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A study by the Cornish Jackdaw Project has revealed the birds leave their friends for new ones if they can get better food but they'll stick with their family no matter what.

In tasks set by researchers the birds happily dumped their mates for access to tastier treats - but stuck with their family even if it meant going hungry.

Leader of the decade-long project, Alex Thornton, said it was a great test of how the bird's social interactions are similar to humans.

He said: "The jackdaws turned out to be very strategic, quickly learning to ditch friends from the other group so they could get the best rewards. However, they made an exception when it came to their close relations even if they get nothing."

Jackdaws certainly aren't the only clever birds around though - read on for more.

Litter-picking crows in Sweden

A company in the Swedish capital, Stockholm, has found an ingenious way to get crows to help clean up the streets.

Every time the wild birds pick up a cigarette butt, they receive a little bit of food in a specially-made machine.

According to the Keep Sweden Tidy Foundation, more than one billion cigarette butts are left on the country's streets each year, making up 62% of all litter there.

It's hoped that this initiative could save at least 75% of costs involved with picking up cigarette butts in the city.

Why pigeons are actually quite clever

Most of us see pigeons pretty much every day, pecking around for food, perching on buildings, going about their pigeon-y business.

You might not think them the smartest creatures around, but it turns out they're a lot more intelligent than we realised.

Researchers in Canada set up an experiment to find out more about how pigeons make decisions.

They found that pigeons, like humans, use maths and probability - how likely something is to happen - to work out how to get what they want.

Study reveals ravens as clever as chimps

Back in 2016, scientists in Sweden testing animal intelligence found that ravens are as smart as chimps, despite having much smaller brains.

Being called 'bird brain' is normally an insult, but not in this case.

Researchers from Lund University in Sweden challenged the animals to complete the same tricky task - to get food out of a tube.

First, they showed the birds that they were putting a treat in a tube with a hole at each end, so that they would know to go through the hole to reach the treat.

Then they repeated the test, but using a see-through tube so the animals could see where the food was.

They wanted to see if the birds would still understand they needed to go through the hole, or if they'd hit the tube sides instead.

The birds remembered that they needed to use the holes - their performance came very close to 100%, comparable to that of gorillas.

Grey parrot outsmarts children and Harvard students in memory tests

Parrots are known for being pretty clever birds, they're able to interact with people and some species can even mimic what humans say.

Experiments carried out by researchers at top American college, Harvard, suggest the colourful birds might be even cleverer than first thought.

The researchers took 21 adults who were all Harvard students, 21 children between the ages of six and eight and an African grey parrot called Griffin. Each person (or bird) took part in a simple game.

A number of small coloured pom-poms were placed under identical cups which were shuffled. Each participant was then shown a pom-pom and had to work out which cup the matching coloured pom-pom was under.

The aim of the exercise was to test how good the brain is at holding on to information about items that are no longer visible and later updating this with new information, like a change in location.

So what were the final results? Well, Griffin the parrot managed to outperform the children across all levels levels of difficulty for the experiment and he performed either as well as or slightly better than the adults during 12 of the 14 trials.

The secret life of crows

Turns out crows are super clever. These New Caledonian crows make hooks from bits of plants.

It means they can stick it into places like tree holes to capture their prey more easily.

Scientists have carried out an experiment with the crows and found that when they use their hooked tools, they're 10 times faster at getting their snack than using just a simple twig.

Animals making tools is a big deal and it's got scientists are pretty excited.