Like I said last week, I saw a cool talk at ESA about tadpole behavior and trematode parasites. And since I liked it, I thought that YOU might like it, too!
When tadpoles can sense that predators are nearby, they alter their behavior by becoming less active. That’s a good way to avoid getting eaten. But do tadpoles alter their activity levels when parasites are nearby? Preston et al. (2014) say no! This seems counter intuitive, because some parasites, like the trematode Ribeiroia ondatrae, can cause a lot of damage to the host tadpole, and even kill it. But like we’ve discussed before, macroparasites (like Ribeiroia) tend to have intensity dependent effects on the host, so that pathology increases with the number of parasites. And it might not be worth altering your behavior if you’re probably just going to get a few parasites, and they probably aren’t going to do much harm to you anyways. Furthermore, just because parasites are nearby doesn’t mean that they’ll be able to successfully infect the tadpole, because tadpoles have other anti-parasite tactics, like immune responses.
But what about after the tadpoles get infected by the parasites? Do the parasites affect tadpole behavior then? You’ll just have to go check out the paper to find out!
Preston, D.L., C.E. Boland, J.T. Hoverman, and P.T.J. Johnson. 2014. Natural enemy ecology: comparing the effects of predation risk, infection risk and disease on host behaviour. Functional Ecology.