A Canadian friend of mine was treated very badly by US immigration (not a tourist, was a work visa issue) and was treated incredibly badly, dumped at the Canadian border in the middle of the night with nothing and told not to come back.
Make sure you have everything that you need and details of where you are going and staying and do everything by the book. One thing I do as a matter of course when travelling is leave copies of all important documents (passport, anything visa related, insurance - unless accessible by email/web) etc...) with someone I know can fax them wherever they might be needed in case of emergency.
I'd have loved to have seen an eagle! I got a little overexcited when I thought I'd seen one and had got a photo but apparently it was probably a turkey vulture - still quite an amazing sight!
Look out for chipmunks too and hummingbirds in Canada generally. I really wanted to see a Racoon (word of warning, locals will think you are wierd - they are pests to them) and managed it on my last night in Toronto. They are scavengers though so you are only likely to see one around rubbish bins and some of them are apparently rabid so you should keep a definite distance - gorgeous creatures though.