How can you measure the intelligence of an animal?

Probably testing its problem solving abilities.

Well, it depends. Problem solving ability is one hallmark of intelligence.

In terms if what a human being might consider intelligent, it is speculative at best.
With wild animals if a species is alive, thriving ( minus environmental factors, hunting, predators, and other natural ebbs and flows to it’s population base ) it is obviously intelligent ENOUGH to remain alive.

A Turkey IS smart enough to BE a Turkey. lol

In terms of our domestic pets, well, intelligence is variable as it is with humans.

Again, it would be based on problem solving ability, quick learning skill and strong memory.

I had a cat once that took 6 months to master the cat door, and others that learned to use it in one afternoon. I have a goose that has mastered how to climb stairs, while his companion is unable to do the same. He has also learned to turn the hose nozzle on and off and flings the hose out of his pool when it is full and he is done playing. lol

I had a Cockatiel once that would follow the chickens to bed and went to roost with them if he was still outside at dusk. He was smart enough to know that if he went into the barn with the hens he would not be Owl food. Safety in numbers, even if the numbers were not his kind. ;-)

As far as observation, time would be a factor. What you could observe in a few minutes vs. a few hours, says, weeks, months. If the animal is wild vs. domestic, if it is your animal or someone elses, if it’s species is known for it’s intelligence, such as Parrots, Rats, Dogs, Pigs, Dolphins, etc.

Then the variables of measurement within the species and the individual manifestations.

Animal intelligence and behavior is a very broad field of research with many variables, just as it is for humans.

I think wiki gives a pretty good explanation of how to measure. What you must determine is if you are looking for the ability to be trained to do certain tasks or whether you want the dog to reason and solve problems.

Often dogs that are easily trained are not necessarily the smartest, they are simply eager to please their masters. I love dogs that think and are problem solvers and therefore usually trouble makers in the home. The breeds I have encountered over many years of dog training and handling that are the smartest are bouviers and akitas. Now I have a dingo/cattle dog mix and she could be the most cunning and devilish of them all. To me that equals smart. She is however very trainable as well, when she wants to be obedient, she is the best I have ever had. When she does not feel like it or her brain is otherwise occupied, she is the worst I have ever had. I love her!

I am curious, what prompts you to ask this question?

I don’t think it can be measured. While an animal can’t hide his intellect it mostly depends how the master raised him. The more different encounters he had with the world the most things he can discern. Though most animals rely on instincts.

There are degrees of intelligence. The more actions a creature can perform, the more conscious ability is required to accommodate.