According to amphibian expert Lou Perrotti, director of conservation at Roger Williams Park Zoo, frogs and salamanders don’t typically migrate to their breeding ponds until mid-March in most areas of the state. During the cold winter of 2015, when many ponds were still frozen until April, amphibian migration was delayed by almost a month. But it’s not unusual for rain showers during an especially warm period in late February to trigger an early migration.