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Publication Metadata only A global analysis of the determinants of alien geographical range size in birds(Wiley, 2016) Dyer, Ellie E.; Franks, Victoria; Cassey, Phillip; Collen, Ben; Cope, Robert C.; Jones, Kate E.; Blackburn, Tim M.; Department of Molecular Biology and Genetics; Şekercioğlu, Çağan Hakkı; Faculty Member; Department of Molecular Biology and Genetics; College of Sciences; 327589Aim Determining the causes of range size variation in the distributions of alien species is important for understanding the spread of invasive species. Factors influencing alien range size have been explored for some species at a regional level, but to date there has been no global analysis of an entire class. Here, we present such an analysis for birds, testing for the effects of introduction event, location and species-level variables on alien range sizes. Location Global. Methods We used a novel dataset on the global distributions of alien bird species to test for relationships between alien range size and colonization pressure, residence time, extent of the global climatic niche, native range size, body mass and specialization, using a statistical approach based on phylogenetic generalized least squares models. We performed this analysis globally, and for separate biogeographical realms. Results Approximately half of the variation in alien bird range size is explained by colonization pressure in univariate analysis. We identified consistent effects of higher colonization pressure at global and realm levels, as well as support for effects of native range size and residence time. We found less support for effects of body mass, specialization or extent of the global climatic niche on alien range size. Main conclusions Alien bird range sizes are generally small relative to their native range sizes, and many are continuing to expand. Nevertheless, current variation is predictable, most strongly by the event-level factor of colonization pressure. Whether a species is widespread is a better predictor of alien range size than whether a species could be widespread (estimated by global climatic niche extent), while we also find effects of residence time on alien range size. These relationships may help to identify those alien species that are more likely to spread and hence have greater environmental and economic impacts where they have been introduced.Publication Open Access Aggression and multi-modal signaling in noise in a common urban songbird(Springer, 2022) Department of Media and Visual Arts; Department of Psychology; Akçay, Çağlar; Yelimlieş, Alper; Önsal, Çağla; Faculty Member; Department of Media and Visual Arts; Department of Psychology; College of Social Sciences and Humanities; 272053; N/A; N/AAnthropogenic noise may disrupt signals used to mediate aggressive interactions, leading to more physical aggression between opponents. One solution to this problem is to switch signaling effort to a less noisy modality (e.g., the visual modality). In the present study, we investigate aggressive behaviors and signaling in urban and rural male European robins (Erithacus rubecula) in response to simulated intrusions with or without experimental noise. First, we predicted that urban birds, living in noisier habitats, would be generally more aggressive than rural birds. We also predicted that during simulated intrusions with experimental noise, robins would increase their physical aggression and show a multi-modal shift, i.e., respond with more visual threat displays and sing fewer songs. Finally, we expected the multi-modal shift in response to noise to be stronger in urban birds compared to rural birds. The results showed that urban birds were more aggressive than rural robins, but an increase in aggression with experimental noise was seen only in the rural birds. Urban but not rural birds decreased their song rate in response to noise. Contrary to the multi-modal shift hypothesis, however, there was no evidence of a concurrent increase in visual signals. These results point to a complex role of immediate plasticity and longer-term processes in affecting communication during aggressive interactions under anthropogenic noise. Significance statement Human activity has an enormous effect on wildlife, including on their social behavior. Animals living in urban areas often tend to be more aggressive than those living in rural areas, which may be due to urban acoustic noise making communication between individuals more difficult. In a study with a common songbird, the European robin, we investigated the role of urban acoustic noise in aggression and territorial communication. Urban robins were more aggressive than rural robins, and additional noise in the territory increased aggression in rural but not urban robins. While urban robins decreased their singing effort with additional noise, they did not increase visual signals concurrently. These results suggest that noise can indeed make animals behave more aggressively although the effect may depend on how noisy it is already. These results further our understanding of how human-made noise changes animal communication and social behavior.Publication Metadata only Are signals of aggressive intent less honest in urban habitats?