Two Weston nature preserves have been closed indefinitely following several reports of aggressive coyotes. According to animal control officers, visitors say they encountered either packs of coyotes or single animals at the Taylor Woods and Tall Pines preserves. Sibylle Thaler says she noticed coyotes while walking her dog. Another woman, Jennifer Grotez, says a coyote followed her home and was snarling before leaving her alone. Officials say coyotes are generally grayish-brown, the size of a German Shepherd and have uncurled, bushy tails. They also urge that people avoid running from them.