Ecological energetics, behavioural variation and wildlife disease

由于全球旅行和贸易影响病原体的传播，环境变化影响宿主的易感性，野生动物的传染病日益受到关注。人们日益认识到，病原体可导致物种灭绝、生物多样性丧失以及对人类公共健康和经济的影响。在北美，冬眠的蝙蝠面临着来自入侵性真菌疾病白鼻综合征的持续保护危机。喜冷的WNS病原体在冬眠期间感染蝙蝠的皮肤，引起一连串的生理变化，最终导致蝙蝠过快地消耗冬季脂肪储备。至于其他增加宿主能量消耗的病原体，帮助蝙蝠增加能量摄入或减少消耗的特征可能对生存至关重要。WNS病原体通过蝙蝠之间的接触传播，但也通过洞穴中受感染的基质传播。因此，社交或探索行为的可重复差异（即，个性），可能会影响病原体暴露的风险并影响生存。我的长期目标是测试广泛的假设，即行为和生理变化之间的个人，社会群体和人口的主机影响主机病原体动态和野生动物疾病的影响。对于这个发现补助金，我的短期目标是在蝙蝠中使用WNS来测试我的长期目标中出现的三个假设：1）具有改善冬季和夏季能量平衡的生理特征的个体（高食物摄入和脂肪储存，体温和新陈代谢周期性降低的高表达，称为迟钝）在入侵后将有更高的年存活率，导致持续存在的蝙蝠种群向这些性状的表型转变; 2）具有降低病原体暴露风险的行为特征的个人（较少社交，探索，较小的homerange）将有较高的年生存率入侵后，导致人口水平的表型转变的行为;以及3）改善能量收支的摄入和输出侧的环境操纵可以改善病原体影响的群体的生命率。为了解决目标1和2，我和我的学生将添加到我们的大型数据集上，这些数据集是关于加拿大中部标记蝙蝠的前WNS能量和行为特征，以及WNS入侵后幸存者的数据。我们还将比较夏季homerange和迟钝的表达之间的WNS敏感和WNS抗性物种。为了解决目标3，我们将测试栖息地操作的影响，可以增加能量摄入或减少能量消耗的生存和繁殖的蝙蝠与WNS。尽管野生动物病原体的潜在影响，我们有相对较少的实验数据揭示宿主种群如何反应，以及很少的工具，以打击野生动物疾病爆发时，他们发生。我的计划将阐明宿主对病原体的反应以及对抗WNS和其他疾病的潜在管理策略。

Infectious diseases of wildlife are an increasing concern as global travel and trade affect pathogen dispersal, and environmental change affects host susceptibility. There is growing realization that pathogens can cause species extinctions, loss of biodiversity and impacts on human public health and the economy. In North America, hibernating bats face an ongoing conservation crisis from the invasive fungal disease white-nose syndrome. The cold-loving WNS pathogen infects the skin of bats during hibernation causing a cascade of physiological changes that ultimately cause bats to expend their winter fat reserves too quickly. As for other pathogens that increase host energetic costs, traits that help bats increase energy intake or reduce expenditure could be crucial for survival. The WNS pathogen is spread by contact between bats but also from infected substrates in caves. Thus repeatable differences in sociability or explorative behaviours (i.e., personality), could affect the risk of pathogen exposure and influence survival. My long-term objective is to test the broad hypothesis that behavioural and physiological variation among individuals, social groups and populations of hosts affects host-pathogen dynamics and wildlife disease impacts. For this Discovery Grant, my short-term objectives are to use WNS in bats to test three hypotheses that emerge from my long-term goal: 1) Individuals with physiological traits that improve winter and summer energy balance (high food intake and fat storage, high expression of periodic reductions in body temperature and metabolism called torpor) will have higher annual survival after invasion resulting in a phenotypic shift toward these traits in persisting bat populations; 2) Individuals with behavioural traits that reduce risk of pathogen exposure (less sociable, explorative, smaller homerange) will have higher annual survival after invasion leading to population-level phenotypic shifts in behaviour; and 3) Environmental manipulations that improve both the intake and output sides of the energy budget can improve vital rates for pathogen-impacted populations. To address Objectives 1 and 2, my students and I will add to our large dataset on pre-WNS energetic and behavioural traits of marked bats in central Canada, with data from survivors that remain after WNS invasion. We will also compare summer homerange and torpor expression between a WNS-susceptible and WNS-resistant species. To address Objective 3 we will test the influence of habitat manipulations that could increase energy intake or reduce energy expenditure on survival and reproduction of bats with WNS. Despite potential impacts of wildlife pathogens, we have relatively few experimental data revealing how host population respond, and few tools to combat wildlife disease outbreaks when they occur. My program will shed light on the evolution of hosts in response to pathogens as well as potential management strategies to combat WNS and other diseases.