• Fire history of Pinus nigra in Western Anatolia: A first dendrochronological study

      Şahan, Evrim A.; Köse, Nesibe; Akkemik, Ünal; Güner, H. Tuncay; Tavşanoğlu, Çağatay; Bahar, Anıl; Trouet, Valerie; Dalfes, H. Nüzhet; Laboratory of Tree-Ring Research, University of Arizona (Elsevier BV, 2021-10)
      Forests in the Mediterranean basin frequently experience fires due to both anthropogenic and natural causes. There are concerns that the fire season will prolong in the Mediterranean basin, the fire frequency will increase with ongoing climate change, moreover, the fire regimes will shift from surface fires to local crown fires. Here, we aim to improve our understanding of the fire regime components of black pine forests in Turkey by 1) reconstructing a high-resolution fire chronology based on tree rings, 2) revealing the seasonality of fires, 3) investigating the relationship between fire and climate, and 4) comparing our reconstruction results with documentary data from forest management units. We collected 62 fire-scarred trees from three sites in Kütahya and developed a 368 year-long (1652–2019) composite fire chronology using dendrochronological methods. We found that at two sites major fire years coincided with dry years. Two major fire years (1853 and 1879) were common to all sites and two additional fire years (1822 and 1894) were found at two sites. Our results show a sharp decline in fire frequency after the beginning of the 20th century at all sites that can be attributed to increased fire suppression efforts and forest management activities in the 20th century. Our results suggest that the spread of fires has been actively suppressed since the first forest protection law in Turkey. Yet, tree-ring based and documentary data corroboration shows that seasonality did not change over the past +350 years. © 2021 Elsevier GmbH
    • Phasing in electric vehicles: Does policy focusing on operating emission achieve net zero emissions reduction objectives?

      Logan, Kathryn G.; Nelson, John D.; Brand, Christian; Hastings, Astley; Arizona Institutes of Resilience, University of Arizona (Elsevier BV, 2021-10)
      Battery electric vehicles (BEVs) are being integrated into the UK transport network to reduce operating emissions (OEs) as BEVs produce zero emission at point of use. True OEs depend upon fuel source emissions, and ‘cradle-to-grave’ life cycle emissions. This paper investigates method comparisons of a simple operation emissions model (OPEM) against a life cycle analysis (LCA) (Transport Energy and Air Pollution Model (TEAM-UK)) approach to inform on the UK's target to achieve net zero emissions. Emission comparisons from internal combustion engine vehicles (ICEVs) and BEVs between 2017 and 2050 using TEAM-UK (estimating both OEs and full LCA) and the OPEM (OEs only) across three vehicle scenarios were analysed: (S1) 100% ICEVs, (S2) new ICEVs banned from 2040, and (S3) new ICEVs banned from 2030. Both model outputs varied between scenarios. The OPEM predicted 19% more emissions in S1 (OEs only comparison). Differences between methods in S2 and S3 were minimal (<0.1% and <3% respectively). Comparing the LCA with its own OE estimate indicates OEs remain at approximately 40% of total emissions suggesting they are a strong candidate for monitoring and policy targeting. These comparisons would imply the simpler OE approach is robust for a precautionary approach to assessing changes in OEs for policy implementation impact assessments of ultra-low emission vehicle initiatives. Development of future emission policies should consider both LCA and OPEMs, as although LCAs give more complete results, OPEMs can provide rapid, low data requirement, useful policy guidance. A stringent shift towards earlier BEV adoption is recommended, however, to approach net zero emissions a mode shift away from private cars is required. © 2021 Elsevier Ltd
    • The Mesozoic exhumation history of the Karatau-Talas range, western Tian Shan, Kazakhstan-Kyrgyzstan

