Publications
Below are publications associated with the Southwest Biological Science Center's research.
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Filter Total Items: 1519
The effect of research activities and winter precipitation on voiding behaviour of Agassiz’s desert tortoises (Gopherus agassizii) The effect of research activities and winter precipitation on voiding behaviour of Agassiz’s desert tortoises (Gopherus agassizii)
Context: There is little information available on how research activities might cause stress responses in wildlife, especially responses of threatened species such as the desert tortoise (Gopherus agassizii). Aims: The present study aims to detect behavioural effects of researcher handling and winter precipitation on a natural population of desert tortoises in the desert of Southwestern...
Authors
Mickey Agha, Mason O. Murphy, Jeffrey E. Lovich, Joshua R. Ennen, Christian R. Oldham, Kathie Meyer-Wilkins, Curtis Bjurlin, Meaghan Austin, Sheila V. Madrak, Caleb L. Loughran, Laura A. Tennant, Steven J. Price
Do management actions to restore rare habitat benefit native fish conservation? Distribution of juvenile native fish among shoreline habitats of the Colorado River Do management actions to restore rare habitat benefit native fish conservation? Distribution of juvenile native fish among shoreline habitats of the Colorado River
Many management actions in aquatic ecosystems are directed at restoring or improving specific habitats to benefit fish populations. In the Grand Canyon reach of the Colorado River, experimental flow operations as part of the Glen Canyon Dam Adaptive Management Program have been designed to restore sandbars and associated backwater habitats. Backwaters can have warmer water temperatures...
Authors
Michael J. Dodrill, Charles B. Yackulic, Brandon Gerig, William E. Pine, Josh Korman, Colton Finch
Not putting all their eggs in one basket: bet-hedging despite extraordinary annual reproductive output of desert tortoises Not putting all their eggs in one basket: bet-hedging despite extraordinary annual reproductive output of desert tortoises
Bet-hedging theory makes the counter-intuitive prediction that, if juvenile survival is low and unpredictable, organisms should consistently reduce short-term reproductive output to minimize the risk of reproductive failure in the long-term. We investigated the long-term reproductive output of an Agassiz's desert tortoise (Gopherus agassizii) population and conformance to a bet-hedging...
Authors
Jeffrey E. Lovich, Joshua R. Ennen, Charles B. Yackulic, Kathie Meyer-Wilkins, Mickey Agha, Caleb L. Loughran, Curtis Bjurlin, Meaghan Austin, Sheila V. Madrak
Comment on Spracklandus Hoser, 2009 (Reptilia, Serpentes, ELAPIDAE): request for confirmation of availability of the generic name and for the nomenclatural validation of the journal in which it was published (Case 3601; BZN 70:234–237; 71:30–38; 13 Comment on Spracklandus Hoser, 2009 (Reptilia, Serpentes, ELAPIDAE): request for confirmation of availability of the generic name and for the nomenclatural validation of the journal in which it was published (Case 3601; BZN 70:234–237; 71:30–38; 13
In Case 3601 Raymond Hoser has asked the Commission to validate for the purposes of nomenclature the name Spracklandus Hoser, 2009, and ‘the journal in which it was published,’ issue 7 of the Australasian Journal of Herpetology (AJH). We note that the entire run of AJH has been written, edited, and published solely by Hoser. Although his requests to the Commission were presented as...
Authors
Anders G.J. Rhodin, Hinrich Kaiser, Peter Paul van Dijk, Wolfgang Wuster, Mark O’Shea, Michael Archer, Mark Auliya, Luigi Boitani, Roger Bour, Viola Clausnitzer, Topiltzin Contreras-MacBeath, Brian I. Crother, Juan M. Daza, Carlos A. Driscoll, Oscar Flores-Villela, Jack Frazier, Uwe Fritz, Alfred L. Gardner, Claude Gascon, Arthur Georges, Frank Glaw, Felipe G. Grazziotin, Colin P. Groves, Gerhard Haszprunar, Peter Havas, Jean-Marc Hero, Michael Hoffmann, Marinus S. Hoogmoed, Brian D. Horne, John B. Iverson, Manfred Jach, Christopher L. Jenkins, Richard K.B. Jenkins, A. Ross Kiester, J. Scott Keogh, Thomas E. Lacher, Jeffrey E. Lovich, Luca Luiselli, D. Luke Mahler, David P. Mallon, Roderic Mast, Roy W. McDiarmid, John Measey, Russell A. Mittermeier, Sanjay Molur, Volker Mosbrugger, Robert W. Murphy, Darren Naish, Manfred Niekisch, Hidetoshi Ota, James F. Parham, Michael J. Parr, Nicolas J. Pilcher, Ronald H. Pine, Anthony B. Rylands, James G. Sanderson, Jay M. Savage, Wulf Schleip, Gustavo J. Scrocchi, H. Bradley Shaffer, Eric N. Smith, Robert Sprackland, Simon N. Stuart, Holger Vetter, Laurie J. Vitt, Tomas Waller, Grahame Webb, Edward O. Wilson, Hussam Zaher, Scott Thomson
Wide-area ratios of evapotranspiration to precipitation in monsoon-dependent semiarid vegetation communities Wide-area ratios of evapotranspiration to precipitation in monsoon-dependent semiarid vegetation communities
Evapotranspiration (ET) and the ratio of ET to precipitation (PPT) are important factors in the water budget of semiarid rangelands and are in part determined by the dominant plant communities. Our goal was to see if landscape changes such as tree or shrub encroachment and replacement of native grasses by invasive grasses impacted ET and ET/PPT and therefore watershed hydrology in this...
