Definitely the most wildlife I’ve ever seen on a trip

You’ll be in for a treat!

Sounds like starting with tethered recall around those distractions is maybe what he needs. Maybe try a leash and/or a long line when training around those distractions, so that you can keep him from running off and can use it to help get his attention and cue him if he doesn't respond when asked. That's one idea. Another idea (either on its own or in addition to the leash/long line, whatever works for you) is using very high value treats - basically, you want to make yourself be more interesting to the dog than whatever it is that he's wanting to chase, so if there's a treat that he will do absolutely anything for, you could try that. I know some people use an ecollar with their dogs, either on its own or in addition to a leash/long line. I'm not a dog trainer, those are just some things I've learned from others/seen other people do (a lot of the ones I've watched on KZbin have trained service dogs, and those living breathing pieces of medical equipment are trained to ignore all kinds of distractions), so take that for what you will. There are a bunch more things I can't think of right now (I'm not sure how various training tools (slip chain, prong, martingale, head halter, etc.) work when attached to a long line, since most of the ones I know of are designed for close up use, i.e. with the dog on a leash, so much closer to you), but hopefully that at least gives you a jumping off point either of where to start to try things out to see what works for you and your dog, or to be able to come up with more ideas of your own. Hope that helps at least a little bit.