      Jepson, Gilby; Glorie, Stijn; Khudoley, Andrey K.; Malyshev, Sergey V.; Gillespie, Jack; Glasmacher, Ulrich A.; Carrapa, Barbara; Soloviev, Alexei V.; Collins, Alan S.; Department of Geosciences, University of Arizona (Elsevier BV, 2021-09)
      The Tian Shan mountain range maintains high topography across the Eurasian continent despite being distal to any modern plate boundary. Previous studies of the Tian Shan have revealed a history of mountain building in response to India-Asia collision which has overprinted much of its Mesozoic history. The Karatau and Talas ranges in the north-western Tian Shan represent a unique opportunity to investigate the erosional response to the Mesozoic tectonics of Central Asia. In this study, we present medium-to-low temperature thermochronology and thermal history modelling from a series of Neoproterozoic to Permian sedimentary and granitoid samples taken from the Karatau and Talas ranges. Our results identify three phases of late Paleozoic-Mesozoic deformation and exhumation: (1) a regional orogenic event in the Permian–Early Triassic (ca. 280–240 Ma) related to the final amalgamation of the Central Asian Orogenic Belt, (2) Late Triassic–Early Jurassic (ca. 230–190 Ma) reactivation in response to the collision of the Qiangtang block with the Eurasian margin, and a (3) phase of rapid basement cooling during the Late Jurassic–Early Cretaceous (ca. 160–140 Ma), associated with the closure of the Meso-Tethys Ocean. These results suggest that the Karatau and Talas ranges preserves extensive Mesozoic erosional signatures, which developed in response to Eurasian amalgamation of Central Asia and progressive closure of the Tethys Ocean.
    • Monetary Policy and Asset Price Bubbles: A Laboratory Experiment

      Galí, Jordi; Giusti, Giovanni; Noussair, Charles N.; Department of Economics, University of Arizona (Elsevier BV, 2021-09)
      Leaning-against the-wind (LAW) policies, whereby interest rates are raised in the face of a growing asset price bubble, are often advocated as a means of dampening such bubbles. On the other hand, there are theoretical arguments suggesting that such a policy could have the opposite effect (Gal í, 2014). We study the effect of monetary policy on asset price bubbles in a laboratory experiment with an overlapping generations structure. Participants in the role of the young generation allocate their endowment between two investments: a risky asset and a one-period riskless bond. The risky asset pays no dividend and thus the possibility of selling it to the next generation is its only source of value. Consequently, its price is a pure bubble. We study how variations in the interest rate affect the evolution of the bubble in an experiment with three treatments. One treatment has a fixed low interest rate, another a fixed high interest rate, and the third has a LAW interest rate policy in place. We observe that the bubble increases (decreases) when interest rates are lower (higher) in the period of a policy change. However, the opposite effect is observed in the following period, when higher (lower) interest rates are associated with greater (smaller) bubble growth. Direct measurement of expectations reveals that traders expect prices to follow previous trends and tend to correct for prior errors in their predictions. © 2021 Elsevier B.V.
    • A hybrid multiscale framework coupling multilayer dynamic reconstruction and full-dimensional models for CO2 storage in deep saline aquifers

      Zheng, Tianyuan; Guo, Bo; Shao, Haibing; Department of Hydrology and Atmospheric Sciences, University of Arizona (Elsevier BV, 2021-09)
      Numerical modeling of CO2 injection in the deep saline aquifer is computationally expensive due to the large spatial and temporal scales. To address the computational challenge, reduced-dimensional models (e.g., vertical equilibrium (VE) and dynamic reconstruction (DR) models) based on vertical integration of the full-dimensional governing equations have been developed. VE models assume rapid segregation of the injected and the resident fluids due to strong buoyancy. Conversely, DR models employ a multiscale framework that relaxes the VE assumption and captures the vertical dynamics of CO2 and brine by solving the vertical two-phase flow dynamics as one-dimensional fine-scale problems. Although DR models relax the VE assumption while maintaining much of the computational efficiency of VE models, they are thus far limited to homogeneous and layered heterogeneous formations. We present a novel hybrid framework that couples a multilayer dynamic reconstruction model and a full-dimensional model. The new hybrid framework allows simulation of CO2 injection in geological formations with local heterogeneities. It employs a full-dimensional model in local heterogeneous regions (where the full-dimensional model should be used for accuracy), while applying the dynamic reconstruction model in the rest of the domain. Numerical simulations of CO2 injection in three heterogeneous reservoirs show that the hybrid model maintains the accuracy of the conventional full-dimensional models with significantly reduced computational cost. © 2021 Elsevier B.V.
    • Multidimensional simulation of PFAS transport and leaching in the vadose zone: Impact of surfactant-induced flow and subsurface heterogeneities

