http://www.sciencemag.org/news/2016/09/ ... ls-talk-us
Scientists taught 23 riding horses of various breeds to look at a display board with three icons, representing wearing or not wearing a blanket. Horses could choose between a “no change” symbol or symbols for “blanket on” or “blanket off.” Previously, their owners made this decision for them.
All 23 horses learned the entire task within 14 days. They were then tested in various weather conditions to see whether they could use the board to tell their trainers about their blanket preferences.
The scientists report online in Applied Animal Behaviour Science that the horses did not touch the symbols randomly, but made their choices based on the weather. If it was wet, cold, and windy, they touched the "blanket on" icon; horses that were already wearing a blanket nosed the “no change” image. But when the weather was sunny, the animals touched the "blanket off" symbol; those that weren’t blanketed pressed the “no change” icon. The study’s strong results show that the horses understood the consequences of their choices, say the scientists
Link to the full study: http://www.appliedanimalbehaviour.com/a ... 0219-2/pdf