e.g., from mark-recapture data where time between captures can range
Survival, growth, and movement of subadult humpback chub, Gila cypha, in the Little Colorado River, Arizona
Ecologists estimate vital rates, such as growth and survival, to better understand population dynamics and identify sensitive life history parameters for species or populations of concern. Here, we assess spatiotemporal variation in growth, movement, density, and survival of subadult humpback chub living in the Little Colorado River, Grand Canyon, AZ from 2001–2002 and 2009–2013. We divided the Li
Evaluation of otoliths Salt Creek pupfish (Cyprinodon salinus salinus) for use in analyses of age and growth
We collected Salt Creek pupfish (Cyprinodon salinus salinus) from Salt Creek, Death Valley, California, in November 2009 and May 2010. The purpose of our study was to determine whether otoliths displayed interpretable marks that might be used for estimating age and growth. Otoliths exhibited alternating bands of opaque and translucent material. Kendall rank correlation between number of bands on o
Using variance components to estimate power in a hierarchically nested sampling design improving monitoring of larval Devils Hole pupfish
We used variance components to assess allocation of sampling effort in a hierarchically nested sampling design for ongoing monitoring of early life history stages of the federally endangered Devils Hole pupfish (DHP) (Cyprinodon diabolis). Sampling design for larval DHP included surveys (5 days each spring 2007–2009), events, and plots. Each survey was comprised of three counting events, where DHP
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
- Science
- Data
Humpback chub (Gila cypha) capture history data (2009-2020), Grand Canyon, Arizona
These tabular data were compiled to estimate abundance from paired physical capture and antenna detection data in closed, open, and robust design mark-recapture models. These data represent humpback chub capture histories in the Little Colorado River (LCR) and in the juvenile chub monitoring (JCM) reach of the Colorado River in the Grand Canyon, Arizona. The dataset includes multistate capture hisHumpback Chub (Gila cypha) capture history data (2009-2017), and code for mark-recapture analysis and stochastic matrix projections, Colorado River and Little Colorado River, Arizona
These data represent capture histories for humpback chub (Gila cypha) that spawn in the Little Colorado River (LCR) from 2009-2017. Capture histories pertain to size class (<150mm total length [TL], 150-199mm TL, 200-249mm TL, and >250mm TL) and spatial location (the juvenile chub monitoring [JCM] reach in the Colorado River [63.4-65.0 river miles downstream of Lees Ferry],Humpback chub spring and fall capture histories in the Little Colorado River, 2009-2019
These data were compiled to examine rates of skipped migration in adult humpback chub that spawn in the Little Colorado River (LCR). These data include mark-recapture information from the lower 13.56 kilometers of the LCR and from the Colorado River, from river kilometer 105.5-145.7 downstream of Glen Canyon Dam. Data also include detections from a multiplexer array (MUX) that is located in the LCMarginalizing Bayesian population models - data for examples in the Grand Canyon region, southeastern Arizona, western Oregon USA - 1990-2015
These data were compiled here to fit various versions of Bayesian population models and compare their performance, primarily the time required to make inferences using different softwares and versions of code. The humpback chub data were collected by US Geological Survey and US Fish and Wildlife service in the Colorado and Little Colorado Rivers from April 2009 to October 2017. Adult fish were capContinuous Detection PIT Array Data & Model
These data represent a set of capture histories of rainbow trout (Oncorhynchus mykiss or RBT) captured in the Colorado River (CR) and(or) detected on the multiplexer array in the Little Colorado River (LCR). Capture trips to the Colorado River occurred in April 2012, July 2012, September 2012, January 2013, April 2013, July 2013, September 2013, January 2014, April 2014, July 2014, and September 2 - Publications
Incorporating antenna detections into abundance estimates of fish
Autonomous passive integrated transponder (PIT) tag antennas are commonly used to detect fish marked with PIT tags but cannot detect unmarked fish, creating challenges for abundance estimation. Here we describe an approach to estimate abundance from paired physical capture and antenna detection data in closed and open mark-recapture models. Additionally, for open models, we develop an approach thaAssessing the population impacts and cost‐effectiveness of a conservation translocation