(Oxford Univ Press Inc, 2020) Beck, Michelle L.; Sewall, Kendra B.; Department of Psychology; Akçay, Çağlar; Faculty Member; Department of Psychology; College of Social Sciences and Humanities; 272053How anthropogenic change affects animal social behavior, including communication is an important question. Urban noise often drives shifts in acoustic properties of signals but the consequences of noise for the honesty of signals-that is, how well they predict signaler behavior-is unclear. Here we examine whether honesty of aggressive signaling is compromised in male urban song sparrows (Melospiza melodia). Song sparrows have two honest close-range signals: the low amplitude soft songs (an acoustic signal) and wing waves (a visual signal), but whether the honesty of these signals is affected by urbanization has not been examined. If soft songs are less effective in urban noise, we predict that they should predict attacks less reliably in urban habitats compared to rural habitats. We confirmed earlier findings that urban birds were more aggressive than rural birds and found that acoustic noise was higher in urban habitats. Urban birds still sang more soft songs than rural birds. High rates of soft songs and low rates of loud songs predicted attacks in both habitats. Thus, while urbanization has a significant effect on aggressive behaviors, it might have a limited effect on the overall honesty of aggressive signals in song sparrows. We also found evidence for a multimodal shift: urban birds tended to give proportionally more wing waves than soft songs than rural birds, although whether that shift is due to noise-dependent plasticity is unclear. These findings encourage further experimental study of the specific variables that are responsible for behavioral change due to urbanization.Publication Metadata only Author Correction: urbanization, climate and species traits shape mammal communities from local to continental scales(Nature Portfolio, 2024) Haight JD, Hall SJ, Fidino M, Adalsteinsson SA, Ahlers AA, Angstmann J, Anthonysamy WJB, Biro E, Collins MK, Dugelby B, Gallo T, Green AM, Hartley L, Jordan MJ, Kay CAM, Lehrer EW, Long RA, MacDougall B, Magle SB, Minier DE, Mowry C, Murray M, Nininger K, Pendergast ME, Remine KR, Ryan T, Salsbury C, Sander HA, Schell CJ, Shier CJ, Simon KC, St Clair CC, Stankowich T, Stevenson CJ, Wayne L, Will D, Williamson J, Wilson L, Zellmer AJ, Lewis JS.; Department of Molecular Biology and Genetics; Şekercioğlu, Çağan Hakkı; Department of Molecular Biology and Genetics; College of SciencesN/APublication Metadata only Avian responses to selective logging shaped by species traits and logging practices(The Royal Society, 2015) Burivalova, Zuzana; Lee, Tien Ming; Giam, Xingli; Wilcove, David S.; Koh, Lian Pin; Department of Molecular Biology and Genetics; Şekercioğlu, Çağan Hakkı; Faculty Member; Department of Molecular Biology and Genetics; College of Sciences; 327589Selective logging is one of the most common forms of forest use in the tropics. Although the effects of selective logging on biodiversity have been widely studied, there is little agreement on the relationship between life-history traits and tolerance to logging. In this study, we assessed how species traits and logging practices combine to determine species responses to selective logging, based on over 4000 observations of the responses of nearly 1000 bird species to selective logging across the tropics. Our analysis shows that species traits, such as feeding group and body mass, and logging practices, such as time since logging and logging intensity, interact to influence a species' response to logging. Frugivores and insectivores were most adversely affected by logging and declined further with increasing logging intensity. Nectarivores and granivores responded positively to selective logging for the first two decades, after which their abundances decrease below pre-logging levels. Larger species of omnivores and granivores responded more positively to selective logging than smaller species from either feeding group, whereas this effect of body size was reversed for carnivores, herbivores, frugivores and insectivores. Most importantly, species most negatively impacted by selective logging had not recovered approximately 40 years after logging cessation. We conclude that selective timber harvest has the potential to cause large and long-lasting changes in avian biodiversity. However, our results suggest that the impacts can be mitigated to a certain extent through specific forest management strategies such as Llengthening the rotation cycle and implementing reduced impact logging.Publication Open Access Avian use of agricultural areas as migration stopover sites: a review of crop management practices and ecological correlates(Frontiers, 2021) Blount, J. David; Horns, Joshua J.; Kittelberger, Kyle D.; Neate-Clegg, Montague H. C.; Department of Molecular Biology and Genetics; Şekercioğlu, Çağan Hakkı; Faculty Member; Department of Molecular Biology and Genetics; College of Sciences; 327589An estimated 17% of migratory bird species are threatened or near threatened with extinction. This represents an enormous potential loss of biodiversity and cost to human