A Gray Whale Nursery: More than half of all gray whale births happen in this busy baby nursery lagoon. No other lagoon has as many whales during the breeding and calving season. The whales begin to appear in late December. The number of whales inside the lagoon builds until mid-February, and then starts to drop as whales head north. By the end of April, all but the last few whales (cows/calf pairs) have begun their journey north. Whales are counted inside the lagoon during the months they are here. Guide Keith Jones sends us field notes and images from this popular lagoon. UNESCO has named this and Laguna San Ignacio a World Heritage Site because these two lagoons are such important breeding and calving areas for gray whales. This site used to be called Scammon's Lagoon after Charles Scammon, a whale-hunting captain who charted these areas in the mid-1800s.