Tears for dinner: Madagascan moths seek salt from birds

Community and Forum → Blog → Tears for dinner: Madagascan moths seek salt from birds

Lev Bely, 24.12.2012 22:05

Some lepidoptera species get nutrition in a very intricate manner, they fish tears out of the sleeping birds' eyes using harpoon-like proboscis with special barbs at its tip. Back in 2006 scientists discovered those moths feeding on birds in Madagascar.

Roland Hilgartner from the German Primate Centre in Göttingen, Germany, and Mamisolo Raoilison from the University of Antananarivo in Madagascar were the first who spotted this curious sight in the island state's Kirindy forest.

Tear-lover moths and butterflies can be as well met in Africa, Asia and South America, where they usually land on large, peaceful animals such as deers, antelopes or crocodiles, which don't knock them off right away. No such big animals in Madagascar where the main mammals are agile lemurs and mongooses, which immediately fling moths off, and birds just fly away after being disturbed.

Not while they're sleeping though. Madagascan moths were spotted sitting on the necks of sleeping magpie robins and Newtonia birds, from where moth could reach the bird's eye. The moth plunged proboscis under the bird's eyelid and sucked out the tear fluid. Interesting that the thing happened in the wet season when the soils lacked sodium, what might have been the reason of such moth behaviour, supposed the scientists.

However this food is not easy to get. Sleeping birds hold their eyelids tightly closed, so the moths' proboscis compared to the one of others drinking tears of large animals is not smooth as a straw but equipped with hooks and “shaped like an ancient harpoon”, Hilgartner says.

Herewith the proboscis is fixed well and doesn't seem to disturb the sleeping bird. There are questions yet to be answered like if moths anaesthetize the eye to reduce the irritation, and if they're all males as well as the other tear-lover moths from elsewhere, for which tears constitute the main share of their nutrition.

New Scientist, http://www.newscientist.com

Photos: (1) moth drinking tears of sleeping bird, (2) moth's proboscis close-up, Roland Hilgartner, Mamisolo Raoilison, http://www.newscientist.com

All the rest posts on: Asia, Africa, Germany, curiosity, science, South America