The Bitterns are back

[Catherine]

Bitterns are a type of heron that is known for boom sound it makes. Their numbers were very low in the Lancashire area.
They are now having a comeback. They require very specific conditions. It has taken work to restore the reedbeds, but it has been successful.

https://www.bbc.com/news/uk-england-lancashire-68740016

It is good to hear that the Bitterns are coming back. |It means conservation  efforts are working. 
Can you imagine a number of birds all making a booming sound. Now you can actually hear it, you don't need to imagine.