Insight into the dietary habits of the Eurasian Otter, Lutra lutra, in the east of Algeria (El-Kala National Park)

EnglishIn 1997, faeces samples (spraints) (n = 175) from the European otter (Lutra lutra) were taken in seven localities of the El-Kala region. This is a restricted ecogeographic complex in which freshwater hydrographical systems, comprising rivers, ponds and wet coastal zones (brackish lagoons, shipping channels), are highly interwoven. The frequency of occurrence and relative abundance of consumed taxons were calculated on the basis of 493 identified prey. Fish made up more than 88% of the otter’s catch (relative abundance), with a strong predominance of Pseudorasbora parva, Luciobarbus callensis and undetermined Cyprinidae. Anuran amphibians made up 9% of the prey. The remainder were represented, in order of significance, by mullets, eels (Anguilla anguilla), bleaks (Alburnus alburnus), perciformes, gobies, insects, birds, crustaceans, etc. However, Cyprinidae, the eel and the barbel dominated in terms of ingested biomass. The otter’s diet varies with local conditions: lagoons and channels have marine or migratory fish; rivers are dominated by barbels; ponds by Cyprinidae. Finally, small-sized fish (topmouth gudgeon and barbel) dominated the diet in terms of numbers: 62% are smaller than 12.5 cm. The introduction of the topmouth gudgeon into the region could have catastrophic consequences for endemic fish, such as Pseudophoxinus callensis. francaisEn 1997, des echantillons de feces (epreintes) (n = 175) de la loutre d’Europe (Lutra lutra) ont ete recoltes dans sept localites dans la region d’El-Kala. C’est un complexe ecogeographique restreint ou les systemes hydrographiques dulcicoles, constitues de rivieres, d’etangs et de zones humides littorales (lagunes saumâtres, chenaux maritimes), sont assez imbriques. Les frequences d’occurrence et l’abondance relatives des taxons consommes ont ete calculees a partir des 493 proies identifiees. Les poissons constituent plus de 88 % des prises (abondance relative) avec une tres large predominance de Pseudorasbora parva, Luciobarbus callensis et des cyprinides indetermines. Les amphibiens anoures constituent 9 % des proies. Le reste est represente, selon l’importance, respective - ment par des mugilides, des anguilles (Anguilla anguilla), l’ablette (Alburnus alburnus) des perciformes, des gobiides, des insectes, des oiseaux, des crustaces... Cependant, les cyprinides, l’an - guille et le barbeau dominent pour la biomasse ingeree. Le regime alimentaire est fonction des conditions locales : les lagunes et chenaux avec des poissons marins ou amphihalins ; les rivieres ou dominent les barbeaux ; les etangs avec les cyprinides. Enfin, les poissons de petite taille (pseudorasbora et barbeau) dominent le regime en nombre : 62 % font moins de 12,5 cm. L’introduction de pseudorasbora dans la region pourrait etre catastrophique pour des poissons endemiques, comme Pseudophoxinus callensis.