Life Sciences Commons^™

A Kin-Selection Model Of Fairness In Heterogeneous Populations, Geoff Wild, Veronica J. Flear, Graham J. Thompson

Biology Publications

Humans and other primates exhibit pro-social preferences for fairness. These preferences are thought to be reinforced by strong reciprocity, a policy that rewards fair actors and punishes unfair ones. Theories of fairness based on strong reciprocity have been criticized for overlooking the importance of individual differences in socially heterogeneous populations. Here, we explore the evolution of fairness in a heterogeneous population. We analyse the Ultimatum Game in cases where players’ roles in the game are determined by their status. Importantly, our model allows for non-random pairing of players, and so we also explore the role played by kin selection in …

Long-Term Winter-Site Fidelity In Song Sparrows (Melospiza Melodia), Tosha R. Kelly, Keith A. Hobson, Garth @. Casbourn, Elizabeth A. Macdougall-Shackleton, Scott A. Macdougall-Shackleton

Biology Publications

In migratory animals, the degree to which individuals return to the same wintering sites across multiple years can affect fitness and population dynamics, and thus has important implications for conservation. Despite this, long-term evaluations of wintering-site fidelity are rare for migratory birds: many populations are intensively studied on their breeding grounds but tracking the migratory movements of small birds once they leave the breeding grounds is challenging. To evaluate patterns of overwintering location and fidelity, we collected winter-grown claw tissue from 301 Song Sparrows (Melospiza melodia; 449 samples) captured in spring at their breeding grounds over six consecutive …

No Evidence That Songbirds Use Odour Cues To Avoid Malaria-Infected Conspecifics, Leanne A. Grieves, Elizabeth A. Macdougall-Shackleton

Biology Publications

Many animals have evolved mechanisms to detect and avoid parasitized conspecifics, primarily through odour cues, but whether birds are capable of odour-mediated parasite avoidance is unknown. Recently, we showed that exposing song sparrows (Melospiza melodia) to avian malaria parasites (Plasmodium sp.) alters the chemical composition of their preen oil, which is the major source of body odour in birds. Here, we presented song sparrows with preen oil from uninfected (sham-inoculated) and malaria-infected conspecifics, predicting that birds would spend more time with odour cues from uninfected than infected birds. Birds without detectable malarial infections spent about 50% more …

Seasonal Migration Distance Varies With Natal Dispersal And Predicts Parasitic Infection In Song Sparrows, Tosha R. Kelly, Heather L. Macgillivray, Yanina Sarquis-Adamson, Matthew J. Watson, Keith A. Hobson, Elizabeth A. Macdougall-Shackleton

Biology Publications

Seasonal migration and natal dispersal represent the major large-scale movements in the lives of animals. Individuals that are relatively prone to movement and exploration might thus be more likely to disperse and also to migrate farther. Such movement might be either negatively associated with parasitic infection (if infection prevents hosts from successful long-distance migration) or positively associated (e.g. if longer-distance migrants encounter more abundant or more diverse parasites). We examined whether natal dispersal tendency predicts seasonal migration distance in song sparrows (Melospiza melodia) and whether migration distance predicts infection with bloodborne parasites upon arrival at the breeding grounds. …

Fish Sound Production: The Swim Bladder, Michael L. Fine, Eric Parmentier

Biology Publications

Analogous to the syrinx in birds and larynx in mammals, the swim bladder is a major sound-producing organ in fishes. It also functions in hearing and is responsible for most returns from sonar. Historically, the swim bladder has been modeled as an underwater resonant bubble, whereas we provide evidence for a forced-response model in which viscous damping of the bladder wall inhibits resonance of the internal bubble. Further experimental work on the shape, wall structure, and mechanical behavior of the swim bladder is required.

An Investigation Of Bubble Resonance And Its Implications For Sound Production By Deepwater Fishes, Mark W. Sprague, Michael L. Fine, Timothy M. Cameron

Biology Publications

Although the continental slope and abyss comprise the largest habitat on earth, the absence of documented fish sounds from deep waters is striking. Fishes with sexually dimorphic muscles attached to their swim bladders suggests that sounds are likely used in male courtship on the upper, mid and lower continental slope. To investigate the effects of environmental extremes on fish sound production, the acoustic behavior of a driven bubble is examined. This study is also relevant to target strength of sonar returns from fish and hearing in auditory specialist fishes. A bubble is a classic, if imperfect, model for swim bladder …

Fear Of Large Carnivores Is Tied To Ungulate Habitat Use: Evidence From A Bifactorial Experiment, Haley K. Epperly, Michael Clinchy, Liana Y. Zanette, Robert A. Mcceery

