At Mora Passage the Waini is about two miles wide and through the choppy waters of the falling tide we steered straight across to the north shore. Between the waters of this river and the ocean extends a long narrow strip of marshy mangrove, for at least forty miles. Both the White and the Red Mangrove are found here, the latter predominating, and this is the breeding sanctuary of the hosts of birds which haunt the mud-flats at low tide and fill the trees with a gorgeous display of color when the feeding grounds are covered at high tide. For the next three hours we were enchanted by a constantly changing panorama of bird life, which in extent and variety can seldom be equalled elsewhere. While crossing the Waini several Swallow-tailed Kites[58] soared screaming overhead, occasionally swooping past for a nearer look at us. As we skirted the great mangrove forest, birds flew up ahead, few at first but in constantly increasing numbers, until several hundred were in sight at once. They showed little fear and were apparently content to vibrate slowly along between launch and shore, accompanying us for fifteen or twenty miles. By far the greater number were Little Blue Herons,[34] the pure white immature and the slaty blue adults being equally numerous. The latter were very inconspicuous among the foliage, while the former stood out like marble statues against green velvet. The coloring showed great asymmetrical variation, and one young bird with a single blue feather in the right wing was so tame that it kept almost abreast of our flotilla. The irregularity of moult resulted in most remarkable patterns, as in several birds, each of which had one white and one bluish wing. Half a dozen Yellow-crowned Night Herons[36] were seen and twenty or thirty of the ill-named Louisianas.[35] A few Great-billed Terns[14] accompanied the herons and later in the afternoon we began flushing Snowy Egrets[33] in ever increasing numbers. No American Egrets were seen. All along the coast were small flocks of Scarlet Ibises,[27] from three to thirty in number, and in an hour we had driven together no less than four hundred. The majority were full plumaged birds clad in burning vermilion, but many were young in moult. We secured a young female in an interesting condition of moult. In the stomach were found the two chelæ or claws of a small crustacean, each about one-third of an inch in length. The wings were wholly of the immature brown, except for one tiny under-edge covert in the right wing. The back, lower breast and under tail-coverts were fairly scarlet and active moult was in progress on the head and neck.