Data from: Compression principle and Zipf’s law of brevity in infochemical communication

Compression has been presented as a general principle of animal
communication. Zipf's law of brevity is a manifestation of this
postulate and can be generalised as the tendency of more frequent
communicative elements to be shorter. Previous works supported this claim,
showing evidence of Zipf's law of brevity in animal acoustical
communication and human language. However, a significant part of the
communicative effort in biological systems is carried out in other
transmission channels, such as those based on infochemicals. To fill this
gap, we seek, for the first time, shreds of evidence of this principle in
infochemical communication by analysing the statistical tendency of more
frequent infochemicals to be chemically shorter and lighter. We analyse
data from the largest and most comprehensive open-access infochemical
database known as Pherobase, recovering Zipf's law of brevity in
interspecific communication (allelochemicals) but not in intraspecific
communication (pheromones). Moreover, these results are robust even when
addressing different magnitudes of study or mathematical approaches.
Therefore, different dynamics from the compression principle would
dominate intraspecific chemical communication, defying the universality of
Zipf's law of brevity. To conclude, we discuss the exception found
for pheromones in the light of other potential communicative paradigms
such as pressures on successful communication or the Handicap principle.