Showing off - Patterns for Life the art of communication An ASAB Education resource by Dr. Nicola Marples Mick Hoult Dr. Michael Dockery

Most edible animals are cryptic (or camouflaged) But some are brightly coloured and obvious

Cryptic animals and plants are protected from predators because they are hard to find But brightly coloured animals are easy to spot, so they are in danger from predators who can easily find and eat them

A blue jay eats a monarch butterfly Brightly coloured animals are often poisonous (contain a toxin) for protection A blue jay eats a monarch butterfly and is sick as a result

They may get the toxins from their food This is called sequestering toxins Here is a caterpillar of the monarch butterfly sequestering a heart poison from the milkweed plant

Here is a sea slug which collects poison from the jellyfish it eats, making it toxic to fish who would otherwise eat it This snake collects poisons from a toxic toad which it eats. It stores the toxins in the yellow area on its neck

If they don’t eat anything poisonous, animals have to make their own poison by special chemical processes in their body, this is called chemical synthesis Wasps synthesise the poison in their sting And dart poison frogs synthesise a toxin so poisonous that one lick of their skin would kill you!

But most toxins are inside the animal Why might that be a problem? (Think before you click!) This often kills it, so how do these species evolve? This butterfly has had its wings bitten by a bird!

To avoid this problem, a toxic animal can spray the toxin at its predator Skunks do this So do ants And bombardier beetles fire boiling acid at their enemies!

Some brightly coloured animals use a different tactic Some brightly coloured animals use a different tactic. They signal to the predators that they are toxic These animals which are both brightly coloured and contain a toxin, are called aposematic animals Another name for this is warning coloration

We use the same colours to signal danger Aposematic animals use colours like: red and yellow with black stripes or spots to signal their toxicity We use the same colours to signal danger

But what makes a signal easy to learn? Their bright, recognisable patterns let the predators learn quickly and easily that animals with those colours are nasty to eat Their signals have evolved to make it easy for the predator to learn But what makes a signal easy to learn?

Learning is helped by the signal being: Conspicuous Unusual Repeated Truthful Consistent Quickly followed by the punishment or reward Confirmed by other signals Think about how you would teach a dog to sit You use simple, fairly loud, clear commands Use a word the dog doesn’t know You reward him each time he sits You reward him if does sit You always reward him, every time You reward him as soon as he sits You may use a hand signal at the same time you say “sit” Each of the factors in the left hand list are being used by the method on the right

Ladybirds produce blood from their joints But aposematic animals don’t limit their signals to colour; they also signal to the predators with smells, tastes, and sounds Ladybirds produce blood from their joints This ‘reflex blood’ tastes very bitter, and has a weird smell called pyrazine

Bees buzz a characteristic warning sound Some cockroaches hiss in warning Rattlesnakes rattle their tails Can you think of any other warning sounds, smells or tastes?

Wouldn’t it just confuse the predator? Does it really help the predator learn if the prey gives several types of signal at once? Wouldn’t it just confuse the predator? Meet Emma Siddall, who has been doing experiments to find out

Emma used chicks as a predator, and the prey ‘insects’ were crumbs of coloured chick food The chick food was dyed yellow or green, and the yellow crumbs made nasty with a bitter chemical called ‘bitrex’ She wanted to test whether the chicks could learn to avoid the yellow crumbs and only eat the green ones

She used pyrazine as the odour, which is what ladybirds smell of The single green or yellow crumbs were offered to the chicks in holes round the edge of a tray. A second signal, a smell, could be put beneath each yellow crumb in a special chamber below each hole She used pyrazine as the odour, which is what ladybirds smell of So the chicks were given two signals: yellow colour, and a warning smell. They walked around the tray choosing what to eat

Did having two signals help the chicks learn to avoid the yellow crumbs? Here you can see the number of crumbs eaten in each trial. The chicks all ate a lot of yellow crumbs in the first trial, but those chicks that experienced the pyrazine odour learned quickly to avoid the yellow crumbs. Those with only one signal, the yellow colour, learned more slowly and ate more yellow crumbs in all. So an insect with two cues, odour and colour, will probably be better at teaching the birds to avoid it than an insect which has only one part to its signal, colour alone

So Emma’s experiments show that at least one aspect of aposematic signals has evolved to aid learning What about the other factors which aid learning? Do aposematic animals show them too? In each of the following slides you need to decide which of the factors which aid learning are definitely being used by the aposematic animal pictured. If you don’t know enough about the animal (maybe no-one does) then don’t count that factor for that animal

Factors which aid learning - The signal is: Conspicuous Unusual Repeated Truthful Consistent Quickly followed by the punishment or reward. Confirmed by other signals

Factors which aid learning The signal is : Conspicuous Unusual Repeated Truthful Consistent Quickly followed by the punishment or reward. Confirmed by other signals These are toxic striped ladybirds which smell of pyrazine and taste horrible. They often aggregate together like this

Factors which aid learning - The signal is : Conspicuous Unusual Repeated Truthful Consistent Quickly followed by the punishment or reward Confirmed by other signals Each spine on this lionfish can give you a very painful sting!

“If red touches yellow, it can kill a fellow” Factors which aid learning - The signal is : Conspicuous Unusual Repeated Truthful Consistent Quickly followed by the punishment or reward Confirmed by other signals “If red touches yellow, it can kill a fellow” This is a very venomous coral snake. A bite would kill a man within hours This is a milk snake. It is totally harmless, but copies the signal of the coral snake, giving a visual signal which is a lie!

So cheats on the signalling system exist So cheats on the signalling system exist. They are called Batesian mimics, and they make the signal harder to learn Here are some other Batesian mimics to finish with, all of which are harmless, but look just like a toxic species. See if you can think of any more! The top frog is harmless, the bottom two species are deadly!

Acknowledgements ASAB would like to thank the following for generously giving us permission to use their photographic images: Professor Lincoln Brower (Sweet Briar College) Paul Knibb Professor Mike Majerus (University of Cambridge) Ian Kimber Bill Hark Tom Murray Professor David Wagner (University of Connecticut) Andrea Farr Dr Bill Rudman (Australian Museum, Sydney) Dr Jim Anderson Dorothy Floyd (Small Life Supplies) Dr John Meyer (North Carolina State University) Dr Deborah Hutchinson (Coastal Carolina University) Roy Leverton Gerry Rome Mick Hoult Creative Commons Dr Nicola Marples.

An ASAB Education resource by Dr. Nicola Marples Mick Hoult Dr. Michael Dockery