Horses tend to be goal-driven innovators around urgent needs involving food and comfort, but devise the greatest variety of innovations when opportunities to play and develop comfort behaviours arise, researchers report.
Horses tend to be at their most innovative when kept in good conditions, the study team reported in the open-access journal PLOS ONE.
Researchers Konstanze Krueger, Laureen Esch and Richard Byrne said debate persists over whether animals develop innovative solutions mainly in response to their needs, or whether they innovate more when basic needs are covered and the opportunity to develop novel behaviour is offered.
In their study, they sourced 746 cases of “unusual” behaviour in equids by contacting owners and caretakers directly, and via a website. They also searched the internet platforms YouTube and Facebook for videos.
The trio investigated several aspects around the innovative behaviour that was seen or recorded, including whether differences in need or opportunity for innovation were reflected in the different types of innovations.
They also looked at the frequencies of repeating an innovative behaviour, as well as the role of sex, age, and breed type, and the possible influence of management factors such as housing condition, access to roughage, access to pasture, and social contact.
Owners of horses, mules and donkeys who submitted innovative behaviours were asked to fill in a questionnaire. The researchers received so many reports of equids opening doors or gates that a more specific questionnaire on this specific behaviour was developed.
The authors collected 632 reports, which described or depicted 1011 innovative behaviours. Of these reports, 254 came from the general questionnaire, 269 from the door-opening questionnaire and 109 from the videos.
The animals comprised 427 horses, 3 mules and 4 donkeys.
Three independent observers — one professor and two individuals with bachelors in equine science — rated the 1011 described behaviours on whether they were “novel” and agreed in 89% of cases. Contentious cases — there were 265 in all — were excluded.
The study team found that numbers of different types of innovation and the frequency of displaying specific innovations were not affected by individual characteristics (sex, age, breed or equid species).
“Few types of innovation in escape and foraging contexts were observed,” they reported, “whilst the comfort, play, and social contexts elicited the greatest variety of innovations.
“We also found higher numbers of different types of innovations in horses kept in groups rather than in individual housing, and with unlimited rather than with restricted access to pasture and roughage.”
Animals with unrestricted contact with others tended to repeat new innovative behaviours more often (mostly more than 20 times) than those kept with restricted contact (mostly between 11 and 20 times).
Looking at their overall findings, the study team suggested that equids produce goal-directed innovations and repeat the behaviour at high frequencies in response to urgent needs for food and free movement, or when kept in conditions with social conflict.
“However, equids devise the greatest variety of innovations when opportunity to play and to develop comfort behaviour arises and when kept in good conditions.”
Discussing their findings, the authors said their study revealed an interesting disconnect between the frequency of repeating innovative behaviours and the number of different types of innovation shown. The former potentially indicates innovation in response to need, while the latter points to innovation resulting from opportunity.
“Equids displayed a restricted range of apparently goal-directed innovations and repeated them at high frequency in circumstances of need, such as for escape and foraging and when the management was restricted or imposed conflict.
“Conversely, equids showed a greater number of innovation types when they had the opportunity to display behaviour related to comfort, play or social behaviour, and when kept in unrestricted management conditions with little conflict.
“It remains to be shown whether this variety of innovative behaviour arises in favourable environments in other species.”
Krueger and Esch are with Nuertingen-Geislingen University in Nürtingen, Germany; Byrne is with the University of St Andrews in Scotland.
Krueger K, Esch L, Byrne R (2021) Need or opportunity? A study of innovations in equids. PLoS ONE 16(9): e0257730. https://doi.org/10.1371/journal.pone.0257730