Mojave desert tortoise (Gopherus agassizii) thermal ecology and reproductive success along a rainfall cline

Desert resource environments (e.g. microclimates, food) are tied to limited, highly localized rainfall regimes which generate microgeographic variation in the life histories of inhabitants. Typically, enhanced growth rates, reproduction and survivorship are observed in response to increased resource availability in a variety of desert plants and short‐lived animals. We examined the thermal ecology and reproduction of US federally threatened Mojave desert tortoises (Gopherus agassizii), long‐lived and large‐bodied ectotherms, at opposite ends of a 250‐m elevation‐related rainfall cline within Ivanpah Valley in the eastern Mojave Desert, California, USA. Biophysical operative environments in both the upper‐elevation, “Cima,” and the lower‐elevation, “Pumphouse,” plots corresponded with daily and seasonal patterns of incident solar radiation. Cima received 22% more rainfall and contained greater perennial vegetative cover, which conferred 5°C‐cooler daytime shaded temperatures. In a monitored average rainfall year, Cima tortoises had longer potential activity periods by up to several hours and greater ephemeral forage. Enhanced resource availability in Cima was associated with larger‐bodied females producing larger eggs, while still producing the same number of eggs as Pumphouse females. However, reproductive success was lower in Cima because 90% of eggs were depredated versus 11% in Pumphouse, indicating that predatory interactions produced counter‐gradient variation in reproductive success across the rainfall cline. Land‐use impacts on deserts (e.g. solar energy generation) are increasing rapidly, and conservation strategies designed to protect and recover threatened desert inhabitants, such as desert tortoises, should incorporate these strong ecosystem‐level responses to regional resource variation in assessments of habitat for prospective development and mitigation efforts.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111753/1/inz212132.pd

Testing hypotheses of invasion pathways of the ladybird Harmonia axyridis into and across South Africa

Harmonia axyridis is an invasive beetle (Coleoptera: Coccinellidae), native to Asia, that has established on four continents beyond its native range and was first observed in South Africa in 2001. Using microsatellite data and a comprehensive geographic coverage of international (17 locations) and South African (14 locations) beetle samples, we inferred the source of colonists invading South Africa and the beetle’s movement within the country. Genetic structure analyses suggest that this species’ populations in South Africa are derived from admixture between beetles originating from eastern North America (which acted as a bridgehead population) and another population not directly sampled in our study. Genetic admixture prior its invasion into South Africa, along with the possibility of multiple introductions from the bridgehead population, may explain the high genetic diversity estimates for South African H. axyridis (HE = 0.582–0.625) compared to beetles from the native range (HE = 0.440–0.636). Harmonia axyridis appear to be frequently exchanging genetic material across South Africa, with no clear genetic structure between sampled locations. However, evidence of weak isolation-by-distance within South Africa suggests that beetles are dispersing less frequently between locations that are furthest apart. This study supports previous findings on global invasion pathways in this species but provides new insights in the context of the invasion in South Africa. We highlight how mixing of distinct lineages from divergent origins prior to the invasion into South Africa has augmented genetic diversity in the region. The high dispersal rates and large effective population sizes inferred from genetic markers suggest that slowing the spread or reducing population abundances of the species in South Africa will be challenging without an integrated, multi-faceted management approach.https://link.springer.com/journal/10530hj2024Forestry and Agricultural Biotechnology Institute (FABI)Zoology and EntomologySDG-15:Life on lan

Navigating through the r packages for movement

Case No. 900052-CA Category No. 14b APPEAL FROM AN ORDER OF SUMMARY JUDGMENT AND DISMISSAL OF COMPLAINT WITH PREJUDICE OF THE SECOND JUDICIAL DISTRICT COURT FOR DAVIS COUNTY, STATE OF UTAH JUDGE DOUGLAS L. CORNABY REPLY BRIEF OF APPELLANT

Predicted decrease in global climate suitability masks regional complexity of invasive fruit fly species response to climate change

Climate change affects the rate of insect invasions as well as the abundance, distribution and impacts of such invasions on a global scale. Among the principal analytical approaches to predicting and understanding future impacts of biological invasions are Species Distribution Models (SDMs), typically in the form of correlative Ecological Niche Models (ENMs). An underlying assumption of ENMs is that speciesenvironment relationships remain preserved during extrapolations in space and time, although this is widely criticised. The semi-mechanistic modelling platform, CLIMEX, employs a top-down approach using species ecophysiological traits and is able to avoid some of the issues of extrapolation, making it highly applicable to investigating biological invasions in the context of climate change. The tephritid fruit flies (Diptera: Tephritidae) comprise some of the most successful invasive species and serious economic pests around the world. Here we project 12 tephritid species CLIMEX models into future climate scenarios to examine overall patterns of climate suitability and forecast potential distributional changes for this group. We further compare the aggregate response of the group against species-specific responses. We then consider additional drivers of biological invasions to examine how invasion potential is influenced by climate, fruit production and trade indices. Considering the group of tephritid species examined here, climate change is predicted to decrease global climate suitability and to shift the cumulative distribution poleward. However, when examining species-level patterns, the predominant directionality of range shifts for 11 of the 12 species is eastward. Most notably, management will need to consider regional changes in fruit fly species invasion potential where high fruit production, trade indices and predicted distributions of these flies overlap.http://link.springer.com/journal/105302017-04-30hb2016Forestry and Agricultural Biotechnology Institute (FABI)Zoology and Entomolog

