Outdoor worker knowledge of ticks and Lyme disease in Québec.

Background And Aims: Lyme disease is a well-known occupational risk across North America caused by exposure to Borrelia burgdorferi via blacklegged ticks (Ixodes scapularis). As the geographic range of B. burgdorferi advances with the increasing distribution of blacklegged ticks, more outdoor workers are at risk of contracting Lyme disease.

High-resolution environmental and host-related factors impacting questing at their northern range edge.

The geographic range of tick populations has expanded in Canada due to climate warming and the associated poleward range shifts of their vertebrate hosts. Abiotic factors, such as temperature, precipitation, and snow, are known to directly affect tick abundance. Yet, biotic factors, such as the abundance and diversity of mammal hosts, may also alter tick abundance and consequent tick-borne disease risk.

Risky business: human-related data is lacking from Lyme disease risk models.

Used as a communicative tool for risk management, risk maps provide a service to the public, conveying information that can raise risk awareness and encourage mitigation. Several studies have utilized risk maps to determine risks associated with the distribution of , the causal agent of Lyme disease in North America and Europe, as this zoonotic disease can lead to severe symptoms. This literature review focused on the use of risk maps to model distributions of and its vector, the blacklegged tick (), in North America to compare variables used to predict these spatial models.

Historical associations and spatiotemporal changes of pathogen presence in ticks in Canada: A systematic review.

Background: Starting in the early 20th century, ticks and their pathogens have been detected during surveillance efforts in Canada. Since then, the geographic spread of tick vectors and tick-borne pathogens has steadily increased in Canada with the establishment of tick and host populations. Sentinel surveillance in Canada primarily focuses on Ixodes scapularis, which is the main vector of Borrelia burgdorferi, the bacterium causing Lyme disease.

Recent and rapid ecogeographical rule reversals in Northern Treeshrews.

Two of the most-studied ecogeographical rules describe patterns of body size variation within species. Bergmann's rule predicts that individuals have larger body sizes in colder climates (typically at higher latitudes), and the island rule predicts that island populations of small-bodied species average larger in size than their mainland counterparts (insular gigantism). These rules are rarely tested in conjunction or assessed across space and time simultaneously.

Emerging Tick-Borne Pathogens in Central Canada: Recent Detections of and .

The spread of emerging tick-borne pathogens has steadily increased in Canada with the widespread establishment of tick vectors and vertebrate hosts. At present, , the bacterium causing Lyme disease, is the most common tick-borne pathogen in Canada and primarily transmitted by . A low prevalence of other emerging tick-borne pathogens, such as , species, , and have also been detected through surveillance efforts in Canada.

Genomic Signatures of Selection along a Climatic Gradient in the Northern Range Margin of the White-Footed Mouse (Peromyscus leucopus).

Identifying genetic variation involved in thermal adaptation is likely to yield insights into how species adapt to different climates. Physiological and behavioral responses associated with overwintering (e.g.

A global synthesis of the small-island effect in habitat islands.

Habitat loss and fragmentation are considered to be the leading drivers of biodiversity loss. The small-island effect (SIE) can be used to predict species extinctions resulting from habitat loss and has important implications for species conservation. However, to date, no study has explicitly evaluated the prevalence of SIEs in habitat islands.

Rule reversal: Ecogeographical patterns of body size variation in the common treeshrew (Mammalia, Scandentia).

There are a number of ecogeographical "rules" that describe patterns of geographical variation among organisms. The island rule predicts that populations of larger mammals on islands evolve smaller mean body size than their mainland counterparts, whereas smaller-bodied mammals evolve larger size. Bergmann's rule predicts that populations of a species in colder climates (generally at higher latitudes) have larger mean body sizes than conspecifics in warmer climates (at lower latitudes).

Microsatellite markers reveal low frequency of natural hybridization between the white-footed mouse (Peromyscus leucopus) and deer mouse (Peromyscus maniculatus) in southern Quebec, Canada.

In some parts of southern Quebec, two closely related rodent species - the white-footed mouse (Peromyscus leucopus) and the deer mouse (Peromyscus maniculatus) - have recently come in contact because of climate-driven changes in the distribution of the former. Both species share similar morphology, ecology, and life history traits, which suggests that natural hybridization may be possible. Hybridization among these two species can have important implications on the ecological roles these rodents play in disease transmission, yet few researchers have attempted to examine this phenomenon and results from previous hybridization experiments have remained inconclusive and conflicting.

The Genetic Signature of Range Expansion in a Disease Vector-The Black-Legged Tick.

Monitoring and predicting the spread of emerging infectious diseases requires that we understand the mechanisms of range expansion by its vectors. Here, we examined spatial and temporal variation of genetic structure among 13 populations of the Lyme disease vector, the black-legged tick, in southern Quebec, where this tick species is currently expanding and Lyme disease is emerging. Our objective was to identify the primary mode of tick movement into Canada based on observed spatial and temporal genetic patterns.

Multi-taxa integrated landscape genetics for zoonotic infectious diseases: deciphering variables influencing disease emergence.

