THE PORPOISE-SONAR PROJECT AT FSU'S MARINE LAB

 

Between 1952 and 1956, Kellogg worked closely with Robert Kohler at FSU's marine lab at Alligator Point, on the Gulf of Mexico just south of Tallahassee, to carry out a project investigating the possibility that porpoises use sonar in navigation and foraging. Bob Kohler was a skilled engineer, with great practical smarts and creativity who, in today's terminology, was a one-man "Technical Support Group" for the entire campus at that time. The first two papers from this project were published in Science in 1952 and 1953, with Kohler as a co-author.

Winthrop Kellogg at FSU Marine Lab,
(early 1950s)

Bob Kohler at FSU Psych Dept Lab (2002)

How Kellogg's Porpoise Research Got Started: Bob Kohler's Account  

During this time [circa 1951] I got involved with Dr. Kellogg of psychology.  I had done a lot of work for the psychology department as a whole and got to know Dr. Kellogg.  One day we went out on his sailboat, and we were just sailing along -- he had a beautiful little sailboat -- just sailing along and here come the porpoises right up by the bow riding the bow wave.  This was in the summertime.  He was looking at those things.  This guy had more sense under his fingernails than I have in my head, you know.  He was really a sharp nail.  He looked at the porpoises, and he looked at the water, and we passed a stake or something in the water -- you know a fisherman would always mark a place by driving a stake down in the bottom.  And he'd say, "Bob, how do they keep from running into these stakes?  Or for that matter, from running into the boats."  And, just joking, I said, "Maybe they have sonar."  I knew that bats had sonar, and so did he.  In fact, another man named Kellogg is the one who discovered this, and there's no relation. Anyway, Kellogg decided by gosh he was going to find out, so he started working on the porpoise problem.  From: Robert Kohler's Oral History (1999), The Reichelt Program for Oral History, Florida State University. 

 

Kellogg's entire research program on porpoises was summarized in several papers and particularly in his book: W.N. Kellogg (1961) Porpoises and Sonar. Chicago: University of Chicago Press.  In the material that follows, we highlight main points of the project as described in Kellogg's book.  However, we urge you to look at a longer and fascinating excerpt from Robert Kohler's Oral History which provides an untold perspective on Kellogg's famous porpoise work and a case study of how behavioral-research methods were combined with state-of-the-art technology in FSU's Psychology Department in the 1950s. The Department's research has reflected that combination ever since expanding and maintaining a world-class Technical Support Group.    Kohler's account provides a unique perspective on how the porpoise work got started and how it proceeded, and is an excellent case history in the scientific method.    

 

THE PROJECT

"The project. . . .was sponsored and supported by the Office of Naval Research (ONR) and the National Science Foundation(NSF). The ONR lent indispensable underwater sound gear, and the NSF gave financial aid in the form of substantial research grants. Additional funds for carrying on the work were obtained from the Psychology Department, the Oceanographic Institute and the research Council of Florida State University (Porpoises and Sonar, 1961, p.IX)."

 

 

THE GOALS OF THE PROJECT: KELLOGG'S STATEMENT

The goals of the project were summarized in Porpoises and Sonar (1961):

"[The] [o]bject of the series of investigations. . . .has been to demonstrate the process of sonar or echo-ranging in the bottle nose dolphin, Tursiops truncates. [I] wanted to find out if a dolphin or porpoise could locate food objects, like fishes, by bouncing echoes off the fishes' bodies. [I] wanted to discover whether it could avoid submerged obstructions by using its ears alone. [Kellogg] wanted to learn if it could navigate at night or in turbid water without employing vision, tough, or any of the chemical senses. To do this under controlled conditions, [he] had to eliminate all of the other sensory avenues which these animals might conceivably make use of in such situations. The research program as a whole … has included both wild or free-swimming, as well as captive, porpoises." (Porpoises and Sonar, 1961, p. 151)