Sex-specific effects of wind on the flight decisions of a sexually-dimorphic soaring bird

1. In a highly dynamic airspace, flying animals are predicted to adjust foraging behaviour to variable wind conditions to minimize movement costs. 2. Sexual size dimorphism is widespread in wild animal populations, and for large soaring birds which rely on favourable winds for energy‐efficient flight, differences in morphology, wing loading and associated flight capabilities may lead males and females to respond differently to wind. However, the interaction between wind and sex has not been comprehensively tested. 3. We investigated, in a large sexually dimorphic seabird which predominantly uses dynamic soaring flight, whether flight decisions are modulated to variation in winds over extended foraging trips, and whether males and females differ. 4. Using GPS loggers we tracked 385 incubation foraging trips of wandering albatrosses Diomedea exulans , for which males are c . 20% larger than females, from two major populations (Crozet and South Georgia). Hidden Markov models were used to characterize behavioural states—directed flight, area‐restricted search (ARS) and resting—and model the probability of transitioning between states in response to wind speed and relative direction, and sex. 5. Wind speed and relative direction were important predictors of state transitioning. Birds were much more likely to take off (i.e. switch from rest to flight) in stronger headwinds, and as wind speeds increased, to be in directed flight rather than ARS. Males from Crozet but not South Georgia experienced stronger winds than females, and males from both populations were more likely to take‐off in windier conditions. 6. Albatrosses appear to deploy an energy‐saving strategy by modulating taking‐off, their most energetically expensive behaviour, to favourable wind conditions. The behaviour of males, which have higher wing loading requiring faster speeds for gliding flight, was influenced to a greater degree by wind than females. As such, our results indicate that variation in flight performance drives sex differences in time–activity budgets and may lead the sexes to exploit regions with different wind regimes

How melanism affects the sensitivity of lizards to climate change

1. The impact of climate change on global biodiversity is firmly established, but the differential effect of climate change on populations within the same species is rarely considered. In ectotherms, melanism (i.e. darker integument due to heavier deposition of melanin) can significantly influence thermoregulation, as dark individuals generally heat more and faster than bright ones. Therefore, darker ectotherms might be more susceptible to climate change. 2. Using the colour-polyphenic lizard Karusasaurus polyzonus (Squamata: Cordylidae), we hypothesized that, under future climatic projections, darker populations will decrease their activity time more than brighter ones due to their greater potential for overheating. 3. To test this, we mechanistically modelled the body temperatures of 56 individuals from five differently coloured populations under present and future climate conditions. We first measured morphological traits and integumentary reflectance from live animals, and then collected physiological data from the literature. We used a biophysical model to compute activity time of individual lizards as proxy for their viability, and thereby predict how different populations will cope with future climate conditions. 4. Contrary to our expectations, we found that all populations will increase activity time and, specifically, that darker populations will become relatively more active than bright ones. This suggests that darker populations of K. polyzonus may benefit from global warming. 5. Our study emphasizes the importance of accounting for variation between populations when studying responses to climate change, as we must consider these variations to develop efficient and specific conservation strategies

Opportunities for behavioral rescue under rapid environmental change

Laboratory measurements of physiological and demographic tolerances are important in understanding the impact of climate change on species diversity; however, it has been recognized that forecasts based solely on these laboratory estimates overestimate risk by omitting the capacity for species to utilize microclimatic variation via behavioral adjustments in activity patterns or habitat choice. The complex, and often context‐dependent nature, of microclimate utilization has been an impediment to the advancement of general predictive models. Here, we overcome this impediment and estimate the potential impact of warming on the fitness of ectotherms using a benefit/cost trade‐off derived from the simple and broadly documented thermal performance curve and a generalized cost function. Our framework reveals that, for certain environments, the cost of behavioral thermoregulation can be reduced as warming occurs, enabling behavioral buffering (e.g., the capacity for behavior to ameliorate detrimental impacts) and “behavioral rescue” from extinction in extreme cases. By applying our framework to operative temperature and physiological data collected at an extremely fine spatial scale in an African lizard, we show that new behavioral opportunities may emerge. Finally, we explore large‐scale geographic differences in the impact of behavior on climate‐impact projections using a global dataset of 38 insect species. These multiple lines of inference indicate that understanding the existing relationship between thermal characteristics (e.g., spatial configuration, spatial heterogeneity, and modal temperature) is essential for improving estimates of extinction risk

