The killer fly hunger games : target size and speed predict decision to pursuit
Wardill, Trevor J.
Olberg, R. M.
Gonzalez-Bellido, Paloma T.
MetadataShow full item record
KeywordCompound eye; Distance estimation; Movement detector; Object motion; Retinal velocity; Target tracking
Predatory animals have evolved to optimally detect their prey using exquisite sensory systems such as vision, olfaction and hearing. It may not be so surprising that vertebrates, with large central nervous systems, excel at predatory behaviors. More striking is the fact that many tiny insects, with their miniscule brains and scaled down nerve cords, are also ferocious, highly successful predators. For predation, it is important to determine whether a prey is suitable before initiating pursuit. This is paramount since pursuing a prey that is too large to capture, subdue or dispatch will generate a substantial metabolic cost (in the form of muscle output) without any chance of metabolic gain (in the form of food). In addition, during all pursuits, the predator breaks its potential camouflage and thus runs the risk of becoming prey itself. Many insects use their eyes to initially detect and subsequently pursue prey. Dragonflies, which are extremely efficient predators, therefore have huge eyes with relatively high spatial resolution that allow efficient prey size estimation before initiating pursuit. However, much smaller insects, such as killer flies, also visualize and successfully pursue prey. This is an impressive behavior since the small size of the killer fly naturally limits the neural capacity and also the spatial resolution provided by the compound eye. Despite this, we here show that killer flies efficiently pursue natural (Drosophila melanogaster) and artificial (beads) prey. The natural pursuits are initiated at a distance of 7.9 ± 2.9 cm, which we show is too far away to allow for distance estimation using binocular disparities. Moreover, we show that rather than estimating absolute prey size prior to launching the attack, as dragonflies do, killer flies attack with high probability when the ratio of the prey's subtended retinal velocity and retinal size is 0.37. We also show that killer flies will respond to a stimulus of an angular size that is smaller than that of the photoreceptor acceptance angle, and that the predatory response is strongly modulated by the metabolic state. Our data thus provide an exciting example of a loosely designed matched filter to Drosophila, but one which will still generate successful pursuits of other suitable prey.
© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Brain, Behavior and Evolution 86 (2015): 28-27, doi:10.1159/000435944.
Suggested CitationBrain, Behavior and Evolution 86 (2015): 28-27
The following license files are associated with this item:
Showing items related by title, author, creator and subject.
Longworth, Brett E.; Robinson, Laura F.; Roberts, Mark L.; Beaupre, Steven R.; Burke, Andrea; Jenkins, William J. (2012-04-17)This paper describes a technique for measuring the 14C content of carbonate samples by producing C-ions directly in the negative ion sputter source of an accelerator mass spectrometer (AMS) system. This direct analysis ...
Characterization of underwater target geometry from Autonomous Underwater Vehicle sampling of bistatic acoustic scattered fields Fischell, Erin M. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2015-06)One of the long term goals of Autonomous Underwater Vehicle (AUV) minehunting is to have multiple inexpensive AUVs in a harbor autonomously classify hazards. Existing acoustic methods for target classification using ...
Endoplasmic reticulum targeted GFP reveals ER organization in tobacco NT-1 cells during cell division Gupton, S. L.; Collings, D. A.; Allen, N. S. (2005-11-07)The endoplasmic reticulum (ER) of plant cells undergoes a drastic reorganization during cell division. In tobacco NT-1 cells that stably express a GFP construct targeted to the ER, we have mapped the reorganization of ...