Firstly I have to say that personally I'm in complete agreement with David,
that a GOOD QUALITY blimp is the best wind protection. I have tried foam with
fur, and feather boa wrap, but none compare with a Rycote blimp ( I don't have
ANY connection with Rycote!). Some years ago I bought off eBay one of the
Indian made blimps with fur cover, and it wasn't until I upgraded to a Rycote
that I realised how poor the Indian one was. In terms of reducing wind noise
there was no comparision, and certainly much better than any foam/fur
combination I had personally tried.
Re recorder, perhaps have a look at the Olympus LS series. In terms of self
noise most of them are much quieter than the DR-40. I myself own an LS-10 which
is superb, and although I've never got around to trying myself, I know that one
of our most respected members Vicky, has used a K6/ME66 combo via inbuilt
battery, directly into her LS-10. If I have any part of that wrong, I'm sure
she'll pop up and correct me!
There will without doubt be other members giving further advice, so take it all
in and don't rush the decision. It may well be suggested that if you are
recording the otters while at the same time watching them, that a parabolic
set-up might be better, but unless you make your own it would be even more
Don't forget also to incorporate into your costing things like monitoring
headphones of some kind (essential), cable, tripod, flash card, batteries etc.