Meet Mr. Porpoise - Ceta-Base

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All during rliis period the babj was receiving nourishment from her parent. In the eleventh week, however, she again swallowed small mullet. During tin- next three weeks the amount of fish consumed rose to about ten pounds. The young one, however, frequently attempted to nurse until the fourteenth week. The second nursing porpoise to be studied in the tanks was captured with her mother in July, 1939. About a month after capture, the female appeared to go dry. The young one, however, made frequent at- tempts to obtain milk. For a ten-day period the little one went apparently without nourishment and lust much weight. Finally she started eating a few fisb a day, but swallowed them with considerable effort. Within a week she was eating up to ten pounds per day and was competing successfully with the adult porpoises. At this writing, she is healthy and filling out rapidly. The portion of the brain devoted to receiving sensations of sound, we learn, is particularly well developed in the porpoise. It is extremely interesting, therefore, to watch the behavior of an animal whose principal concept of his surroundings comes to him through his auditory apparatus. The auditory apparatus has been considerably modified in the case of these sea-going mammals. No outer ear is visible on the head of the porpoise. If we look closely, however, in the region a few inches behind and lower than the eye, we notice an almost in- visible opening, the rudiment of the auditory canal. In the case of the animal we are watching, it is scarcely large enough to permit the entrance of a toothpick. Water is an excellent conductor of sound. This closure of the auditory canal, therefore, does not im- pair the animal's sense of hearing, as sound vibrations are carried directly to the bones of the skull. The porpoise is interested principally in the sounds transmitted through water, and has been able to close his external auditory canal without endangering his survival. The importance that this sense of hearing plays in feeding has been particularly interesting. The first porpoise to be captured and placed in the tanks here in March, 1938, showed no interest whatsoever in dead fish that were presented to him. Accidentally, however, it was discovered that if the fish hit the water broadside, with a splash, it was immediately taken by the porpoise. Thereafter, fish were slapped on the surface several times and were then thrown to the porpoise in such a manner that they landed broadside on the water. The significance of this discovery is interesting because we know that here in the murky inland waters of the Florida coast, mullet frequently leap clear of the water to land on the surface with a splash. The possibility is offered, therefore, that the J let. The importance that sound plays in the life porpoise lias ] (-d to much discussion about the of communication among whales, dolph siderable reference- have been made in literature to or calls uttered bj ing mammals. particularly, when harpooned oi OVeries made at Marine Studio- with porpoises was that the animals are capa A sharp whistling sound was clearly evident in the corridors surrounding the circular tank after the first bottle-nosed dolphin was introduced. The sound was -0011 noted to be caused by the 1 air from the blowhole. Subsequent observations led to the : tion that the sharp whistling sound made by porpoises was possiblj similar in origin. During the first week or two of captivity all of the specimens whistled constantlj and swam about the tank nervously. Afterthey became acclimated, bow ever, the whistling was heard less frequently and appar- ent [j served as a method of communication. I mals made this sound less frequently during the day- light than at night. Apparently the animals used variations in this whistling sound to indicate different emotional states. L sually when one or several of the animals w ere chasing a live fish, they would be whistling excitedly. When any disturbing object, such as a net. was pres- ent, this was also true. This sound was transmitted well through water and was heard distinctly in the corridors surrounding our tanks above the scuffling of feet and the chatter of voices. A\ hen it was necessary to move two porpoises, the original mother and daughter, from the rectangular tank into the circular one, a very clear example of the function of the sound was obtained. The parent was netted first and moved through the shallow connecting tank into the circular. The water level was then lowered in order to catch the young one. The two animals remained in their respective tanks close to the wire mesh gates that separated them from each other, the young one whistling madly and the parent frequently answering her. As soon as the water level in the two tanks dropped low enough, so that the connecting tank was dry, and the watery, and therefore sound-conducting connection between the two tanks was severed, the parent left her position at the gate and swam about the whole tank, even showing some interest in chasing live fish. The young one persisted in whistling as loudly as ever although the parent never whistled again after she was unable to hear the young one. Within a short time the young one was captured and placed in the tank with its parent, where they joyfully renewed their life together. MEET MISTER PORPOISE J 9
photo by "' (Left) The concrete SHELL surrounding the steel tanks encloses observation corridors. Stairiuays lead to a top deck from which the surface of the tanks can be viewed. Flocks of pelicans pass overhead continually and egrets dot the marsh expanses to the west (Right) A NEWLY-CAPTURED porpoise in the well of the collecting boat Porpoise. The steel doors at the distant end of the ivell open to the sea through the stern making it possible to bring large specimens in under water. The pad and sling at the left will be placed under the porpoise preparatory to hoisting Anyone who has swum under water knows how poorly we can see beneath the surface. How then can the porpoises and whales, which were once land crea- tures, pursue their submarine existence? A frequently observed fact, has been that whales, such as the killer, raise their heads out of water at the edge of ice floes, apparently looking for prey. The captive dolphins at Marine Studios frequently peer, head out of water, and undoubtedly perceive with some degree of definition, moving objects at a distance of at least 50 feet. Whenever anyone walks out on the feeding plat- (Below) Young porpoise about to catch a live fish while "Ma" looks on approvingly. When live fish are introduced the animals work together and herd the school against the ivall where they can be more easily caught Photo by Wtn. F. Gerecke Photo by Mrs. C. V. Whit form, whether carrying food or not, all the porpoises gather in anticipation, raising half their bodies out of water as they follow the movements of the human. One of our young porpoises, which became very tame, was a particularly keen observer of above water ac- tivity. While this young one was resting at the surface, its attention could be attracted by a hand waving at a distance of 50 feet. The animal would come rac- ing across the tank and leap out of water to investigate the waving object. All porpoises after being acclimated to captivity will follow a fish thrown through the air 20 feet The single closed blowhole shows up prominently on the heads of these porpoises. The large animal in the cen- ter is an adult female, and her young nursing offspring follows in typical manner close behind Photo by Mrs. C. V. Whitney NATURAL HISTORY, JANUARY, 194O
Page 1 and 2: MEET MISTER By Arthur F. McBride cu
Page 3: gether as it exists in the open sea
Page 7 and 8: This photograph was taken when the
Page 9 and 10: to have a complete understanding of
Page 11 and 12: Young PORPOISE leaping for food. Th
Page 13 and 14: tivity, they were also found to be

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