caa a22 4500 465782159 CHVBK 20180323111958.0 cr unu---uuuuu 170327e19900401xx s 000 0 eng 10.1007/BF00178323 doi (NATIONALLICENCE)springer-10.1007/BF00178323 Cords Marina Ethologie und Wildforschung, Zoologisches Institut, Universität Zürich-Irchel, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland aut Vigilance and mixed-species association of some East African forest monkeys [Elektronische Daten] [Marina Cords] Summary: The frequency of looking up was scored as a measure of vigilance behavior in two species of African forest monkeys (genus Cercopithecus) that often associate in mixed-species groups. The fact that looking up decreased with increasing foliage density around focal individuals was taken as evidence that looking up is an expression of vigilance for predators. The rate of looking up was higher in single-species groups than in mixed species groups for both species. Association had a more marked effect on the rate of looking up when monkeys fed on plant material as opposed to insects. The adjustment of the rate of looking up with respect to association status does not reflect the presence or absence of other monkeys in the same feeding tree. Although a reduction in vigilance levels probably leads to increased feeding efficiency, it is not a sufficient explanation of mixed-species association in the species under study. Springer-Verlag, 1990 Behavioral Ecology and Sociobiology Springer-Verlag 26/4(1990-04-01), 297-300 0340-5443 26:4<297 1990 26 265 https://doi.org/10.1007/BF00178323 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00178323 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Cords Marina Ethologie und Wildforschung, Zoologisches Institut, Universität Zürich-Irchel, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland aut NATIONALLICENCE 773 0- Behavioral Ecology and Sociobiology Springer-Verlag 26/4(1990-04-01), 297-300 0340-5443 26:4<297 1990 26 265 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer