Habitat and food preferences in a guild of insectivorous mammals in the Western Pyrenees

Abstract

Habitat and food preferences in a guild of insectivorous mammals in the Western Pyrenees Enrique CASTIEN and Joaquim GOSALBEZ Castien E. and Gosälbez J. 1999. Habitat and food preferences in a guild of insectivorous mammals in the Western Pyrenees. Acta Theriologica 44: 1-13.The use of trophic and spatial resources in a guild composed of five species of insectivorous mammals (Galemys pyrenaicus, Talpa europaea, Neomys fodiens, Sorex coronatus, and Sorex minutus) was studied. The characteristics of the macrohabitat were studied based on data from trap lines. Those pertaining to the microhabitat were examined through a study of the sites where each animal was caught. The diet was studied by analysis of the digestive tract as well as the availability of resources in various microhabitats. The results show a high level of segregation in the use of trophic resources. The microhabitat used on the ground surface has a low level of segregation among the shrews. A comparison of the diet of each species with the results from the invertebrate sampling carried out in different microhabitats (water, subsoil, humus, ground surface) shows that there is a relation between the food consumed and its availability in the microhabitats utilised by each species. This study suggests that the coexistence among the insectivorous species studied may be explained by the use of the microhabitat and diet segregation. The differences in diet would be a consequence of the use of different microhabitats.

Comparison of diet and prey selectivity of the Pyrenean desman and the Eurasian water shrew using next-generation sequencing methods

“…This study also provides unprecedented insights into the summer trophic niche of N. fodiens, by identifying prey identity at the family and genus levels for the first time (but see at the order level: Castién and Gosálbez, 1999;Churchfield, 1985;Churchfield and Rychlik, 2006). In accordance with previous studies conducted at a higher taxonomic level, we found that N. fodiens fed on terrestrial prey at a larger extent than G. pyrenaicus, with a dominance of terrestrial Diplopoda and Insecta in its diet.…”

“…Several aquatic or semi-aquatic animals are known to prey and use similar food and habitat resources as G. pyrenaicus and act as potential competitors for resource acquisition: the brown trout Salmo trutta and the dipper Cinclus cinclus (Bertrand, 1994;Santamarina, 1993;Santamarina and Guitian, 1988), the Eurasian water shrew Neomys fodiens (Castién and Gosálbez 1999;Morueta-Holme et al, 2010;Santamarina and Guitian 1988), the Mediterranean water shrew Neomys anomalus (Santamarina, 1993) and the Pyrenean brook newt Calotriton asper (Bertrand, 1994). Among these species N. fodiens exhibits similar habitat preferences as G. pyrenaicus, i.e.…”

“…cavities) on the riverbeds (Greenwood et al, 2002;Keckel et al, 2014). N. fodiens is also known as an opportunistic feeder consuming both aquatic (e.g., crustaceans, insect larvae) and terrestrial (e.g, coleopterans, gastropods, spiders, earthworms) prey (Castién and Gosálbez, 1999;Churchfield, 1985;Churchfield and Rychlik, 2006;Haberl, 2002). Moreover, N. fodiens exhibits a similar polyphasic activity pattern as G. pyrenaicus (Melero et al, 2014), with activity phases varying across seasons (Churchfield, 1984;Greenwood et al, 2002;Keckel et al, 2014;Rychlik, 2000).…”

“…Despite important similarities in their habitat, resource preferences and life style, few studies have focused on the trophic overlap between N. fodiens and G. pyrenaicus to date. These studies, limited to small samples sizes (e.g., only six G. pyrenaicus samples in Santamarina, 1993) and relying solely on the visual inspection of prey remains in faeces or gut content, concluded that coexistence and diet differentiation were likely the result of a different use of micro-habitats (Castién and Gosálbez, 1999).…”

Local habitat management and landscape‐scale restoration influence small‐mammal communities in grasslands

“…Finally, small mammals are important in grassland food 80 webs, both as consumers or top-down regulators of vegetation and arthropods (e.g. most shrews are 81 insectivores), and as a food resource for reptiles, birds and mammals (Castién and Gonsálbez, 1999;82 Mohammadi, 2010; Torre et al, 2007;Vieira et al, 2009 (Gerla et al, 2012). The impact of grassland restoration on small 87 mammals has been addressed in a handful of studies in North America.…”