Wood warblers are ground nesting birds and vulnerable.....

Wood warbler predation

In June I was involved in an interesting project on wood warblers. These lovely little birds nest on the ground in dome-shaped nests. About 30% of the nests are predated by a variety of birds, mammals and rodents. They are monitored by the RSPB on Dartmoor woodland and as part of that, I set up a small analogue camera close to a nest. The camera was connected to a small single channel recorder and a lithium battery.

Waving fronds of bilberry gave rather a number of false positives, but I could see the adult birds and monitor their progress. The eggs hatched and the birds were busy feeding the young. As soon as the young start calling for food, they can be heard by predators and unfortunately in this case, this is what happened.

In the video you will see a jay sitting on a tree, then swooping down and predating the nest. The camera is far enough away that the gory details are not seen, but it is still poignant, although at least it is natural.

Later that morning the adults returned several times to the nest site, looking in vain for their chicks. Nature is not always kind.