societies due to the economic benefits that birds provide through ecosystem services and ecotourism. Conservation of migratory bird species presents many unique challenges, as these birds rely on multiple geographically distinct habitats, including breeding grounds, non-breeding grounds, and stopover sites during migration. In particular, stopover habitats are seldom studied relative to breeding and non-breeding habitats, despite their importance as refueling stations for migratory birds. In this study, we summarize the current research on the use of temporary primary crops by birds during migration and we assess the species characteristics and agricultural practices most often associated with the use of cropland as stopover habitat. First, we conducted a systematic review of the literature to document the effects various farming practices and crop types have on the abundance and diversity of migratory birds using agricultural areas for stopovers. Second, we analyzed the ecological correlates of bird species in the Northern Hemisphere that predict which species may use these areas while migrating. We ran a GLMM to test whether primary diet, diet breadth, primary habitat, habitat breadth, or realm predicted stopover use of agricultural areas. Our review suggests that particular crop types (principally rice, corn, and sunflower), as well as farming practices that result in higher non-cultivated plant diversity, encourage the use of agricultural areas by migrating birds. We found that cropland is used as stopover habitat by bird species that can utilize a large breadth of habitats, as well as species with preferences for habitat similar in structure to agricultural areas.Publication Open Access Combining models of environment, behavior, and physiology to predict tissue hydrogen and oxygen isotope variance among individual terrestrial animals(Frontiers, 2020) Magozzi, Sarah; Vander Zanden, Hannah B.; Wunder, Michael B.; Trueman, Clive N.; Pinney, Kailee; Peers, Dori; Dennison, Philip E.; Horns, Joshua J.; Bowen, Gabriel J.; Department of Molecular Biology and Genetics; Şekercioğlu, Çağan Hakkı; Faculty Member; Department of Molecular Biology and Genetics; College of SciencesVariations in stable hydrogen and oxygen isotope ratios in terrestrial animal tissues are used to reconstruct origin and movement. An underlying assumption of these applications is that tissues grown at the same site share a similar isotopic signal, representative of the location of their origin. However, large variations in tissue isotopic compositions often exist even among conspecific individuals within local populations, which complicates origin and migration inferences. Field-data and correlation analyses have provided hints about the underlying mechanisms of within-site among-individual isotopic variance, but a theory explaining the causes and magnitude of such variance has not been established. Here we develop a mechanistic modeling framework that provides explicit predictions of the magnitude, patterns, and drivers of isotopic variation among individuals living in a common but environmentally heterogeneous habitat. The model toolbox includes isoscape models of environmental isotopic variability, an agent-based model of behavior and movement, and a physiology-biochemistry model of isotopic incorporation into tissues. We compare model predictions against observed variation in hatch-year individuals of the songbird Spotted Towhee (Pipilo maculatus) in Red Butte Canyon, Utah, and evaluate the ability of the model to reproduce this variation under different sets of assumptions. Only models that account for environmental isotopic variability predict a similar magnitude of isotopic variation as observed. Within the modeling framework, behavioral rules and properties govern how animals nesting in different locations acquire resources from different habitats, and birds nesting in or near riparian habitat preferentially access isotopically lighter resources than those associated with the meadow and slope habitats, which results in more negative body water and tissue isotope values. Riparian nesters also have faster body water turnover and acquire more water from drinking (vs. from food), which exerts a secondary influence on their isotope ratios. Thus, the model predicts that local among-individual isotopic variance is linked first to isotopic heterogeneity in the local habitat, and second to how animals sample this habitat during foraging. Model predictions provide insight into the fundamental mechanisms of small-scale isotopic variance and can be used to predict the utility of isotope-based methods for specific groups or environments in ecological and forensic research.Publication Open Access Counter-interception and counter-exploitation features of noise radar technology(Multidisciplinary Digital Publishing Institute (MDPI), 2021) Galati, Gaspare; Pavan, Gabriele; Wasserzier, Christoph; Department of Electrical and Electronics Engineering; Savcı, Kubilay; Department of Electrical and Electronics Engineering; Graduate School of Sciences and EngineeringIn defense applications, the main features of radars are the Low Probability of Intercept (LPI) and the Low Probability of Exploitation (LPE). The counterpart uses