Charles B Yackulic, Ph.D.
Charles Yackulic is a research statistician with the Southwest Biological Science Center.
Dr. Yackulic's research primarily focuses on developing and fitting statistical models that integrate multiple data sources, link environmental drivers and management actions to population and ecosystem processes, and can be used to make near and long-term forecasting of system dynamics under different management alternatives. Areas of particular interest include species distribution dynamics, population dynamics, interspecific interactions, animal movement, food web dynamics and river metabolism.
Professional Experience
2011-present: Research Statistician, USGS Southwest Biological Science Center, Flagstaff, AZ
2010-2011: National Science Foundation (NSF) postdoc in Bioinformatics, USGS Patuxent Wildlife Research Center, MD
2009-2010: Postdoctoral Researcher, Columbia University, NY
Education and Certifications
2009 - Ph.D. in Ecology and Evolutionary Biology, Columbia University, NY
2003 - MSc. in Environmental Change and Management, Oxford University, UK
2001 - B.A. in Biology (major) and Math (minor), Columbia University, NY
Science and Products
Filter Total Items: 29
Ground-dwelling arthropods along the Colorado River in Arizona, USAData
These data were compiled from pitfall traps deployed at three sites, along a 25 kilometers (km) stretch of the Colorado River, immediately downstream of Glen Canyon Dam, in Glen Canyon National Recreation Area. Each site had both pre and post-dam riparian habitats present. Sampling for ground-dwelling arthropods using pitfall traps occurred continuously between June 17 and September 9...
Count and detection-nondetection survey data of barred owls (Strix varia) in historical breeding territories of Northern Spotted Owls (Strix occidentalis caurina) in the Oregon Coast Range, 1995-2016
This dataset contains count and detection-nondetection data of Barred Owls from 106 historical breeding territories of Northern Spotted Owl territories (i.e. sites) in the Oregon Coast Ranges from 1995 to 2016. Data collected from 1995 to 2014 are partitioned into 2-week periods from 1 March - 31 August each year, totaling 12 possible sampling periods per year. Data collected from 2015...
Bioelectrical impedance analysis for an endangered desert fishData
These data were used to examine the effectiveness of a non-lethal tool (Bioelectrical Impedance Analysis, "BIA") to estimate the physiological condition of endangered and threatened fishes in the Colorado River Basin. We conducted laboratory trials using hatchery-raised Humpback Chub and Bonytail and wild-captured Roundtail Chub, where fish were subjected to different feeding trials to...
Full Annual Cycle Bioenergetics model of migration applied to Galapagos tortoisesData
Ambient-shade temperature was measured every 4 h with iButton thermochrons (Maxim Integrated Products, Inc., Sunnyville, CA, USA) placed at 1m above-ground level for a previous paper (Blake et al., 2012 DOI 10.1111/1365-2656.12020). The Normalized Difference Vegetation Index (NDVI) of the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument (Huete et al. 2002 - http://dx.doi...
Flow management and fish density regulate salmonid recruitment and adult size in tailwaters across western North AmericaData
This data is a compilation of fishery monitoring data collected by state agencies over several decades in tailwaters downriver of dams in Colorado, Utah, Montana, Wyoming, Idaho, New Mexico, Arizona, California, and Oregon. Specifically, the data contained herein is summary data used in four generalized linear mixed models that were developed to assess the biological and hydrologic...
Filter Total Items: 115
Divergent climate impacts on C3 versus C4 grasses imply widespread 21st century shifts in grassland functional composition
AimGrasslands cover a third of Earth's landmass and provide critical ecosystem services. Anticipating how perennial C3 (cool-season) and C4 (warm-season) grasses respond to climate change will be key to predicting future composition and functioning of grasslands. Here, we evaluate environmental drivers of C3 and C4 perennial distributions and assess how C3 and C4 grass distributions...