Biology Publications

The fear large carnivores inspire in large ungulates has been argued to have cascading effects down food webs. However, a direct link between ungulate habitat use and their fear of large carnivores has not been experimentally tested. To fill this critical gap, we conducted a bi-factorial experiment in an African savanna. We removed shrub cover and broadcast large carnivore vocalizations (leopard, hyena, dog) or non-threatening control vocalizations in both experimentally cleared and shrubby control sites. We recorded the proactive (frequency of visitation) and reactive (fleeing or vigilance) responses of multiple prey (impala, warthog, nyala and bushbuck). Critically, we found a …

High-Resolution Imaging As A Tool For Identifying Quantitative Trait Loci That Regulate Photomorphogenesis In Arabidopsis Thaliana, Stephen D. Deslauriers

Biology Publications

A primary component of seedling establishment is the photomorphogenic response as seedlings emerge from the soil. This process is characterized by a reduced growth rate in the hypocotyl, increased root growth, opening of the apical hook and expansion of the cotyledons as photosynthetic organs. While fundamental to plant success, the photomorphogenic response can be highly variable. Additionally, studies of Arabidopsis thaliana are made difficult by subtle differences in growth rate between individuals. High-resolution imaging and computational processing have emerged as useful tools for quantification of such phenotypes. This study sought to: (i) develop an imaging methodology which could capture changes …

Erratum: Publisher Correction: Fear Of Large Carnivores Is Tied To Ungulate Habitat Use: Evidence From A Bifactorial Experiment (Scientific Reports (2021) 11 1 (12979)), Haley K. Epperly, Michael Clinchy, Liana Y. Zanette, Robert A. Mccleery

Biology Publications

No abstract provided.

Fear Of Predators In Free-Living Wildlife Reduces Population Growth Over Generations, Marek C. Allen, Michael Clinchy, Liana Y. Zanette

Biology Publications

Data set for article in Fear of predators in free ‐ living wildlife reduces population growth over generations

in

Proceedings of the National Academy of Sciences of the United States of America

Epigenetic Memories And The Evolution Of Infectious Diseases, Geoff Wild

Biology Publications

Genes with identical DNA sequence may show differential expression because of epigenetic marks. Where epigenetic marks respond to past conditions, they represent a form of “memory”. Despite their medical relevance, the impact of memories on the evolution of infectious diseases has rarely been considered. Here we explore the evolution of virulence in pathogens that carry memories of the sex of their previous host. We show that this form of memory provides information about the sex of present and future hosts when the sexes differ in their pathogen’s transmission pattern. Memories of past hosts enable the evolution of greater virulence in …

Persistence Of Diet Effects On The Drosophila Suzukii Microbiota, Yanira Jiménez Padilla, Ebenezer Esan, Kevin D. Floate, Brent J. Sinclair

Biology Publications

The insect commensal microbiota consists of prokaryotes and eukaryotes. The effect of diet and the persistence of the gut microbiota in Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) are not well-understood. We transferred subsets of a single population of D. suzukii to different fruit-based diets (blueberry, raspberry, and strawberry) for three generations and then returned them to a common, banana-based, laboratory diet. We used 16S (bacteria) and ITS (fungi) sequencing of female endosymbiont-free flies to identify the microbiota. We identified 2700 bacterial and 350 fungal OTUs; there was no correlation between the number of bacterial and fungal OTUs in a sample. Bacterial …

Reversing Sodium Differentials Between The Hemolymph And Hindgut Speeds Chill Coma Recovery But Reduces Survival In The Fall Field Cricket, Gryllus Pennsylvanicus, Jacqueline E. Lebenzon, Lauren E. Des Marteaux, Brent J. Sinclair

Biology Publications

Chill-susceptible insects enter the reversible state of chill coma at their critical thermal minimum (CT_min­). During chill coma, movement of Na⁺ and water from the hemolymph to the gut lumen disrupt ion and water balance. Recovery from cold exposure requires re-establishment of this balance, and failure to do so results in chilling injury or death. We hypothesized that the passive leak of Na⁺ and consequently water during cold exposure is driven by the [Na⁺] differential between the gut and hemolymph. To determine the extent to which this [Na⁺] differential affects cold …

Dissection Of Anoplophora Glabripennis (Coleoptera: Cerambycidae) Larval Tissues For Physiological And Molecular Studies, Alex S. Torson, Lauren E. Des Marteaux, Susan Bowman, Meng Lei Zhang, Kevin Ong, Daniel Doucet, Brent J Sinclair, Amanda D. Roe

