Electricity
Electricity had an immediate effect on all tested groups, i.e. the animal immediately terminated the bite. The immediate effect seems to be working in all three tested species, yet the long lasting effects of the electric shocks were different.
Wolves
Moody was the only wolf exposed to electricity. He released the dummy within 0.18 seconds after the electric shock. The lasting effect seems to be more than a month after two exposures.
African wild dogs
The African wild dogs released the dummy on average after 0.58 seconds. However there were some bites when the dummy was not released even after longer exposure. It is possible that in these cases the dogs managed to bite into the dummy in a way that they were not connected to both electric poles, and hence were not shocked. As the reaction of the wild dogs to an electric shock was usually obvious, sometimes including a fear vocalization, this hypothesis is likely. There were ten cases without clear response to the electricity out of a total of 52 bites. Excluding these cases from the analysis results in an average release time after the shock of 0.18 seconds. This is the same time as for Moody, keeping in mind that the accuracy of the time is limited by the frame rate in the video, i.e. 1/25 of a second or 0.04 s.
The lasting effect on the African wild dogs in this study was comparably smaller. They were biting the dummy more than once after 17 out of 52 bites. The maximum number shocks per trial that one individual received was three.
Dholes
The dholes released the dummy on average 0.72 seconds after the shock. There was one bite without a clear response towards the dummy, with the same possible explanation as above for the wild dogs. Excluding this case the average release time was 0.33 seconds. Hence the dholes hold on slightly longer to the dummy than the other species. Whether or not this would make any difference to a dog being bitten remains to be investigated. The dummy used for the dholes was different compared to the one used with the African wild dogs and the wolves. It might be that the transmission of the shock through the cables is slightly different. Furthermore the dholes had the only set-up where the dummy was lying and dragged in the snow during the experiment. The dummy inevitably got wet, especially on days with less cold weather and it is likely that the wires on the dummy got at least partly short circuited. Hence the intensity of the shock for a dhole biting into the far end of the dummy might have been reduced.
The lasting effect on dholes is not that easy to figure out as it was not possible to distinguish between the individual animals. Still, the dholes showed no intense fear response towards the dummy. Arguing that it might be possible, that in later trials only those dholes were biting that had not been shocked before, a more nervous and fearful behavior of the pack would be expected as a majority (12-13 shocks with 13 individuals) would have been shocked. As there was more than one dhole biting in the end it is unlikely that they were deterred from biting the dummy by only one electric shock. It can therefore be assumed that the dholes bite again in following trials after being shocked.
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Director of undergraduate studies Biology
Last updated:
05/24/10