Many of us, especially those often working with or in contact with animals, will have wondered what their noises mean… And why do they make noises at all? We humans are a very noisy kind of social animal; the many different languages and dialects found around the world are only proof of how crucial communication has been for our evolution. The fact that we do not understand what animals mean when they communicate with each other (or us) does not mean there is no meaning behind it.
Animals tend to also use body language significantly more than humans. Body language being silent, often we might think they are not communicating at all when in fact they are using the equivalent of screaming in their language! Most social animals have evolved different ways to communicate with members of their species; solitary species are less in need of using refined communication, but able to use it nonetheless.
Livestock species are also social animals
In the wild but also when farmed, they are grouped and moved; to maintain their hierarchy, social standing and group interactions they must communicate with each other. A good farmer should be able to guess the meaning of some of the exchanges. Animals speak volumes with behaviours, not just noises.
Take sheep for example
We all learn when as toddlers that sheep “Baa”; when you walk on a sheep farm though, there will be different kinds of “Baa” (or bleating) heard. The different times of the year would have an effect – for example if there are lambs around, ewes are much more likely to speak up. What different types of bleats can we find?
Rams communicate with each other and with ewes, by behaviours (e.g. fighting another ram), body language (walking after ewes in season), flehmen (the sniffing at the air, with a curled top lip funny face) and the occasional deep voiced bleat. As mating season approaches, the increase in circulating testosterone can cause changes in the rams’ voice boxes and their voice “breaks”.
Ewes have a very specific soft bleat they only use with their newborns, while cleaning them and encouraging them to get up. During this bonding time, the ewe learns to recognise the lamb’s smell and the lambs learn their mother’s voice. If they get separated within the larger flock, by shouting they are (usually) able to find each other again.
Although sheep are very stoic animals, some may vocalise when in pain. I am a vet called to assist with lambings; as a parent having been through childbirth I can sympathise. The situation is deeply unpleasant for the ewe if she is being manipulated roughly and without pain relief and/or appropriate analgesia for the procedure (such as local anaesthetic/epidural). It would not be uncommon for them to grunt or bleat during the birth.
Although, as we’ve said, sheep tend to be fairly quiet animals, if we sat out of sight and watched them go about their business we would no doubt hear the occasional gentle bleat of the unconcerned sheep. We can assume she is just talking to her friend – “You know Janet, I find myself in a terrible situation; clover gives me awful bloat but is so sweet. I just can’t have enough!” “Why, yes awfully so. The other day I was so bloated I ended up on my back and if farmer hadn’t found me, I would not longer be of this world! I say Rhoda, what is the world coming to?”
Sheep can be fearful animals; they are not renowned for being brave! They’ll almost always choose to run, rather than fight. At times their fear might be expressed with a startled bleat. Lambs that have temporarily lost their mother are always loudly bleating for her – it wouldn’t be foreign to imagine they are a bit afraid.
Different types of “baa”
Research has shown that sheep can produce high frequency (open mouth) and low frequency (closed mouth, also called “rumbles”) vocalisations. In sheep, the rate of vocalisation (how often they make noises) may be useful to distinguish “negative” situations – i.e. there would be more bleating in situations that are likely to negatively impact the individual/flock. Although certain associations could be observed between a type of vocalisation and a specific situation – for example, a loud, high frequency open mouth bleat produced when reunited with a flock mate, it is still unclear whether any parameter apart from vocalisation rate could be used to monitor a potentially positive or negative situation.
Animals’ welfare and their freedoms to express normal species-specific behaviours would cover the freedom to express normal vocalisations as well. The Animal Welfare Act is the legal framework that allows livestock keepers to make sure the animals in their care are well looked after – basically that regardless of their final purpose, they can have a life worth living. If further research could show us reliable parameters to monitor sheep vocalisations in relation to their welfare, it would certainly be a valuable addition to our understanding of their physiology.
We ought to be careful not to attribute all the human emotions (and corresponding vocalisation) to animals. Personally, as a vet I have often wished to be a sort of Dr Dolittle and be able to understand in clear English what my patients are saying. It would save so much guesswork if they could tell me where it hurts or what happened – though I would need to listen to all of Janet and Rhoda’s chit chat!