Biology Publications

Many biological processes are partitioned among organs and tissues, necessitating tissue-specific or organ-specific analysis (particularly for comparative -omics studies). Standardised techniques for tissue identification and dissection are therefore imperative for comparing among studies. Here we describe dissection protocols for isolating six key tissues/organs from larvae of the Asian longhorned beetle, Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae): the supraoesophageal ganglion, posterior midgut, hindgut, Malpighian tubules, fat body, and thoracic muscle. We also describe how to extract haemolymph and preserve whole larvae for measurements such as protein, lipid, and carbohydrate content. We include dissection protocols for both fresh-killed and previously frozen specimens. Although …

A Comparison Of Low Temperature Biology Of Pieris Rapae From Ontario, Canada, And Yakutia, Far Eastern Russia, Natalia G. Li, Jantina Toxopeus, Martin Moos, Jesper G. Sørensen, Brent J. Sinclair

Biology Publications

Low temperatures limit the distribution and abundance of ectotherms. However, many insects can survive low temperatures by employing one of two cold tolerance strategies: freeze avoidance or freeze tolerance. Very few species can employ both strategies, but those that do provide a rare opportunity to study the mechanisms that differentiate freeze tolerance and freeze avoidance. We showed that overwintering pupae of the cabbage white butterfly Pieris rapae can be freeze tolerant or freeze avoidant. A population of P. rapae in northeastern Russia (Yakutsk) froze at c. -9.3 °C and were freeze-tolerant in 2002-2003 when overwintered outside. However, P. rapae from …

Thermal Variability And Plasticity Drive The Outcome Of A Host-Pathogen Interaction, Laura V. Ferguson, Brent J. Sinclair

Biology Publications

Variable, changing, climates may affect each participant in a biotic interaction differently. We explored the effects of temperature and plasticity on the outcome of a host-pathogen interaction to try to predict the outcomes of infection under fluctuating temperatures. We infected Gryllus veletis crickets with the entomopathogenic fungus Metarhizium brunneum under constant (6 °C, 12 °C, 18 °C or 25 °C) or fluctuating temperatures (6 °C to 18 °C or 6 °C to 25 °C). We also acclimated crickets and fungi to constant or fluctuating conditions. Crickets acclimated to fluctuating conditions survived best under constant conditions if paired with warm-acclimated fungus. …

Decreased Temperature Variance Associated With Biotic Composition Enhances Coastal Shrub Encroachment, Lauren K. Wood, Spencer Hays, Julie C. Zinnert

Biology Publications

Regime shift from grasslands to shrub-dominated landscapes occur worldwide driven by altered land-use and climate change, affecting landscape function, biodiversity, and productivity. Warming winter temperatures are a main driver of expansion of the native, evergreen shrub, Morella cerifera, in coastal landscapes. Shrub establishment in these habitats alters microclimate, but little is known about seasonal differences and microclimate variance. We assessed influence of shrubs on microclimate variance, community composition, and community physiological functioning across three vegetation zones: grass, transitional, and shrub in a coastal grassland. Using a novel application of a time-series analysis, we interpret microclimatic variance modification and elucidate …

Topography And Disturbance Influence Trait‐Based Composition And Productivity Of Adjacent Habitats In A Coastal System, Joseph K. Brown, Julie C. Zinnert

Biology Publications

Coastal systems experience frequent disturbance and multiple environmental stressors over short spatial and temporal scales. Investigating functional traits in coastal systems has the potential to inform how variation in disturbance frequency and environmental variables influence differences in trait‐based community composition and ecosystem function. Our goals were to (1) quantify trait‐based communities on two barrier islands divergent in topography and long‐term disturbance response and (2) determine relationships between community trait‐based composition and ecosystem productivity. We hypothesized that locations documented with high disturbance would have habitats with similar environmental conditions and trait‐based communities, with the opposite relationship in low‐disturbance locations. Furthermore, we …

Seasonal Facilitative And Competitive Trade‐Offs Between Shrub Seedlings And Coastal Grasses, Michael N. Sinclair, Natasha N. Woods, Julie C. Zinnert

Biology Publications

Shrub expansion is occurring in grasslands globally and may be impacted by the balance of competition and facilitation with existing grasses. Along the mid‐Atlantic and Gulf coasts, the native shrub Morella cerifera (wax myrtle) is rapidly expanding and displacing other native coastal species. Recent research suggests that much of this expansion is due to warming winter temperatures, as temperatures below −15°C kill M. cerifera. The objective of this project was to understand the importance of species interactions with grasses on the growth and physiology of M. cerifera at the seedling life stage through both field and laboratory experiments. In …