more and more capable intercept receivers and signal processors thanks to the ongoing technological progress. Noise Radar Technology (NRT) is probably a very effective answer to the increasing demand for operational LPI/LPE radars. The design and selection of the radiated waveforms, while respecting the prescribed spectrum occupancy, has to comply with the contrasting requirements of LPI/LPE and of a favorable shape of the ambiguity function. Information theory seems to be a “technologically agnostic” tool to attempt to quantify the LPI/LPE capability of noise waveforms with little, or absent, a priori knowledge of the means and the strategies used by the counterpart. An information theoretical analysis can lead to practical results in the design and selection of NRT waveforms.Publication Metadata only Determinants of data deficiency in the impacts of alien bird species(Wiley, 2018) Evans, Thomas; Pigot, Alex; Kumschick, Sabrina; Blackburn, Tim M.; Department of Molecular Biology and Genetics; Şekercioğlu, Çağan Hakkı; Faculty Member; Department of Molecular Biology and Genetics; College of Sciences; 327589To identify the factors that influence the availability of data on the negative impacts of alien bird species, in order to understand why more than 70% are currently classified as Data Deficient (DD) by the Environmental Impact Classification of Alien Taxa (EICAT) protocol. Information on factors hypothesised to influence the availability of impact data were collated for 344 alien bird species (107 with impact data and 237 DD). These data were analysed using mixed effects models accounting for phylogenetic non-independence of species (MCMCglmm). Data deficiency in the negative impacts of alien birds is not randomly distributed. Residence time, relative brain size and alien range size were found to be strongly related to the availability of data on impacts. The availability of data on the negative impacts of alien birds is mainly influenced by the spatial and temporal extents of their alien ranges. The results of this study suggest that the impacts of some DD alien birds are likely to be minor (e.g. species with comparatively long residence times as aliens, such as the common waxbill Estrilda astrild and the Java sparrow Padda oryzivora). However, the results also suggest that some DD alien birds may have damaging impacts (e.g. species from orders of alien birds known for their impacts to biodiversity but with comparatively small alien ranges, such as the New Caledonian crow Corvus moneduloides). This implies that at least some DD alien birds may have impacts that are being overlooked. Studies examining the traits that influence the severity of alien bird impacts are needed to help to predict which DD species are more likely to impact upon biodiversity.Publication Metadata only Ecological and biogeographical predictors of taxonomic discord across the world's birds(Wiley, 2021) Neate-Clegg, Montague H. C.; Blount, J. David; Department of Molecular Biology and Genetics; Şekercioğlu, Çağan Hakkı; Faculty Member; Department of Molecular Biology and Genetics; College of Sciences; 327589Aim Species delimitation is fundamental to biology, but disagreement in species concepts and the application of those concepts can lead to substantial variation in species lists, with important implications for conservation. For birds, there are four widely used global checklists that vary in length and application. Here, we investigate the biogeographical and ecological predictors of taxonomic disagreement between the four world bird species lists. Location Global. Time period Present. Major taxa studied Birds. Methods We determined taxonomic agreement based on whether each bird species name represented only one species ('agreement'), that is, no authorities have split the species, or represented multiple species ('disagreement') including disputed splits recognised by some authorities. We examined taxonomic agreement for all birds and for each family and biogeographical region. We then modelled taxonomic agreement as a function of six biogeographical and ecological variables: latitude, island endemism, log(mass), forest dependency, primary diet, and migratory status. Results Overall taxonomic agreement was 89.5%, and the remaining 10th of taxonomic names represented disputed splits upon which the four authorities disagreed. We found that taxonomic agreement was lowest for species in Southeast Asia/Australasia and the Southern Ocean, understudied regions where islands have driven high levels of cryptic diversification. In contrast, agreement was highest in the temperate Northern Hemisphere where diversity is lower and research is more extensive. Agreement was also higher for large, migratory species living in open habitats. Main conclusions Taxonomic agreement was higher for species that are easier to study such as large, temperate species from open habitats. In addition, agreement was lower for lineages that are more likely to undergo cryptic divergence such as island endemics with intermediate forest dependency and mobility. Species with these traits should be the focus of taxonomic research in order to achieve reconciliation of the world's bird lists and to better conserve extant biodiversity.