Parasites of an Arctic scavenger; the wolverine (Gulo gulo)

Parasites are fundamental components within all ecosystems, shaping interaction webs, host population dynamics and behaviour. Despite this, baseline data is lacking to understand the parasite ecology of many Arctic species, including the wolverine (<i>Gulo</i> <i>gulo</i>), a top Arctic predator and scavenger. Here, we combined traditional count methods (i.e. adult helminth recovery, where taxonomy was confirmed by molecular identification) with 18S rRNA high-throughput sequencing to document the wolverine parasite community. Further, we investigated whether the abundance of parasites detected using traditional methods were associated with host metadata, latitude, and longitude (ranging from the northern limit of the boreal forest to the low Arctic and Arctic tundra in Nunavut, Canada). Adult parasites in intestinal contents were identified as <i>Baylisascaris devosi</i> in 72% (n = 39) of wolverines and <i>Taenia</i> spp. in 22% (n = 12), of which specimens from 2 wolverines were identified as <i>T. twitchelli</i> based on COX1 sequence. 18S rRNA high-throughput sequencing on DNA extracted from faeces detected additional parasites, including a pseudophyllid cestode (<i>Diplogonoporus</i> spp. or <i>Diphyllobothrium</i> spp.), two metastrongyloid lungworms (<i>Angiostrongylus</i> spp. or <i>Aelurostrongylus</i> spp., and <i>Crenosoma</i> spp.), an ascarid nematode (<i>Ascaris</i> spp. or <i>Toxocara</i> spp.), a <i>Trichinella</i> spp. nematode, and the protozoan <i>Sarcocystis</i> spp., though each at a prevalence less than 13% (n = 7). The abundance of <i>B. devosi</i> significantly decreased with latitude (slope = -0.68; R² = 0.17; P = 0.004), suggesting a northerly limit in distribution. We describe <i>B. devosi</i> and <i>T. twitchelli</i> in Canadian wolverines for the first time since 1978, and extend the recorded geographic distribution of these parasites ca 2000 km to the East and into the tundra ecosystem. Our findings illustrate the value of molecular methods in support of traditional methods, encouraging additional work to improve the advancement of molecular screening for parasites.