Tag Archives: toxic

Do As I Do

Predators like these Great tits (Parus major) eat a wide variety of insects, but some of those insects are so unpleasant to eat that birds tend to avoid them. How does this trait evolve in prey animals when its maintenance and origin depend on the predators learning by eating them? (Image Credit: Shirley Clarke, CC BY-SA 3.0).

Social information use about novel aposematic prey is not influenced by a predator’s previous experience with toxins (2019) Hämäläinen et al., Functional Ecology, https://dx.doi.org/10.1111/1365-2435.13395

The Crux

Many animals in nature have evolved a defense strategy known as aposematism, meaning that they display warning colors or patterns that tells predators that they are not worth eating due to their toxicity. Predators can learn to avoid aposematic prey by either sampling different prey animals and learning for themselves, or they can watch other predators eat different prey species and, depending on the reaction of that predator, learn what may or may not be good to eat.

The paradox of the evolution of this aposematic trait is that toxic prey species are not only highly visible and easily noticed by predators, but they must be attacked in order for predators to learn that they shouldn’t eat them, meaning that these prey species may not even survive long enough for them to enjoy the benefits of predator avoidance. The question then becomes are aposematic prey able to persist in nature because predator learn to avoid them? The authors of today’s paper wanted to investigate how predators that have learned to avoid toxic prey will watch and learn from other predators eating new, possibly toxic prey.  Read more

The Asian Ladybeetle

The Asian Ladybeetle, which has now established itself in Norway and will likely be a permanent fixture in our ecosystem

The Asian Ladybeetle, which has now established itself in Norway and will likely be a permanent fixture in our ecosystem (Image Credit: Scott Bauer, CC0)

Reasons for deliberately introducing novel species vary, from their aesthetic appeal to a boost they may provide the economy with. Using them for biological control is another, and it has led to some of the world’s most infamous biological invasions. Today we look at the Asian Ladybeetle, which Norwegian farmers were keen on importing into the country to use to control pest species that were damaging local crops.

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