Back in 2006 I took part in the ‘ten birds’ meme. If infected (do people normally speak of being ‘infected’ by memes?), you were supposed to write about ten birds that you found ‘beautiful’. I decided to distort it slightly and make the birds the ten that I found most ‘beautifully interesting’. Here’s one of them, the others may or may not follow too.
Originally described by DeVis in 1890 as Todopsis kowaldi, Ifrita was independently ‘discovered’ by Walter Rothschild in 1898 and named by him Ifrita coronata. A passerine endemic to moist montane forests on New Guinea, Ifrita is remarkable for two reasons. Firstly, nobody really knows what it is and over the years it’s been classified in several different, disparate passerine families. It’s been allied with warblers, log-runners, and corvids. Secondly, it’s poisonous. I’ll repeat that for those people who hadn’t heard it before. It’s poisonous. While it’s nowadays reasonably well known that pitohuis (a group of six species of pachycephalid passerines, also endemic to New Guinea) produce batrachotoxin in their skin and feathers, it was shown in 2000 that Ifrita does too (Dumbacher et al. 2000). It’s thought that the poisons present in these birds are sequested from poisonous insect prey, but last I heard this was still under debate [there seem to be only three photos of Ifrita available on the web; the one shown here is the most oft-used].
As for why these birds are poisonous, it’s been widely suggested that the poisons they harbour function as a chemical defence against snakes, raptors and predatory mammals. However, they may also protect the birds against parasites (Mouritsen & Madsen 1994). Incidentally, (1) it seems that not all pitohui species are poisonous (although further study is required to be absolutely sure about this), (2) that another New Guinean passerine, the Rufous shrike-thrush Colluricincla megarhyncha, also produces batrachotoxin, and (3) that multiple other non-poisonous New Guinea passerines (including some other pitohuis) may mimic poisonous pitohuis and therefore gain protection from predators too (Diamond 1992, Dumbacher & Fleischer 2001).
Refs – –
Diamond, J. M. 1992. Rubbish birds are poisonous. Nature 360, 19-20.
Dumbacher, J. P. & Fleischer, R. C. 2001. Phylogenetic evidence for colour pattern convergence in toxic pitohuis: Müllerian mimicry in birds? Proceedings of the Royal Society of London B 268, 1971-1976.
– ., Spande, T. F. & Daly, J. W. 2000. Batrachotoxin alkaloids from passerine birds: a second toxic bird genus (Ifrita kowaldi) from New Guinea. Proceedings of the National Academy of Sciences 97, 12970-12975.
Mouritsen, K. N. & Madsen, J. 1994. Toxic birds: defence against parasites? Oikos 69, 357-358.