Managers often move, or translocate, organisms into habitats that are assumed to be suitable, however the consequences of these translocations are usually not rigorously assessed. Robust assessment of these management experiments should consider impacts to both donor and recipient populations and compare the cost‐effectiveness of translocations to other actions.Here we evaluate translocations of aPartial migration and spawning movements of humpback chub in the Little Colorado River are better understood using data from autonomous PIT tag antennas
Choosing whether or not to migrate is an important life history decision for many fishes. Here we combine data from physical captures and detections on autonomous passive integrated transponder (PIT) tag antennas to study migration in an endangered fish, the humpback chub (Gila cypha). We develop hidden Markov mark-recapture models with and without antenna detections and find that the model fit wiChanges in prey, turbidity, and competition reduce somatic growth and cause the collapse of a fish population
Somatic growth exerts strong control on patterns in the abundance of animal populations via effects on maturation, fecundity, and survival rates of juveniles and adults. In this paper, we quantify abiotic and biotic drivers of rainbow trout growth in the Colorado River, AZ, and the resulting impact on spatial and temporal variation in abundance. Inferences are based on approximately 10,000 observaA need for speed in Bayesian population models: A practical guide to marginalizing and recovering discrete latent states
Bayesian population models can be exceedingly slow due, in part, to the choice to simulate discrete latent states. Here, we discuss an alternative approach to discrete latent states, marginalization, that forms the basis of maximum likelihood population models and is much faster. Our manuscript has two goals: 1) to introduce readers unfamiliar with marginalization to the concept and provide workedInferring species interactions through joint mark–recapture analysis
Introduced species are frequently implicated in declines of native species. In many cases, however, evidence linking introduced species to native declines is weak. Failure to make strong inferences regarding the role of introduced species can hamper attempts to predict population viability and delay effective management responses. For many species, mark–recapture analysis is the more rigorous formEstimating disperser abundance using open population models that incorporate data from continuous detection PIT arrays
Autonomous passive integrated transponder (PIT) tag antenna systems continuously detect individually marked organisms at one or more fixed points over long time periods. Estimating abundance using data from autonomous antennae can be challenging, because these systems do not detect unmarked individuals. Here we pair PIT antennae data from a tributary with mark-recapture sampling data in a mainstemIncorporating temporal heterogeneity in environmental conditions into a somatic growth model
Evaluating environmental effects on fish growth can be challenging because environmental conditions may vary at relatively fine temporal scales compared to sampling occasions. Here we develop a Bayesian state-space growth model to evaluate effects of monthly environmental data on growth of fish that are observed less frequently (e.g., from mark-recapture data where time between captures can rangeSurvival, growth, and movement of subadult humpback chub, Gila cypha, in the Little Colorado River, Arizona
Ecologists estimate vital rates, such as growth and survival, to better understand population dynamics and identify sensitive life history parameters for species or populations of concern. Here, we assess spatiotemporal variation in growth, movement, density, and survival of subadult humpback chub living in the Little Colorado River, Grand Canyon, AZ from 2001–2002 and 2009–2013. We divided the LiEvaluation of otoliths Salt Creek pupfish (Cyprinodon salinus salinus) for use in analyses of age and growth
We collected Salt Creek pupfish (Cyprinodon salinus salinus) from Salt Creek, Death Valley, California, in November 2009 and May 2010. The purpose of our study was to determine whether otoliths displayed interpretable marks that might be used for estimating age and growth. Otoliths exhibited alternating bands of opaque and translucent material. Kendall rank correlation between number of bands on oUsing variance components to estimate power in a hierarchically nested sampling design improving monitoring of larval Devils Hole pupfish
We used variance components to assess allocation of sampling effort in a hierarchically nested sampling design for ongoing monitoring of early life history stages of the federally endangered Devils Hole pupfish (DHP) (Cyprinodon diabolis). Sampling design for larval DHP included surveys (5 days each spring 2007–2009), events, and plots. Each survey was comprised of three counting events, where DHPNon-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.