Behaviour of cranes (family Gruidae) mirrors their phylogenetic relationships

Background The behavioural repertoire of every species evolved over time and its evolution can be traced through the phylogenetic relationships in distinct groups. Cranes (family Gruidae) represent a small, old, monophyletic group with well-corroborated phylogenetic relationships on the species level, and at the same time they exhibit a complex and well-described behavioural repertoire. Methods We therefore investigated the evolution of behavioural traits of cranes in a phylogenetic context using several phylogenetic approaches and two types of trait scoring. The cranes exhibit more than a hundred behavioural displays, almost one third of which may be phylogenetically informative. Results More than half of the analysed traits carry a significant phylogenetic signal. The ancestor of cranes already exhibited a quite complex behavioural repertoire, which remained unchanged in Balearicinae but altered greatly in Gruinae, specifically by the shedding of traits rather than their creation. Trait scoring has an influence on results within the Gruinae, primarily in genera Bugeranus and Anthropoides. Conclusions Albeit the behavioural traits alone cannot be used for resolving species-level relationships within the Gruidae, when optimized on molecular tree, they can help us to detect interesting evolutionary transformations of behaviour repertoire within Gruiformes. The Limpkin (Aramus guarauna) seems to be the most enigmatic species and should be studied in detail for its behavioural repertoire, which may include some precursors of crane behavioural traits.

Automated summary

The study found that over half of the behavioural traits of cranes carry a significant phylogenetic signal, with the ancestor already exhibiting complex behavioural complexity. The evolution of behavioural repertoire differs across different subfamilies, with trait scoring influencing results. While behavioural traits alone cannot resolve species-level relationships within the Gruidae, optimization on molecular trees can help detect evolutionary transformations in behaviour within Gruiformes.