Gerard Baerends

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Gerardus Pieter Baerends (born March 30, 1916 in The Hague ; † September 1, 1999 ) was one of the most important representatives of so-called classical comparative behavioral research in the tradition of Nikolaas Tinbergen and Konrad Lorenz . Baerends' behavioral research group was the first of its kind in the Netherlands and is still considered one of the most productive in the world today, as it alone resulted in 43 doctoral theses .

In 1948 Baerends founded the magazine Behavior together with Tinbergen and William Thorpe and remained its editor until 1991.

Life

Gerard Baerends - as he always called himself - grew up in The Hague. At the age of 12 he joined the Nederlandse Jeugdbond voor Natuurstudie ; He already dealt with biological topics as a schoolboy and got to know Niko Tinbergen through his membership in the nature conservation association, who at that time was also active in the association as a student and was employed as a scientific assistant for zoology at the University of Leiden from 1933 . After graduating from high school in 1934, Baerends began studying biology in Leiden . Already in the first year of study, Baerends supported Tinbergen in his behavioral studies in a gull colony and wrote ethograms on the behavior of gray herons during pair formation. Like Tinbergen before, Baerends also dealt with the behavior of digger wasps , especially Ammophila campestris . In 1941 he was the first student to receive a doctorate under the guidance of Niko Tinbergen ; a year later, his doctoral supervisor was arrested by the German occupiers because he protested against the dismissal of three Jewish professors.

In order to avoid the takeover of power by the National Socialists at the universities, numerous Dutch scientists gave up their academic positions, and Baerends also found a job as a marine biologist at a state institute for fisheries research in 1942 . However, his plan to study tropical marine biology in the Dutch East Indies was soon thwarted when this area was conquered by Japanese forces in 1942 . After all, he was fortunate enough to be able to devote himself to fishing biology questions at home during and after the Second World War : Baerends used catch records and other literature to investigate the relationship between fishing and the size of the Atlantic herring population in the North Sea . He was able to prove that the reduced fishing catches due to the war had led to a recovery of the herring stocks. In an obituary for Baerends, George Barlow wrote : "This study may have been one of the first publications to document the consequences of overfishing ."

When Niko Tinbergen moved to the University of Oxford in 1949 , he recommended Gerard Baerends as his successor to the chair in Leiden, which he refused. Baerends had already accepted a chair for zoology at the University of Groningen in 1946 - as the successor to the physiologist Engel Hendrik Hazelhoff (1900–1945) - where until then only a handful of students had studied biology each year. As a prerequisite for his move to Groningen , he had stipulated that he would be allowed to carry out field studies and combine ecological aspects with behavioral aspects and continue to dedicate himself to marine biology. Looking back on his research career, he called this combination of ethology and marine biology "the two pillars of wisdom"; How unusual this connection was at the time becomes clear when you consider that Baerends was only the second researcher in the Netherlands, after Niko Tinbergen, who had obtained his doctorate through field studies in behavioral biology.

In the following decades Baerends stayed in Groningen and became the most important representative of behavioral biology in the Netherlands; At times the Nederlands Instituut voor Onderzoek der Zee (NIOZ), the Nederlands Instituut voor Visserij Onderzoek (RIVO) and the Koninklijke Nederlandse Akademie van Wetenschappen (KNAW) were headed by former Baerends students. Thanks to him, the expansion and the associated “modernization” of the subject of biology also contributed to the fact that the decline of the second oldest university in the Netherlands was stopped and it was saved from a previously repeated threat of closure. So he provided u. a. for Luuk Tinbergen , Niko's younger brother, whom Baerends had known since his school days, to teach ecology at the University of Groningen from 1949. Luuk Tinbergen had written his doctoral thesis on sparrowhawks ( Accipiter nisus ) three years earlier in Leiden : His dissertation was only the second animal-ecological field study that had been accepted in the Netherlands after that by Huib Kluijver.

At the beginning of the 1970s, Baerends did not agree with the consequences of a higher education reform in the Netherlands because, in his view, the professors were burdened with too much administrative burden, with the result that there was too little time for research. In 1972 he was determined to accept the offer to succeed Konrad Lorenz at the Max Planck Institute for Behavioral Physiology in Germany. However, the immediate consequence of this plan was that the Dutch Ministry of Science offered him additional scientific staff and a pure research chair, i.e. the release from all administrative tasks, so that in 1973 he decided to stay in Leiden.

Gerard Baerends had been with the biologist Dr. Jos van Roon, who had also written her doctoral thesis under Nikolaas Tinbergen and later u. a. Published studies on the play behavior of cats ; the couple had four children.

Research topics

After his behavioral studies on digger wasps in Leiden and the fishery biology studies on herring, Baerends' working group u. a. important studies on the breeding behavior of cichlids and black-backed gulls , the sexual behavior of guppies ( Poecilia reticulata ; formerly: Lebistes reticulatus ) and the behavior of gray herons .

