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Brian Cade, Ph.D.

Brian Cade is a Research Statistician at the Fort Collins Science Center. 

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Greater sage-grouse lek in central Wyoming

Evaluating Trends in Greater Sage-Grouse Populations With Quantile Regression

USGS scientists are evaluating the use of quantile regression to develop models of sage-grouse population changes across the United States.
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Ecosystems Mission Area, Land Management Research Program, Fort Collins Science Center
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Evaluating Trends in Greater Sage-Grouse Populations With Quantile Regression

USGS scientists are evaluating the use of quantile regression to develop models of sage-grouse population changes across the United States.
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Wind turbines in a corn field.

Biometrics

Mathematical and statistical methods used to analyze biological data are powerful research tools that play several important roles in conceptualizing and understanding the structure and dynamics of ecological systems. Through the development of specialized and sophisticated quantitative tools and models, the complex nature of data arising from studies of ecological systems can be understood.
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Fort Collins Science Center
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Biometrics

Mathematical and statistical methods used to analyze biological data are powerful research tools that play several important roles in conceptualizing and understanding the structure and dynamics of ecological systems. Through the development of specialized and sophisticated quantitative tools and models, the complex nature of data arising from studies of ecological systems can be understood.
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A cutthroat trout. Photo by James Roberts, USGS.

Using Quantile Regression to Investigate Ecological Limiting Factors

Unexplained heterogeneity in statistical models of animal responses to their physical environment is reasonable to expect because the measured habitat resources are a constraint on—but not the sole determinant of—abundance, survival, fecundity, or fitness. The ecological understanding and reliability of management predictions based on animal habitat models can be improved by shifting focus from...
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Ecosystems Mission Area, Species Management Research Program, Wildlife Program (unpublished), Fort Collins Science Center
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Using Quantile Regression to Investigate Ecological Limiting Factors

Unexplained heterogeneity in statistical models of animal responses to their physical environment is reasonable to expect because the measured habitat resources are a constraint on—but not the sole determinant of—abundance, survival, fecundity, or fitness. The ecological understanding and reliability of management predictions based on animal habitat models can be improved by shifting focus from...
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The sunset on the main city beach in Laguna Beach, CA.

Quantitative and Statistical Research Collaboration

Mathematical and statistical models are powerful research tools that play several important roles in conceptualizing and understanding the structure and dynamics of complicated ecological systems, including developing mechanistic hypotheses pertaining to ecological systems, designing studies that elucidate ecosystem structure and function, and extracting information from data.
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Ecosystems Mission Area, Species Management Research Program, Fort Collins Science Center
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Quantitative and Statistical Research Collaboration

Mathematical and statistical models are powerful research tools that play several important roles in conceptualizing and understanding the structure and dynamics of complicated ecological systems, including developing mechanistic hypotheses pertaining to ecological systems, designing studies that elucidate ecosystem structure and function, and extracting information from data.
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USGS science for a changing world logo

Hydraulic Fracturing and Water Resources: An Assessment of the Potential Effects of Shale Gas Development on Water Resources in the United States

Shale gas is a key source of onshore domestic energy for the United States and production of this resource is increasing rapidly. Development and extraction of shale gas requires hydraulic fracturing, which entails horizontal drilling, perforation of steel casing and cement grout using explosive charges, and expansion of fractures using fluids under high pressure. Concern over potential environmen
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John Wesley Powell Center for Analysis and Synthesis
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Hydraulic Fracturing and Water Resources: An Assessment of the Potential Effects of Shale Gas Development on Water Resources in the United States

Shale gas is a key source of onshore domestic energy for the United States and production of this resource is increasing rapidly. Development and extraction of shale gas requires hydraulic fracturing, which entails horizontal drilling, perforation of steel casing and cement grout using explosive charges, and expansion of fractures using fluids under high pressure. Concern over potential environmen
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Sagebrush recovery analyzed with a dynamic reference approach in southwestern Wyoming, USA 1985-2018

