Horses (Equus caballus) were first domesticated around 6,000 years ago and have performed many important roles since then, but their ability to understand the gestures of their human handlers remained unstudied until fairly recently.
To date research has suggested that while horses are able to understand some signals, such as pointing, they are only able to use these signals when the human remains near to the reward.
Their level of ability has previously been said to be similar to that of goats and cats, they are able to use human gestures even though they cannot be said to understand the meaning attached to the gesture.
A study in 2004 suggested that horses had limited short-term memory and may not have a prospective memory, which reminds them to do something at a later date, but more recent studies have shown horses do use short-term memory in foraging tasks.
Now a group of Italian-based scientists have demonstrated that horses are not only capable of reading human actions but can also change the way they respond to a task based on their own experiences.
“It is easy to understand in humans but not usual when referring to animals,” said one of the authors, Dr Paolo Baragli, from the University of Pisa, Italy.
“If an animal doesn’t solve a task as we expected this doesn’t mean that it’s not able. There is the possibility that it is using a different strategy to what we expect.”
Twenty four adult horses of different breeds were trained to approach an overturned bucket and move it to find a carrot hidden underneath it. They were then split into two groups of 12.
The findings are published in the journal Applied Animal Behaviour Science.
In the experiment the first group of horses had to find a piece of carrot under one of three overturned buckets after seeing a person hide it. The horses had to wait 10 seconds after it had been hidden and the person had left the area before attempting to locate it.
Speed over accuracy
The same experiment was carried out with another 12 horses that had to find the food on their own without any additional information from a human.
To begin with the horses that had seen the carrot being hidden chose the correct bucket on their first attempt more often than those who had not seen the carrot being hidden, although they took more time to do it.
Later the same horses found the carrot in less time but took more attempts to find it.
The authors suggest that this was because the human's signals became less important, as the horses learned that they received the same reward whether they took the time to make a decision or simply guessed.
In the later trials, researchers also found that the horses that had seen the carrot being hidden tended to go to the bucket where they had found the food in their last attempt.
This indicates that horses can remember where food is hidden even after a delay, by understanding the meaning of a person being near to the target location (the bucket with the carrot underneath).
Horses are also able to change their decision-making strategy between the reliability suggested by human signals and a more immediate reward. This means they can choose whether or not to use signs given by humans depending on whether they desire speed or accuracy.
Dr Baragli said that rather than being developed abilities, the researchers think these cognitive skills are essential for the horse’s survival.
“To our knowledge this paper is the first to demonstrate that horses are able to make a choice based on information obtained by environmental stimulus (humans), and then the same horses can change their behavioural strategy based on experience to better solve the same problem,” Dr Baragli said.
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