Activity and predator escape performance of common greenfinches Carduelis chloris infected with sindbis virus

The fitness effects of parasites on their hosts are often unknown. For mostavian viruses, no records of clinical disease have been associated withinfections. In this study we tested if birds would alter their behaviour duringan infection with an avian virus that naturally occurs in passerines. Wemeasured spontaneous locomotion activity and take-off performance ofCommon Greenfinches Carduelis chloris at the peak of infection with theSindbis virus (Togavirid , Alphavirus). We found that virus-treated birdshad lower locomotion activity than saline-treated birds the third day afterthe injection. When exposed to a simulated predator attack, virus-treatedbirds reduced their take-off speed from before to after treatment, whereassaline-treated birds did the opposite. This difference between treatments inchange in flight speed from before to after treatment was only detected inthe evenings, when the birds were heavy. Furthermore, virus-treated birdsincreased in body mass from before to after treatment, whereas saline-treatedbirds did the opposite. Our results suggest that the infection with Sindbisvirus is accompanied by energetic or pathological costs, and that infectedbirds accounted for these cost by reducing locomotion activity whileincreasing their energy intake. Down-regulating important behaviours suchas take-off flight speed may have implications for the chances of survivalof infected birds.

Lindstrom K.M., I.T. van der Veen, B-A. Legault & J.O. Lundstrom, Ardea 91(1): 103-111