Woodpigeons

Woodpigeons fill their crop with large meals and then they spend long periods resting and digesting.

I have recently discovered Woodpigeons' love of berries. Partly through reading a treasure-trove of a book "Birds and Berries" by Snow and Snow (1988), which I recommend to any bird-watcher. Since starting reading it I see things I missed before, just by paying more attention and 'expecting' things. While they carried out their detailed research on the interaction between berry-producing plants and berry-eating birds of the British Isles, the Snows discovered that Woodpigeons actually disperse many berry seeds. It was previously thought that pigeons crushed seeds in their muscular gizzards, together with grit they ate, and therefore acted as 'seed predators'. Although this can be true, it likely depends on the diet of the pigeon. Woodpigeons feeding on berries apparently do not ingest grit and many, if not most seeds are found intact in their droppings - and some at least have been proven to germinate after this. The Snows documented 711 bouts of berry feeding in Woodpigeons in 10 species of native plants. More than half of these were on Ivy (a total of  476), and many in Haws, Elder and Holly. Woodpigeons took both ripe and unripe Ivy and elder.
  I have been watching Woodpigeons feed on an ornamental hawthorn and a Cotoneaster near to where I work. There are a couple of sibling juveniles that feed on them and they are very funny to watch, doing acrobatics to reach the berries.

This one is almost upside down.

Ornamental Hawthorn berries