      Zeng, Jicai; Guo, Bo; Department of Hydrology and Atmospheric Sciences, University of Arizona (Elsevier BV, 2021-09)
      PFAS are emergent contaminants of which the fate and transport in the environment remain poorly understood. As surfactants, adsorption at air–water and solid–water interfaces in soils complicates the retention and leaching of PFAS in the vadose zone. Recent modeling studies accounting for the PFAS-specific nonlinear adsorption processes predicted that the majority of long-chain PFAS remain in the shallow vadose zone decades after contamination ceases—in agreement with many field measurements. However, some field investigations show that long-chain PFAS have migrated to tens to a hundred meters below ground surface. These discrepancies may be attributed to model simplifications such as a one-dimensional (1D) homogeneous representation of the vadose zone. Another potentially critical process that has not been fully examined by the 1D models is how surfactant-induced flow (SIF) influences PFAS leaching in multidimensions. We develop a new three-dimensional model incorporating the PFAS-specific flow and transport processes to quantify the impact of SIF and subsurface heterogeneities. Our simulations and analyses conclude that 1) SIF has a minimal impact on the long-term leaching of PFAS in the vadose zone, 2) preferential flow pathways generated by subsurface heterogeneities lead to early arrival and accelerated leaching of (especially long-chain) PFAS, 3) the acceleration of PFAS leaching in high water-content preferential pathways or perched water above capillary barriers is more prominent than conventional contaminants due to the destruction of air–water interfaces, and 4) subsurface heterogeneities are among the primary sources of uncertainty for predicting PFAS leaching and retention in the vadose zone. © 2021 Elsevier Ltd
    • Evidentiary and theoretical foundations for virtual simulation in nursing education

      Dolan, Hanne; Amidon, Brayton J.; Gephart, Sheila M.; University of Arizona, College of Nursing (Elsevier BV, 2021-09)
      Virtual simulation has been used extensively in nursing education since the beginning of the COVID-19 pandemic due to the unavailability of clinical sites. Extant research supports substitution of up to 50% of nursing clinical hours with simulation. However, in many nursing programs virtual simulation is currently substituting more than half of traditional clinical hours, and the knowledge gaps and limitations surrounding virtual simulation exist. The purpose of this paper is to describe the evidentiary and theoretical foundations for virtual simulation. Through examination of adult learning theories, learning styles and Bloom's Revised Taxonomy, recommendations for maximizing the use of virtual simulation in the current clinical learning environment are outlined. Debriefing is a vital component of virtual simulation. Synchronous debriefing with nursing students, faculty, preceptors, and peers provides the opportunity for scaffolding to support students’ learning needs and foster reflection and evaluation to mitigate shortcomings of virtual simulation in the current clinical learning environment. © 2021 Elsevier Inc.
    • Do Foreign Component Auditors Harm Financial Reporting Quality? A Subsidiary‐Level Analysis of Foreign Component Auditor Use