"[The] study of porpoise sonar has been divided into three main steps or stages. First, [I] analyzed the sound pulses which these animals emit for the purpose of echo-ranging. [I] sought to determine whether any of their water-borne noises possess the necessary temporal and acoustic characteristics for proper use as sonar signals. Second, [I] turned to the receiving side to find out if the echoes from porpoise sound pulses could be adequately decoded and analyzed. Lastly, [I] studied the porpoise in action by examining its ability to use its own sound signals in navigation and in orientation. This last stage has taken up the greater portion of the book" (Porpoises and Sonar, 1961, p. 152)

 

THE LAB AT ALLIGATOR POINT

Kellogg, Kohler and others working with porpoises at the FSU Marine laboratory (circa 1953)

Kellogg (center, in ball cap) setting up for a testing session at the lab (circa 1953)

Apparatus used for analyzing porpoise sounds. The equipment shown here produced the photographs of echo-ranging pulses seen next . (1) Audio-amplifier. (2) Loud-speaker. (3) Oscilloscope camera. (4) Cathode-ray oscilloscope. (5) Audio-oscillator (for calibration). (6) Band-pass filter. (7-7') Ampex tape recorder from which porpoise noises are sent to oscilloscope. (8) Auxiliary recorder

 
SOME MAIN RESULTS

DESCRIPTION OF PORPOISE SOUNDS

"The underwater sounds which porpoises produce[d] most often [were] successive series of rapidly repeated clicks or pings. These noises [were] analyze[d] acoustically by several methods and in several places. [The noises]. . . .contained a wide band of both sonic and ultrasonic frequencies extending as high as 170,00 cycles per second. Echoes from such clicks have been measured and photographed." (Porpoises and Sonar , 1961, p.153)

 
Oscilloscopic photographs of porpoise clicks or sound pulses used in echo-ranging. (Top) Filmstrip showing a brief train of porpoises clicks beginning about half-second after a surface splash. Several harmonics are indicated by the different densities of the spikes. The noise of the splash is shown at the left of the film. The clicks in this picture were photographed live as the porpoise made them. (Bottom) The same train of sound-pings photographed from the play-back of Ampex magnetic tape. The two pictures will be seen to be identical except for a slight AC modulation in the base line of the lower photograph.
(Top) Photograph of the cathode-ray screen of a panoramic ultrasonic analyzer, showing frequency components occurring between 80 and 120kc. in a series of porpoise clicks. Separate pips represent coincidence of the sweep of the cathode-ray tube with different clicks. Twelve clicks that occurred during the photographic exposure (0.5 sec. in this instance) thus contained frequencies extending at least to 120kc. (Bottom) Photograph of the cathode-ray tube of the panoramic analyzer when the tuning range was 10-200kc. The strongest frequencies, so far as intensity is concerned, will be seen to lie below 25 kc., but the short pips at the right indicate the presence of frequencies of 140, 155, and 170 kc., respectively.
Underwater photograph shows animals examining a hydrophone which was submerged in order to pick up their sounds. (Courtesy Marine Studios)

A series of clicks expanded laterally on this 35-mm. Filmstrip so to show echoes. The large vertical spike represents the original pulse, and secondary spike immediately to the right of each pulse is its echo.

 THE PORPOISE SONAR SYSTEM - EAR AND BRAIN

"The ear and brain of the animal have been shown to be highy advanced in development. They possess important adaptations for the perception and analysis of underwater sounds. The acoustic receptor is able to compensate for changes in external pressure due to water depth. Porpoises have a much greater range of hearing than human beings and, consequently respond to many vibrations in the field of ultrasound. The unusual sonar pulses which they send out, and the excellent receptor which they possess, constitute an acute transmitting-receiving mechanism. The brain, moreover, adapted as it is to the sense of hearing, appears to be well equipped to act as a decoder and computer for the neural impulses reaching it." (Porpoises and Sonar, 1961, p.153)
Diagram showing probable action of the blowhole in closed (left) and open (right) positions. The external valve and the anterior-posterior projecting processes are indicated. Auditory vibrations could conceivably be made whether by the lip of the blowhole, or lower down in the passage (modified from Howell).
A comparison of the brain cavity of a porpoise with that of an adult human being. The tops of the skulls were sawed off of these diagrams. The human skull is on the left. The frontal portion of both skulls points upward. The lateral dimension of the porpoise brain is greater than its anterior-posterior dimension. This is reversed from the proportions of the human brain and that of other mammals.