Humans, But Not Their Dogs, Displace Pumas From Their Kills: An Experimental Approach, Justin P. Suraci, Justine A. Smith, Michael Clinchy, Liana Y. Zanette, Christopher C. Wilmers

Biology Publications

Domestic dogs are the most abundant large carnivore on the planet, and their ubiquity has led to concern regarding the impacts of dogs as predators of and competitors with native wildlife. If native large carnivores perceive dogs as threatening, impacts could extend to the community level by altering interactions between large carnivores and their prey. Dog impacts may be further exacerbated if these human-associated predators are also perceived as indicators of risk from humans. However, observational approaches used to date have led to ambiguity regarding the effects of dog presence on wildlife. We experimentally quantified dog impacts on the behavior …

Thermal Limits Of Summer-Collected Pardosa Wolf Spiders (Araneae: Lycosidae) From The Yukon Territory And Greenland, Susan E. Anthony, Christopher M. Buddle, Toke T. Høye, Brent J. Sinclair

Biology Publications

Arctic and sub-Arctic terrestrial ectotherms contend with large daily and seasonal temperature ranges. However, there are few data available on the thermal biology of these high-latitude species, especially arachnids. We determined the lower and upper thermal limits of seven species of wolf spider from the genus Pardosa (Araneae: Lycosidae) collected in summer from the Yukon Territory (Canada) and Southern Greenland. None of these species survived freezing, and while spiderlings appeared freeze-avoidant, surviving to their supercooling point (SCP, the temperature at which they spontaneously freeze), chill-susceptible adults and juveniles died at temperatures above their SCP. The critical thermal minimum (CTmin, the …

Fear Of Humans As Apex Predators Has Landscape-Scale Impacts From Mountain Lions To Mice, Justin P. Suraci, Michael Clinchy, Liana Y. Zanette, Christopher C. Wilmers

Biology Publications

Apex predators such as large carnivores can have cascading, landscape-scale impacts across wildlife communities, which could result largely from the fear they inspire, although this has yet to be experimentally demonstrated. Humans have supplanted large carnivores as apex predators in many systems, and similarly pervasive impacts may now result from fear of the human ‘super predator’. We conducted a landscape-scale playback experiment demonstrating that the sound of humans speaking generates a landscape of fear with pervasive effects across wildlife communities. Large carnivores avoided human voices and moved more cautiously when hearing humans, while medium-sized carnivores became more elusive and reduced …

Playback Of Predator Calls Inhibits And Delays Dawn Singing In A Songbird Community, Peter Santema, Mihai Valcu, Michael Clinchy, Liana Zanette, Bart Kempenaers

Biology Publications

Recent studies have demonstrated that experimental increases in perceived predation risk can substantially impair breeding behavior and reduce reproductive success. Perceived predation risk may also occur in the context of sexual signaling, with potential consequences for sexual selection. In songbirds, singing at dawn is an important sexual signal but may also attract predators. Here, we report on 2 experiments designed to test whether perceived predation risk affects the occurrence and timing of dawn singing in a songbird community. In a pilot experiment, we broadcast predator playbacks intermittently across half a forest plot and nonpredator playbacks across the other half throughout …

Gut Yeasts Do Not Improve Desiccation Survival In Drosophila Melanogaster, Joanne M. Tang, Yanira Jiménez Padilla, Marc-André Lachance, Brent J. Sinclair

Biology Publications

A healthy gut microbiota generally improves the performance of its insect host. Although the effects can be specific to the species composition of the microbial community, the role of gut microbiota in determining water balance has not been well explored. We used axenic and gnotobiotic (reared with a known microbiota) Drosophila melanogaster to test three hypotheses about the effects of gut yeasts on the water balance of adult flies: 1) that gut yeasts would improve desiccation survival in adult flies; 2) that larval yeasts would improve adult desiccation survival; 3) that the effects would be species-specific, such that yeasts closely …

Overwintering Red Velvet Mites Are Freeze Tolerant, Susan E. Anthony, Brent J. Sinclair

Biology Publications

Although many arthropods are freeze tolerant (able to withstand internal ice), small-bodied terrestrial arthropods such as mites are thought to be constrained to freeze avoidance. We field-collected active adult red velvet mites, Allothrombium sp. (Trombidiidae), in winter in Southwestern Ontario, Canada, where temperatures drop below −20°C. These mites froze between −3.6° and −9.2°C and survived internal ice formation. All late-winter mites survived being frozen for 24 h at −9°C, and 50% survived 1 wk. The lower lethal temperature (LLT50; low temperature that kills 50% of mites) was ca. −20°C in midwinter. Hemolymph osmolality and glycerol concentration increased in midwinter, accompanied …

