You may also want to check out Fuji digital cameras (especially what I would call the bridge models).Many of themuse AA batteries and have good resolution 8MP and 9MP depending on the camera. The S9100 has a 10x zoom and the s8000fd has 18x zoom. The long zoom will come in hndy for those bird and butterfly images you may want to take. The S9100 which I own will allow you to use filters in case you want to use a polizier or UV filter on the front of the lens.
Make sure whatever camera you get for your trip that you have enough battery power to last until you have the chance to chrage your batteries especially if you out in the field in the middle of nowhere. Also make sure you have enough memory card space to store all those images until you have a chance to off load them or get home to your computer. If you don't want to take your laptop a wolverine flashpack device 7000 series may be an option you want to look at as they can store 40GB+ of files from your memory card while your away, so you don;t have to carry loads of memory cards with you. If you don't go this route then carry at least 2 memory cards in case onedevlopes issues in the middle of an animal outing.......
I learned the hard way in 2006 when I went to Nashville and ran out of both battery power in the middle oftry to shoot some inner hotel scenesand on day 2 of 3 was down to only 12 more frames on my second of 2x 256MB memory cards.I ended up having to buy another memory card and paid double what I should have for it.Ever since then when I travel away from home I carry I always carry 4 sets of batteries and a 60GB wolverine storeage device.
I would recommend a 16GB transcend 133x CF card if you get the Fuji S9100 or another camera that can use CF cards. Its a nice card and has loads of room for all your photos.
Also carry something to clean the lense with as the sandy, dirt and dust will make your lense or filter dirty....
Hope these suggestions help make your trip memoriable.