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| Albrecht, Helmut. |
| Four species of sympatric damselfishes (Eupomacentrus, Pomacentridae) produce and apparently use sounds in their courtship behaviour. Up to now, time structure elements were considered the key parameters in species recognition. Audible differences between the species, that can be ascribed to frequency characteristics of these sounds, are described here for the first time. It was found that both classes of parameters, i.e. of time structure and of frequency, can equally be responsible for species specificity within one locality. In other localities, different parameters (e.g. optical signals) or different combinations of different modalities could lead to the same result. |
| Tipo: Article / Letter to the editor |
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| Ano: 1984 |
URL: http://www.repository.naturalis.nl/record/503900 |
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| Albrecht, Helmut. |
| Four species of sympatric damselfishes (Eupomacentrus, Pomacentridae) from certain Florida reefs can be distinguished by certain sound characteristics used during courtship. Apparently the fish use these characteristics for species recognition. These characteristics involve the temporal structure of a sound, i.e. the length of the pulse interval, containing the necessary code for communication. In Curaçao members of the same species did not use the same sound characteristics for species recognition as in Florida. Strangely enough, some were able to differentiate between local congeners, but unable to recognize members of their own species. The question arises whether local dialects are in different codes, in different parts of the species’ distribution... |
| Tipo: Article / Letter to the editor |
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| Ano: 1981 |
URL: http://www.repository.naturalis.nl/record/504553 |
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| Dunnett, Sinclair; Orshoven, Jo van; Albrecht, Helmut. |
| Pendant une mission d’étude de l’Université d’Amsterdam sur le comportement des chimpanzés à l’état sauvage (République de Guinée, province de Kindia) les auteurs se sont intéressés également aux relations entre ces anthropoïdes et les êtres humains. La population humaine se montre très tolérante et plutôt indifférente envers les chimpanzés malgré que ces derniers peuvent faire des dégats à leurs produits agricoles. De ce point de vue l’avenir des chimpanzés est assuré dans cette province de la République de Guinée à la condition que les autres facteurs qui peuvent nuire à la presence de chimpanzés ne changeraient pas. |
| Tipo: Article / Letter to the editor |
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| Ano: 1970 |
URL: http://www.repository.naturalis.nl/record/504085 |
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