Ecological drivers of helminth infection patterns in the Virunga Massif mountain gorilla population. (April 2022)

• Record Type: Journal Article
• Authors: Petrželková, K.J.; Samaš, P.; Romportl, D.; Uwamahoro, C.; Červená, B.; Pafčo, B.; Prokopová, T.; Cameira, R.; Granjon, A.C.; Shapiro, A.; Bahizi, M.; Nziza, J.; Noheri, J.B.; Syaluha, E.K.; Eckardt, W.; Ndagijimana, F.; Šlapeta, J.; Modrý, D.; Gilardi, K.; Muvunyi, R.; Uwingeli, P.; Mudakikwa, A.; Mapilanga, J.; Kalonji, A.; Hickey, J.R.; Cranfield, M.
• Is Part Of: International journal for parasitology. Volume 17(2022)
• Page Start: 174
• Page End: 184
• Publication Date: 2022-04
• Subjects: Mountain gorilla -- Helminth infection -- Strongylid nematode -- Tapeworm -- Environmental and host factors; Parasites -- Periodicals; Parasitology -- Periodicals; Animals -- Periodicals; Wildlife diseases -- Periodicals; Parasites -- Periodicals; Animals, Wild -- Periodicals; Animals; Parasites; Parasitology; Wildlife diseases; Periodicals; 591.7857
• DOI: 10.1016/j.ijppaw.2022.01.007
• Languages: English
• ISSNs: 2213-2244

Abstract

Abstract: The Virunga Massif mountain gorilla population has been periodically monitored since the early 1970s, with gradually increasing effort. The population declined drastically in the 1970s, but the numbers stabilized in the 1980s. Since then, the population has been steadily increasing within their limited habitat fragment that is surrounded by a dense human population. We examined fecal samples collected during the Virunga 2015–2016 surveys in monitored and unmonitored gorilla groups and quantified strongylid and tapeworm infections using egg counts per gram to determine environmental and host factors that shape these helminth infections. We showed that higher strongylid infections were present in gorilla groups with smaller size of the 500-m buffered minimum-convex polygon (MCP) of detected nest sites per gorilla group, but in higher gorilla densities and inhabiting vegetation types occurring at higher elevations with higher precipitation and lower temperatures. On the contrary, the impact of monitoring (habituation) was minor, detected in tapeworms and only when in the interaction with environmental variables and MCP area. Our results suggest that the Virunga mountain gorilla population may be partially regulated by strongylid nematodes at higher gorilla densities. New health challenges are probably emerging among mountain gorillas because of the success of conservation efforts, as manifested by significant increases in gorilla numbers in recent decades, but few possibilities for the population expansion due to limited amounts of habitat. Graphical abstract: Image 1 Highlights: We quantified helminth infections in fecal samples from Virunga 2015–2016 surveys. Higher strongylid infections were in higher densities groups with smaller MCPs. Higher helminth infections occurred in gorilla groups in certain vegetation types. Impact of monitoring (habituation) was minor. Virunga mountain gorilla population may be regulated by strongylid nematodes.