By Stephanie Rosenbloom, New York Times Some of the most engaging and meaningful vacations have long been entwined with learning, be it visiting museums and libraries or touring historic properties. Nowadays, though, many vacations are outdoor excursions. Yet that doesn’t mean learning is strictly about survival skills. Rather, an outdoor vacation is an opportunity to explore the wonders of ocean life, geology, botany, ornithology, zoology and astronomy — particularly with the help of some portable tools that put field guides, encyclopedias, atlases and expert research in your pocket. Whether teaching you how to identify what you see and hear (trees, flowers, birds, bugs, stars), or explaining the features and workings of the natural world (tides, bioluminescence, migration, meteorites), these nature apps, podcasts and websites aim to help all ages roam and learn. Ornithology Audubon Bird Guide: A striking field guide to more than 800 species of colorful North American birds, this app from the National Audubon Society uses the month, location and details you provide — like tail shape, voice and size — to help you identify the winged beauties that catch your eye.