Bert Hölldobler
Behavioral Physiology and Behavioral Ecology; Sociobiology; Biology of Social Insects; Chemical Ecology; Evolutionary Biology
I am interested in the evolution of social organizations in insects and in the underlying mechanisms that make insect societies work. Ants, in particular, are great model systems for studying various evolutionary grades of socio-complexity, ranging from primitive eusocial organizations with not more than hundreds of individuals, to complex superorganismic constructs consisting of hundreds of thousands, and in some species even millions of individuals.. This also entails the study of evolutionary transitions from hierarchical organizations in primitive insect societies to systems of distributed networks in evolutionary advanced societies.
All these different social organizations exhibit various degrees of cooperation and division of labor. Such cooperative systems can only work by means of communication. Without communication there is no cooperation or division of labor in any social system, whether it is an assembly of genes, organelles, cells, or organisms.
We continue to work on the disentangling of the complex communication system in ant societies. Ants communicate mainly by means of chemical signals, which, however, often consist of multiple components, and are modulated by additional mechanical stimuli.
Closely connected with this work is our comparative analysis of the regulatory mechanisms of reproduction in primitive ant societies, where each member has the potential of becoming a reproductive individual, and in highly evolved superorganismic societies, which have only one or a few reproductive individuals, (the queens), and millions of sterile workers that comprise the somatic body of the superorganism.
Communication is essential for the functioning of insect societies, but it is also an important feature in regulating intraspecific competition among neighboring ant societies. In animal species that live in social groups, contests for limited resources are usually not between single individuals, instead groups of individuals compete as units. In such cases differences in the number of individuals per group determine the outcome of the contest. Certain ant species employ ritualized tournaments during which they collectively communicate information about their size and "resource holding potential". We have developed several models envisioning how this collective assessment might work, but we are far from understanding this remarkable territorial behavior, which has a striking analogy to the so called "nothing fights" described by anthropologists in tribes of New Guinea.
Selected Publications | CV (PDF)
Bert Hölldobler and Edward O. Wilson, THE ANTS, Harvard University Press, (Cambridge MA, London UK), 1990, pp 732
Bert Hölldobler and Edward O. Wilson, JOURNEY TO THE ANTS, Harvard University Press, (Cambridge MA, London UK), 1994, pp 228 ( this book appeared in 13 languages)
R.Wirth, H. Herz, R. Reyel, W. Beyschlag, B. Hölldobler, HERBIVORY IN LEAF-CUTTING ANTS, Springer Verlag (Heidelberg, London, New York, Tokio), 2003, pp 230