GlobTherm, a global database on thermal tolerances for aquatic and terrestrial organisms

CITATION: Bennett, J. M., et al. 2018. GlobTherm, a global database on thermal tolerances for aquatic and terrestrial organisms. Scientific Data, 5:180022, doi:10.1038/sdata.2018.22.The original publication is available at https://www.nature.comHow climate affects species distributions is a longstanding question receiving renewed interest owing to the need to predict the impacts of global warming on biodiversity. Is climate change forcing species to live near their critical thermal limits? Are these limits likely to change through natural selection? These and other important questions can be addressed with models relating geographical distributions of species with climate data, but inferences made with these models are highly contingent on non-climatic factors such as biotic interactions. Improved understanding of climate change effects on species will require extensive analysis of thermal physiological traits, but such data are both scarce and scattered. To overcome current limitations, we created the GlobTherm database. The database contains experimentally derived species’ thermal tolerance data currently comprising over 2,000 species of terrestrial, freshwater, intertidal and marine multicellular algae, plants, fungi, and animals. The GlobTherm database will be maintained and curated by iDiv with the aim to keep expanding it, and enable further investigations on the effects of climate on the distribution of life on Earth.https://www.nature.com/articles/sdata201822Publisher's versio

The harlequin ladybird, Harmonia axyridis: global perspectives on invasion history and ecology

The harlequin ladybird, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), is native to Asia but has been intentionally introduced to many countries as a biological control agent of pest insects. In numerous countries, however, it has been introduced unintentionally. The dramatic spread of H. axyridis within many countries has been met with considerable trepidation. It is a generalist top predator, able to thrive in many habitats and across wide climatic conditions. It poses a threat to biodiversity, particularly aphidophagous insects, through competition and predation, and in many countries adverse effects have been reported on other species, particularly coccinellids. However, the patterns are not consistent around the world and seem to be affected by many factors including landscape and climate. Research on H. axyridis has provided detailed insights into invasion biology from broad patterns and processes to approaches in surveillance and monitoring. An impressive number of studies on this alien species have provided mechanistic evidence alongside models explaining large-scale patterns and processes. The involvement of citizens in monitoring this species in a number of countries around the world is inspiring and has provided data on scales that would be otherwise unachievable. Harmonia axyridis has successfully been used as a model invasive alien species and has been the inspiration for global collaborations at various scales. There is considerable scope to expand the research and associated collaborations, particularly to increase the breadth of parallel studies conducted in the native and invaded regions. Indeed a qualitative comparison of biological traits across the native and invaded range suggests that there are differences which ultimately could influence the population dynamics of this invader. Here we provide an overview of the invasion history and ecology of H. axyridis globally with consideration of future research perspectives. We reflect broadly on the contributions of such research to our understanding of invasion biology while also informing policy and people.  Additional co-authors: Artur Gil, Audrey A. Grez, Thomas Guillemaud, Danny Haelewaters, Annette Herz, Alois Honek, Andy G. Howe, Cang Hui, William D. Hutchison, Marc Kenis, Robert L. Koch, Jan Kulfan, Lori Lawson Handley, Eric Lombaert, Antoon Loomans, John Losey, Alexander O. Lukashuk, Dirk Maes, Alexandra Magro, Gilles San Martin, Zdenka Martinkova, Ingrid A. Minnaar, Oldřich Nedved, Marina J. Orlova-Bienkowskaja, Naoya Osawa, Wolfgang Rabitsch, Hans Peter Ravn, Gabriele Rondoni, Steph L. Rorke, Sergey K. Ryndevich, May-Guri Saethre, John J. Sloggett, Antonio Onofre Soares, Riaan Stals, Axel Vandereycken, Paul van Wielink, Sandra Viglášová, Peter Zach, Ilya A. Zakharov, Tania Zaviezo, Zihua Zha

GlobTherm, a global database on thermal tolerances for aquatic and terrestrial organisms

This database includes thermal tolerance metrics for 2,133 species of multicellular algae, plants, fungi, and animals in 43 classes, 203 orders and 525 families from both aquatic, and terrestrial realms, extracted from published studies. Abbreviated citations are included in the 'REF_min' and 'REF_max' variable in the data file. For full citations, please see the attached workbook, "References_1_09_2017.xlsx". The data are available in both Excel and CSV formats in the Dryad Digital Repository (doi:10.5061/dryad.1cv08). Updates to the data and metadata will be curated through the iDiv data portal (https://idata.idiv.de/). For example, in the future we plan to include interspecific variation in the dataset, to provide multiple estimates of thermal tolerance limits for a given species where estimates determined using the best possible methods will be more highly ranked