      Docimo, William M.; Gunn, Joshua L.; Li, Chan; Michas, Paul N.; University of Arizona (Wiley, 2021-08-19)
      We hypothesize and find that financial reporting quality at the foreign subsidiaries of US multinational companies (MNCs) is higher when the MNC's principal auditor engages a component auditor to audit the foreign subsidiary on its behalf. An important innovation of this study is that we focus on comparing the financial reporting quality of equivalent subsidiaries with and without component auditor work. Our approach contrasts with extant studies that examine the consequences of variation in the total amount of component auditor work at the MNC level. Our results are important for two reasons. First, we provide an alternative view on the consequences of component auditor use compared to the emerging literature in this area, which typically finds a negative association between the extent of component auditor use and financial reporting quality at the MNC level. Thus, we show that a different research design, conducted at the level at which component auditors actually perform their work, yields different inferences. Second, we demonstrate that using component auditors on US MNC group audits is an avenue through which US auditing institutions can affect financial reporting quality in foreign locations. We also reconcile our subsidiary-level results to the MNC level by introducing a new MNC-level component auditor “coverage” variable. Overall, we highlight that the best way to audit a foreign subsidiary is likely to be with a component auditor in the local country, which informs the debate surrounding recently proposed PCAOB guidance.
    • Archives as Spaces of Radical Hospitality

      Lee, Jamie A.; School of Information, University of Arizona (Informa UK Limited, 2021-08-19)
      Deploying feminist notions of embodied, relational archival practices, this article critically defines and creatively unites both ‘radical’ and ‘hospitality’ as a tool for enacting generosity in archives. Drawing on the complexities of Derrida’s Of Hospitality (Cultural Memory in the Present) alongside feminist scholarship and, what Cherríe Moraga calls ‘theories of the flesh’, it elucidates the urgent work of imagining archives as spaces of radical hospitality. The article uses embodied knowledges and storytelling as an archival methodology to propose a set of elements of radical hospitality and what it means and does in and for the community archives. It attends to the creative possibilities that acknowledging the relational complexities of the archives, its collections, and its records as integral to establishing socially just and generative spaces for its records creators and its visitors. Radical hospitality becomes not only a possibility but also the lively, animated, and joyous archival body and all of its parts.
    • Nonparametric segmentation methods: Applications of unsupervised machine learning and revealed preference

      Blumberg, Joey; Thompson, Gary; Department of Agricultural and Resource Economics, University of Arizona (Wiley, 2021-08-18)
      Many recent efforts by econometricians have focused on supervised machine learning techniques to aid in empirical studies using experimental data. By contrast, this article explores the merits of unsupervised machine learning algorithms for informing ex ante policy design using observational data. We examine the extent to which groups of consumers with differing responses to economic incentives can be identified in a context of fruit and vegetable demand. Two classes of nonparametric algorithms—revealed preference and unsupervised machine learning—are compared for segmenting households in the National Consumer Panel. Nonlinear almost-ideal demand models are estimated for all segments to determine which methods group households into segments with different expenditure and price elasticities. In-sample comparisons and out-of-sample prediction results indicate methods using price-quantity data alone—without demographic, geographic, or other variables—perform better at segmenting households into groups with sizeable differences in price and expenditure responsiveness. These segmentation results suggest considerable heterogeneity in household purchasing behavior of fruits and vegetables. © 2021 Agricultural & Applied Economics Association.
    • The Evolution of Resource Provisioning in Pollination Mutualisms

      McPeek, Sarah J.; Bronstein, Judith L.; McPeek, Mark A.; Department of Ecology and Evolutionary Biology, University of Arizona (University of Chicago Press, 2021-08-18)
      Resource dynamics influence the contemporary ecology of consumer-resource mutualisms. Suites of resource traits, such as floral nectar components, also evolve in response to different selective pressures, changing the ecological dynamics of the interacting species at the evolutionary equilibrium. Here we explore the evolution of resource-provisioning traits in a biotically pollinated plant that produces nectar as a resource for beneficial consumers. We develop a mathematical model describing natural selection on two quantitative nectar traits: maximum nectar production rate and maximum nectar reservoir volume. We use this model to examine how nectar production dynamics evolve under different ecological conditions that impose varying cost-benefit regimes on resource provisioning. The model results predict that natural selection favors higher nectar production when ecological factors limit the plant or pollinator’s abundance (e.g., a lower productivity environment or a higher pollinator conversion efficiency). We also find that nectar traits evolve as a suite in which higher costs of producing one trait select for a compensatory increase in investment in the other trait. This empirically explicit approach to studying the evolution of consumer-resource mutualisms illustrates how natural selection acting via direct and indirect pathways of species interactions generates patterns of resource provisioning seen in natural systems. © 2021 The University of Chicago. All rights reserved.
    • Quasi-Locality Bounds for Quantum Lattice Systems. Part II. Perturbations of Frustration-Free Spin Models with Gapped Ground States

