Complexity in Animal Communication: Estimating the Size of N-Gram Structures

• Published in: Entropy
• Main Author: Reginald Smith
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2014
• Subjects: animal communication; information theory; dolphin; humpback whale; bird song; phonology; Science; Q; Astrophysics; QB460-466; Physics; QC1-999; Humpback Whale
• Online Access: https://doi.org/10.3390/e16010526; https://doaj.org/article/505e9fd833c443f5a2caa2aade03feb4

In this paper, new techniques that allow conditional entropy to estimate the combinatorics of symbols are applied to animal communication studies to estimate the communication’s repertoire size. By using the conditional entropy estimates at multiple orders, the paper estimates the total repertoire sizes for animal communication across bottlenose dolphins, humpback whales and several species of birds for an N-gram length of one to three. In addition to discussing the impact of this method on studies of animal communication complexity, the reliability of these estimates is compared to other methods through simulation. While entropy does undercount the total repertoire size due to rare N-grams, it gives a more accurate picture of the most frequently used repertoire than just repertoire size alone.