Pheasants will get out of the preserves in the breeding season and wander into the mounds, so that the space the keeper has to range is then enlarged threefold.

Both pheasants and partridges are frequently killed on their nests; when the eggs are hard the birds remain to the last moment, and are often knocked over.
Besides poachers, the eggs have to run the chance of being destroyed by carrion crows, and occasionally by rooks.

Rooks, though generally cleanly feeders, will at times eat almost anything, from a mussel to a fledgeling bird.

Magpies and jays are accused of being equally dangerous enemies of eggs and young birds, and so too are snakes.

Weasels, stoats, and rats spare neither egg, parents, nor offspring.