The causes and consequences of interspecific variation in sex-specific contributions to animal parental care are relatively well understood during pregnancy or incubation and during offspring provisioning, but comparative patterns of sex-biased investment during nest-, den-, or other shelter-building have been almost completely overlooked. This is surprising because birthing shelter properties have important fitness consequences for both parents and offspring. Here, we address this gap in our knowledge by testing predictions concerning sex-specific contributions to avian...

Pathogen interactions arising during coinfection can exacerbate disease severity, for example, when the immune response mounted against one pathogen negatively affects defense of another. It is also possible that host immune responses to a pathogen, shaped by historical evolutionary interactions between host and pathogen, may modify host immune defenses in ways that have repercussions for other pathogens. In this case, negative interactions between two pathogens could emerge even in the absence of concurrent infection. Parasitic...

1. Invasive species have the ability to rapidly adapt in the new regions where they are introduced. Classic evolutionary theory predicts that the accumulation of genetic differences over time in allopatric isolation may lead to reproductive incompatibilities resulting in decreases in reproductive success and, eventually, to speciation. However, experimental evidence for this theoretical prediction in the context of invasive species is lacking. We aimed to test for the potential of allopatry to determine reproductive success...

The sympatric existence of genetically distinct populations of the same species remains a puzzle in ecology. Coexisting salmonid fish populations are known from over 100 freshwater lakes. Most studies of sympatric populations have used limited numbers of genetic markers making it unclear if genetic divergence involves only certain parts of the genome. We return to the first reported case of salmonid sympatry, initially detected through contrasting homozygosity at a single allozyme locus (coding for lactate...

Datasets generated and analyzed within the study area located in the Côte-Nord region of Québec, Canada. "DataFinal_Vegetation.csv" was used to evaluate the availability of deciduous vegetation (column Cover_Deciduous) in stands impacted by the spruce budworm (SBW, severity index values presented in column SBW_SevCum) outbreak and test our prediction that the reduction in canopy cover caused by SBW in coniferous stands would result in greater deciduous vegetation. We determined the percentage cover of deciduous vegetation for...

Fire regimes are shifting under climate change. Decadal-scale shifts in fire regime can disrupt the biogeochemical cycling of carbon (C), nitrogen (N), and phosphorus (P) within forest ecosystems, but the full extent of these disruptions is unknown. It is also unclear whether these disruptions have consequences for the ecological characteristics (e.g., biomass, abundance, and composition) of microbial and invertebrate communities, which together comprise the majority of terrestrial biodiversity and underpin many ecosystem processes. The theoretical...

The size and frequency of resource pulses can affect plant interactions and increase the abundance of invasive species relative to native species. We examined resource pulses generated during desiccation and rehydration of communities of native biological soil crust (biocrust) forming mosses, in the context of positive associations between biocrusts and the invasive forb, Centaurea stoebe. We surveyed Centaurea and biocrust cover and evaluated how interactions among Centaurea, biocrusts, and water pulses influenced plant biomass and...

Manuscript Abstract: Ecologists have long sought to understand space use and mechanisms underlying patterns observed in nature. We developed an optimality landscape and mechanistic territory model to understand mechanisms driving space use and compared model predictions to empirical reality. We demonstrate our approach using gray wolves (Canis lupus). In the model, simulated animals selected territories to economically acquire resources by selecting patches with greatest value, accounting for benefits, costs, and tradeoffs of defending and using...

Endosymbioses influence host physiology, reproduction, and fitness, but these relationships require efficient microbe transmission between host generations to persist. Maternally transmitted Wolbachia are the most common known endosymbionts, but their frequencies vary widely within and among host populations for unknown reasons. Here we integrate genomic, cellular, and phenotypic analyses with mathematical models to provide an unexpectedly simple explanation for global wMel Wolbachia prevalence in Drosophila melanogaster. Cooling temperatures decrease wMel cellular abundance at a key...

Recent experiments support the idea that upper thermal limits of aquatic insects arise, at least in part, from a lack of sufficient oxygen: rising temperatures typically stimulate metabolic demand for oxygen more than they increase rates of oxygen supply from the environment. Consequently, factors influencing oxygen supply, like water flow, should also affect thermal and hypoxia tolerance. We tested this hypothesis by measuring the effects of experimentally manipulated flows on the heat and hypoxia tolerance...

Migration allows animals to use resources that are variable in time and/or space, with different migratory strategies depending on the predictability of resource variation. When food varies seasonally, obligate migrants anticipate and prepare for migration. In contrast, facultative migrants, whose movements are unpredictable in timing and destination, may either prepare for migration or escape when resources are depleted. We propose and test two alternative hypotheses regarding the behavioral and physiological responses of facultative migrants to...

Endangered species policies and their associated recovery documents and management actions do not always sufficiently address the importance of migratory behavior and seasonal ranges for imperiled populations. Using a telemetry location dataset spanning 1981 – 2018, we tested for changes in prevalence of migratory tactics (resident, migrant) over time, switching between tactics, shifts in seasonal space-use including migration corridors, and survival consequences of migrant and resident tactics for 237 adult female endangered woodland mountain caribou...