      Nachtergaele, Bruno; Sims, Robert; Young, Amanda; Department of Mathematics, University of Arizona (Springer Science and Business Media LLC, 2021-08-14)
      We study the stability with respect to a broad class of perturbations of gapped ground-state phases of quantum spin systems defined by frustration-free Hamiltonians. The core result of this work is a proof using the Bravyi–Hastings–Michalakis (BHM) strategy that under a condition of local topological quantum order (LTQO), the bulk gap is stable under perturbations that decay at long distances faster than a stretched exponential. Compared to previous work, we expand the class of frustration-free quantum spin models that can be handled to include models with more general boundary conditions, and models with discrete symmetry breaking. Detailed estimates allow us to formulate sufficient conditions for the validity of positive lower bounds for the gap that are uniform in the system size and that are explicit to some degree. We provide a survey of the BHM strategy following the approach of Michalakis and Zwolak, with alterations introduced to accommodate more general than just periodic boundary conditions and more general lattices. We express the fundamental condition known as LTQO by means of an indistinguishability radius, which we introduce. Using the uniform finite-volume results, we then proceed to study the thermodynamic limit. We first study the case of a unique limiting ground state and then also consider models with spontaneous breaking of a discrete symmetry. In the latter case, LTQO cannot hold for all local observables. However, for perturbations that preserve the symmetry, we show stability of the gap and the structure of the broken symmetry phases. We prove that the GNS Hamiltonian associated with each pure state has a non-zero spectral gap above the ground state. © 2021, The Author(s).
    • Privacy protections and law enforcement use of prescription drug monitoring databases

      Boustead, Anne E.; School of Government and Public Policy, University of Arizona (Wiley, 2021-08-14)
      Prescription drug monitoring programs (PDMPs) are databases that can be used by healthcare professionals to identify problematic drug-seeking behavior. Law enforcement officers can also obtain PDMP information, raising significant privacy concerns. In this paper, I use regression analysis to explore the association between state PDMP protections and law enforcement information requests. I find that while requiring law enforcement to meet a specified standard of proof prior to accessing PDMP information is associated with fewer requests, other methods of regulating law enforcement access are not. These findings provide important and novel evidence about law enforcement behavior in response to privacy protections.
    • Neither acquiescence nor defiance: Tuscan wineries' “flexible reactivity” to the Italian government's quality regulation system

      Yoo, Taeyoung; Schilke, Oliver; Bachmann, Reinhard; Eller College of Management, University of Arizona (Wiley, 2021-08-13)
      This article introduces the concept of “flexible reactivity” to describe and analyze a form of economic actors' response to multiple judgment devices. Using the example of government regulation in the Tuscan wine industry, we show that wineries can in part comply with the government's quality classifications system while, at the same time, also offering products outside the official classification system. Through this research, we provide novel insights into the role of judgment devices and contribute to a more nuanced understanding of organizational responses to institutional pressures. Extending prior institutional-complexity research, our study illustrates that organizations' reactions to judgment devices are not limited to only the two options of either acquiescence or defiance. The third option—flexibile reactivity—encompasses an explicit combination of acquiescence and defiance at the actor level. Our findings shed new light on how organizations can cope with contradictory external demands such that contrasting logics compete for organizational resources and breed heterogeneous and continuously shifting product offerings. © 2021 London School of Economics and Political Science
    • Screening barley varieties tolerant to drought stress based on tolerant indices

