River management and habitat characteristics of three sympatric aquatic rodents: common muskrat, coypu and European beaver

Abstract

International audienceThe ecological environment of three aquatic rodents was studied in the French Ardennes region. Two species, the coypu () and the common muskrat (), are invasive. By contrast the native European beaver () was extirpated from the region, subsequently reintroduced, and currently is protected. The aim of this study was to compare the ecological requirements of these three species and predict their future range distributions. We studied the relationship between the species and describe the characteristics of waterways and riparian vegetation in 29 sampling sites. Coypus and muskrats were observed in a variety of riparian habitats and their probability of detection appeared to be independent of waterway width, bank height or bank slope. The availability of numerous herbaceous plants, known to be consumed by these species, may facilitate their settlement. Muskrats are widespread on the French Ardennes waterways, but coypus have not yet colonised the northern part of the region. On the other hand, the beaver was observed primarily in the widest waterways with high banks, where woody plant species, such as , and , are found in abundance. Potentially favourable sites for beaver and coypu settlement were analysed to suggest appropriate management according to each species' status. However, the number of sample sites is weak, especially for sites with beaver, limiting our conclusion

Evaluating simplistic methods to understand current distributions and forecast distribution changes under climate change scenarios: an example with coypu (Myocastor coypus)

“…The target background approach of using locations for similar species is recommended when using a presence-background method where the data are likely to have sampling bias (Phillips et al 2009). Coypu and muskrats are sympatric species because both rodents are aquatic, are herbivores, are burrowers, and have similar global distributions (Ruys et al 2011). By using a targeted background approach, biases in the presence locations are also assumed to occur in the background and thus cancel each other to some degree, similar to presence and absence data collected using the same methodology.…”

Can Recent Global Changes Explain the Dramatic Range Contraction of an Endangered Semi-Aquatic Mammal Species in the French Pyrenees?

“…sedimentation rate, concentration of nutrients and organic particles) [ 99 ]. Therefore, stream flow determines the heterogeneity of aquatic habitats and indirectly the distribution and diversity of organisms, such as macro-invertebrates [ 45 ], water birds [ 100 ] or aquatic mammals [ 101 ]. Integrated modelling approaches coupling hydrological models with SDMs have already shown promising results [ 44 – 46 ] but need to be explored further.…”

Distribution patterns of the native Eurasian and the non-native North American beaver in Finland—possible factors affecting the slow range expansion of the native species

“…In a previous study with partly the same data, both beaver species seemed to prefer 5-20 m streams and avoid small streams (Alakoski et al 2020). Wider rivers have also been preferred in other countries and they might be more utilized as dispersal routes (Ruys et al 2011). Perhaps these preferred habitats were more available in the novel areas because of lower overall beaver densities compared to the areas near the reintroduction site with a high density of beavers.…”