Coexistence between the southern river otter and the alien invasive N orth A merican mink in marine habitats of southern C hile

• Published in: Journal of zoology (1987) 2013-05, Vol.290 (1), p.27-34
• Main Authors: Medina‐Vogel, G., Barros, M., Organ, J. F., Bonesi, L.
• Format: Article
• Language: English
• ISSN: 0952-8369; 1469-7998
• DOI: 10.1111/jzo.12010

The interaction between native and introduced predators can be an important determinant of the success of introduced species and of the magnitude of their effects. In E urope, it has been shown that the A merican mink N eovison vison can be affected by native competitors; however, such evidence has not been found in S outh A merica. We studied the southern river otter L ontra provocax and the A merican mink at five marine sites, where they coexisted, and at one freshwater site, where only mink were present, in southern C hile. We used the signs of both species to study their habitat use and diet, and radio tracking to study their activity patterns. The results indicated that otters and minks tended to use different habitats in marine environments, the otter favouring littoral areas that are rocky and steep while the mink favours areas of gravel with a gently sloping intertidal zone. These differences were also reflected in their diets. At one of the coastal sites where the diet of the two species was similar, the activity pattern of minks was mostly diurnal, which is unusual. While differential habitat use may be the way through which the A merican mink is able to coexist with the southern river otter in coastal habitats of southern C hile, it is possible that otters are having an effect on individual minks by affecting their activity patterns, although more observations are needed to confirm this hypothesis.