Interpreting the meaning behind canid body language, and subsequently categorizing it, is not a straightforward task because there is a striking, albeit superficial, similarity between domination and play. Indeed, anyone who has witnessed domestic dogs playing together will probably have noticed that the ‘rough and tumble’ can appear quite aggressive to the casual human observer. While screaming and actions aimed at causing physical injury (i.e. biting, scratching, etc.) are good indicators that the animals are fighting, much body language (gaping, pouncing, erect ears and tail, rolling around together, etc.) appear in playful and aggressive encounters. Moreover, tensions can rise and fall quickly, such that what starts out as a playful encounter could end up an aggressive one.
David Macdonald found that, in his captive group, the dog often found it difficult to solicit play from the vixens because of their subordinate behaviour towards him; in one example, this led to the dog trying to drag the vixen to her feet, which involved grabbing her by the neck and trying to lift her off the ground. Macdonald conceded that to many the result could look murderous, with the vixen being dragged back and forth by the throat. Mike Towler, by contrast, described no such issues in his foxes.
Canid behaviourist Marc Bekoff noted there were usually subtle differences in some of the facial expressions when used for play rather than aggression. The play face, for example, involves opening the mouth by between two and five degrees and pulling the lips back horizontally; this is often accompanied by a brief shake of the head, before the animal darts off in a ‘catch me if you can’ pattern. In my experience, even full gapes can be associated with play and foxes may even bite at each other, although without any obvious ferocity. There is a calmer—more ‘light-hearted’, if you like—ambiance to the proceedings; when the foxes turn aggressive, the fur literally starts flying.
Another indication that the aim is play, rather than aggression, is to look at the tail. In How to Spot a Fox, David Henry notes that a tail forming an ‘upside down U-shape’, combined with ears flattened to the side of the head signifies play. In my experience, play bows are often employed, especially when foxes are trying to solicit play from domestic dogs or cats. Mike Towler recounts many fascinating observations of fox society in his 2015 book My Friends the Foxes. In particular Mike has noted how foxes gently grip each other (and sometimes him) as a sign of friendship and a gape with closed eyes being an invitation to play. Indeed, in his book, Mike wrote:
“Studying wildlife has taught me something about people – our superb ability to ‘get it wrong’. No, I’m not throwing bricks. It’s terribly easy to make mistakes. We place too much reliance on our reasoning ability. ... You will never discover that a ‘vicious snap’ may be fantastically gentle until you are the recipient. That foxes facing each other, mouths wide open to display their impressive dentistry, are not being aggressive or (as I have seen it described) ‘establishing dominance’. In fact this mouth agape stance is a greeting, a display of friendship, possibly an invitation to play. Seen from a distance nobody would notice that one party may have their eyes closed.”
Interestingly, one facial expression that seems to be lacking in the Red fox’s repertoire is the snarl. Despite some suggestions to the contrary in the tabloids, most authors seem to agree that foxes do not snarl. Photos of foxes mid-chew, or at the start or end of a yawn can often give the appearance of snarling, but the skin and musculature of the rostrum is not pulled back to the same extent as in other canids. Indeed, Macdonald pointed out that a snarling fox was something you only saw in erroneous taxidermy specimens; Henry concurred, noting:
“Foxes don’t snarl. Wolves do. Dogs do. But not foxes. Snarling is a ‘close-in’ facial expression useful in highly social animals like wolves and dogs, but not for the solitary fox.”