Imagine a population migrating across a mountain range: Some communities settle in the valleys, others climb the mountains. Over time, these mountaintop societies become increasingly isolated. Over generations, the isolated populations become more different.

If the distant relatives were to meet, would they look alike? Would they speak the same language? Sing the same songs?

In the sky islands of India's Western Ghats mountain range, ecologist V.V. Robin is studying the impact of isolation on the language of birds.

Over the last 15 years, Robin has understood how the birds in these mountains landed here millions of years ago - and then stayed behind. Isolated on the mountaintops, their genetic makeup has diverged quickly. Their songs have diverged even more.

These unique birds and their songs are in threatened due to destruction of habitat by humans. But recently, an encounter that started on Twitter is helping to bring these sounds to the rest of world - through beatboxing. This bird beatboxing could inspire a new generation to sit up and pay attention.

Marooned on a sky island

The birds in the sky islands of the Western Ghats have been isolated for about 5 million years, says Robin. These birds came south from the Himalayas when the entire Indian subcontinent was connected by forest about 8 million years ago.

"Then they got isolated up on the mountaintops as the climate changed," Robin explains. "As the wetter climate moved up, the birds moved up with it. And got stuck."

These birds are highly specialized - some of them are understory birds, which means they don't fly over the canopy. Rather, they live on the mountain floor, explains Robin. "They're small birds - they don't move far."

This isolation is why their mountaintop range is called "sky islands" - the birds never come below an altitude of 1,300 meters, and are essentially marooned on the tops of these mountains. This isolation is why their songs have diverged so much.

Just as human languages and dialects become more different as the space between them grows, birds separated by valleys have different songs. This didn't surprise Robin. But what did surprise him was that even recent isolation caused by human encroachment on a single mountain resulted in song variation.

Deforestation and even plantation of crops or other plants have acted as barriers between subgroups of birds.

The divergence is like, say, Dutch and German.

But across mountains, it's like Greek and Tamil.

Birdsong - with a beat

In urban areas where most people live, the cawing crows and chirping sparrows we hear are not technically singing - they are calling out, to share warnings and alerts about food and danger.

Songbirds sing for the specific purpose of mating. Only males sing - to impress a female.

And in the tranquil sky islands of the Western Ghats, these songs are totally unique - because birds like the Nilgiri pipit, the white-bellied shortwing and laughing thrushes are indigenous to the region. These birds and their songs are found nowhere else in the world.

The pipit is one such endangered bird that lives on only two mountains. Its population is dwindling because human plantations have reduced up to 85 percent of its grassland habitat.

Robin found that people in the region don't even recognize these birds, let alone their songs. He realized that working in an academic bubble wasn't going to help them and though they're not critically endangered yet, he didn't want to wait until it was too late.

Unexpected Twitter encounter

On Twitter, Robin found about American musician Ben Mirin. Ben beatboxes - that is, he makes percussion sounds with his lips and tongue, and loops these sounds in a recorder. But Mirin is not your average beatboxer - he uses bird song to punctuate his own body music.

Robin invited Mirin to India, and soon they'd created not just songs featuring the bird's melodies, but also workshops to engage students. Along with Presanjeet Yadav, a videographer and photographer, they are now teaching teenagers to identify these local birds, sample the bird songs and make their own tunes.

Through interactive bird beatboxing sessions, they are inspiring a new generation to pay attention to these birds and their role in the local ecology.

"Some of the teachers wrote to us and told us many of the students are now going and recording bird songs on their mobile phones," he said.

Robin continues to focus on mapping the diverging songs of several birds across these geographies. And through birdbeatboxing, he hopes to bridge the gap between birds and humans.

Though he can't bring the birds down from the mountains, he hopes to at least bring their songs down to the rest of the world.