Some buns molt in patches. That is often the case when you see spots of hair loss but no accompanying skin problem. With mites and fungus you see some changes to the skin, such as dandruff, redness, irritation, scabs (can be skin colored, so easier felt than seen).

The quality of the hair in the patches feels different from the rest of the fur because rabbit fur consists of two layers, outer guard hairs and and undercoat of wool for isolation. These two layers of hair are most often not the same color, so when one has grown out or one has been shed, the color and texture of the bun’s fur seems to have changed. This is just temporary, though, unless it’s a young bun who is shedding it’s baby coat. The adult coat is often different in color and texture from the baby coat.

i’d just keep an eye and also do some brushing.

Keep an eye, if it is mites it will likely get worse and you’ll see dandruff-like flakes. Many buns are not bothered by mites and they are easy to get rid of with Revolution (selamectin).

And since we’re on the subject of anti parasitics, here’s a public message that we always issue: Never use any compound containing fipronil on a bun. Fipronil is sold OTC under many different names (Frontline, Sentry, Effipro are a few of them) and it’s widely used in cats and dogs. It’s deadly toxic to rabbits.  End of public service message!

I looks like normal shedding to me. But if it gets worse, do as Bam suggested.