African elephants address one another with individually specific calls

Personal names are a universal feature of human language, yet few analogs exist in other species. While dolphins and parrots address conspecifics by imitating the calls of the addressee 1,2, human names are not imitations of the sounds typically made by the named individual 3. Labeling objects or individuals without relying on imitation of the sounds made by the referent radically expands the expressive power of language. Thus, if non-imitative name analogs were found in other species, this could have important implications for our understanding of language evolution. Here, we present evidence that wild African elephants address one another with individually specific calls, likely without relying on imitation of the receiver. We used machine learning to demonstrate that the receiver of a call could be predicted from the call’s acoustic structure, regardless of how similar the call was to the receiver’s vocalizations. Moreover, elephants differentially responded to playbacks of calls or..., , Excel or similar spreadsheet program to open CSV files. R or RStudio to open and run code, and to open RDS file.
Observational dataset (.csv file): Behavioral context information for vocalizations recorded from wild African elephants in Samburu and Buffalo Springs National Reserves, Kenya between November 2019 and April 2022. Each row represents a single call and information such as identity of the caller, identity of the addressee, and behavioral context, is provided. Information is also included linking each call to the original sound file and Raven Pro selection table from which it came (but the sound files and Raven Pro selection tables are not included in this archive).
Acoustic measurements dataset (.rds file): R list object containing vectors of acoustic measurements for each call. The list is two-tiered; each outer slot corresponds to a single call, and each inner slot corresponds to an acoustic measurement, represented as a vector of numbers.
R code (.R file): Code for aligning..., ## # African elephants address one another with individually specific calls

We investigated the hypothesis that elephants address individual members
of their family group with name-like calls. We recorded contact,
greeting, and caregiving rumbles from wild African elephants in Samburu
& Buffalo Springs National Reserves, northern Kenya and Amboseli
National Park, southern Kenya, noting when possible the identity of the
caller and the identity of the receiver. We measured a suite of acoustic
features on each call and found that calls were specific to individual
receivers and receiver identity could be predicted from call structure
at better than chance levels. We also played back calls to the elephants
and found that elephants responded more quickly and vocalized more in
response to calls that were originally addressed to them compared to
calls from the same caller that were originally addressed to someone
else. These results provide the first evidence that elephants address
one ano...