Baerends' own studies on the herring gulls continued the work of Niko Tinbergen from 1950 after he had left the Netherlands on the island of Terschelling , where Baerends used a bunker from the time of the Second World War as an observation post in the middle of the dune landscape . These studies quickly found their way into behavioral biology textbooks. A special aspect, the mechanisms of egg recognition in the black-backed gulls, was presented decades after the beginning of the field studies on Terschelling in two comprehensive reviews by Baerends and his student Rudi Drent. Among other things, it was shown that the gulls prefer to incubate artificial, extremely large eggs over normal-sized, self-laid eggs, from which it was concluded that the egg size can be interpreted as an innate trigger in the breeding business of birds.

Investigations on the guppy

The results of the studies on the guppy were also included in numerous textbooks in behavioral biology, as here in exemplary fashion u. a. the influence of external and z. T. ecological factors on the courtship behavior could be shown. In addition, certain “triggers” (so-called key stimuli ) could be determined which were interpreted according to the principle of double quantification . Specifically, it was proven that the willingness to mate in the male guppy is not a static permanent state. Rather, his willingness to act is influenced by the interaction of at least two factors: On the one hand, according to Baerends' interpretation, these are internal, instinctual states (later studies by other researchers mention, among other things, hormones such as dopamine in mammals as a possible influencing variable); on the other hand, these are external factors that are typical for a certain situation, occur regularly and therefore became important as “triggers” for instinctive behavior in the course of tribal history .

As an expression of the principle of double quantification , for example, the behavior of a person can be interpreted in which long-term food deprivation (subjectively perceived as a strong feeling of hunger ) leads to eating the food even with an extremely weak external factor (for example a moldy piece of bread), while after Excessive food consumption (subjectively perceived as a feeling of satiety ) at best a small and particularly tasty treat leads to further food consumption.

In the courtship behavior of the male guppy, Baerends' work group was able to demonstrate that the intensity of the coloration of his dandruff is directly proportional to the - hormonally controlled - willingness to mate (that is, it allows conclusions to be drawn about the internal state of the male) and that the height of the female from the point of view of the male the external factor is: the more pronounced the color of the male, the smaller the females are pinned at; And vice versa: the less pronounced the so-called wedding dress, the larger ( anthropomorphically formulated: the more attractive) a female has to be in order to be pinned at.

Publications on instinct theory

In contrast to his mentor Tinbergen, who mainly devoted himself to the observation of mostly wild animals, Gerard Baerends distinguished himself as a theorist of behavior in addition to his field studies - similar to Konrad Lorenz in Germany - and published various treatises on the hierarchy of instincts .

In 1958 Baerends published a synopsis of behavioral and phylogenetic data, which is considered to be one of the main works of comparative behavioral research.

In contrast to Konrad Lorenz, who hardly ever considered ecological aspects in his scientific work, Baerends also stimulated ecological research projects throughout his life , so that almost half of the students in his working group were always ecologists and he also became a pioneer in behavioral ecology . After Konrad Lorenz's retirement in 1973, Baerends was asked by the German Max Planck Society to take over the position of director at the Max Planck Institute for Behavioral Physiology as Konrad Lorenz's successor , but Baerends refused: Although he knew that the institute was a enjoyed a high reputation; At the same time, however, he also knew that Konrad Lorenz's group had hardly ever used quantitative methods in behavioral research. He therefore doubted whether he would be able to bring about the necessary “scientific revolution” in this institute.

Honors

Gerard Baerends had been a member of the Koninklijke Nederlandse Akademie van Wetenschappen (KNAW) since 1958 and of the Koninklijke Hollandsche Maatschappij der Wetenschappen since 1968 and, through his work in this institution, also influenced the further development of scientific research in the Netherlands. Since 1959 he was a member of the German Academy of Sciences Leopoldina .

From 1967 to 1975 Baerends was a member of the Scientific Advisory Board of the Serengeti Research Institute in Tanzania .

The main lecture at the annual meetings of the Nederlandse Vereniging voor Gedragsbiologie (NVG; Dutch Association for Behavioral Biology ) has been called Gerard Baerends Lecture since Baerends' death . The University of Groningen has dedicated the Gerard Baerends Visiting Chair of Biology - a visiting professorship - to his memory .

His best known students were Rudolf Drent (later ornithologist at the University of Groningen) and Piet Wiepkema (later cognitive researcher at the University of Wageningen ).

