Post provided by Chloe Robinson

Dance has been part of human culture for millennia. Some scholars refer to dance as a specific language, dependent on the space and time in which it exists and dependent on the power structures that rule in that time. April 29^th marks International Dance Day; a day initiated in 1982 by the International Dance Committee of the UNESCO International Theatre Institute to commemorate the birthday of Jean-Georges Noverre, a distinguished French choreographer.

For humans, dance is considered a sacred ritual, sometimes a form of communication and sometimes an important social and courtship activity. A recent study has even linked the innate ability to dance with greater survival rates in prehistoric times. However, for certain species of wild animal, dance-like behaviours are crucial for communication and mating. In this blog, I am going to highlight the evolutionary foundations of dance in wild animals and explore some of the ways that dance is used in ecology.

Evolution of Dance

For most wild animals, motion vision is critical for controlling locomotion, foraging, predator evasion and communication. A recent study by Bian et al., in Methods in Ecology and Evolution, provided some insights into the evolution of motion signals, particularly regarding the effects of habitat physical structure, on the types of visual signals used by animals. These visual signals can be in the form of ritualised movements, which can be related to food acquisition, communication and/or courtship. Ritualised movements performed by wild animals can be interpreted as ‘dance’ and have clear evolutionary traits associated with them.

Studies have shown that motor imitation plays a part in the evolution of dance, both in humans and non-human animals. Imitation is a general process supporting social learning in a variety of behaviours. Overall, it is considered that the tendency for displaying socially motivated coordination with conspecifics has resulted in diverse patterns of co-timing, or dance, that we see today.

Communicating Through Dance

For some species, performing dance-like movements can be crucial for the performance and survival of conspecifics. The honeybee (Apis mellifera) is famous for the celebratory waggle dance, whereby bees communicate the location of profitable food sources to other bees in the hive through dance. Waggle dances consist of figure-of-eight-shapes movements including a ‘waggle’ phase, with information about the direction of the food conveyed based on the orientation of the body of the dancer relative to gravity. As well as communication the location of food, the waggle dance benefits pollen foraging on diverse plant resources and thereby contributes to high quality nutrition.

However, bees are not the only invertebrate known to bust a move for directionality. Dung beetles (Scarabaeidae) are known to perform a dance before rolling away a new ball of dung and if they lose control of a dung ball. This dance features a dung beetle climbing on top of a dung ball and rotating about their vertical axis. Studies suggest that this dance is a way of the beetles being able to collect visual celestial cues to enable them to move the dung ball in a straight-line – the most direct route – away from the dung pile and away from competitors. The information collected via their ‘sky dance’ is stored in their robust, internal compass and to date, these beetles use a larger repertoire of celestial cues than is known to be used by any other species.

One of the most bizarre and yet strikingly beautiful dancing phenomena occurs when colonies of algae come together. Spherical alga, Volvox, are found in freshwater and consist of approximately 1,000 cells arranged on the surface of a spherical matrix. These colonies move using flagella, which also make them spin about an axis. When colonies swim close together, they can bind in two states: the “waltz” and “minuet”. The “waltz” is a state where the two colonies orbit around each other like a planet circling the sun, and the “minuet” is where the colonies oscillate back and forth as if held by an elastic band between them. Unlike the honey bee and dung beetles, Volvox do not perform these moves consciously, instead hydrodynamic attraction combined with lubrication forces explain how these colonies move in the way they do.

Dance as a Courtship Strategy

In the same way that dung beetles use body movement to navigate, other invertebrate species use their bodies as a way to attract potential mates. Peacock spiders (Maratus volans) have one of the most elaborate courtship displays in arthropods. During courtship, male peacock spiders raise their brightly coloured abdomen and wave it in synchronicity with their third pair of legs in attempts to impress a female. To add an extra layer to their dance, peacock spiders also lay down a beat, quite literally. A study in PLoS ONE reported the first evidence of peacock spiders using vibratory signals in conjunction with ‘dancing’. The combination of colourful visuals, synchronised dance moves and a catchy beat is what makes the courtship displays of peacock spiders so elaborate.

Bird species are known to commonly use a combination of bright colouration and intricate dance moves to attract a mate. Lekking is where males (typically birds) gather together and put on an impressive show to attract a female. A study by Mennill et al., in Methods in Ecology and Evolution explained that for the neotropical passerine bird species, long‐tailed manakins (Chiroxiphia linearis), the top two males in the lekking hierarchy first attract females by singing and then perform cooperative dances for any females which come to watch.

Some species of bird however do not like sharing the limelight when it comes to dancing. The Golden‐collared manakin (Manacus vitellinus), spends several hours per day in their own personal court, performing displays either with or without the presence of a female. For one particular species of bird, male and female pairs participate in couples dancing during the courting process. The blue-capped cordon-bleu (Uraeginthus cyanocephalus) include rapid step-dancing to their visual courtship displays, which is so rapid that it was only discovered by recording using a high-speed video camera.

Summary

Whether it is waggling for food sources, pirouetting for navigation or tap dancing with your mate, the ritualised movement of dance is evident in wild animals. We wanted to mark this International Dance Day by celebrating the various species who dance, from multicellular algae to jackass penguins, and highlight the evolutionary significance of dance in the animal kingdom.

To read more about using 3D animation to explore motion ecology, check out the Methods in Ecology and Evolution article, ‘Integrating evolutionary biology with digital arts to quantify ecological constraints on vision‐based behaviour’.

 To find out more about how we can use a digital telemetry system for studying mate choice in a lekking tropical birds, check out the Methods in Ecology and Evolution article, ‘A novel digital telemetry system for tracking wild animals: a field test for studying mate choice in a lekking tropical bird’.