Side and end views of the tympanic bulla and the periotic bones of the porpoise ear. The ossicles (not shown here) lie between these two bony parts. The cochlea and vestibular canals are in the periotic bone.
 

BEHAVING WITHOUT VISION

"Another way of eliminating vision which proved effective was to conduct tests during the night, when it was so dark 'you couldn't see your hand before your face.' Still a third method was to immerse invisible obstructions, like sheets of plate glass and transparent Plexiglas, and to see whether the animal could avoid colliding with them. (Porpoises and Sonar, 1961, p.153)."
DISTINGUISHING BETWEEN FISHES
"[I] learned. . . .porpoises are able to differentiate between food-fish of different sizes by listening to the echoes reflected from the fishes' bodies. This came to light in a discrimination experiment. In the tests which were made, the two fish to be distinguished not only had different reflecting areas, but they were also of different species. One of the fishes was distasteful or unpalatable to the porpoise, and it would reject this variety of fish even after it had one in its mouth. The other or "positive' food-fish was a species which was much sought after." (Porpoises and Sonar, 1961, p.155) 
The turbidity of the water acted somewhat like a one-way-vision screen. The experimenters above the water level could see sufficiently far beneath the surface to observe the porpoise's head and mouth, but the animal could not detect the target fishes in a horizontal direction. The difference between the absolute threshold for distance and the differential threshold-to-threshold of discrimination between the target fishes is also illustrated in this figure.

 

 

AVOIDING INVISIBLE SURFACES

"In another situation, a pair of desirable or preferred food-fish were used as rewards. Each fish was now identical in size and visual appearance; yet the arrangement was such that one of the paired fishes was always offered behind an invisible sheet of plate glass. The remaining fish was readily available and could be taken and eaten by the animal. The glass was sometimes in front of the right-hand fish and sometimes in front of the left-hand fish. If a porpoise relied on vision in such a situation, it would certainly make some approaches to the glass. Yet, because a sheet of glass 'sounds different' from a small fish, no mistakes at all occurred in more than 200 trials (Porpoises and Sonar, 1961, p.155)."
Plan of the net experiment. A steel net or fence was stretched tightly across the porpoise pool beneath the water, dividing it into two sections. Two openings or doorways in the fence permitted the animals to swim from one section of the pool to the other. A heavy sheet of clear Plexiglas was used as a barrier to block one of the openings. An opaque plastic curtain, manipulated from the bank, was lowered between trials to cover both openings.
 

 

EXPLORING WITH SOUND
"During intensive work with two experimental subjects, many interesting discoveries came to light. [Kellogg] found, for one thing, that the noises of a splash upon the surface of the water inevitably triggered a series of porpoise sound pulses. The animals appeared to be "looking with their ears" to find out if some foreign object had entered the water. If a splash was made alone, without the immersion of a target, the sputtering signals stopped after a few seconds. When a splash was followed by the presence of some new object in the water, exploratory sound signals continued-presumably until the size and distance of the object had been determined (Porpoises and Sonar, 1961, p. 154)."
RUNNING AN OBSTACLE COURSE
"Thirty-six sheet-metal poles were suspended over an enclosed area. These could be simultaneously lowered into the water by assistants who operated tackle from the shore. Only a limited space was allowed for movement between these submerged obstructions. Each pole gave off a bell-like ring when touched or struck, so that collisions were automatically registered on sound-recording tape even though they could not be seen. A few collisions occurred at first, but as soon as the [porpoises] got used to making the short and difficult turns required in this situation, the errors ceased. Even at night, there were no further collisions." (Porpoises and Sonar, 1961, p. 156)

 

 
General design of the outdoor "porpoise laboratory." The dimensions of the pool were 55 by 70 feet. Overhanging cables between rows of telephone poles to the east and west were used for supporting underwater apparatus or partitions. A small crane or hoist to the south permitted lowering of heavy acoustical equipment.
 