Authors
Caroline A. Havrilla, John B. Bradford, Charles Yackulic, Seth M. Munson
Impeding access to tributary spawning habitat and releasing experimental fall-timed floods increases brown trout immigration into a dam's tailwater
River ecosystems have been altered by flow regulation and species introductions. Regulated flow regimes often include releases designed to benefit certain species or restore ecosystem processes, and invasive species suppression programs may include efforts to restrict access to spawning habitat. The impacts of these management interventions are often uncertain. Here, we assess hypotheses...
Authors
Brian D. Healy, Charles Yackulic, Robert C. Schelly
Drought related changes in water quality surpass effects of experimental flows on trout growth downstream of Lake Powell reservoir
Flows released from reservoirs are often modified to mitigate the negative ecosystem effects of dams. We estimated the effects of two experimental flows, fall-timed floods and elimination of sub-daily variation in flows on weekends, on growth rates of rainbow trout (Oncorhynchus mykiss) in the Colorado River downstream from Glen Canyon Dam. Experimental flow effects were compared to...
Authors
Josh Korman, Bridget Deemer, Charles Yackulic, Theodore Kennedy, Mariah Aurelia Giardina
The hydroclimate niche: A tool for predicting and managing riparian plant community responses to streamflow seasonality
Habitat suitability is a consequence of interacting environmental factors. In riparian ecosystems, suitable plant habitat is influenced by interactions between stream hydrology and climate, hereafter referred to as “hydroclimate”. We tested the hypothesis that hydroclimate variables would improve the fit of ecological niche models for a suite of riparian species using occurrence data...
Authors
Bradley J. Butterfield, Emily C. Palmquist, Charles Yackulic
The Colorado River – The science-policy interface
No abstract available.
Authors
John C. Schmidt, Lindsey Bruckerhoff, Jianghao Wang, Charles Yackulic
Dry forest decline is driven by both declining recruitment and increasing mortality in response to warm, dry conditions
Aim: Anticipating when and where changes in species' demographic rates will lead to range shifts in response to changing climate remains a major challenge. Despite evidence of increasing mortality in dry forests across the globe in response to drought and warming temperatures, the overall impacts on the distribution of dry forests are largely unknown because we lack comparable large...
Authors
Robert K. Shriver, Charles Yackulic, David M. Bell, John B. Bradford
Quantifying flow and nonflow management impacts on an endangered fish by integrating data, research, and expert opinion
Managers charged with recovering endangered species in regulated river segments often have limited flexibility to alter flow regimes and want estimates of the expected population benefits associated with both flow and nonflow management actions. Disentangling impacts on different life stages from concurrently applied actions is essential for determining the effectiveness of each action...
Authors
Charles Yackulic, Thomas P Archdeacon, Richard A. Valdez, Monika Hobbs, Michael D. Porter, Joel Lusk, Ashley M. Tanner, Eric J Gonzales, Debbie Y Lee, Grace M Haggerty
Little bugs, big data, and Colorado River adaptive management: Preliminary findings from the ongoing bug flow experiment at Glen Canyon Dam
The undammed Colorado River in Grand Canyon was characterized by spring snow-melt floods that sometimes exceeded 100,000 cubic feet per second (cfs). These were followed by occasional flash floods during summer monsoons, then by low flows from fall through early spring (Figure 1; Topping and others, 2003). This seasonally variable flow regime carried huge loads of sediment and was an...
Authors
Theodore Kennedy, Anya Metcalfe, Bridget Deemer, Morgan Ford, Cheyenne Maxime Szydlo, Charles Yackulic, Jeffrey Muehlbauer
Exploring metapopulation-scale suppression alternatives for a global invader in a river network experiencing climate change
Invasive species can dramatically alter ecosystems, but eradication is difficult, and suppression is expensive once they are established. Uncertainties in the potential for expansion and impacts by an invader can lead to delayed and inadequate suppression, allowing for establishment. Metapopulation viability models can aid in planning strategies to improve responses to invaders and...
