Marnie Chesterton

The lemur called Tammy and feeds him some grapes while he discusses how lemurs use stinky smells to communicate with each other. Luckily they don't do that actually in the room, but it's just this really lovely interaction between David and Tammy there in front of the cameras. Yeah, it's really gorgeous.

So the reason that Helen told us that he was unsure about doing these lectures is because they're televised live and he was worried about all the animals misbehaving. So, you know, they say never work with children or animals. And the absolute irony of this is that who was the person who made the decision that the annual lectures ought to be broadcast live? Yes, it was Sir David Attenborough back when he was controller of BBC Two.

Real editor vibes there. Now we've got another correspondence from Andrew Wilson, who's worked on the sound for wildlife documentaries for 40 years, including the iconic David Attenborough series, Blue Planet and Planet Earth.

Pohja äänti. Pohja äänti.

Oh, that is lovely. If anyone is inspired to tell us any more anecdotes, then I've given out the details several times. But thank you to everyone that wrote in, including...

Randy in Rochester, who gets a special mention because a couple of weeks ago we had a frog-themed episode. And he writes, you talked about frogs and you asked listeners to send you letters from countries that have frog stamps. Well, I just had to write. I love to write and I have lots of stamps to use up.

Oh wow, he really used up a lot of stamps. One, two, three, four, five, six. So the stamps on this letter include two ornate chorus frogs, a blue spotted salamander and an American kestrel. So full points to Randy. Do keep all of those emails, messages and letters coming in. Next up, do all animals see at the same speed? That's after this.

Well done if you got that right. And I really recommend checking out the other things named after David Attenborough.

And we have a question from Adam in London on a surprising variation in the natural world.

Thank you for your question, Adam. So, is there a frame rate, I guess, to how we see? And why does that vary if it varies? Okay, to answer, we reached out to Dr. Clinton Harlem, who researches the speed of visual perception in humans and animals at Trinity College Dublin. And he began by telling us what exactly the speed of sight is.

So, animals have a frame rate for processing visual information, which is affected by the way each experiences the world. Clinton told us that peregrine falcons can see two to three times faster than humans because they need to effortlessly track and catch fast-moving prey.

Their visual processing goes up to 129 frames per second, while ours sits at around 40 to 60 frames per second. So there is a range to human speed of sight as well, but what causes it? So it does vary, and there are a lot of things that can affect how fast we see. So when you think about all the external factors, they all have to do with

Thank you to Clinton Harlem there and thank you to Adam for your question. Listeners, if you have any questions and you'd like the Unexpected Elements team to have a stab at answering it, the email address is unexpected at bbc.co.uk or you can send us a message or a voice note to WhatsApp. It is plus 44 330 678 3080.

David Attenborough turning 100 has not gone unnoticed by our colleagues over in news, which is good because that means that we can pick the news peg of David Attenborough's 100th birthday for this entire show. But it does mean that there's quite a lot of Attenborough-related content on the airwaves at the moment.

When I was listening to the radio earlier this week, I caught a discussion of his influence on a group of wildlife documentary makers who'd worked with him. This was on a BBC World Service programme called Outside Source. Here's wildlife documentary maker Victoria Bromley. David has been a witness in his lifetime to the very quick change to where we've arrived at today. As I say, he has a very deep understanding of that.

Mutta hän kuitenkin on kuitenkin kokemusta ja ymmärrystä. Hän ei todennäköisesti ole seuraava uusista kehityksistä. Hän on erittäin yllättynyt teknologiasta ja uusista kokemuksista. Se on myös se, mikä on suosittanut hänen karjansa. Hän on nähnyt, mitä on mahdollista.

Wow, the changes that he must have seen over his century. That was the big thing that struck me. What must he have seen? Not just seen, but shared with us, highlighting the life cycles and the threats facing other species that share the planet with us.

In wildlife conservation, animals get the lion's share of the attention, pardon the pun. But according to research that's out this week by the Royal Botanic Gardens Q and the Zoological Society of London, the world's flowering plants are in serious trouble.

So that is one of the co-authors, Dr. Felix Forrest, who I didn't even notice is a case of nominative determinism until my producer Alice pointed it out. Well done, Alice. So Felix has calculated the genetically distinct plants, the ones called Edge. And as he said, a fifth of them around the world are under threat. So why is that a problem?

So, there's a lot to lose, but identifying the edge plants gives conservation scientists a list of priorities, what to focus on first. So what exactly is being saved, though, and where? Oh, everywhere. I mean, this is global efforts. So Mozambique, Mexico, Nepal, where you just were, Chavi, Mali, Philippines, India. I did ask Felix for his favorite tree, and...