The best time for viewing wildlife is frequently dawn and dusk.

Clothing : The fact that you're not lugging a 45-pound pack doesn't mean you can dress like you're grocery shopping. You might be out at dawn, so you'll need to dress in layers in order to be comfortable as daily temperatures rise and fall. Ask specific questions. How wet or muddy will you get? Should you bring spare dry clothes? And don't forget to wear clothing in neutral colors. You're trying to watch wildlife, not the other way around.

Food : Your guide should be very clear about what meals, snacks, and drinks are provided, but consider bringing a personal stash of favorite snacks, too. The best items will be somewhat crushproof, for those times when everyone's daypack is tossed into the rear of the van while the group moves to another site. And bring your own drink, even if the brochure says they are provided. They might be conveniently provided in the other van.

Other items : Unless there's snow on the ground, pack insect repellent. Another item I never go wildlife watching without: A good map, preferably topographic, of the area I'll be in. Even when I've paid for a guide, I want to mark prime viewing locations on my own map. For when I return on my own dime.