H. Kasozi & R. A. Montgomery, 2018, How do giraffes locate one another? A review of visual, auditory, and olfactory communication among giraffes. Journal of Zoology, vol. 306, pp. 139-146, https://doi.org/10.1111/jzo.12604
Communication involves the exchange of information among individuals of the same or different species. It is obvious that communication plays an integral role in human society, where a miscommunication can lead to confusion. This same concept is thought to be relevant to animal societies. Animal communication mediates social relations, fosters interactions between and among species, and also facilitates fundamental behaviors such as mate choice, predator avoidance, and foraging, among others. Communication is therefore crucial for animal survival and reproduction. As a consequence, several species of animals have developed novel ways of conveying vital information to each other, for instance through sounds (e.g. dogs bark, lions roar, birds sing etc.), visual displays (e.g. in birds), color change (e.g. in octopuses, chameleons and cuttlefish) and others. Interestingly, when it comes to the communication of giraffes – one of the most fascinating species of African wildlife – we know precious little. No one can really say how giraffes exchange information among each other.
Giraffes were long thought to be mute until the late 1970’s when it was discovered that giraffes do indeed vocalize. Giraffe vocalizations, though quiet, have been described as hums, snorts, growls, hisses, and bursts. Of course, in addition to vocalizations, giraffes could communicate with one another in olfactory and visual ways. Scientific research to date has only been successful at describing signals and sensory organs that are thought to be useful in giraffe communication. Current work has focused on describing the anatomy of giraffe eyes and visual capabilities, scent organs and chemical signals, and vocal signals. Hardly any work, however, has been done to examine the intent, cause, and context of these signals. Given the marginal research on this topic, several outstanding questions relating to giraffe communication remain. These include: how exactly do giraffes locate one another? What inspires them to live in groups? How do they maintain social cohesion? How do they ‘speak’ to each other?
To get a better understanding of what is known about how giraffes communicate, we were inspired to conduct a review and synthesis of existing published literature to evaluate our interesting research questions. In August of 2017, we conducted a thorough search of all published literature referencing giraffe communication. We searched across renowned databases including the Web of Science, Scopus, Wildlife Studies Worldwide and the Michigan State University libraries. To our surprise, the initial search only returned a meagre 10 studies. From these we could hardly extract comprehensive information on how giraffes exchange information among each other.
We did not despair! We conducted another round of searches and found there are only 21 studies published between 1958 and 2018 referencing giraffe communication across olfactory (chemical), visual and auditory dimensions. A common theme we found among these studies was description of different signals and sensory organs with no direct communication context. Only five studies referencing giraffe auditory communication provided direct communication context. These found that giraffes produce infrasonic and audible vocalizations (i.e., hums, snorts, growls, hisses, bursts). The studies that focused on the olfactory and visual communication dimensions investigated form and structure of the organs responsible for the production of these signals. These studies found substantive evidence that giraffes have acute visual and olfactory senses. Giraffe eyes are well developed and the vomeronasal organ well suited for detecting chemical signals. These ultimately facilitate giraffe vision, individual recognition (especially among mothers and their calves) and mate choice. No experiments have so far been carried out to determine the cause, context and intent of these signals.
Our review article synthesizes published information on giraffe communication across visual, auditory and olfactory dimensions. We describe what is currently known of these dimensions and codify potential avenues for further giraffe communication research. Overall, the existing studies are too few to warrant any meaningful conclusions relating to giraffe communication. Thus the context in which the visual, olfactory and auditory modalities maybe used in giraffe communication remains largely unclear. As a result, uncertainty relating to the nature of giraffe communication remains. We suggest that more work be done to; (1) assess importance of pelage odor in sexual selection and individual recognition, (2) investigate and identify chemicals and glands involved in female receptivity and sexual attraction, (3) evaluate the giraffe olfactory system and relevance of olfaction in mediating giraffe social structures, (4) evaluate the role and relevance of visualization in giraffe communication, and (5) harmonize and expand on the current information on giraffe vocalizations.