Alexander J. Boucher
Department of Biology
Concordia University (Loyola Campus)
7141 Sherbrooke St. W. H4B 1R6
Montreal, QC, Canada
Office: SP 301.09
(514) 848-2424 (ext. 4021)
2021 – Present: MSc student in Biology at Concordia University, Montreal, Canada
2017-2019: B.Sc Biology with a specialization in Ecology and Environmental Science at Vancouver Island University, Nanaimo, BC, Canada
2015-2017: Associates of Science, North Island College, Comox Valley, BC, Canada
Factors influencing formant frequencies of rutting male reindeer (Rangifer tarandus) vocalisations, and implications for sexual selection
Sexual selection is a central component of natural selection. Consequently, how effectively females can assess the fitness of prospective partners can significantly affect the fitness of their offspring. Within Cervidae, much of the primary mate selection is made through acoustic cues. As a gregarious, polygynous species that organize into herds, reindeer (Rangifer tarandus) are organized by social hierarchy, wherein communication guides interactions. During the autumn rut, males produce grunts, a series of short, hoarse calls made by a series of quick exhalations. These grunts antagonize competitive males and court female mates. However, to date, how these grunts differ between males and within a male’s repertoire has been understudied.
To study these vocalisations, we will apply the theory of source filtering. In tandem with advances in computational power and digital analysis, the theory of source filtering allows for the deconstruction of acoustic structures. Consequently, it allows us to test hypotheses when related to phenotypic, behavioural or context-specific information.
The research will be conducted at the Kutuharju research site in Kaamanen, Finland (69.1° N, 27.2°E). The herd is kept within a 13.8 km enclosure during the autumn rut, consisting of about 110 individuals (males, females, and offspring). To find and identify the herds, males will be outfitted with GPS transmitters. Moreover, to subsequently identify each of the females, each one wears a unique collar. Further information on the ecology and behaviour of the reindeer and their herds are provided by the Finnish Reindeer Herders Association, which manages and cares for the animals.
Acoustic data will be collected from males during the rut. Handheld sound recorders will be used to record the reindeer’s vocalisations. In addition, focal behavioural observation sessions will be conducted to give the vocalisations context, which will note group composition (identities and numbers of females and males), vocalisation context (herding females or antagonizing opposing males) and general behaviour trends. With this data, I will explore the acoustic structure of the grunts and compare the extracted information to herd, social context and behavioural data.
My research will determine how herd composition, behaviour, and social context affect the formant frequency, call rate, and call duration of male reindeer and how these affect different males’ vocalisations. For example, in related Cervidae, the acoustic structure of grunts differs among males because of context, and researchers have determined that vocalisations convey information for sexual selection7,8. Thus, I hope to elucidate similar results from the vocalisations of reindeer.