What do theses frogs have to do with Star Trek?

If you were challenged to do an impression of a frog, the chances are you would let out a little croak, but a new discovery proves that not all frogs sound the same.

Researchers have discovered seven new species of frogs in the East African Island of Madagascar, which instead make high-pitched whistling noises which they say sound like something from the sci-fi series Star Trek.

The sounds reminded the team so much of the show, that they named the seven species after characters from the series.

Professor Miguel Vences who is from the Technische Universitat Braunschweig in Germany, led the research team.

Professor Vences said they named the frogs after "seven of the most iconic captains from the sci-fi series".

The frogs can be found across the rainforests of Madagascar

The frog species have been named after Kirk, Picard, Sisko, Janeway, Archer Burnham and Pike - which were all characters in the series.

But Assistant Professor Mark Scherz, who was also part of the study, said the names and sounds aren't the frogs' only connection to the show.

He said the team had to go on "major expeditions to remote forest fragments and mountain peaks" to find and study the frogs.

"There's a real sense of scientific discovery and exploration here, which we think is in the spirit of Star Trek," he added.

The different species were named after captains from the Star Trek series including Captain Jean-Luc Picard who was played by Patrick Stewart

The high pitched calls of the frogs are said to sound like something a bird or insect would make.

The scientists say that the males might use them to communicate with females, and tell them about their suitability for breeding.

The species were found living in the rainforest alongside fast-flowing streams, which can be quite loud, something which is thought could explain why they make such an unusual sound.

Dr Jorn Kohler who is the Senior Curator of Vertebrate Zoology at the Hessisches Landesmuseum Darmstadt, Germany, said: "If the frogs just croaked like our familiar European frogs, they might not be audible over the sound of rushing water from the rivers they live near.

"Their high-pitched trills and whistles stand out against all that noise."