A study carried out by researchers from the Forest Technology Center of Catalonia and the Doñana Biological Station (CSIC), and published inJournal of Biogeography, shows that improving lhe environmental conditions have allowed the expansion of the otter ( Lutra lutra ) in Andalusiain the last 20 years.
This species is “rare” in the most humanized areas, and tends to be permanently present in the “less impacted” river courses. “The otter prefers to occupylowland rivers, where food is more abundant, but they are precisely the most affected by human activities, “says Miguel Clavero, co-author of the study.
The scientists analyzed 1,038 Andalusian sub-basins sampled during the three national otter surveys carried out in 1985, 1995 and 2005, and coordinated by the Spanish Society for the Conservation and Study of Mammals (SECEM). The results show that the otter has made a “remarkable” recovery over the past 20 years.The presence of the species in Andalusian rivers has increased by about 70%, and hisexpansionit is“a generalized process” in most of the PeninsulaIberian.
According to the researcher, the increase in the range of the otter in Andalusia is mainly due to the colonization of river courses in which the human impact is “moderate”. Theimprovement of the quality of aquatic ecosystems, especially with regard to pollution, it can favor the otter directly, and through an increase in the abundance of fish, its main prey. To this is also added the great availability of a new trophic resource, theRed crab(Procambarus clarkii), introduced in the mid-1970s, and which is very abundant in rivers and wetlands at low and medium altitudes in Andalusia.
