Bertel Møhl (2 January 1936 – 13 September 2017) was a Danish marine

zoologist Zoology ( , ) is the scientific study of animals. Its studies include the structure, embryology, classification, habits, and distribution of all animals, both living and extinct, and how they interact with their ecosystems. Zoology is one ...

and

physiologist Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a subdiscipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out chemical and ...

. He contributed significantly to the understanding of auditory physiology and

bioacoustics Bioacoustics is a cross-disciplinary science that combines biology and acoustics. Usually it refers to the investigation of sound production, dispersion and reception in animals (including humans). This involves neurophysiology, neurophysiological ...

bats Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

and

marine mammals Marine mammals are mammals that rely on marine ecosystems for their existence. They include animals such as cetaceans, pinnipeds, sirenians, sea otters and polar bears. They are an informal group, unified only by their reliance on marine env ...

. Bertel Møhl was born in

Copenhagen Copenhagen ( ) is the capital and most populous city of Denmark, with a population of 1.4 million in the Urban area of Copenhagen, urban area. The city is situated on the islands of Zealand and Amager, separated from Malmö, Sweden, by the ...

in 1936, as oldest son of paleozoologist and

taxidermist Taxidermy is the art of preserving an animal's body by mounting (over an armature) or stuffing, for the purpose of display or study. Animals are often, but not always, portrayed in a lifelike state. The word ''taxidermy'' describes the process ...

Ulrik Møhl and

potter A potter is someone who makes pottery. Potter may also refer to: Places United States *Potter, originally a section on the Alaska Railroad, currently a neighborhood of Anchorage, Alaska, US *Potter, Arkansas *Potter, Nebraska *Potters, New Jerse ...

Felix Møhl (born Elka Lütken Petersen). He studied zoology at University of Copenhagen and graduated in 1965 ( Mag.Scient.), worked first at the

NATO The North Atlantic Treaty Organization (NATO ; , OTAN), also called the North Atlantic Alliance, is an intergovernmental organization, intergovernmental Transnationalism, transnational military alliance of 32 Member states of NATO, member s ...

funded Porpoise Research station in

Strib :''Strib is also the nickname of the Minneapolis Star Tribune'' Strib is a town in Region of Southern Denmark, Denmark, with a population of 5,280 (1 January 2025).Denmark Denmark is a Nordic countries, Nordic country in Northern Europe. It is the metropole and most populous constituent of the Kingdom of Denmark,, . also known as the Danish Realm, a constitutionally unitary state that includes the Autonomous a ...

, then as postdoctoral fellow with professor Keith Ronald at

University of Guelph The University of Guelph (abbreviated U of G) is a comprehensive Public university, public research university in Guelph, Ontario, Canada. It was established in 1964 after the amalgamation of Ontario Agricultural College (1874), the MacDonald I ...

and finally as associate professor in sensory physiology at

Aarhus University Aarhus University (, abbreviated AU) is a public research university. Its main campus is located in Aarhus, Denmark. It is the second largest and second oldest university in Denmark. The university is part of the Coimbra Group, the Guild, and Ut ...

, where he remained until his retirement in 2007. His early work dealt with anatomy and physiology of hearing in

true seals True most commonly refers to truth, the state of being in congruence with fact or reality. True may also refer to: Places * True, West Virginia, an unincorporated community in the United States * True, Wisconsin, a town in the United States * ...

, which included the first description of the soft tissue anatomy of the pinniped

middle ear The middle ear is the portion of the ear medial to the eardrum, and distal to the oval window of the cochlea (of the inner ear). The mammalian middle ear contains three ossicles (malleus, incus, and stapes), which transfer the vibrations ...

, the first audiogram of a pinniped and studies of the electrophysiology of the seal cochlea. Together with Ken Norris he published a seminal paper in 1983 on the so-called acoustic big-bang theory, in which it was proposed that

toothed whales The toothed whales (also called odontocetes, systematic name Odontoceti) are a parvorder of cetaceans that includes dolphins, porpoises, and all other whales with teeth, such as beaked whales and the sperm whales. 73 species of toothed whales are ...

might be able to generate sounds loud enough to incapacitate or even kill their prey. Although the theory is no longer consistent with experimental data, the paper itself served as a significant inspiration for studies in odontocete bioacoustics and in the experimental approach to testing the hypothesis a number of significant findings were made, including the loudest sound pressures ever measured from any animal (from

sperm whale The sperm whale or cachalot (''Physeter macrocephalus'') is the largest of the toothed whales and the largest toothed predator. It is the only living member of the Genus (biology), genus ''Physeter'' and one of three extant species in the s ...

s); the first odontocete feeding sounds recorded in the wild (

narwhal The narwhal (''Monodon monoceros'') is a species of toothed whale native to the Arctic. It is the only member of the genus ''Monodon'' and one of two living representatives of the family Monodontidae. The narwhal is a stocky cetacean with a ...

s); first experimental evidence for the sound transmission pathway in the

nose; and the hyperdirectionality of the sperm whale echolocation sound beam. In the 1970s and 1980s Bertel Møhl concurrently studied biosonar in bats. He was particularly interested in the nature of the detection process and through a series of experiments provided substantial evidence against the at the time dominant theory of

coherent Coherence is, in general, a state or situation in which all the parts or ideas fit together well so that they form a united whole. More specifically, coherence, coherency, or coherent may refer to the following: Physics * Coherence (physics ...

signal processing by the bat auditory system.

Sources

* Madsen, P. T., K. Beedholm, J. Tougaard, and M. Wahlberg. 2018. Bertel Møhl 1936–2017. Marine Mammal Science 34:556–562.
Wahlberg, M., and W. W. L. Au. 2018. Obituary Bertel Møhl 1936–2017. Acoustics Today 14(1):75.

Bertel Møhl genealogy on www.gruthansen.org

References

{{DEFAULTSORT:Møhl, Bertel Danish marine biologists Danish zoologists Marine zoologists 1936 births 2017 deaths Academic staff of Aarhus University