Tim Harford

So it was, when we got this email from Matthew Clark. Investigation is what we do, Matthew. So our team went straight to the source. Who was it who made this eyebrow-raising claim?

To successfully fledge, each chick will require 20,000 caterpillars. It's a tall order that must be completed within three weeks. Wait, we're fact-checking Sir David Attenborough? The national treasure who just celebrated his hundredth birthday? Are you trying to get me fired? Without fear or favour, Tim. Without fear or favour.

Mikä olen minä kysymään teidän tuotantoon? Kaikki, joiden nimet on avaamassa tämän programin krediteissä. Jos minä menen takaisin... Minä otan sinut kaikki takaisin! Joten onko oikein, että jokainen bluetittikki tarvitsee 20 000 katapiljoa viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä viimeisenä

Puhuimme Dr. Malcolm Burgessin, principal conservation scientist at the RSPB and more or less his resident blue tit consultant. He looked at the scientific literature on the topic and did some quick calculations for us. So each chick will be receiving about 90 caterpillars per day. The blue tit nestlings are in the nest for about 16 to 20 days. So say 20 days, 20 times, 90 caterpillars per day.

saa noin 1,800 katapuljaa per katapulja. Joten lähes 2,000 katapuljaa per katapulja on paljon tarpeellisempi, mutta David Attenborough sanoi 20,000. Joten mitä olisi tullut väärin? Muistakaa, että siinä on enemmän kuin yksi katapulja kaupungissa. Yleensä katapulja saa noin 10 katapuljaa. Voi olla enemmän tai vähemmän, mutta esim. 10. Joten 10 kertaa 1,800 saa 18,000 katapuljaa.

18 000 katapuulaa koko kivun 10 kivun kivun kivun kivun kivun kivun kivun

After we got in touch with the makers of the Secret Garden documentary, the BBC published an official correction. We've added a clarification strap at the start of the episode and apologise for the error in the narration. And who did that narration again? When caterpillars are in short supply, spiders will have to do. So we fact-checked David Attenborough. Next on our National Treasure list is Paddington Bear.

That's all we have time for this week, but please keep your questions and comments coming to moreorless at bbc.co.uk, because there's a whole series to get through, and we couldn't do it without your ideas. Until next time, goodbye!

If you've got a scrolling problem, then this is the podcast for you. It's called Top Comment with me, Matt Shea. And me, Marianna Spring. We both investigate social media for a living.

We're supposed to learn from our own mistakes, but other people's errors can be instructive too.

From efforts to control the weather that went disastrously awry, to the untimely death of the Segway boss, history is a treasure trove of mishaps and meltdowns that can teach us all.

I'm Tim Harford, host of Cautionary Tales, the podcast that mines the greatest fiascos of the past for their most valuable lessons.

Listen to Cautionary Tales wherever you get your podcasts.

We're supposed to learn from our own mistakes, but other people's errors can be instructive too.

From efforts to control the weather that went disastrously awry, to the untimely death of the Segway boss, history is a treasure trove of mishaps and meltdowns that can teach us all.

I'm Tim Harford, host of Cautionary Tales, the podcast that mines the greatest fiascos of the past for their most valuable lessons.

Listen to Cautionary Tales wherever you get your podcasts.