The American mink, Neovison vison, is an established, alien invasive species in the United Kingdom that originally colonized the country at a time when two native mustelids (otters, Lutra lutra, and polecats, Mustela putorius) were largely absent. Both of these species are now recovering their populations nationally. We compared the relative abundance and the behavior of mink in the 1990s and in the 2000s in an area of southern England where both otters and polecats were absent in the 1990s but reappeared in the intervening years. We found that mink were still abundant in the 2000s in the presence of otters and polecats, but that they appeared to have altered some aspects of their behavior. In accordance with previous studies, we found that mink consumed fewer fish in the presence of otters. We also found that mink were predominantly nocturnal in the 1990s (in the absence of competitors) but were predominantly diurnal in the 2000s (in the presence of competitors). We hypothesize that this temporal shift may be an avoidance mechanism allowing the coexistence of mink with the otter and the polecat, although we are unable to attribute the shift to one or the other species. We also found that mink in the presence of competitors weighed less but remained the same size, suggesting the possibility of a competitor‐mediated decline in overall body condition.This is one of very few field studies demonstrating a complete temporal shift in apparent response to competitors. The implications of this study are that recovering otter populations may not lead to significant and long‐term reductions in the number of invasive mink in the United Kingdom as has been suggested in the media, although we cannot exclude the possibility of a decline in mink in the longer‐term.

Wildlife commodification can generate benefits for biodiversity conservation, but it also has negative impacts; overexploitation of wildlife is currently one of the biggest drivers of vertebrate extinction risk. In the present article, we highlight 10 issues that in our experience impede sustainable and humane wildlife trade. Given humanity's increasing demands on the natural world we question whether many aspects of wildlife trade can be compatible with appropriate standards for biodiversity conservation and animal welfare, and suggest that too many elements of wildlife trade as it currently stands are not sustainable for wildlife or for the livelihoods that it supports. We suggest that the onus should be on traders to demonstrate that wildlife use is sustainable, humane, and safe (with respect to disease and invasion risk), rather than on conservationists to demonstrate it is not, that there is a need for a broad acceptance of responsibility and, ultimately, widespread behavior change. We urge conservationists, practitioners, and others to take bold, progressive steps to reach consensus and action.

The spatial organization of a species on a landscape is influenced, at least in part, by the presence of sympatric competitors. Interspecific relatio