Habitat preferences of four sympatric species of shrews

Abstract

Habitat preferences were studied in a shrew community of two semiaquatic species, Neomys anomalus Cabrera, 1907 and N. fodiens (Pennant, 1771), and two terrestrial species, Sorex araneus Linnaeus, 1758 and S. minutus Linnaeus, 1766, in a study area (5600 m ) alongside a small stream in Białowieża Forest (E Poland). Preferences were estimated by relating frequency of captures with macro-and microhabitat characteristics of trapping points. Distance to the stream and ground wetness appeared to be more important than macrohabitat and plant cover in separation of habitat niches. N. fodiens was trapped at places significantly wetter and closer to the stream than the three other species, N. anomalus was captured at places wetter and closer to the stream than S. araneus and S. minutus was trapped closer to the stream than S. araneus. Habitat preferences of these species reflected vertical segregation in their foraging. The interspecific overlaps in habitat preferences were lowest between N. fodiens and the two Sorex species and highest between N. anomalus and S. araneus and between the two Sorex species. An inverse relationship between the breadths of the trophic and habitat niches of the shrews appeared: the greatest trophic specialist S. minutus had the broadest habitat niche, whereas the greatest trophic generalist N. fodiens had the narrowest habitat niche. High interspecific overlaps in habitat preferences and little overlaps in spatial distribution suggest that the separation of ecological niches of these four species in the study site reflects other mechanisms in addition to habitat preferences.

Responses of small mammals to clear-cutting in temperate and boreal forests of Europe: a meta-analysis and review

“…The Eurasian pygmy shrew is more strongly associated with wet habitats than the common shrew (Rychlik 2000). Therefore, clear-cuts, which are generally drier than closed forest (Hansson 1992b), could be less suitable for S. minutus than for S. araneus.…”

“…It is reasonable to assume that in the long term, the effects of disturbance on species abundance will taper off and finally disappear as was the case in North America (Zwolak 2009). Both analyzed species of shrews are considered habitat generalists (Churchfield et al 1997a), but the Eurasian pygmy shrew has wider niche breadth (Rychlik 2000) and is less dependent on habitat productivity than the common shrew (Hanski and Kaikusalo 1989;Churchfield et al 1997b). Therefore, lack of response of the Eurasian pygmy shrew to habitat change in both zones may be attributed to opportunistic traits of this species.…”

A northern refugium of the Mediterranean water shrew Neomys anomalus in Słowiński National Park (N Poland)

“…On the other hand, N. anomalus rather avoids places with high wetland vegetation. Similar microhabitat preferences were displayed by this species in the Białowieża Forest (Rychlik 2000(Rychlik , 2001. Thus, as previously suggested by Rychlik & Pucek (1995), also on the basis of the present results it can be concluded that leaving unmown wet meadows and sedge swamps seems to be indispensable for maintenance of this species.…”

“…A similar trend in this species (and also in other shrews, e.g. Sorex araneus and S. minutus, and the root vole Microtus oeconomus) was observed by Rychlik (2000Rychlik ( , 2001, who suggested that roots of trees and the gaps between tussocks of sedges and the tree trunks provide the animals with good shelters and nesting dens.…”

“…Both species are semi-aquatic but N. anomalus is less adapted to this lifestyle: it has proportionately smaller feet with fewer fringes and a shorter tail with a shorter keel on its ventral side than N. fodiens (Pucek 1984). In the Białowieża Forest, N. anomalus occurs more frequently in ecotones than in dense forest stands or open sedge swamps, and prefers wet places but located at some distance from deep water (Rychlik 2000). It dives less often than N. fodiens and ineffectively forages in deep water (Rychlik 1997;SoaReS & Rychlik 2009), thus its diet includes a smaller proportion of aquatic invertebrates and it mostly consists of typical terrestrial organisms (e.g.…”