Eighteen fawns included in a University of Zurich field study had to be shot this week after it was found that their tracking collars – placed in early summer – had malfunctioned and were not adapting to their increasing neck size.
The research study, financed in part by the Federal Office for the Environment, was investigating the effect of the lynx population on the habits of deer in canton Bern.
In order to study the behaviour of deer in the presence of lynx, 99 deer were fitted with radio collars in 2011 and 2012. In 2013 an additional 46 fawns were fitted with fabric collars which were supposed to expand over time as the thread holding them together dissolved.
In mid-August the problem with the collars was identified and the animals were located and observed. A total of 30 animals were found to be wearing defective collars. Six of those opened in spite of the defect.
Because stunning the remaining deer to replace their collars would have caused them too much stress, 18 deer were shot by rangers. Six deer are not yet accounted for.
The University of Zurich researchers are investigating why the collars failed to expand, and will decide whether to continue the research study. Both the university and the Federal Office for the Environment expressed regret over the situation.
The number of deer killed in connection with the study was comparatively small. According to a spokesman from the Federal Office for the Environment, 42,000 deer are shot by hunters annually in Switzerland, more than 9,000 are hit by cars, 700 are killed by trains, 700 by avalanches, and 700 by dogs.