Onderzoek verklaring likken en kauwen

[Maaike]

Licking and chewing –
submission or stress?

Horses sometimes lick and chew during training and this has often been
interpreted as a sign that the horse is learning or showing ‘submission’ to the
trainer. However, a new study suggests that this non-nutritive licking and
chewing behaviour is a natural behaviour that is shown after a stressful
situation.




To gain insight into the function of licking and non-nutritive chewing
behaviour in horses, a team of equine scientists from the Norwegian University
of Life Sciences observed the social behaviour of feral horses under natural
conditions.


M.Sc. Margrete Lie and Prof. Ruth Newberry spent 80 hours observing feral
horse herds in Ecuador and collected data on 202 sequences of behaviour when
licking and chewing behaviour occurred. Margrete Lie presented her findings at
the 14^th International Society of Equitation Science (ISES)
conference in Rome last week.



The team wanted to investigate whether non-nutritive chewing was performed to signal submission to another horse and also to study whether horses performed
the behaviour in between stressed and calm situations.


To find out whether non-nutritive chewing was performed to signal submission the researchers tested the idea that when one horse (the aggressor) approached
another horse (the recipient) in a threatening manner, the recipient but not the aggressor would perform the behaviour. The team observed and recorded
different behavioural sequences that involved aggressive interactions (for example if one horse herded or threatened another) and recorded whether the
chewing behaviour was performed by either horse.

The results were fascinating: the team found that the chewing behaviour was performed by both the approaching and the recipient horses. Non-nutritive
chewing was actually performed more often by the aggressor than the recipient, refuting the assumption this behaviour is a submissive signal.

The researchers also investigated whether non-nutritive chewing occurred between tense and relaxed situations. When observing the horses’ behavioural
sequences, they found that the majority of the behaviours before chewing were tense and the majority of behaviours after chewing were relaxed. The chewing
behaviour occurred when the horses transitioned from a tense to a relaxed state.

The researchers concluded that chewing could be associated with a switch from a dry mouth caused by stress (sympathetic arousal) to salivation
associated with relaxation (parasympathetic activity).

The results of this study suggest that non-nutritive chewing was not used as a submissive signal by horses in the contexts observed, but it occurred after a
tense situation, likely as a response to a dry mouth.

The research team acknowledge that further research is required to measure the stress responses associated with non-nutritive chewing. However, this study
does highlight that licking and chewing likely occurs after a stressful situation and may be used as a behavioural indicator that the previous situation was perceived as stressful by the horse.

To view the ISES position statement on the use/misuse of leadership and dominance concepts in horse training please visit:

https://equitationscience.com/equitation/position-statement-on-the-use-misuse-of-leadership-and-dominance-concepts-in-horse-training).

From researcher Margrete Lie:

“We looked at feral horses living with as little human interference as possible to see how they behaved in their natural habitat. It was important to look at
completely natural behaviour and therefore we wanted to see horses living without restriction. These horses were living in a 334 km² national
park, and in the area we observed there were a little under 200 horses. No stallions had been removed from the population as is so common in domestic horses.”

“It was interesting to see how often the horses performed the chewing behaviour and also how clear it was that all individuals did chew – not only
‘submissive’ individuals.”

“The study showed that the horses were chewing between calm and relaxed situations, but it does not say if chewing comes as a response to relaxing or
if chewing helps them relax. To able to look at this more closely I believe a more controlled study with stress measurements is needed.”

[marions]

Interessant weer Maaike! Ik ben wel benieuwd, wat haal jij er uit in praktische zin van trainen en het lezen van signalen? (of anders gevraagd, hoe vertaal je dit naar info die je bij/op je paard toepast?)

[Maaike]

Ja ze brengen leuk onderzoek naar buiten. Laatst ook weer 1 over stress bij wennen aan bit. Dat ze vaak wel verhoogde hartslag hebben terwijl je gedragsmatig eigenlijk geen stress signalen ziet.

Ik vind het vooral mooi dat ze allerlei ongefundeerde interpretaties van gedrag die demogevers beziggen onderzoeken. ISES heeft ook mooi stuk geschreven over menselijk concept van hiërarchie paarden weinig zegt. Voor paarden is de verhouding tussen zichzelf en elk ander paard in de groep afzonderlijk. Alleen daar al kan ik erg van genieten.

Ik heb effe nagedacht over je vraag en toen kwam ik er vooral op dat ik dit gedrag eigenlijk nooit zie bij Sjø en Poez. Misschien omdat ik beter dan vroeger weet wat ik wanneer kan vragen en hoe ver ik kan gaan.. Misschien heeft het ook iets te maken met het gebruik van positieve bekrachtiging zorgt voor een meedenk mindset en daardoor gevoel van controle bij de paarden die mogelijk stressvolle situaties door druk van mij of van buitenaf verminderd.

Wat doe jij met deze info in de training?