Capture and consumption of prey of the otter (Lutra lutra) in Mediterranean freshwater habitats of the Iberian Peninsula
[EN]: The otter feeds almost exclusively on aquatic and semiaquatic species, catching them in watercourses and waterbodies. Foraging and prey consumption studies in freshwater habitats are scarce. Iberian otters caught between 3 and 5 fish/hour of observation in Mediterranean rivers, except during p...
| Autores: | , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 1998 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/180330 |
| Acesso em linha: | http://hdl.handle.net/10261/180330 |
| Access Level: | acceso abierto |
| Palavra-chave: | Food Mediterranean habitats Otter Predation Alimentación Depredación Hábitats mediterráneos Nutria |
| Resumo: | [EN]: The otter feeds almost exclusively on aquatic and semiaquatic species, catching them in watercourses and waterbodies. Foraging and prey consumption studies in freshwater habitats are scarce. Iberian otters caught between 3 and 5 fish/hour of observation in Mediterranean rivers, except during periods of fish shortage, when dropped to 1 fish/hour or less. On 98.2% of occasions the consumption of prey took place in the water, upon river features such as rocks, islands or stones, or at less than 1.50 m from the water edge. Almost all fish of less than 100 g were eaten whole, but left parts of large fish; gravide fish females; claws, legs and heads of crayfish; and toad skins. A food-limited species like the otter is under pressure to optimise the use if its food resources. The prey or parts of prey are left as a last resort in order to avoid injury, intoxications, because the daily food needs have been met, because disturbance, or because of immature behaviour in the case of cubs. For this reason, densities of fish remains are very low, but crayfish and toad remains densities can be high. Density of remains of prey depends more on the characteristics of the prey than the abundance of otters and prey. Results obtained are of importance when evaluating the biomass of the prey in the studies of diet, because parts of prey which are not consumed systematically. |
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