Identifying ecologically relevant reference sites is important for evaluating ecosystem recovery, but the relevance of references that are temporally static is unclear in the context of vast landscapes with disturbance and environmental contexts varying over space and time. This question is pertinent for landscapes dominated by sagebrush (Artemisia spp.) which face a suite of threats from disturba
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Land Management Research Program, Fort Collins Science Center

Native Bee Genera in Colorado Conservation Reserve Program Fields, Collected from 2012-2014

Data included in this data set are for blue vane trap captured native bees from Logan County, Colorado starting in 2012 and ending in 2014. Data collected were the number of bees captured per date, per field, and identified to genus. Net level data contains 16,229 records.
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Fort Collins Science Center

Water quality, atmospheric nitrogen deposition and herbaceous plant species richness in the USA, 1970-2011.

This data release is comprised of a data set that contains specific conductance and chloride concentration data in HUC-8 watersheds that intersect with areas with unconventional oil and gas plays, and a data set that contains atmospheric nitrogen deposition rates and herbaceous plant species richness values across sample sites in the USA.
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Fort Collins Science Center
Filter Total Items: 76

Potential cheatgrass abundance within lightly invaded areas of the Great Basin

ContextAnticipating where an invasive species could become abundant can help guide prevention and control efforts aimed at reducing invasion impacts. Information on potential abundance can be combined with information on the current status of an invasion to guide management towards currently uninvaded locations where the threat of invasion is high.ObjectivesWe aimed to support management by develo
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Ecosystems Mission Area, Fort Collins Science Center

Assessing vegetation recovery from energy development using a dynamic reference approach

Ecologically relevant references are useful for evaluating ecosystem recovery, but references that are temporally static may be less useful when environmental conditions and disturbances are spatially and temporally heterogeneous. This challenge is particularly acute for ecosystems dominated by sagebrush (Artemisia spp.), where communities may require decades to recover from disturbance. We demons
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Ecosystems Mission Area, Fort Collins Science Center, Southwest Biological Science Center

Thermal stability of an adaptable, invasive ectotherm: Argentine giant tegus in the Greater Everglades ecosystem, USA

Invasive species globally threaten biodiversity and economies, but the ecophysiological mechanisms underlying their success are often understudied. For those alien species that also exhibit high phenotypic plasticity, such as habitat generalists, adaptations in response to environmental pressures can take place relatively quickly. The Argentine giant tegu (Salvator merianae; tegu) is a large omniv
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Ecosystems Mission Area, Fort Collins Science Center

Comment on “Female toads engaging in adaptive hybridization prefer high-quality heterospecifics as mates”

Chen and Pfennig (Reports, 20 March 2020, p. 1377) analyze the fitness consequences of hybridization in toads but do not account for differences in survival among progeny. Apparent fitness effects depend on families with anomalously low survival, yet survival is crucial to evolutionary fitness. This and other analytical shortcomings demonstrate that a conclusion of adaptive mate choice is not yet
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Ecosystems Mission Area, Fort Collins Science Center

Latitudinal patterns of alien plant invasions

Latitudinal patterns of biodiversity have long been a central topic in ecology and evolutionary biology. However, while most previous studies have focused on native species, little effort has been devoted to latitudinal patterns of plant invasions (with a few exceptions based on data from sparse locations). Using the most up‐to‐date worldwide native and alien plant distribution data from 801 regio
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Ecosystems Mission Area, Fort Collins Science Center

Diversity and abundance of wild bees in an agriculturally dominated landscape of eastern Colorado

Agricultural intensification has resulted in loss of natural and semi-natural habitats impacting several important ecosystem services. One group of organisms that has suffered greatly are the bees and hence pollination, the supporting ecosystem service they complete. The United States Department of Agriculture (USDA) Conservation Reserve Program (CRP) has implemented conservation practices designe
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Ecosystems Mission Area, Fort Collins Science Center

Effects of environmental variables on invasive amphibian activity: Using model selection on quantiles for counts

Many different factors influence animal activity. Often, the value of an environmental variable may influence significantly the upper or lower tails of the activity distribution. For describing relationships with heterogeneous boundaries, quantile regressions predict a quantile of the conditional distribution of the dependent variable. A quantile count model extends linear quantile regression meth
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Ecosystems Mission Area, Fort Collins Science Center