Loss Of Ion Homeostasis Is Not The Cause Of Chill Coma Or Impaired Dispersal In False Codling Moth Thaumatotibia Leucotreta (Lepidoptera: Tortricidae), Minette Karsten, Jacqueline E. Lebenzon, Brent J. Sinclair, John S. Terblanche

Biology Publications

Dispersal is a central requirement of a successful sterile insect release programme, but field-released false codling moth (FCM) typically suffer from poor dispersal ability, especially at low ambient temperatures. Here we test the hypothesis that poor activity and dispersal in FCM is caused by delayed or perturbed recovery of ion and/or water homeostasis after chilling for handling and transport prior to field release. Hemolymph and flight muscle were collected from two treatment groups at three time points that targeted thermal conditions above and below the chill coma induction threshold of ~ 6 °C: 1) control moths kept at 25 °C, …

How Crickets Become Freeze Tolerant: The Transcriptomic Underpinnings Of Acclimation In Gryllus Veletis, Jantina Toxopeus, Lauren E. Des Marteaux, Brent J. Sinclair

Biology Publications

Some ectotherms can survive internal ice formation. In temperate regions, freeze tolerance is often induced by decreasing temperature and/or photoperiod during autumn. However, we have limited understanding of how seasonal changes in physiology contribute to freeze tolerance, and how these changes are regulated. During a six week autumn-like acclimation, late-instar juveniles of the spring field cricket Gryllus veletis (Orthoptera: Gryllidae) become freeze tolerant, which is correlated with accumulation of low molecular weight cryoprotectants, elevation of the temperature at which freezing begins, and metabolic rate suppression. We used RNA-Seq to assemble a de novo transcriptome of this emerging laboratory model for …

Incorporating Temperature And Precipitation Extremes Into Process-Based Models Of African Lepidoptera Changes The Predicted Distribution Under Climate Change, Madeleine G. Barton, John S. Terblanche, Brent J. Sinclair

Biology Publications

Terrestrial insects are responding to ongoing climate change. While these responses have been primarily linked to rising temperatures, insects are sensitive to desiccation, and the impacts of altered precipitation regimes remain relatively unexplored. Here, we develop a mechanistic model of survival and performance responses to both temperature and desiccation stress, focussing on Lepidoptera in Africa, where a general understanding of such responses to climate change is urgently required. We run the model with climate data from general circulation models at daily time intervals under current (2011–2015) and projected future (2046–2050) climate scenarios. We first simulate four hypothetical, but typical, Lepidoptera …

Laboratory Acclimation To Autumn-Like Conditions Induces Freeze Tolerance In The Spring Field Cricket Gryllus Veletis (Orthoptera: Gryllidae), Jantina Toxopeus, Alexander H. Mckinnon, Tomáš Štětina, Kurtis F. Turnbull, Brent J Sinclair

Biology Publications

Many temperate insects encounter temperatures low enough to freeze their body fluids. Remarkably, some insects are freeze-tolerant, surviving this internal ice formation. However, the mechanisms underlying freeze tolerance are not well-understood, in part due to a lack of tractable model organisms. We describe a novel laboratory model to study insect freeze tolerance, the spring field cricket Gryllus veletis (Orthopera: Gryllidae). Following acclimation to six weeks of decreasing temperature and photoperiod, G. veletis become freeze-tolerant, similar to those exposed to natural autumn conditions in London, Ontario, Canada. Acclimated crickets suppress their metabolic rate by c. 33%, and survive freezing for up …

Interaction Of Seed Dispersal And Environmental Filtering Affects Woody Encroachment Patterns In Coastal Grassland, Natasha N. Woods, Benjamin L. Dows, Evan B. Goldstein, Laura J. Moore, Donald R. Young, Julie C. Zinnert

Biology Publications

Encroachment of woody plants into grasslands has occurred worldwide and includes coastal ecosystems. This conversion process is mediated by seed dispersal patterns, environmental filtering, and biotic interactions. As spatiotemporally heterogeneous, harsh environments, barrier islands present a unique set of challenges for dispersal and establishment. Environmental conditions act as filters on dispersed seeds, thereby influencing encroachment and distribution patterns. Seldom have patterns of propagule dispersal been considered in the context of woody encroachment. We quantified dispersal and post‐dispersal processes of an encroaching woody population of Morella cerifera relative to directional rate of encroachment and observed distribution patterns on an Atlantic coastal …