Ancient poo gives scientists a history lesson in seabirds

It's not every day you get to say the answer lies in bird poo, but this time, you do.

Scientists have been able turn back time and get a greater understanding of seabird history by rummaging around in their old poo.

It wasn't just ordinary poo though. It's ancient droppings preserved in peatlands - which are areas of land that prevent plant materials from fully decomposing.

After finding layers of seabird poo in the peatlands, scientists can now look into 8,000 years of seabird history.

Read on to find out what they discovered.

The scientists were studying on the sub-Antarctic island of Bird Island, in the South Atlantic Ocean.

The international research team found out that if they analysed the mercury content in the poo, they could work out the size of past seabird populations.

Mercury from the fish the birds eat goes inside the birds' bodies and then passes into their poo.

That mercury then becomes trapped in layers of peat, creating a chemical record of how many birds were nesting there at the time.

Through studying the preserved poo the researchers found out that the seabird colonies on Bird Island were actually a thousand years older than previously thought.

As seabirds are top predators which move across large areas, they can often signal large-scale changes in ecosystems.

This discovery is helpful as the scientists can now look across the colonies' history and see where there were changes in population sizes, and how this matches up with changes in the climate.

The lead researcher, Dr Chuxian Li, says their new method "will provide new opportunities to reconstruct historical ecosystems".

As well as helping us to "understand how seabirds respond to today's climate changes".