Jardin des Plantes Menagerie and the Museum National d'Histoire Naturelle is a 1.3 mile moderately trafficked point-to-point trail located near the city of Paris that offers the chance to see wildlife and is good for all skill levels. The trail is primarily used for walking, nature trips, and birding and is accessible year-round.
No trip to Paris is complete without a visit to the second-oldest zoo in the world Paris' Parc Zoologique (the zoo most likely mentioned in your guidebook) is closed for renovations. So to enjoy a gorgeous Parisian afternoon, head over to the Jardin des Plantes along the Seine and check out the Menagerie. This is more than a zoo -- it's a bit of history. The Menagerie is the second-oldest zoo in Europe (created after the French Revolution as a place to house the animals in the royal menagerie at Versailles) and well worth a gander. Your child can check out birds, big cats, monkeys and plenty of other interesting (and often endangered) species. And while he or she is enjoying the antics of the animals, you can revel in the incredible architecture, a nice walk and the fact that the gift shop is all but hidden (a rarity in most zoos). Be prepared to walk in circles--it's easy to get turned around. But honestly, it's all part of the fun. You can also find the Museum of Natural History nearby -- a place to consider heading for your outing if the weather turns on you.