Pheasants are most likely to be killed by predators on unfamiliar ground, according to new research involving the University of Plymouth.
A new study showed most animals live within a certain area, known as their “home range”, and they know the central areas better than the edges.
To examine how this impacted their outcomes, researchers assessed the performance of 126 captive-reared pheasant chicks on a range of cognitive puzzles. They were then released into the wild and tracked using a high-precision tagging system.
About 40% were killed by predators during the six-month study period – almost all by foxes – and the pheasants were far more likely to die towards the edge of their range.
The findings show this was due to inexperience in these areas, because other birds that knew the same spots well were not likely to die there.
The study, funded by the European Research Council, assessed two kinds of spatial memory in each pheasant before their release, using a maze and a memory task.
The results, published in the journal Nature Ecology and Evolution, showed chicks with high cognitive abilities grew up to have a larger range.