Fonts (selection)

  • Reproductive behavior and orientation of the digger wasp Ammophila campestris. In: Tijdschrift voor Entomologie. Volume 84, 1941, pp. 68-275.
  • with Jos M. Baerends-van Roon: An introduction to the study of ethology in cichlid fishes. In: Behavior. Suppl. 1, 1950, pp. 1-242.
  • GP Baerends et al .: Ethological studies on Lebistes reticulatus (Peters). In: Behavior. Volume 8, 1955, pp. 249-332.
  • Structure of animal behavior. In: Johann-Gerhard Helmcke: Handbook of Zoology. Volume VIII, 7th delivery. de Gruyter, Berlin 1956, pp. 1-32.
  • Comparative methods and the concept of homology in the study of behavior. In: Archives Néerlandaises de Zoologie. Volume 13, Suppl. 1. 1958, pp. 401-417.
  • with Rudolf H. Drent: The herring gull and its egg. Part 1. In: Behavior. Suppl. 17, 1970, pp. 1-312. Part 2 in: Behavior. Volume 82, 1982, pp. 1-415.
  • with Martin Lindauer (Ed.): Modern methods and results of behavior research in animals. Westdeutscher Verlag, 1972, ISBN 3-531-08218-3 .
  • as editor: Function and evolution in behavior. Essays in honor of Niko Tinbergen. Clarendon Press, Oxford 1975, ISBN 0-19-857382-0 .
  • The functional organization of behavior. In: Animal Behavior. Volume 24. 1976, pp. 726-738.

literature

  • Rudolf H. Drent: In memoriam Gerard Baerends. In: Ardea - Official journal of the Netherlands Ornithologists' Union. Volume 88, Issue 1, 2000, pp. 113-118.

Web links

Individual evidence

  1. ↑ George Barlow : Gerardus Pieter Baerends, March 30, 1916 - September 1, 1999. In: Ethology . Volume 106, No. 6, 2000, pp. 481-482, doi: 10.1046 / j.1439-0310.2000.00600.x .
  2. ↑ Gerard P. Baerends: Two Pillars of Wisdom. In: Donald A. Dewsbury: Studying Animal Behavior. University of Chicago Press, Chicago and London 1985, pp. 13-14, ISBN 0-226-14410-0 .
  3. ^ GP Baerends: The rational exploitation of the sea fisheries with particular reference to the fish stock of the North Sea. In: Spec. Sci. Rep. Fish. Volume 13, USA Dept. of Int. Fish Wildl. Serv. 1950, pp. 1-102.
  4. ↑ That must be one of the first papers to document the effect of over-fishing. George Barlow in Ethology , Volume 106, No. 6, 2000, pp. 481-482.
  5. ↑ Gerard P. Baerends, Two Pillars of Wisdom, p. 13.
  6. ↑ so the assessment of the Tinbergen pupil Hans Kruuk in the biography written by him Niko's Nature. The Life of Niko Tinbergen and his Science of Animal Behavior. Oxford University Press, 2003, p. 336, ISBN 0-19-851558-8 .
  7. ↑ This is what Rudi Drent mentions in his obituary for Baerends in the NVG Nieuwsbrief , Volume 8, No. 2, of November 2, 1999 of the Nederlandse Vereniging voor Gedragsbiologie .
  8. ↑ Gerard P. Baerends, Two Pillars of Wisdom, pp. 35-36.
  9. ↑ JM Baerends-van Roon, GP Baerends (1979): The morphogenesis of the behavior of the domestic cat. In: Verh. Kon. Ned. Akad. Wet., Aft. Certificate of nature. Volume 72, No. 2, pp. 1–116, full text (PDF) .
  10. ↑ Kenneth A. Klivington: Brain and Spirit (The science of mind) . 1992: Heidelberg, Berlin, Oxford, Spektrum Akademischer Verlag.
  11. ↑ Gerard Baerends: Structure of animal behavior. In: Handbook of Zoology. Volume 8: Mammalia. 10th part, 1st half, pp. 1–32.
  12. ↑ Gerard Baerends: Comparative methods and the concept of homology in the study of behavior. In: Archives Neerlandaises de Zoologie. Volume 13, Suppl. 1. 1958, pp. 401-417.
  13. ↑ Lynne D. Houck, Lee C. Drickamer (Eds.): Foundations of Animal Behavior: Classic Papers with Commentaries. 1996: University of Chicago Press, ISBN 0226354571
  14. ↑ also according to Hans Kruuk; Baerends 'student Rudi Drent mentions in the obituary for his doctoral supervisor that 20 of the 43 doctoral theses from Baerends' work group dealt with ecological topics.
  15. ↑ Rudi Drent formulated this fact in his obituary for Baerends as follows: He doubted whether he could carry through what there was to a scientific revolution at the Seewiesen institute.
personal data
SURNAME Baerends, Gerard
ALTERNATIVE NAMES Baerends, Gerardus Pieter
BRIEF DESCRIPTION Dutch ethologist
DATE OF BIRTH March 30, 1916
PLACE OF BIRTH The hague
DATE OF DEATH September 1, 1999