I think so. Giraffe and Okapi seem prone to this in Zoos. Possibly because in the wild they browse for much of their time- in Zoos real browsing time( not hay snatching) is limited to the periods when Foliage is supplied- maybe once or twice a day.
Yes, there has been a lot of research done on this, and it is thought to be a type of oral stereotypical behaviour. Over-grooming or hair chewing in both giraffe and okapi is also another well-known example. Lots of enrichment helps to keep those tongues occupied!
I've seen the Okapi, at London in particular, engaged in obviously stereotyped behaviour of this type. They mouth and suck at a particular branch or gate post, or rub their mouths across a bar, for long periods of time.
