Dolphins are amazing, aren't they? We know that they can solve problems, understand some complex communication from us, and they do have a big brain, even if you count in their size. They also pass the self-awareness test of recognizing themselves in mirrors. In fact, dolphins seem to be able to do this at 7 months, while humans can't do this until they are a year old. Chimps don't recognize themselves until they're two years old. There are very few animals that can do that. Most treat their reflections as other individuals or simply ignore them after a while.

Evaluating who is more intelligent is not as easy as it sounds because there are many different ways to show intelligence. As you say, echolocation is a pretty awesome skill. Bats have it too. Obviously, we usually don't, but humans can learn to do a bit of it. Even measuring intelligence within our own species is controversial. One person may be able to fix anything, another can play complex music after hearing it once, someone else can beat everyone at chess, another understands complicated emotions and behaviors of other people. Who is smarter? It all depends on how you decide to test intelligence.

It might seem like intelligence is always a good thing, but there are a few reasons why we don't expect all animals to be smart. One is that there's a trade-off between being born (or hatched) with a complete set of behaviors that usually work and having to learn most of your behaviors. Animals that don't live long don't have time to learn anything. On the other hand, that can't adjust to changing conditions. Smarter animals can solve new problems and make all sorts of adjustments, but it takes them a long time to learn and they may need protection, or even teaching, while they learn. Brains are expensive in terms of the energy they use, so animals don't usually have more brains than they need. What do the smart animals have in common? One thing is they live a long time. Another is that they usually live in groups. Figuring out how to interact with others is complicated.

We think of speech as being very advanced because language is such a powerful tool. It allows us to communicate, obviously, but it also allows us to think and plan. Writing lets us remember and even pass knowledge down through many generations. Human speech is not the only kind of speech, though. Many animals have complex communication, even if we don't always understand it.

There are hundreds of millions of species on Earth, living and thriving without speech. What are some of the strategies that make them successful?

Well, humans are not the only animal that speak and live and thrive - we speak to a greater degree than most other animals, but there are other animals that communicate.

As for dolphins, they are very intelligent. I'm not sure we know that they're the second-most-intelligent; there are a lot of other very intelligent animals as well, so dolphins have a lot of competition. Having a large brain does help with intelligence, but it isn't the only factor. For example, octopus are about as intelligent as most mammals, but their brains are no larger than those of most fish.

It’s true that dolphins have one of the largest brains measured lb brain mass per lb body mass , but there are many other animals which use echolocation such as bats, whales, shrews, swiftlets, and oilbirds. I would hesitate to say dolphins are “more intelligent” than other animals because measures of intelligence are subjective, or that use of echolocation makes an animal “more advanced” than another animal because adaptations are simply a product of the environment an animal lives in.

Certainly, dolphins in captivity have been trained successfully to do all kinds of tricks, and even to solve puzzles which makes them a fascinating species to interact with. On the other hand, crows have also exhibited an ability to problem solve, and use tools.

In 2018, the BBC reported on a recent experiment where New Caledonian crows were able to learn to use fishing hooks and vending machines. So dolphins are not the only animals which exhibit these abilities.

Similarly, echolocation is an amazing, specialized adaptation that allows dolphins to hunt in environments where visibility is not always good. But other animals use these same techniques as I mentioned before, and still others have other specialized skills - for example, salmon travel hundred of miles from the open ocean back to the exact river bed where they hatched and nobody knows how they do it. Since evolution of species involves multiple branchings based on the conditions each organism lived in, it is difficult to say whether one species is “more advanced” than another, especially when you are looking at the entire animal kingdom.

Many species of animals thrive on planet Earth, and many have their own ways of communicating with each other whether through sound, body language, or even chemical excretions. However, the question of why and how humans developed complex spoken language is still a topic of debate among evolutionary biologists and linguists. Some theories include that language was developed to facilitate trade, or it spontaneously developed from more rudimentary systems of communication as they naturally grew in complexity.

The study of language is called linguistics, and it’s a fascinating field that sits at the intersection of history, biology and genetics, and humanities. Maybe one day you will make a discovery about how ancient humans developed language!