 

 

SUMMARY AND CONCLUSION

The major contribution of the Porpoise and Sonar (1961) project was not that porpoises made sounds, which had been recorded by the US Navy in the early 1940s, but what the sounds were used for. The findings were even viewed as "… have a bearing on national defense, as a means of improving Navy sonar or echo ranging of the porpoise is superior in many respects to the best that man has yet been able to develop …" (Porpoises and Sonar, 1961, p.152).

In a second porpoise project carried out in California after Kellogg left Florida State University, he tested the visual and problem-solving capacities of porpoises above and below the water line. A summary of this work is found in Kellogg and Rice (1966) and in Benjamin & Bruce (1982, p. 475-478).

 


 

Robert Kohler (1922 - 2011):  Obituary in the Tallahassee Democrat, October 30, 2011 (with highlighted section)

Robert Kohler, 88, of Tallahassee, Florida, passed away on Friday, 0ctober 28, 2011. Born October 31, 1922, in Milwaukee, Wisconsin, to Robert Urban Kohler and Helen Schlumn Kohler.

He moved to Midway, Florida in 1936, and graduated from Shanks High School. Robert voluntarily enlisted in the Army 1942, serving in the Air Corps as a Radar Repairman during WWII, then in Japan as part of the reconstruction. Upon return to Tallahassee, he enrolled at the Florida State College for Women (summer enrollment allowed for male students), joined the opening class of the Tallahassee Branch of the University of Floirida as a student at Florida State University when it became coed. He completed both Bachelor's and Master's degrees in Physics at FSU. He met his future wife, Marie Aiken, at FSU, and they were wed on January 28, 1950 in Tallahassee.

Robert worked as an Electronics Engineer at FSU, designing and installing equipment for many departments. Of these, he most enjoyed his work with Winthrop Kellogg, PhD, developing the equipment for the original research on echolocation in porpoises. He designed and built three early Tallahassee radio stations, including the first WFSU AM and FM stations, where he was also the first disc jockey. In addition, Robert along with Bill Ragsdale ("Willie the weatherman") designed and built WFSU-TV. He also worked at WTAL as an engineer and disc jockey. He became the Radiation Safety Officer at FSU, then worked for the FSU extension programs teaching Civil Defense and Disaster Preparedness to county personnel throughout the state. Finally, he worked for the State of Florida in Disaster Planning and nuclear power plant safety. He was known for his ability to find creative solutions to problems, and his ability to make needed equipment out of found materials, recycling and re-purposing before those words were in the dictionary. Robert was constantly being asked to fix equipment for many people, including the late Ruby Diamond, who engaged him to keep her music boxes working, and the Tallahassee Regional Airport, where he was called upon to repair the radar and air traffic control communications systems at many odd hours for years. He enjoyed what his family called "tinkering", fixing clocks, musical instruments, and electronic equipment of all kinds.

Robert was an active member of the Tallahassee Elks Lodge 937 for many years, serving as Tiler from 1990 until his death. He enjoyed traditional Jazz music, and collected a large number of recordings over the years. He is survived by his wife of 62 years, Marie Aiken Kohler, his children, James Kohler, Lisa Jernigan (Doug), and Lori Kohler, grandchildren (who called him "Oompah") Emily Kohler, Samuel Rozar, Leah Rozar, Sara Rozar, and Robert Kohler, as well as Ruth Kohler, plus many friends from his work days and the Elks Club.

He was predeceased by his brothers, James Kohler and Gerald Kohler.

A memorial service will be held on his birthday, Monday, October 31, 2011, 4 pm, at the Tallahassee Elks Lodge, 276 N. Magnolia Drive.

 

 

Back to Kellogg Site