Jacopo Di Clemente
Foraging, movements and communication of elusive rorqual whales under anthropogenic pressure
Distinct cetacean populations of the same species living in different oceans may be exposed to different sources and/or levels of exogenous disturbance but have to meet the same endogenous needs such as foraging.
The mouths of filter-feeding cetaceans, such as rorquals (Balaenopteridae), are not built to depredate human fishing gear. As a result, human fishing activities are for them at best neutral, and at worst a severe threat due to potential injuries and noise pollution. In contrast, although deep diving odontocetes hunting with echolocation seem to be more directly and negatively impacted by anthropogenic noise, some populations have learned to take advantage of interactions with fishing activities by eating fish captured by humans.
In both scenarios, there is currently a lack of research quantifying whether prey field and anthropogenic disturbance affect the foraging behaviour of these animals and, as a result, also their foraging kinematics and energetics. Using a combination of non-invasive state-of-the-art technologies and modelling, this project aims to discover if foraging energetics and efficiency in both typical feeding and depredation events change when exposed to different levels of stress in different environments.
Funding: QATO fonden; The Carlsberg Foundation; Torben og Alice Frimodts Fond
Credits: Jacopo Di Clemente
Credits: Delbars via Getty Images Pro
Vocal communication in social networks: the case of the plains zebra (Equus quagga)
Funding: China Scholarship Council, Carlsberg Research Infrastructure
Horse vocal communication: investigating the function of biphonation
Vocalisations constitute an efficient and rapid means of transmitting information to conspecifics. Such information can be encoded in the sequence of elements composing an utterance, or in the acoustic structure of the vocalisation itself (i.e. duration, frequency, amplitude). To be transmitted efficiently, pieces of information that can vary independently from each other (e.g. information about the emotion and identity of the caller) should be encrypted in different and non-correlated acoustic features (“segregation of information”). Biphonation, i.e. the presence of two independent fundamental frequencies (lowest frequency of a periodic waveform), constitutes one ideal way to achieve such segregation. A good example of this phenomenon has recently been demonstrated in horses, which produce whinnies made of two fundamental frequencies, a rare phenomenon among mammals. Interestingly, the lowest frequency (“F0”) of whinnies encodes the arousal (intensity) of the emotion experienced by the caller, while the highest frequency (“G0”), encodes the emotional valence (positive vs negative). In this project, we propose to explore the implication of these two frequencies for horse communication.
Funding: Swiss National Science Foundation
Credits: alexeys via Getty Images Pro
Credits: Isabel Driscoll
Encoding of affective state in meerkat vocalisations
Animals’ production of vocalisations varies between being solely dependent on arousal, to referring to a specific object or event in their environment, and in the case of meerkats a combination of both. Meerkat alarm calls are thought to encode predator type (referential) and level of urgency (arousal). We are currently working on whether these calls are truly referential and how much of a role affective state plays on their production. We are doing this by investigating how alarm call production and structure are influenced by an individual’s affective state, and also how this variation may affect the response of the receiver.
Funding: Swiss National Science Foundation, NCCR Evolving Language
Kinship and its impact on mate choice, vocalization and behaviour in southern white rhinoceros
Southern white rhinoceros are in severe need of conservation management to secure their long-term survival. The main threats this charismatic herbivore is facing are poaching and habitat fragmentation, resulting in small and isolated populations. Consequently, the risk of inbreeding increases, which will impact the already low genetic variability of this species. Kin discrimination is one way to avoid the costs of inbreeding. By applying genetic methods, bioacoustics and network analysis, we aim to improve our sparse knowledge of mate choice and kin recognition in white rhinoceros.
Credits: Damaris Riedner
Credits: Gustavo_Asciutti from Getty Images
Communication, emotion and defamation in an eupsittula parakeet
The existence of complex social systems might have driven the evolution of advanced communication and cognitive abilities, as individuals need to memorise past interactions and many individuals’ identities. However, how these memories are formed and shape social relationships in animals is poorly known. In birds, vocal communication is of utmost importance no matter if the species lives in big social groups or is solitary. The aim of this study is to investigate how vocal information affects the behaviour not only of one individual but of entire groups. Using Eupsittula parakeets, we will study the impact of vocalisations on emotions, pairwise relationships, and how this affects group movement dynamics as a result.
Funding: The Carlsberg Foundation
Malene Friis Hansen
The Long-Tailed Macaque Project
A conservation collaboration seeking to influence long-tailed macaque conservation and welfare through scientific evidence using population census surveys, trade investigation and human-macaque interface evaluation.
Funding: Animal Protection Denmark; long-tailed macaque habitat country research is partially funded by local NGOs and Research Councils; The Carlsberg Foundation
Credits: Malene Friis Hansen
Credits: Matthis Voldquardsen via Pexels
Vocal contagion of emotions in sheep
Emotional states (short-term behavioural, physiological and cognitive reactions to specific events) and their communication are central to establish and maintain social interactions and have the potential to affect individual and group movements. Numerous evidence of vocal expression of emotions have been reported in mammals and birds. As vocal signals are particularly under selective pressure, since they are often loud and hence highly detectable by predators, the existence of vocal markers of emotions in multiple species rises the question of the co-evolution and adaptive significance or emotional perception and contagion. The aim of the project is to investigate how emotional states expressed in vocalizations propagate within groups, as well as the consequences on group movement. Sheep (Ovis aries) is a gregarious and vocal species, known for massive group movements, particularly suitable to investigate this question. The research will be conducted in collaboration with INRAE, at the experimental facilities of La Fage, France, where a model of robust and free ranging sheep have been selected. Bringing insights into the mechanisms of vocal contagion of emotions in a gregarious and domesticated species such as sheep will enable a better understanding of the evolution of communication of emotions. On a more applied point of view, findings on sheep will provide valuable knowledge on how emotions spread in herds, which can help improve animal welfare on farm.
Funding: The Carlsberg Foundation
The biological underpinnings of pied babbler combinatorial communication
One of human language’s defining features is its combinatorial capacity, which enables the communication of infinite messages based on the productive use of a finite set of acoustic sounds. Emerging comparative research on non-human animal species reveals intriguing analogues in the way animals and humans combine acoustic elements to diversify and accumulate meaning. Yet, whilst providing insights into potential early rudiments of “language-like” structures, the biological underpinnings of combinatorial communication are largely neglected. This project will investigate how pied babbler combinatorial vocalisations are acquired during ontogeny, and how caller attributes and a caller’s social environment impact on combinatorial features and their acoustic characteristics. The aim of this bottom-up approach is to shed light on the factors that shape and promote the emergence of combinatorial features.
Funding: The Carlsberg Foundation
Credits: Sabrina Engesser
Credits: 12019–12919 via Pixabay
Social structure of giraffes: effect of social and physical environment
Recent studies have shown that wild giraffes (Giraffa camelopardalis) form non-random associations with each other. In this project we use social network analysis (SNA) to investigate how such associations may be controlled or driven by factors like sex, age, kinship and season. The long-term study takes place in Pilanesberg National Park (PNP), South Africa, in collaboration with Copenhagen Zoo, which offers accommodation in a newly established field laboratory. PNP has a population of about 200 giraffes most of which have been individually identified based on their distinctive coat pattern on both sides of their bodies. A photo archive of the individuals has been constructed and Copenhagen Zoo has started up sampling biopsies from the identified individuals to investigate the relatedness between them. The first results using SNA confirm that giraffes form non-random associations and show that they maintain a stable overall social structure over at least 3½ years and between seasons. This applies to the whole population and to each sex separately, although there are sexual differences in how seasons may affect the social coherence.