Investigations of american mink diving in invaded areas: England and Patagonia

„X HARRINGTON, L.A., FASOLA, L., HARRINGTON, A.L., HAYS, G., RIGHTON, D., MACDONALD, D..

Mendoza, Argentina

Congreso; 10th International Mammalogical Congress. Mendoza; 2009

The American mink (Neovison vison) is an invasive species that has spread (via the fur trade) from its native North America to Europe, the former USSR and South America (Patagonia). American mink are hugely adaptable in terms of prey they can consume, habitats and climates that they can exist in. They are particularly interesting because they are adapted to foraging both in water and on land. However, until recently little was known of the diving behaviour of wild mink, and the methodology to study diving in small, shallow-diving species was lacking. The deployment of temperature depth recorders (TDRs-CEFAS Technology) adapted for shallow divers allowed us to investigate the diving ability and behaviour of wild mink on lowland rivers in southern England. We deployed 31 TDRs on 24 mink and obtained data for 16 individuals (6m; 10f). The total number of dives recorded per individual (over the 5-6 day recording period) ranged from 5 to 789. Mean dive depth was 0.53 m (maximum 2.96 m); mean dive duration was 13.1 s (maximum 57.9 s) - both were similar between sexes and seasons, and were significantly higher than recorded in earlier laboratory studies. Per day, the total number of dives ranged from 12 to 189, with females diving significantly more than males. Surprisingly, most dives occurred during daylight. We discuss the relevance of this type of information for understanding the adaptability of mink, their behavioural ecology and intraguild interactions. Finally, we outline our future goals for mink studies, in England and in Argentinean Patagonia, using this technique.