      Saed-Moucheshi, Armin; Pessarakli, Mohammad; Mozafari, Ali Akbar; Sohrabi, Fatemeh; Moradi, Mahsa; Marvasti, Fatemeh Barzegar; School of Plant Sciences, College of Agriculture & Life Sciences, The University of Arizona (Informa UK Limited, 2021-08-13)
      With regards to the importance of drought stress and genotype screening under stress conditions, the current study was conducted to evaluate barley varieties in response to drought stress and find the tolerant ones, along with the determination of the influential ratio of each yield component on grain yield under both conditions. Accordingly, 25 barley varieties were evaluated under two water regimes including 100% (normal condition) and 50% (drought stress) of field capacity. Cluster analysis grouped the genotypes into four and three clusters under normal and stressful conditions, respectively, indicating that drought might limit the phenotypic variability among the verities. Based on the feature selection, spike weight, leaf area, and grain number per spike under normal condition, and the number of fertile spikelets and grain number per spike under water deficit conditions were the most influential traits on grain yield which verifies the impact of drought on the relationship among the agronomic traits. The overall results of biplot showed that varieties Danesiah, Eram, and Yoosef, which had higher grain yield than average for both conditions, were suitable varieties in order to be screened for both normal and drought stress conditions. Finally, according to the results of correlation of tolerance indices with grain yield, stress tolerance index (STI), harmonic mean productivity (HMP), and mean productivity (MP) which showed high correlations with grain yield under both conditions can be introduced as proper indices for screening tolerance genotypes of barley. © 2021 Taylor & Francis Group, LLC.
    • ProcData: An R Package for Process Data Analysis

      Tang, Xueying; Zhang, Susu; Wang, Zhi; Liu, Jingchen; Ying, Zhiliang; University of Arizona (Springer, 2021-08-11)
      Process data refer to data recorded in log files of computer-based items. These data, represented as timestamped action sequences, keep track of respondents’ response problem-solving behaviors. Process data analysis aims at enhancing educational assessment accuracy and serving other assessment purposes by utilizing the rich information contained in response processes. The R package ProcData presented in this article is designed to provide tools for inspecting, processing, and analyzing process data. We define an S3 class ‘proc’ for organizing process data and extend generic methods summary and print for ‘proc’. Feature extraction methods for process data are implemented in the package for compressing information in the irregular response processes into regular numeric vectors. ProcData also provides functions for making predictions from neural-network-based sequence models. In addition, a real dataset of response processes from the climate control item in the 2012 Programme for International Student Assessment is included in the package. © 2021, The Psychometric Society.
    • Why Are Bidder Termination Provisions Included In Takeovers?

      Chen, Zhiyao; Mahmudi, Hamed; Virani, Aazam; Zhao, Xiaofei; University of Arizona, Eller College of Management (Cambridge University Press (CUP), 2021-08-10)
      We present a rationale for bidder termination provisions that considers their effect on bidders' and targets' joint takeover gains. The provision's inclusion can create value by enabling termination when the target becomes less valuable to the bidder than on its own, but creates a trade-off because termination may also occur when the target is more valuable to the bidder than on its own. This trade-off explains why the provision is included in only some deals, and explains variation in termination fees. Inclusion of the provision is associated with larger combined announcement returns, provided that the termination fee is priced appropriately.
    • Theoretical analysis of Fresnel reflection and transmission in the presence of gain media

