Ecological energetics, behavioural variation and wildlife disease

随着全球旅行和贸易对病原体传播的影响以及环境变化对宿主易感性的影响，野生动物传染病日益受到关注。人们越来越认识到，病原体可能导致物种灭绝、生物多样性丧失，并对人类公共卫生和经济产生影响。在北美，冬眠的蝙蝠面临着侵袭性真菌疾病白鼻综合征的持续保护危机。喜冷的WNS病原体在蝙蝠冬眠期间感染皮肤，引起一系列生理变化，最终导致蝙蝠过快消耗冬季脂肪储备。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能量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，但也可通过洞穴中受感染的基质传播。因此，社交能力或探索行为（即个性）的可重复差异可能影响病原体暴露的风险并影响生存。我的长期目标是测试个体、社会群体和宿主种群之间的行为和生理变化影响宿主-病原体动力学和野生动物疾病影响的广泛假设。对于这个发现基金，我的短期目标是在蝙蝠中使用WNS来测试从我的长期目标中产生的三个假设：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，高表达的周期性体温降低和新陈代谢称为冬眠）在入侵后会有更高的年存活率，导致表型向这些特征转移在持续存在的蝙蝠种群中；2)具有降低病原体暴露风险的行为特征的个体（较少社交，探索性，较小的家园）在入侵导致种群水平的行为表型转变后，将具有更高的年存活率；3)改善能量收支的摄入和输出两方面的环境操纵可以提高受病原体影响的种群的存活率。为了解决目标1和2，我和我的学生将在我们的大型数据集中添加WNS入侵前加拿大中部标记蝙蝠的能量和行为特征，以及WNS入侵后幸存蝙蝠的数据。我们还将比较wns敏感和抗wns物种之间的夏季大黄蜂和冬眠表达。为了解决目标3，我们将测试栖息地操作对WNS蝙蝠生存和繁殖的影响，这些操作可以增加能量摄入或减少能量消耗。尽管野生动物病原体具有潜在的影响，但揭示宿主种群如何应对的实验数据相对较少，而且当野生动物疾病爆发时，我们也很少有工具来对抗它们。我的项目将阐明宿主对病原体的反应进化，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.