02062nas a2200181   4500008004100000245014000041210006900181520139100250653001601641653001401657653002201671653002801693653003301721100002001754700002401774700001901798856006301817       2020                        eng d00aBrevity is not a universal in animal communication: evidence for compression depends on the unit of analysis in small ape vocalizations0 aBrevity is not a universal in animal communication evidence for 3 a<p>Evidence for compression, or minimization of code length, has been found across biological systems from genomes to human language and music. Two linguistic laws&mdash;Menzerath&rsquo;s Law (which states that longer sequences consist of shorter constituents) and Zipf&rsquo;s Law of abbreviation (a negative relationship between signal length and frequency of use)&mdash; are predictions of compression. It has been proposed that compression is a universal in animal communication, but there have been mixed results, particularly in reference to Zipf&rsquo;s Law of abbreviation. Like songbirds, male gibbons (Hylobates muelleri) engage in long solo bouts with unique combinations of notes which combine into phrases. We found strong support for Menzerath&rsquo;s Law as the longer a phrase, the shorter the notes. To identify phrase types, we used state-of-the-art affinity propagation clustering, and were able to predict phrase types using support vector machines with a mean accuracy of 74%. Based on unsupervised phrase type classification, we did not find support for Zipf&rsquo;s Law of abbreviation. Our results indicate that adherence to linguistic laws in male gibbon solos depends on the unit of analysis. We conclude that principles of compression are applicable outside of human language, but may act differently across levels of organization in biological systems.</p>
10acompression10aHylobates10aMenzerath’s Law10aunsupervised clustering10aZipf’s Law of abbreviation1 aClink, Dena, J.1 aAhmad, Abdul, Hamid1 aKlinck, Holger  uhttps://royalsocietypublishing.org/doi/10.1098/rsos.200151