Don't Push Me! Flesh fly chases off greenbottles

Flesh fly chasing off greenbottles

Today I saw a large chequered flesh fly (Sarcophaga spp. on a dead chick being irritated by, and chasing off the more numerous greenbottles (Lucilia caesar) that were also trying to get to the feast. The video above shows the live action over a continuous recording stretch of 2 minutes or so with several battles being fought. The video below shows the actual fight clips at 1/10th speed (slow motion).

The attacks by the flesh fly were quite selective, with some greenbottles being attacked whilst others were not. The main response was to a greenbottle moving along, which would first attract the flesh fly's attention and with further movement, stimulate an attack,

The attacks appeared to be pushing off the greenbottle into the grass, where the victim froze and the flesh fly returned to its feeding patch. I'm not sure, but it looks as if in one or two clips the greenbottles were in turn buzzing the flesh fly.

However other greenbottles appeared to be able to feed quite close to the flesh fly without arising its ire.

The behaviour would suggest that this is a male flesh fly, as these are known to display territorial behaviour towards other male flesh flies and other species of fly. See http://bioweb.uwlax.edu/bio203/f2013/griffin_chri/reproduction.htm, and source reference Paquette et al., 2008 http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3032.2008.00646.x/full