We know that in captivity these birds fade out, usually in a single moult, from the most vivid scarlet to a pale salmon hue, but as to the cause we are still in the dark. The same is true of American Flamingos and Spoonbills. During this trip we made certain of a fact which helps slightly to clear this problem—this being that Scarlet Ibises fade as quickly and completely when in captivity in their native country as in the north. This is confirmed by many birds kept formerly in Georgetown and also on the Island of Marajo at the mouth of the Amazon. We have noticed an interesting fact in regard to this fading out of birds in captivity. Whether the salmon tints appear in the first moult, or more gradually in several, the lesser wing-coverts and the upper and under tail-coverts are the last to loose the scarlet color, retaining it sometimes for five or six years. These feathers in the nearly related but pale Roseate Spoonbill are those which are normally scarlet, and this resemblance may be more than a coincidence. About four o’clock we were surprised to see a large black and white bird with long gray beak and red legs fly up from a mud-flat ahead and swing outward and around us. The glasses showed a Maguari Stork[29] in full breeding color; even the red caruncles around the eye and the long, filmy neck feathers being visible. We had never expected to see the bird away from the pampas of the interior and the sight of the splendid Stork was most exciting. It is almost as large as the Jabiru, white with black wings, scapulars and tail and is one of the most picturesque of the larger waders. We have had a pair of these birds alive for some time and have observed a curious thing about the tail. The real tail-feathers are forked, swallow-like, while the intervening space is filled up with the long, stiff under tail-coverts. In flight the whole are spread, making a parti-colored fan of some eighteen feathers instead of the usual six pairs. These under tail-coverts are a full inch longer than the regular tail feathers and seem to be usurping their function. Two old friends of northern waters appeared in small numbers, Ospreys[59] circling about high in the air with now and then a meteor-like dive, while Spotted Sandpipers[22] looped from one headland to another ahead of us. At half-past four in the afternoon we had our first sight of the great flocks of birds which seem characteristic of this season. Quite high in air, clear of the tops of the tallest trees we saw a black cloud of birds approaching. We soon made them out to be Greater Anis,[79] or as the natives called them “Big Witch” or “Jumbie Birds.” When first seen they were in a dense, compact mass headed straight toward us.