Quantile regression applications in ecology and the environmental sciences

No abstract available.
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Ecosystems Mission Area, Fort Collins Science Center, John Wesley Powell Center for Analysis and Synthesis

Logistic quantile regression provides improved estimates for bounded avian counts: A case study of California Spotted Owl fledgling production

Counts of avian fledglings, nestlings, or clutch size that are bounded below by zero and above by some small integer form a discrete random variable distribution that is not approximated well by conventional parametric count distributions such as the Poisson or negative binomial. We developed a logistic quantile regression model to provide estimates of the empirical conditional distribution of a b
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Ecosystems Mission Area, Fort Collins Science Center

Efficacy of SpayVac® as a contraceptive in feral horses

ABSTRACT We tested the efficacy of 2 formulations of the immunocontraceptive SpayVac1, which packages the immunogen porcine zona pellucida (PZP) and an adjuvant in multilamellar liposomes, as a contraceptive in captive feral horses (Equus caballus) for 3 consecutive breeding seasons (Pauls Valley, OK, USA; 2012–2014) following a single inoculation. Annual fertility rates in control adult female ho
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Ecosystems Mission Area, Fort Collins Science Center

Conditional vulnerability of plant diversity to atmospheric nitrogen deposition across the United States

Atmospheric nitrogen (N) deposition has been shown to decrease plant species richness along regional deposition gradients in Europe and in experimental manipulations. However, the general response of species richness to N deposition across different vegetation types, soil conditions, and climates remains largely unknown even though responses may be contingent on these environmental factors. We ass
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Ecosystems Mission Area, Western Ecological Research Center (WERC), John Wesley Powell Center for Analysis and Synthesis

Trophic magnification of organic chemicals: A global synthesis

Production of organic chemicals (OCs) is increasing exponentially, and some OCs biomagnify through food webs to potentially toxic levels. Biomagnification under field conditions is best described by trophic magnification factors (TMFs; per trophic level change in log-concentration of a chemical) which have been measured for more than two decades. Syntheses of TMF behavior relative to chemical trai
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Ecosystems Mission Area, Toxic Substances Hydrology, Environmental Health Program, Fort Collins Science Center

Non-USGS Publications**

Terrell, J.W., B.S. Cade, J. Carpenter, and J.M. Thompson. 1996. Modeling stream fish habitat limitations from wedge-shaped patterns of variation in standing stock. Transactions of the American Fisheries Society. 125(1): 104-
Cade, B. S., and J. D. Richards. 1996. Permutation tests for least absolute deviation regression. Biometrics. 52: 886-9.
Kennedy, P.E., and B.S. Cade. 1996. Randomization tests for multiple regression. Communications in Statistics - Simulation and Computation. 25(4): 923-936.
Baker, B.W. and B.S. Cade. 1995. Predicting biomass of beaver food from willow stem diameters. Journal of Range Management. 48(4): 322-326.
Baker, B.W., B.S. Cade, W.L. Mangus, and J.L. McMillen. 1995. Spatial analysis of sandhill crane nesting habitat. Journal of Wildlife Management. 59(4): 752-7.
Stauffer, D. F., A. H. Farmer, and B. S. Cade. 1992. Use of Wildlife Habitat Models for Habitat Management planning. Proceedings: Resource Technology 90, Second International Symposium on Advanced Technology in Natural Resources Management. Bethesda, MD: American Society of Photogrammetry and Remote Sensing. p. 609-6.

**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.

Blossom Statistical Package for R

Blossom is an R package with functions for making statistical comparisons with distance-function based permutation tests developed by P.W. Mielke, Jr. and colleagues at Colorado State University, and for testing parameters estimated in linear models with permutation procedures developed by B. S. Cade and colleagues at the U.S. Geological Survey' Fort Collins Science Center, U.S. Geological Survey.
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Fort Collins Science Center

Blossom Statistical Package

Blossom is an interactive program for making statistical comparisons with distance-function based permutation tests and for testing parameters estimated in linear models with permutation procedures.

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Fort Collins Science Center

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