Charlotte McDonald

One thing that's definitely not true is that wind turbines are killing all the birds.

The back of an envelope calculation is even harder for the total US bird population.

But Hannah had a look at the data to try and give us a rough idea.

Birds also often reproduce pretty fast and have quite short lifespans.

So there's a lot going on in this number.

So what's the final verdict?

Should the number of birds being killed make us reconsider our use of wind turbines?

Thanks to Hannah Ritchie, Deputy Editor at Our World in Data and Senior Researcher at the University of Oxford.

If you've seen a number or another bird-related hazard you think we should look at, email moreorless at bbc.co.uk.

Until next week, goodbye.