Zoonotic disease transmission systems involve sets of species interacting with each other and their environment. This complexity impedes development of disease monitoring and control programs that require reliable identification of spatial and biotic variables and mechanisms facilitating disease emergence. To overcome this difficulty, we propose a framework that simultaneously examines all species involved in disease emergence by integrating concepts and methods from population genetics, landscape ecology, and spatial statistics.

Phylogeographic Structure of the White-Footed Mouse and the Deer Mouse, Two Lyme Disease Reservoir Hosts in Québec.

Modification of a species range is one of many consequences of climate change and is driving the emergence of Lyme disease in eastern Canada. The primary reservoir host of the bacteria responsible for Lyme disease, Borrelia burgdorferi, is the white-footed mouse (Peromyscus leucopus), whose range is rapidly shifting north into southern Québec. The deer mouse, P.

Applying evolutionary concepts to wildlife disease ecology and management.

Existing and emerging infectious diseases are among the most pressing global threats to biodiversity, food safety and human health. The complex interplay between host, pathogen and environment creates a challenge for conserving species, communities and ecosystem functions, while mediating the many known ecological and socio-economic negative effects of disease. Despite the clear ecological and evolutionary contexts of host-pathogen dynamics, approaches to managing wildlife disease remain predominantly reactionary, focusing on surveillance and some attempts at eradication.

Climate change and habitat fragmentation drive the occurrence of Borrelia burgdorferi, the agent of Lyme disease, at the northeastern limit of its distribution.

Lyme borreliosis is rapidly emerging in Canada, and climate change is likely a key driver of the northern spread of the disease in North America. We used field and modeling approaches to predict the risk of occurrence of Borrelia burgdorferi, the bacteria causing Lyme disease in North America. We combined climatic and landscape variables to model the current and future (2050) potential distribution of the black-legged tick and the white-footed mouse at the northeastern range limit of Lyme disease and estimated a risk index for B.

Climate warming and Bergmann's rule through time: is there any evidence?

Climate change is expected to induce many ecological and evolutionary changes. Among these is the hypothesis that climate warming will cause a reduction in body size. This hypothesis stems from Bergmann's rule, a trend whereby species exhibit a smaller body size in warmer climates, and larger body size under colder conditions in endotherms.

Congruent morphological and genetic differentiation as a signature of range expansion in a fragmented landscape.

Phenotypic differentiation is often interpreted as a result of local adaptation of individuals to their environment. Here, we investigated the skull morphological differentiation in 11 populations of the white-footed mouse (Peromyscus leucopus). These populations were sampled in an agricultural landscape in the Montérégie region (Québec, Canada), at the northern edge of the distribution of the white-footed mouse.

Poleward expansion of the white-footed mouse (Peromyscus leucopus) under climate change: implications for the spread of lyme disease.

The white-footed mouse (Peromyscus leucopus) is an important reservoir host for Borrelia burgdorferi, the pathogen responsible for Lyme disease, and its distribution is expanding northward. We used an Ecological Niche Factor Analysis to identify the climatic factors associated with the distribution shift of the white-footed mouse over the last 30 years at the northern edge of its range, and modeled its current and potential future (2050) distributions using the platform BIOMOD. A mild and shorter winter is favouring the northern expansion of the white-footed mouse in Québec.

Genetic structure of the white-footed mouse in the context of the emergence of Lyme disease in southern Québec.

The white-footed mouse (Peromyscus leucopus) has expanded its northern limit into southern Québec over the last few decades. P. leucopus is a great disperser and colonizer and is of particular interest because it is considered a primary reservoir for the spirochete bacterium that causes Lyme disease.

Mammals evolve faster on smaller islands.

Island mammals often display remarkable evolutionary changes in size and morphology. Both theory and empirical data support the hypothesis that island mammals evolve at faster rates than their mainland congeners. It is also often assumed that the island effect is stronger and that evolution is faster on the smallest islands.

Morphological evolution is accelerated among island mammals.

Dramatic evolutionary changes occur in species isolated on islands, but it is not known if the rate of evolution is accelerated on islands relative to the mainland. Based on an extensive review of the literature, I used the fossil record combined with data from living species to test the hypothesis of an accelerated morphological evolution among island mammals. I demonstrate that rates of morphological evolution are significantly greater--up to a factor of 3.

Ecotypic variation in the context of global climate change: revisiting the rules.

Patterns of ecotypic variation constitute some of the few 'rules' known to modern biology. Here, we examine several well-known ecogeographical rules, especially those pertaining to body size in contemporary, historical and fossil taxa. We review the evidence showing that rules of geographical variation in response to variation in the local environment can also apply to morphological changes through time in response to climate change.

Climate change and size evolution in an island rodent species: new perspectives on the island rule.

As stated by the island rule, small mammals evolve toward gigantism on islands. In addition they are known to evolve faster than their mainland counterparts. Body size in island mammals may also be influenced by geographical climatic gradients or climatic change through time.