I think a 70-300 should be fine. I use to go there just with my 18-200mm VR and get some decent photos.
I now use a 300mm f4. It's not great in my opinion. I'm poor so I try to get in as close as possible to the bird. Even though most of the birds at Reifel are fairly use to humans, especially the ducks, I still don't want to scare them off so I try to sneak up on them without making a sound. I then wait until I see the bird fly then I snap away.
There was some guy who decided to do a "stop and chat" with me, I don't know why but he went on how I should get all this gear but sadly I don't have 30k to blow like he does. He had a few Canons with 800 and 1400mm lens. I never knew they made a 1400, unless he had a bunch of converters on it. He told me about the new gimble head and tripod he just bought in the morning and how great it was, I was like... ya, cool, right on... there I was with my shitty broken tripod and tiny 300mm.
