The Israel Nature and Parks Authority provides the public with an opportunity to bond with nature this Purim. Saturday at Appolonia Park north of Herzliya, a Purim festival will be held among the ancient Crusader fortress. Walking tours and workshop, including an origami one for making masks and baskets for mishloach manot (Purim gift packages) will be held. Shabbat observers will have a rare opportunity to take part in a park event this week: free non-Saturday birdwatching sessions on the cormorants. The species are getting ready to migrate to colder climates as Israel's winter draws to a close. The lectures will take place at the birds' resting site in Hadera, today at 11 a.m. and on Tuesday and Wednesday at noon. For details about these and other Purim events in the national parks, call *3693.