jeudi 4 janvier 2018

MSc student project at Budongo on the alarm calling system of Blue Monkeys

Project proposal for MSc student
Project title: The semantics of the alarm calling system of wild blue monkeys (Cercopithecus mitis stuhlmanni)
Supervision: Dr. Guillaume Dezecache and Pr. Klaus Zuberbühler
Location: Institute of Biology, Université of Neuchâtel & Budongo Forest Reserve, Masindi, Uganda
Research objectives. Recent work on the alarm calling system of a number of primate species have revealed some interesting properties about their semantics (Schlenker, Chemla, Schel, et al., 2016; Schlenker, Chemla, & Zuberbühler, 2016). One is the likely presence of so-called “general” calls. As opposed to “specific” calls, general calls are given in a wider set of circumstances, of which the circumstances leading to the production of specific calls constitute subsets. As such, the various alarm calls of a given species can be ranked according to their “Informativity”, i.e., their relation of entailment with other calls of the repertoire.
This proposition seems particularly suitable to describe the semantics of the alarm calling system of the blue monkeys (Cercopithecus mitis stuhlmanni). Male blue monkeys give a variety of calls during predation events (Fuller, 2014; Murphy, Lea, & Zuberbühler, 2013). While the katrain call is mostly given upon encountering avian predators, ants are produced in response to terrestrial threat, while the most common call, the pyow appears in a greater variety of contexts, including non-predatory circumstances (Fuller & Cords, 2017). A potential semantics of this repertoire, proposed by Schlenker and colleagues (Schlenker, Chemla, Schel, et al., 2016) states that katrain is more informative than ant, itself more informative than pyow. By the ‘Informativity principle’ (i.e., the utterance of a sentence S implies that the strictly more informative alternative S’ is false), the production of pyow (any kind of alert) implies the falsity of ant (serious alert) and katrain (non-ground alert). The production of ant implies the falsity of katrain, excluding the possibility that the threat is aerial, and the implausibility of pyow, excluding the possibility that the threat is non-serious.
The proposition that monkeys interpret calls that are given as a function of the meaning of others calls of the repertoire now requires empirical examination (Seyfarth & Cheney, 2016). In this project, we will examine whether monkeys make use of (or expect their congener to abide by) an informativity scale within their alarm calling system. At the same time, we will consider an alternative to the hypothesis that pyow constitutes a general call, namely that, despite not being linked to specific circumstances (by contrast with katrains and to a lesser extent, ants), pyow is nonetheless specific as it triggers specific behavioral responses in recipients. One hypothesis is that pyows function as attention-getters. The fact that redirection of attention towards a speaker playing pyows is suppressed or reduced when pyow follows a contextual element (e.g., a falling tree) would constitute strong evidence that pyows do not merely function as attention-getters but can be semantically bound to environmental circumstances. Results in putty-nosed monkeys (who also use pyow- signals in a fashion similar to blue monkeys) favor this hypothesis (Arnold & Zuberbühler, 2013). Our own study should eventually replicate this finding (modification of behavioral response to pyows as a function of contextual information) while shedding light on the informativity relations between pyows and other alarm calls of the repertoire of Blue monkeys.
General methods. This project will be conducted in the Budongo Forest Reserve, Western Uganda, ideally during a 6 months period. During the first month, the student will habituate her/himself to following and observing groups of unhabituated blue monkeys, with the assistance of a fieldworker, and to the experimental protocol. During the remaining five months, the student will be in charge of conducting experiments co-designed together with Dr. Guillaume Dezecache and Pr. Klaus Zuberbühler.
Relevance to conversation. The Budongo Forest Reserve is home of an important population of blue monkeys which are otherwise less frequent in other Uganda
forests (e.g., Kibale) (Plumptre & Cox, 2006). Although the conservation status of the blue monkeys is currently of  least concern, the population is decreasing and remains under the risk of habitat fragmentation (IUCN, 2008).The continuous monitoring of several groups of blue monkeys in the forest of Budongo constitutes an important research effort to maintain and monitor this population. The current project will foster this monitoring effort through fundamental research.
Budget. Dr. Guillaume Dezecache will assist the student in applying to funding to help cover the travel and living expenses during the fieldwork period.
Contact. If you are interested, please contact Guillaume Dezecache:
Arnold, K., & Zuberbühler, K. (2013). Female Putty-Nosed Monkeys Use Experimentally Altered Contextual Information to Disambiguate the Cause of Male Alarm Calls. PLoS ONE, 8(6), e65660.
Fuller, J. L. (2014). The vocal repertoire of adult male blue monkeys (Cercopithecus mitis stulmanni): a quantitative analysis of acoustic structure. American Journal of Primatology, 76(3), 203–216.
Fuller, J. L., & Cords, M. (2017). Multiple functions and signal concordance of the pyow loud call of blue monkeys. Behavioral Ecology and Sociobiology, 71(1), 19.
IUCN. (2008). Cercopithecus mitis ssp. stuhlmanni: Kingdon, J.: The IUCN Red List of Threatened Species 2008: e.T39991A10287748 [Data set]. International Union for Conservation of Nature.
Murphy, D., Lea, S. E., & Zuberbühler, K. (2013). Male blue monkey alarm calls encode predator type and distance. Animal Behaviour, 85(1), 119–125.
Plumptre, A. J., & Cox, D. (2006). Counting primates for conservation: primate surveys in Uganda. Primates; Journal of Primatology, 47(1), 65–73.
Schlenker, P., Chemla, E., Schel, A. M., Fuller, J., Gautier, J.-P., Kuhn, J., … Keenan, S. (2016). Formal monkey linguistics. Theoretical Linguistics, 42(1–2), 1–90.
Schlenker, P., Chemla, E., & Zuberbühler, K. (2016). What Do Monkey Calls Mean? Trends in Cognitive Sciences, 20(12), 894–904.
Seyfarth, R. M., & Cheney, D. L. (2016). Schlenker et al.’s informativity principle. Theoretical Linguistics, 42(1–2), 155–158.