Dave Bevan / Eurasian jay (Garrulus glandarius) retrieving acorns from a cache in a rotting gatepost, Carmarthenshire, Wales, UK, November.

Dave Bevan / Eurasian jay (Garrulus glandarius) retrieving food from a cache in a snow covered gatepost, Carmarthenshire, Wales, UK, November.

Brian Bevan / Eurasian jay (Garrulus glandarius) feeding from a cache, Carmarthenshire, Wales, UK, December.

Brian Bevan / Eurasian jay (Garrulus glandarius) and Eurasian magpie (Pica pica) feeding from a cache, Carmarthenshire, Wales, UK, December.

Dave Bevan / Female Great spotted woodpecker (Dendrocopos major) trying to break into a nut cached in a tree, Carmarthenshire, Wales, UK, November.

Dave Bevan / Jay (Garrulus glandarius) feeding from a cache in a tree branch, Carmarthenshire, Wales, UK, November.

Dave Bevan / Male Great spotted woodpecker (Dendrocopos major) trying to open a hazelnut cached in a branch, Carmarthenshire, Wales, UK, November.

Dave Bevan / Jay (Garrulus glandarius) landing on a fence post and feeding on cached acorns, Carmarthenshire, Wales, UK, November.

Dave Bevan / Jay (Garrulus glandarius) feeding from a cache, Carmarthenshire, Wales, UK, November.

Dave Bevan / Grey squirrel (Sciurus carolinensis) feeding from a cache in a stump, Carmarthenshire, Wales, UK, November.

Dave Bevan / Grey squirrel (Sciurus carolinensis) feeding from a cache in a stump, Carmarthenshire, Wales, UK, November.

Fabrice Cahez / Red squirrel (Sciurus vulgaris) searching in cache in tree, Allier, Auvergne, France, July.