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conspicuous the animal the greater is the surprise of the average man when he fails to find it as conspicuous in the landscape as he had supposed; he thinks of a zebra, for instance, as jumping to the eye as it does in a menagerie; 5 and when he finds this not to be the case, he goes to the opposite extreme and supposes that the zebra's coloration is concealing. As a matter of fact it is not concealing, it is highly advertising, when close at hand; but when

over three or four hundred yards off the black and white 10 stripes merge together, and the coat becomes mono

colored, but catches the sunlight in such shape as still to render the bearer conspicuous. The narrow stripes of the big Grévey's zebra fade together at a shorter distance

than is the case with the broader stripes of the smaller 15 zebra; the broad bands on the rump of the latter can be

seen at a long distance. The zebra is purely a beast of the *open plains; it never seeks to conceal itself, but trusts always to seeing its foes. When under or among thin

leaved, scattered thorn trees it is still usually conspicuous; 20 although now and then a peculiar light and shadow effect may conceal it.

It never goes into thick cover save at drinking places, and then only if it is unavoidable; it does not come down stealthily to drink, but openly and warily,

always on the watch and continually galloping off on false 25 alarms; it returns to the plains as soon as it has drank;

and as such an animal can never escape observation when in motion, and as it is never motionless when at or near the drinking places, it is impossible that its coloration

can in any way conceal it at such times. Mr. Thayer's 30 ingenious theories of how all the various stripings on a

zebra obliterate it are without the smallest foundation in fact. So far as the coloration of the zebra has any effect at all, as regards beasts of prey, it is an advertising, not a concealing, effect. The wildebeest and topi, which are found in company with it, are more conspicuous; the hartebeests sometimes more and sometimes less, according to the sunlight; the eland and oryx and gazelle less. 5 A moment's thought ought to show Mr. Thayer and his adherents that animals so differently colored as these, all leading their lives under similar conditions, cannot possibly all be concealingly colored. As a matter of fact none of them owe their safety to concealing coloration, 10 and the majority of them are advertisingly colored. In East Africa the lion preys chiefly on zebra and hartebeest, which live under precisely the same conditions, have the same habits and associate in the same herds; yet two more differently colored animals cannot be im- 15 agined, and neither is concealed in the slightest degree by its coloration. Among the hunter-naturalists to whom we owe most of our knowledge of the enthrallingly interesting life-histories of African big game, Captain Stigand comes second only to Mr. Selous. When I wrote of pro- 20 tective coloration in "African Game Trails,” I had had opportunity only to glance at Stigand's admirable book on the game of British East Africa. In this he discusses the subject in masterly fashion, and with a knowledge that could only come to a trained big game hunter and 25 field naturalist gifted with exceptionally keen powers of observation and analysis. I quote a few lines: “Very few animals seem to rely on protective coloration as a means of escaping observation, however they may be colored. They appear to rely on fleetness of foot, quick-30 ness of eye and ear, or on scenting powers .. (the animals that do trust to hiding) seem to rely more on cover

and concealment or partial concealment than on any great similarity to natural objects ... even if (the larger game of the plains) were perfect examples of protective harmony, which I do not admit, it would avail them little 5 when their lives are spent in walking about in the open. For a moving object even if it assimilates in color to its surroundings always catches the eye of a practiced observer. The two most absurd, but often quoted, examples

of wonderful instances of protective coloration are the 10 zebra and the giraffe. It is true that the zebra in very

long grass is sometimes difficult to pick out, but so is any animal almost entirely concealed from view—even an elephant if the grass in long enough. In their usual East

African habitat (the plains) zebras are strikingly con15 spicuous, turning from black to white as they move and

their sides are alternately in shadow or exposed sunlight. ... A giraffe near, or even in the far distance, when not screened from view, is a most conspicuous object to the practiced eye.”



WHEN I contemplated going on this trip the first thing I did was to get in touch with Dr. Frank M. Chapman of the American Museum. I wanted to get from him information as to what we could do down there and whether it would be worth while for the Museum to send a couple 5 of naturalists with me. On any trip of this kind-on any kind of a trip I have ever taken—the worth of the trip depends not upon one man but upon the work done by several men in co-operation. This journey to South America would have been not worth the taking, had it 10 not been for the two naturalists from the American Museum who were with me, and for the Brazilian officerso skilled in cartographical work who joined the expedition.

I thought of making the trip a zoological one only, when I started from New York, but when I reached Rio Janeiro 15 the Minister of Foreign Affairs, Mr. Lauro Müller, whom I had known before, told me that he thought there was a chance of our doing a piece of geographical work of importance. In the course of the work of the telegraph commission under Colonel Rondon, a Brazilian engineer, 20 there had been discovered the headwaters of a river running north through the center of Brazil. To go down that river, and put it on the map would be interesting, but he wanted to tell me that one cannot guarantee what may happen on unknown rivers—there might be some 25

1 A lecture delivered before the members of the American Museum of Natural History, December 10, 1914. Reprinted by permission from the American Museum Journal, vol. xv, page 35, (February, 1915.)


surprises before we got through. Of course we jumped at the chance, and at once arranged to meet Colonel Rondon and his assistants at the head of the Paraguay, to go down from there with them.

We touched at Bahia and Rio Janeiro and then came down by railway across southern Brazil and Uruguay to Buenos Aires and went through the Argentine over to Chili. We traveled south through Chili and then crossed

the Andes. That sounds a very elaborate thing to do, but 10 as a matter of fact it was pure pleasure. It was a wonder

ful trip. The pass through which we crossed was like the Yosemite, with snow-capped volcanie mountains all about. Afterward we went across Patagonia by auto

mobile and then started up the Paraguay. Our work did 15 not begin until we were inside the Tropic of Capricorn.

We took mules at Tapirapoan and went up through the high central plateau of Brazil—not a fertile country but I have no question but that great industrial communities will grow up there.

The hard work on the unknown river came during the first six weeks. In those forty-two days we made only an average of about a mile and a half a day and toward the end we were not eating any more than was necessary and

that was largely monkey and parrot. The parrots were 25 pretty good when they were not tough but I can assure

Mr. Hornaday that he could leave me alone in the monkey cage at the New York Zoological Gardens with perfect safety.

Both of the naturalists who were with me and I myself 30 were interested primarily in mammalogy and ornithology.

We were not entomologists and studied only those insects that forced themselves upon our attention. There were


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