Giraffes can think rationally according to this study published in the journal Scientific Reports. The scientists are based at the University of Barcelona. Alvaro Caicoya (PhD student) and colleagues discovered that in the tests described below giraffes chose the boxes containing their favorite food.
Four giraffes at Barcelona Zoo were shown 2 transparent boxes. One contained mostly carrots (their favorite) and some courgettes. The other contained mostly courgettes, which they like less, and some carrots. The researcher reached into each box simultaneously and picked out a vegetable. The giraffe could not see which vegetable they had taken. The giraffes consistently selected the box with the most carrots.
Same giraffes. They were offered a box with 20 carrots and 100 courgettes or a box with 20 carrots and four courgettes. They chose the latter. This suggested to the researchers that they chose the box with the best vegetables and not the box with the most vegetables. The ratio of carrots to courgettes (quality) was prioritised over the total number of vegetables (quantity).
[We have] been studying the cognitive abilities of ungulates [hooved animals] for several years. Interestingly, giraffes have consistently demonstrated superior performance.
The giraffes were able to weigh the odds of something happening.
Being able to identify from a distance which trees have the best proportion of leaves and flowers likely provides an evolutionary advantage. The ability allows giraffes to conserve energy by avoiding unnecessary travel and focus their efforts on reaching the trees that provide the most beneficial nutrients.
The ability of animals to make statistical inferences had only previously been seen in species with larger brains such as the great apes, certain monkeys and the kea, a clever parrot.