They come in off the Pacific in tight vee, dip over the shingle bar that shields the Ashburton River and lagoon from the sea, then sail into the water. There, they thrash, cavort and dive. This is the behaviour of the spotted shag, and there are many thousands at the Ashburton river mouth. NZ Birds Online says shags dive from the sea surface to catch fish and marine invertebrates with slender hooked bills, propelling themselves underwater with webbed feet. They breed in colonies of a few pair to 700 pair. They occur mainly around South Island coastal waters. Forest and Bird said the green facial skin and mohawk were typical of shag during breeding. See video on this page.