Authors
Brian D. Healy, Phaedra E. Budy, Charles Yackulic, Brendan P. Murphy, Robert C. Schelly, Mark C. McKinstry
Range-wide sources of variation in reproductive rates of northern spotted owls
We conducted a range-wide investigation of the dynamics of site level reproductive rate of northern spotted owls using survey data from 11 study areas across the sub-species geographic range collected during 1993–2018. Our analytical approach accounted for imperfect detection of owl pairs and misclassification of successful reproduction (i.e., at least one young fledged) and contributed...
Authors
Jeremy T. Rockweit, Julianna M Jenkins, James E. Hines, James D. Nichols, Katie Dugger, Alan B. Franklin, Peter C. Carlson, William L. Kendall, Damon B. Lesmeister, Christopher McCafferty, Steven H. Ackers, L. Steven Andrews, Larissa Bailey, Jesse Burgher, Kenneth P. Burnham, Tara E. Chestnut, Mary M Conner, Raymond J. Davis, Krista E. Dilione, Eric D. Forsman, Elizabeth M. Glenn, Scott A. Gremel, Keith A. Hamm, Dale R. Herter, J. Mark Higley, Rob B. Horn, David W Lamphear, Trent L. McDonald, Janice A Reid, Carl J. Schwarz, David C. Simon, Stan G Sovern, James K. Swingle, David Wiens, Heather Wise, Charles B. Yackulic
Southeast Utah Group climate and drought adaptation report: Exposure and perennial grass sensitivity
National Park Service (NPS) managers face growing challenges resulting from the effects of climate change. In particular, as temperatures rise in coming decades, natural resource management in the western United States must cope with expectations for elevated severity and frequency of droughts. These challenges are particularly pronounced for vegetation managers in dryland environments...
Authors
John B. Bradford, Caroline Havrilla, Jessica A. Hartsell, Daniel Rodolphe Schlaepfer, Molly L. McCormick, Seth M. Munson, Charles Yackulic, Terry T Fisk, David Thoma, Dusty Perkins, Dana L. Witwicki, Matt VanScoyoc, Michael C. Duniway, Sasha C. Reed
Experimental reductions in sub-daily flow fluctuations increased gross primary productivity for 425 river kilometers downstream
Aquatic primary production is the foundation of many river food webs. Dams change the physical template of rivers, often driving food webs toward greater reliance on aquatic primary production. Nonetheless, the effects of regulated flow regimes on primary production are poorly understood. Load following is a common dam flow management strategy that involves sub-daily changes in water...
Authors
Bridget Deemer, Charles Yackulic, Robert O Hall Jr., Michael Dodrill, Theodore Kennedy, Jeffrey Muehlbauer, David Topping, Nicholas Voichick, Michael D. Yard
Science and Products
Filter Total Items: 29
Ground-dwelling arthropods along the Colorado River in Arizona, USAData
These data were compiled from pitfall traps deployed at three sites, along a 25 kilometers (km) stretch of the Colorado River, immediately downstream of Glen Canyon Dam, in Glen Canyon National Recreation Area. Each site had both pre and post-dam riparian habitats present. Sampling for ground-dwelling arthropods using pitfall traps occurred continuously between June 17 and September 9...
Count and detection-nondetection survey data of barred owls (Strix varia) in historical breeding territories of Northern Spotted Owls (Strix occidentalis caurina) in the Oregon Coast Range, 1995-2016
This dataset contains count and detection-nondetection data of Barred Owls from 106 historical breeding territories of Northern Spotted Owl territories (i.e. sites) in the Oregon Coast Ranges from 1995 to 2016. Data collected from 1995 to 2014 are partitioned into 2-week periods from 1 March - 31 August each year, totaling 12 possible sampling periods per year. Data collected from 2015...
Bioelectrical impedance analysis for an endangered desert fishData
These data were used to examine the effectiveness of a non-lethal tool (Bioelectrical Impedance Analysis, "BIA") to estimate the physiological condition of endangered and threatened fishes in the Colorado River Basin. We conducted laboratory trials using hatchery-raised Humpback Chub and Bonytail and wild-captured Roundtail Chub, where fish were subjected to different feeding trials to...