Interspecific variation in sex-specific contributions to prenatal parental care, including avian nest building, remain poorly understood. Here, we examined whether the colouration of the parents and of their eggs covary with sex-specific nest building contributions in 521 species of Western Palearctic birds. Having colourful plumages and laying colourful eggs are both costly because of the deposition of pigments (in feathers and eggs) and/or forming costly nanostructural substrates (in feathers), and so it is expected that...

1. Most studies in global change biology predict biological impacts of warming from information on macroclimates. Most organisms, however, live in microhabitats with physical conditions which are decoupled to varying degrees from those in macroclimates depending partly on organism body size. 2. Small ectotherms of a few millimetres in length live deep in surface boundary layers such that their heat budgets are dominated by different processes compared to larger ectotherms, whose bodies emerge from surface...

Heritable symbionts have diverse effects on the physiology, reproduction, and fitness of their hosts. Maternally transmitted Wolbachia are one of the most common endosymbionts in nature, infecting about half of all insect species. We test the hypothesis that Wolbachia alter host behavior by assessing the effects of 14 different Wolbachia strains on the locomotor activity of nine Drosophila host species. We find that Wolbachia alter the activity of six different host genotypes, including all hosts...

PREMISE Across taxa, vegetative and floral traits that vary along a fast-slow life-history axis are often correlated with leaf functional traits arrayed along the leaf economics spectrum, suggesting a constrained set of adaptive trait combinations. Such broad-scale convergence may arise from genetic constraints imposed by pleiotropy (or tight linkage) within species, or from natural selection alone. Understanding the genetic basis of trait syndromes and their components is key to distinguishing these alternatives and predicting evolution...

Increasing wildfire activity in western North America has the potential to remove forest canopy cover over large areas, increasing the vulnerability of understory plants and juvenile trees to microclimatic extremes. To understand the impacts of wildfire on forest microclimatic buffering, we monitored daily temperature and vapor pressure deficit (VPD) in 33 plots over the first two growing seasons following two wildfires from 2017. The Lolo Peak and Sunrise fires occurred during a regionally extensive fire...

Anthropogenic linear features facilitate access and travel efficiency for predators, and can influence predator distribution and encounter rates with prey. We used GPS collar data from eight wolf packs and characteristics of seismic lines to investigate whether (1) ease-of-travel or (2) access to areas presumed to be preferred by prey best explained seasonal selection patterns of wolves near seismic lines, and whether the density of anthropogenic features led to functional responses in habitat selection. At...

Animals serve as hosts for complex communities of microorganisms, including endosymbionts that live inside their cells. Wolbachia bacteria are perhaps the most common endosymbionts, manipulating host reproduction to propagate. Many Wolbachia cause cytoplasmic incompatibility (CI), which results in reduced egg hatch when uninfected females mate with infected males. Wolbachia that cause intense CI spread to high and relatively stable frequencies, while strains that cause weak or no CI tend to persist at intermediate, often variable,...

A paradigm in the plant defense literature is that defending against herbivores comes at a cost to growth, resulting in a growth-defense tradeoff. However, while there is strong evidence for growth-defense tradeoffs across species, evidence is mixed within species. Several mechanisms can account for this equivocal support within species, but teasing them apart requires examining growth-defense relationships both within and among populations, an approach seldom employed. We examined correlations between plant biomass (growth) and terpene...

Ecogeographical rules attempt to explain large-scale spatial patterns in biological traits. One of the most enduring examples is Bergmann’s rule, which states that species should be larger in colder climates due to the thermoregulatory advantages of larger body size. Support for Bergmann’s rule, however, is not consistent across taxonomic groups, raising questions about what factors may moderate its effect. Behaviour may play a crucial, yet so far underexplored, role in mediating the extent to which...

The 2020 fire season punctuated a decades-long trend of increased fire activity across the western United States, nearly doubling the total area burned in the central Rocky Mountains since 1984. Understanding the causes and implications of such extreme fire seasons, particularly in subalpine forests that have historically burned infrequently, requires a long-term perspective not afforded by observational records. We place 21st century fire activity in subalpine forests in the context of climate and fire history...

While feeding, foragers can alter their environment. Such alteration constitutes ecological niche construction (ENC) if it enables future benefits for the constructor and conspecific individuals. The environmental modification may also affect non-constructing, bystander species, especially if they share resources with constructor species. If so, ENC could confer the constructor species a competitive advantage by both enhancing its foraging returns and reducing those of bystander species. Expectations – (E1) ENC frequency should vary positively with the...

Under the selfish centromere model, costs associated with female meiotic drive by centromeres select on interacting kinetochore proteins to restore Mendelian inheritance. We directly test this model in yellow monkeyflowers (Mimulus guttatus), which are polymorphic for a costly driving centromere (D). We show that the D haplotype is structurally and genetically distinct and swept to a high stable frequency within the past 1500 years. Quantitative genetic analyses reveal that variation in the strength of drive...

Summer diets are crucial for large herbivores in the subarctic and are affected by weather, harassment from insects and a variety of environmental changes linked to climate. Yet understanding foraging behavior and diet of large herbivores is challenging in the subarctic because of their remote ranges. We used GPS video-camera collars to observe behaviors and summer diets of the migratory Fortymile Caribou Herd (Rangifer tarandus granti) across Alaska, USA and the Yukon, Canada. First, we...