uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
The Killer Fly Hunger Games: Target Size and Speed Predict Decision to Pursuit
Show others and affiliations
2015 (English)In: Brain, behavior, and evolution, ISSN 0006-8977, E-ISSN 1421-9743, Vol. 86, no 1, 28-37 p.Article in journal (Refereed) Published
Abstract [en]

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 <i>(Drosophila melanogaster)</i> 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 <i>Drosophila</i>, but one which will still generate successful pursuits of other suitable prey.

Place, publisher, year, edition, pages
2015. Vol. 86, no 1, 28-37 p.
National Category
URN: urn:nbn:se:uu:diva-263165DOI: 10.1159/000435944ISI: 000361782600004OAI: oai:DiVA.org:uu-263165DiVA: diva2:857065
Swedish Research Council, 2012-4740
Available from: 2015-09-28 Created: 2015-09-28 Last updated: 2015-11-03Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full texthttp://www.karger.com/DOI/10.1159/000435944

Search in DiVA

By author/editor
Nordström, Karin
By organisation
In the same journal
Brain, behavior, and evolution

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 265 hits
ReferencesLink to record
Permanent link

Direct link