Full Annual Cycle Bioenergetics model of migration applied to Galapagos tortoisesData
Ambient-shade temperature was measured every 4 h with iButton thermochrons (Maxim Integrated Products, Inc., Sunnyville, CA, USA) placed at 1m above-ground level for a previous paper (Blake et al., 2012 DOI 10.1111/1365-2656.12020). The Normalized Difference Vegetation Index (NDVI) of the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument (Huete et al. 2002 - http://dx.doi...
Flow management and fish density regulate salmonid recruitment and adult size in tailwaters across western North AmericaData
This data is a compilation of fishery monitoring data collected by state agencies over several decades in tailwaters downriver of dams in Colorado, Utah, Montana, Wyoming, Idaho, New Mexico, Arizona, California, and Oregon. Specifically, the data contained herein is summary data used in four generalized linear mixed models that were developed to assess the biological and hydrologic...
Filter Total Items: 115
Divergent climate impacts on C3 versus C4 grasses imply widespread 21st century shifts in grassland functional composition
AimGrasslands cover a third of Earth's landmass and provide critical ecosystem services. Anticipating how perennial C3 (cool-season) and C4 (warm-season) grasses respond to climate change will be key to predicting future composition and functioning of grasslands. Here, we evaluate environmental drivers of C3 and C4 perennial distributions and assess how C3 and C4 grass distributions...
Authors
Caroline A. Havrilla, John B. Bradford, Charles Yackulic, Seth M. Munson
Impeding access to tributary spawning habitat and releasing experimental fall-timed floods increases brown trout immigration into a dam's tailwater
River ecosystems have been altered by flow regulation and species introductions. Regulated flow regimes often include releases designed to benefit certain species or restore ecosystem processes, and invasive species suppression programs may include efforts to restrict access to spawning habitat. The impacts of these management interventions are often uncertain. Here, we assess hypotheses...
Authors
Brian D. Healy, Charles Yackulic, Robert C. Schelly
Drought related changes in water quality surpass effects of experimental flows on trout growth downstream of Lake Powell reservoir
Flows released from reservoirs are often modified to mitigate the negative ecosystem effects of dams. We estimated the effects of two experimental flows, fall-timed floods and elimination of sub-daily variation in flows on weekends, on growth rates of rainbow trout (Oncorhynchus mykiss) in the Colorado River downstream from Glen Canyon Dam. Experimental flow effects were compared to...
Authors
Josh Korman, Bridget Deemer, Charles Yackulic, Theodore Kennedy, Mariah Aurelia Giardina
The hydroclimate niche: A tool for predicting and managing riparian plant community responses to streamflow seasonality
Habitat suitability is a consequence of interacting environmental factors. In riparian ecosystems, suitable plant habitat is influenced by interactions between stream hydrology and climate, hereafter referred to as “hydroclimate”. We tested the hypothesis that hydroclimate variables would improve the fit of ecological niche models for a suite of riparian species using occurrence data...
Authors
Bradley J. Butterfield, Emily C. Palmquist, Charles Yackulic
The Colorado River – The science-policy interface
No abstract available.
Authors
John C. Schmidt, Lindsey Bruckerhoff, Jianghao Wang, Charles Yackulic
Dry forest decline is driven by both declining recruitment and increasing mortality in response to warm, dry conditions
Aim: Anticipating when and where changes in species' demographic rates will lead to range shifts in response to changing climate remains a major challenge. Despite evidence of increasing mortality in dry forests across the globe in response to drought and warming temperatures, the overall impacts on the distribution of dry forests are largely unknown because we lack comparable large...
Authors
Robert K. Shriver, Charles Yackulic, David M. Bell, John B. Bradford
Quantifying flow and nonflow management impacts on an endangered fish by integrating data, research, and expert opinion
Managers charged with recovering endangered species in regulated river segments often have limited flexibility to alter flow regimes and want estimates of the expected population benefits associated with both flow and nonflow management actions. Disentangling impacts on different life stages from concurrently applied actions is essential for determining the effectiveness of each action...
