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Otter predation in a trout fish farm of Central–East Portugal: preference for ‘fast‐food’?
Author(s) -
Marques C.,
Rosalino L. M.,
SantosReis M.
Publication year - 2007
Publication title -
river research and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.679
H-Index - 94
eISSN - 1535-1467
pISSN - 1535-1459
DOI - 10.1002/rra.1037
Subject(s) - lutra , otter , guild , rainbow trout , trout , predation , fishery , trophic level , biomass (ecology) , ecology , biology , generalist and specialist species , range (aeronautics) , geography , fish <actinopterygii> , habitat , materials science , composite material
The Eurasian otter ( Lutra lutra ) is a known piscivorous predator throughout its distribution range, although in some regions a more generalist behaviour emerged, such as in southern European latitudes. We evaluated otter feeding preference/avoidance towards the elements of the fish guild inhabiting a Mediterranean environment (Côa River, Central Portugal) and assessed the influence of proximity to a surplus of trophic resources (a rainbow trout production farm) on the species diet. Almost two years of collected spraints revealed that otters subsisted by consuming almost exclusively fish (94% of consumed biomass), especially the rainbow trout (87% of consumed biomass), although in summer this consumption is complemented with reptiles and amphibians. Due to the presence of the trout farm, and the consequent constancy in the availability of trout, the observed otter specialization in rainbow trout represents an extreme opportunistic behaviour. Copyright © 2007 John Wiley & Sons, Ltd.