Upadhayay Pooja, Chapman Colin A, Mastromonaco Gabriela F, Schoof Valerie A M
Department of Biology, Faculty of Graduate Studies, York University, Toronto, Ontario, Canada.
Department of Biology, Vancouver Island University, Nanaimo, British Columbia, Canada.
PLoS One. 2025 Jan 30;20(1):e0316728. doi: 10.1371/journal.pone.0316728. eCollection 2025.
Relationships between parasites, host physiology, and behaviours are complex. Parasites can influence host hormonal microenvironment and behaviour through "sickness behaviours" that generally conserve energy. Using a parasite removal experiment, we examined the effects of gastrointestinal parasites on fecal glucocorticoid metabolites (fGC) and behaviours of vervet monkeys (Chlorocebus pygerythrus) at Lake Nabugabo, Uganda. We collected parasitological, hormonal, and behavioural data from adult and subadult male and female vervets (N = 19) in 2014 across four study phases: pre-deworming, post-deworming, early reinfection, and late reinfection as well as in 2015. Overall, there was no decrease in fGC after deworming, but there was an increase following natural reinfection. There was no change in feeding across study phases; however, moving, grooming, and resting changed between the post-deworming and late reinfection phases, but not always in the predicted direction. Comparing behaviour across the same months in the following year as in the 2014 experimental study period, we found no differences in moving, feeding, grooming, and resting events. Despite behavioural variation between study phases, we cannot conclude that behavioural changes are due to parasitism rather than other seasonal variation. However, fGC increased following reinfection, which is consistent with parasitism being costly for hosts.
寄生虫、宿主生理机能和行为之间的关系错综复杂。寄生虫可通过通常能节省能量的“疾病行为”来影响宿主的激素微环境和行为。我们通过一项寄生虫清除实验，研究了乌干达纳布加博湖绿猴（Chlorocebus pygerythrus）体内胃肠道寄生虫对粪便糖皮质激素代谢物（fGC）及行为的影响。2014年，我们在四个研究阶段，即驱虫前、驱虫后、早期再感染和晚期再感染阶段，以及2015年，收集了成年和亚成年雄性及雌性绿猴（N = 19）的寄生虫学、激素和行为数据。总体而言，驱虫后fGC没有下降，但自然再感染后有所增加。各研究阶段的进食情况没有变化；然而，在驱虫后和晚期再感染阶段之间，移动、梳理毛发和休息行为发生了变化，但并不总是朝着预期的方向。将2014年实验研究期间相同月份的行为与次年进行比较，我们发现移动、进食、梳理毛发和休息活动没有差异。尽管各研究阶段之间存在行为差异，但我们不能得出行为变化是由寄生虫感染而非其他季节变化导致的结论。然而，再感染后fGC增加，这与寄生虫感染对宿主造成代价是一致的。
