Need or opportunity? A study of innovations in equids

Abstract

Debate persists over whether animals develop innovative solutions primarily in response to needs or conversely whether they innovate more when basic needs are covered and opportunity to develop novel behaviour is offered. We sourced 746 cases of “unusual” behaviour in equids by contacting equid owners and caretakers directly and via a website (https://innovative-behaviour.org), and by searching the internet platforms YouTube and Facebook for videos. The study investigated whether differences in need or opportunity for innovation were reflected in the numbers of different types of innovations and in the frequencies of repeating a once-innovative behaviour (i) with respect to the equids’ sex, age, and breed type, (ii) across behavioural categories, and whether (iii) they were affected by the equids’ management (single vs group housing, access to roughage feed, access to pasture, and social contact). We found that the 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, 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. Equids in permanent social contact performed high rates of once-innovative behaviour. We suggest that equids produce goal-directed innovations and repeat the behaviour at high frequency 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.

Tool Use in Horses

“…Tool use has been described in a wide range of animal species [ 1 ], meeting the definition “… the external employment of an unattached environmental object to alter more efficiently the form, position, or condition of another object, another organism, or the user itself when the user holds or carries the tool during or just prior to use and is responsible for the proper and effective orientation of the tool”. In horses, mules and donkeys, tool use has not yet been demonstrated, even though it may be considered likely [ 2 ] as equids are mostly kept under human management and tool use has been reported more frequently in captive animals [ 3 , 4 ].…”

“…That horses may have the ability to use tools is suggested by evidence of their innovative abilities. Equids developed innovative solutions for handling complicated feeders [ 5 ] and for dealing with environmental restrictions in foraging, movement and social contact [ 6 , 7 , 8 , 9 , 10 ], for example, by opening locked doors and gates and by harvesting apples by kicking the trees [ 2 , 11 ]. Others developed “less immediately functional” innovations for play and comfort, such as playing with sticks and piling up soft bedding for resting and sleeping [ 2 ].…”

“…Equids developed innovative solutions for handling complicated feeders [ 5 ] and for dealing with environmental restrictions in foraging, movement and social contact [ 6 , 7 , 8 , 9 , 10 ], for example, by opening locked doors and gates and by harvesting apples by kicking the trees [ 2 , 11 ]. Others developed “less immediately functional” innovations for play and comfort, such as playing with sticks and piling up soft bedding for resting and sleeping [ 2 ]. Some of the innovations were solitary and served the innovator itself, but others were social and were directed towards conspecifics and humans [ 2 ].…”

“…Others developed “less immediately functional” innovations for play and comfort, such as playing with sticks and piling up soft bedding for resting and sleeping [ 2 ]. Some of the innovations were solitary and served the innovator itself, but others were social and were directed towards conspecifics and humans [ 2 ]. The observation of innovative social behaviour is in line with prior demonstrations of horses using symbols for heterospecific communication, that is to say, communication with another species, when requesting humans to put on or take off a rug [ 12 ], or for prompting people to open gates to allow access to feed [ 13 , 14 ].…”

“…Evidence for the existence of such rare behaviour may be obtained from crowdsourcing [ 15 ]. For example, previous crowdsourcing studies have analysed the range of flexibility of animal problem-solving abilities [ 16 ], cognitive capacities in goats [ 17 ], door opening techniques, and innovative behaviour in horses [ 2 , 11 ]. Several methods have been used.…”