Authors
Charles Yackulic, Thomas P Archdeacon, Richard A. Valdez, Monika Hobbs, Michael D. Porter, Joel Lusk, Ashley M. Tanner, Eric J Gonzales, Debbie Y Lee, Grace M Haggerty
Little bugs, big data, and Colorado River adaptive management: Preliminary findings from the ongoing bug flow experiment at Glen Canyon Dam
The undammed Colorado River in Grand Canyon was characterized by spring snow-melt floods that sometimes exceeded 100,000 cubic feet per second (cfs). These were followed by occasional flash floods during summer monsoons, then by low flows from fall through early spring (Figure 1; Topping and others, 2003). This seasonally variable flow regime carried huge loads of sediment and was an...
Authors
Theodore Kennedy, Anya Metcalfe, Bridget Deemer, Morgan Ford, Cheyenne Maxime Szydlo, Charles Yackulic, Jeffrey Muehlbauer
Exploring metapopulation-scale suppression alternatives for a global invader in a river network experiencing climate change
Invasive species can dramatically alter ecosystems, but eradication is difficult, and suppression is expensive once they are established. Uncertainties in the potential for expansion and impacts by an invader can lead to delayed and inadequate suppression, allowing for establishment. Metapopulation viability models can aid in planning strategies to improve responses to invaders and...
Authors
Brian D. Healy, Phaedra E. Budy, Charles Yackulic, Brendan P. Murphy, Robert C. Schelly, Mark C. McKinstry
Range-wide sources of variation in reproductive rates of northern spotted owls
We conducted a range-wide investigation of the dynamics of site level reproductive rate of northern spotted owls using survey data from 11 study areas across the sub-species geographic range collected during 1993–2018. Our analytical approach accounted for imperfect detection of owl pairs and misclassification of successful reproduction (i.e., at least one young fledged) and contributed...
Authors
Jeremy T. Rockweit, Julianna M Jenkins, James E. Hines, James D. Nichols, Katie Dugger, Alan B. Franklin, Peter C. Carlson, William L. Kendall, Damon B. Lesmeister, Christopher McCafferty, Steven H. Ackers, L. Steven Andrews, Larissa Bailey, Jesse Burgher, Kenneth P. Burnham, Tara E. Chestnut, Mary M Conner, Raymond J. Davis, Krista E. Dilione, Eric D. Forsman, Elizabeth M. Glenn, Scott A. Gremel, Keith A. Hamm, Dale R. Herter, J. Mark Higley, Rob B. Horn, David W Lamphear, Trent L. McDonald, Janice A Reid, Carl J. Schwarz, David C. Simon, Stan G Sovern, James K. Swingle, David Wiens, Heather Wise, Charles B. Yackulic
Southeast Utah Group climate and drought adaptation report: Exposure and perennial grass sensitivity
National Park Service (NPS) managers face growing challenges resulting from the effects of climate change. In particular, as temperatures rise in coming decades, natural resource management in the western United States must cope with expectations for elevated severity and frequency of droughts. These challenges are particularly pronounced for vegetation managers in dryland environments...
Authors
John B. Bradford, Caroline Havrilla, Jessica A. Hartsell, Daniel Rodolphe Schlaepfer, Molly L. McCormick, Seth M. Munson, Charles Yackulic, Terry T Fisk, David Thoma, Dusty Perkins, Dana L. Witwicki, Matt VanScoyoc, Michael C. Duniway, Sasha C. Reed
Experimental reductions in sub-daily flow fluctuations increased gross primary productivity for 425 river kilometers downstream
Aquatic primary production is the foundation of many river food webs. Dams change the physical template of rivers, often driving food webs toward greater reliance on aquatic primary production. Nonetheless, the effects of regulated flow regimes on primary production are poorly understood. Load following is a common dam flow management strategy that involves sub-daily changes in water...
Authors
Bridget Deemer, Charles Yackulic, Robert O Hall Jr., Michael Dodrill, Theodore Kennedy, Jeffrey Muehlbauer, David Topping, Nicholas Voichick, Michael D. Yard