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
n
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: guillaume.dezecache@gmail.com
References.
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. https://doi.org/10.1371/journa
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. https://doi.org/10.2305/IUCN.U
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. https://doi.org/10.1007/s10329
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.