I have a foster dog who has started barking for seemingly no reason on our walks. She's a 12/13 year old hound mix, is a friendly girl, and is generally a good walker. She is not my first dog but I've never experienced this type of barking before. She hasn't shown any reactivity to other dogs, people, or vehicles on our walks so I'm kinda stumped on where this is all coming from.
On a typical walk she'll bark when we get out my apartment building as she knows she's not allowed to bark while we're inside the halls. She'll stop for a bit to sniff, potty, and walk a bit before starting up again, and will just repeat this cycle throughout our 20-30 min walk. Usually she'll start barking when there's nothing going on around us so I've ruled out it being to alert me, especially as her body language does not seem tense or anything like that. I used to think she was excitedly barking because it was so nice out and that she loved being outside however now I'm not sure how to stop this behavior when it becomes too much. The barking also seems to rile up our other dog who is leash reactive and I feel bad for our neighbors whenever she goes off during our morning and nightly walks.
She really only barks while we're on a walk so that adds to my confusion and frustrations.
If there is anyone who can give me some advice on how to curb this behavior that would be greatly appreciated!!