Authors
Edward P. Glenn, Russell L. Scott, Uyen Nguyen, Pamela L. Nagler
Assessing juvenile native fish demographic responses to a steady flow experiment in a large regulated river Assessing juvenile native fish demographic responses to a steady flow experiment in a large regulated river
The Colorado River below Glen Canyon Dam, Arizona, is part of an adaptive management programme which optimizes dam operations to improve various resources in the downstream ecosystem within Grand Canyon. Understanding how populations of federally endangered humpback chub Gila cypha respond to these dam operations is a high priority. Here, we test hypotheses concerning temporal variation...
Authors
Colton G. Finch, William E. Pine, Charles B. Yackulic, Michael J. Dodrill, Michael D. Yard, Brandon S. Gerig, Coggins, Josh Korman
Urgent need for warming experiments in tropical forests Urgent need for warming experiments in tropical forests
Although tropical forests account for only a fraction of the planet's terrestrial surface, they exchange more carbon dioxide with the atmosphere than any other biome on Earth, and thus play a disproportionate role in the global climate. In the next 20 years, the tropics will experience unprecedented warming, yet there is exceedingly high uncertainty about their potential responses to...
Authors
Molly A. Calaveri, Sasha C. Reed, W. Kolby Smith, Tana E. Wood
Flow management and fish density regulate salmonid recruitment and adult size in tailwaters across western North America Flow management and fish density regulate salmonid recruitment and adult size in tailwaters across western North America
Rainbow and brown trout have been intentionally introduced into tailwaters downriver of dams globally and provide billions of dollars in economic benefits. At the same time, recruitment and maximum length of trout populations in tailwaters often fluctuate erratically, which negatively affects the value of fisheries. Large recruitment events may increase dispersal downriver where other...
Authors
Kimberly L. Dibble, Charles B. Yackulic, Theodore A. Kennedy, Phaedra E. Budy
Turbidity, light, temperature, and hydropeaking control primary productivity in the Colorado River, Grand Canyon Turbidity, light, temperature, and hydropeaking control primary productivity in the Colorado River, Grand Canyon
Dams and river regulation greatly alter the downstream environment for gross primary production (GPP) because of changes in water clarity, flow, and temperature regimes. We estimated reach-scale GPP in five locations of the regulated Colorado River in Grand Canyon using an open channel model of dissolved oxygen. Benthic GPP dominates in Grand Canyon due to fast transport times and low...
Authors
Robert O. Hall, Charles B. Yackulic, Theodore A. Kennedy, Michael D. Yard, Emma J. Rosi-Marshall, Nicholas Voichick, Kathrine E. Behn
C3 and C4 plant responses to increased temperatures and altered monsoonal precipitation in a cool desert on the Colorado Plateau, USA C3 and C4 plant responses to increased temperatures and altered monsoonal precipitation in a cool desert on the Colorado Plateau, USA
Dryland ecosystems represent >40 % of the terrestrial landscape and support over two billion people; consequently, it is vital to understand how drylands will respond to climatic change. However, while arid and semiarid ecosystems commonly experience extremely hot and dry conditions, our understanding of how further temperature increases or altered precipitation will affect dryland plant...
Authors
Timothy M. Wertin, Sasha C. Reed, Jayne Belnap
The dominance of introduced plant species in the diets of migratory Galapagos tortoises increases with elevation on a human-occupied island The dominance of introduced plant species in the diets of migratory Galapagos tortoises increases with elevation on a human-occupied island
The distribution of resources and food selection are fundamental to the ecology, life history, physiology, population dynamics, and conservation of animals. Introduced plants are changing foraging dynamics of herbivores in many ecosystems often with unknown consequences. Galapagos tortoises, like many herbivores, undertake migrations along elevation gradients driven by variability in...
Authors
Stephen Blake, Anne Guezou, Sharon L. Deem, Charles B. Yackulic, Fredy Cabrera
Using motion-sensor camera technology to infer seasonal activity and thermal niche of the desert tortoise (Gopherus agassizii) Using motion-sensor camera technology to infer seasonal activity and thermal niche of the desert tortoise (Gopherus agassizii)
Understanding the relationships between environmental variables and wildlife activity is an important part of effective management. The desert tortoise (Gopherus agassizii), an imperiled species of arid environments in the southwest US, may have increasingly restricted windows for activity due to current warming trends. In summer 2013, we deployed 48 motion sensor cameras at the...
Authors
Mickey Agha, Benjamin Augustine, Jeffrey E. Lovich, David F. Delaney, Barry Sinervo, Mason O. Murphy, Joshua R. Ennen, Jessica R. Briggs, Robert J. Cooper, Steven J. Price