2024-03-28T20:25:27Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1467962020-04-07T08:41:52Zcom_10261_108com_10261_8col_10261_487
Bueno-Enciso, Javier
DÃaz-Ruiz, Francisco
Almeida, David
Ferreras, Pablo
2017-03-15T12:49:25Z
2017-03-15T12:49:25Z
2012
TEMPRIV 2012
http://hdl.handle.net/10261/146796
In temporary rivers, ecological resources greatly fluctuate due to the high hydrological variability throughout the year. However, flow regulation prevents this natural regime, and moreover non-native species are commonly associated with regulated water courses. This situation disturbs the structure of aquatic communities and therefore prey availabilities for native predatory species. Yet few studies have tested spatial and temporal interactions of these two disruptive factors. Thus, the aim of this study was to assess the effect of flow regulation and non-native species on seasonal feeding habits of Eurasian otter Lutra lutra in Mediterranean streams. Bullaque River (Guadiana River basin, central Spain) was monthly sampled for otter spraints and prey abundances during 2010. Three stretches were considered: high (source of the river, non-regulated), medium (transition, regulated) and low (mouth, regulated). Diet varied from native prey (amphibians, insects and endemic cyprinids such as Pseudochondrostoma willkommii) in the high stretch to non-native species in the low stretch (red-swamp crayfish Procambarus clarkii and pumpkinseed Lepomis gibbosus). Seasonally, ingested biomass of native prey increased in spring and autumn in the high stretch. Irrespective of the season, diet was more diverse in the high stretch. Otter selected P. willkommii in the high stretch throughout the year, whereas crayfish was selected in other stretches during autumn and winter, when native preys were less available. Overall results show the importance of maintaining natural regimes in temporary rivers, which contributes to preserve native prey communities for otters, and thus the conservation of least-impacted food webs in Iberian fresh waters.
eng
closedAccess
Effects of two disruptive factors on feeding tactics of Eurasian otter Lutra lutra: flow regulation and non-native species
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