Abstract
BackgroundThe parasitic fauna of beavers (Castor fiber and C. canadensis) has been well studied in many parts of their respective areas of distribution. In Scandinavia there have, however, been limited investigations conducted on the parasites of beavers in recent times. The present study is the first quantitative survey of parasites on beavers living in Sweden and elsewhere in Scandinavia. We investigated the parasitic fauna of the Eurasian beaver (C. fiber) in a North–South gradient in Sweden. The aim of the study was to investigate parasite distribution and prevalence in particular, related to average yearly air temperature and different age groups of beavers. A total of 30 beavers were sampled at eight localities, spanning a 720 km North–South gradient during the springs of 1997 and 1998.ResultsFive parasite taxa were identified. Four of these were present in all of the examined beavers, Stichorchis subtriquetrus (trematode), Travassosius rufus (nematode), Platypsyllus castoris (coleopteran), and Schizocarpus spp. (arachnid). A higher number of new infections of S. subtriquetrus, and more adults of T. rufus, were seen in beavers in southern Sweden where temperatures are higher. One-year old beavers had a higher infestation of S. subtriquetrus, but not of T. rufus, than older individuals.ConclusionsThe parasite fauna of Swedish beavers mirrored the impoverished parasite fauna of the original Norwegian population, and the high prevalence of parasites could be due to low major histocompatibility complex (MHC) polymorphism. Young beavers had a higher load of trematodes, probably depending on behavioural and ecological factors. Warmer temperatures in southern localities likely contributed to increased endoparasite loads.
Highlights
The parasitic fauna of beavers (Castor fiber and C. canadensis) has been well studied in many parts of their respective areas of distribution
Castor canadensis has been introduced to other localities, including Europe
All beavers examined in the present study were infected by four parasite taxa—the trematode S. subtriquetrus, the nematode T. rufus, the beaver beetle P. castoris, and beaver mites Schizocarpus spp
Summary
The parasitic fauna of beavers (Castor fiber and C. canadensis) has been well studied in many parts of their respective areas of distribution. The present study is the first quantitative survey of parasites on beavers living in Sweden and elsewhere in Scandinavia. We investigated the parasitic fauna of the Eurasian beaver (C. fiber) in a North–South gradient in Sweden. Eurasian beavers were severely reduced in numbers over the course of many centuries and, by the early twentieth century, only about 1200 individuals remained in scattered refugia across Europe and Asia, including southern Norway [1]. A small number of beavers, about 80 individuals, were trapped from the remnant population in SouthEast Norway to re-establish the population in Sweden, likely, no more than 46 individuals were successfully introduced [3, 4].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
