Hi experts! Newbie here. Need a few tips for a one nite evening/night photography in a nature park overseas (Cuc Phuong National Park, Vietnam). Nite trekking will take about 2-3 hrs. I have a D70s and one kit lens provided. One extra 3rd party battery, 2 x 2GB CF cards, 1 x 1GB CF card. Bag, tripod. I currently lack a flash, but will the build-in flash suffice, or will I need an external flash? WIll be taking pictures of anything that moves. Lizards, frogs, huntsmen, etc. All advice welcome! Thanks!