      Mansuripur, Masud; Jakobsen, Per K.; College of Optical Sciences, The University of Arizona (Springer Science and Business Media LLC, 2021-08-09)
      When a monochromatic electromagnetic plane-wave arrives at the flat interface between its transparent host (i.e., the incidence medium) and an amplifying (or gainy) second medium, the incident beam splits into a reflected wave and a transmitted wave. In general, there is a sign ambiguity in connection with the k-vector of the transmitted beam, which requires at the outset that one decide whether the transmitted beam should grow or decay as it recedes from the interface. The question has been posed and addressed most prominently in the context of incidence at large angles from a dielectric medium of high refractive index onto a gain medium of lower refractive index. Here, the relevant sign of the transmitted k-vector determines whether the evanescent-like waves within the gain medium exponentially grow or decay away from the interface. We examine this and related problems in a more general setting, where the incident beam is taken to be a finite-duration wavepacket whose footprint in the interfacial plane has a finite width. Cases of reflection from and transmission through a gainy slab of finite-thickness as well as those associated with a semi-infinite gain medium will be considered. The broadness of the spatiotemporal spectrum of our incident wavepacket demands that we develop a general strategy for deciding the signs of all the k-vectors that enter the gain medium. Such a strategy emerges from a consideration of the causality constraint that is naturally imposed on both the reflected and transmitted wavepackets. © 2021, The Optical Society of Japan.
    • A priori and a posteriori error analysis of an unfitted HDG method for semi-linear elliptic problems

      Sánchez, Nestor; Sánchez-Vizuet, Tonatiuh; Solano, Manuel E.; Department of Mathematics, The University of Arizona (Springer Science and Business Media LLC, 2021-08-07)
      We present a priori and a posteriori error analysis of a high order hybridizable discontinuous Galerkin (HDG) method applied to a semi-linear elliptic problem posed on a piecewise curved, non polygonal domain. We approximate Ω by a polygonal subdomain Ω h and propose an HDG discretization, which is shown to be optimal under mild assumptions related to the non-linear source term and the distance between the boundaries of the polygonal subdomain Ω h and the true domain Ω. Moreover, a local non-linear post-processing of the scalar unknown is proposed and shown to provide an additional order of convergence. A reliable and locally efficient a posteriori error estimator that takes into account the error in the approximation of the boundary data of Ω h is also provided.
    • Factors influencing detectability and responses of Elf Owls to playback of conspecific vocalizations

      Flesch, Aaron D.; Boone, John; Pluym, David Vander; Sabin, Laura Beth; School of Natural Resources and the Environment, University of Arizona (Wiley, 2021-08-06)
      Broadcasting conspecific vocalizations is commonly used to survey secretive, inconspicuous, and uncommon species of birds, but information about how response behaviors vary across temporal and broad spatial gradients is limited for most species despite the importance of such data for guiding survey efforts. We assessed response patterns and detection probability of Elf Owls (Micrathene whitneyi) across broad ecological gradients in the Sonoran and Chihuahuan deserts of Arizona that spanned much of their breeding range in the United States. From March to June 2015–2017, we examined response times and distances of an estimated 587 Elf Owls detected during playback surveys at 1488 stations along 121 transects (193 km). Additionally, from April to June 2010–2011 and 2016–2017, we examined detection probability during 255 playback experiments at occupied nests and modeled the influence of spatial, temporal, moon illumination, vegetation, conspecific densities, and weather-related factors on detection probability. During transect surveys, response times were rapid (mean = 2.0 min), with 75% of detections within 3 min. Owls often responded close to broadcast stations (mean = 103 m), with only 25% of responses at distances > 140 m and none > 400 m. Response times were faster and from greater distances in the more arid western portion of our study area. During playback experiments at nests, detection probability averaged 0.65 and declined with increasing time of night, time of season, and noise levels. Detection probability also declined with increasing distance from target owls, but at lower rates in the western than the eastern portion of our study area. Spatial variation in detectability was primarily due to surveyors failing to detect responding owls in areas with higher owl densities in more resource-rich environments in the east, not differences in underlying responsiveness. Our results suggest that 5 or 6 min surveys within ˜4 h of sunset and early in the breeding season will be most effective and that spacing survey stations from 100 to 150 m apart, depending on local densities and study objectives, is adequate for estimating occupancy and abundance with relatively low false absence rates.