Titre |
Cues for prey location by aye-ayes (Daubentonia madagascariensis). |
Résumé |
Aye-ayes (Daubentonia madagascariensis) locate the mines of xylophagous insects by tapping the middle finger on wood surfaces. When a mine is found, the wood is gnawed away and the prey is extracted, using the same digit [1, 2]. This method of foraging might appear inefficient [3, 4], particularly since wood-boring insect larvae often tunnel long distances [5]. Indeed, in a field study, aye-aye excavations were found not only at the terminus of such mines, where grubs are most likely to be found, but also at their midsections [5], although it remained unclear whether the latter represented errors or placements resulting in prey capture. The mines become secondarily occupied by elaterid, buprestid and tenebrionid beetle larvae, adult katydids, crabs and frogs [5], and Pollock et al. [6] have suggested that aye-ayes may eat both frogs and elaterids. However, it is unknown whether aye-ayes can detect such prey if they are not located in close proximity to woodborers. Further, as they bore forward, coleopteran and lepidopteran larvae pack their mines with masticated wood similar to sawdust ('frass') and it is unknown whether the frass aids or interferes with the aye-aye's detection capabilities. The present study simulates some of these subsurface conditions and provides experimental analysis of the search cues available to aye-ayes. |