tree holes Traditional Cache

Many caches around the world are placed in various hiding spots ,various common spots include, rocky areas, under fallen trees , in natural holes and in trees . Some are naturally produced holes from wear and tear and others are made from humans and various species of animals and birds . It facinates me as to what causes the various holes both new and old and what has lived there before , so here is a brief description i found .

• Woodpeckers generally excavate new holes each year, often in wood weakened by fungal attack. Holes are usually a few metres up, but can be quite close to the ground.
• Some wood chips can be seen at the base of the tree. It can take two weeks to dig out the nesting chamber.
• Entrance holes are nearly spherical and just big enough for a woodpecker to slip through – 5.5cm diameter for great spotted woodpecker, 6.5cm–7.5cm for green.
• Cavities from previous years are used by a wide range of other species; starlings can oust woodpeckers from their holes.

• Treecreepers live in large trees. They make small nests concealed behind loose bark or in crevices.
• The nest is a loose cup, 7.5cm across, made of twigs, roots, moss and grass.

• Bats such as noctules and serotines roost in tree holes, often in old woodpecker holes or natural crevices.
• The trunk below the hole is darkly stained with droppings and urine.
• In tight crevices, the sides of the hole are often greasy where the bats squeeze in.

• Nuthatches use natural crevices or woodpecker nests. The mouth of the nest hole is reduced in size with mud mixed with saliva (very hard when dry) to leave a hole about 3cm across.
• Nuthatches block up holes in nestboxes in the same way.

• Grey squirrels mainly use dreys, but will gnaw small cavities in trees, often in rotten wood where a dead branch has fallen off.
• They like dense ivy cover. Teeth marks are generally visible around the edge of the hole.

• Starlings use holes at any height in trees, cliffs and walls. In trees, they often use woodpecker holes.
• The untidy nest of straw, dead grass, feathers etc is often visible. You may also see droppings on the tree trunk (under the hole) squirted out by nestlings.

• Tawny owls generally nest in tree cavities, but will use rock crevices and nests of other birds.
• The holes are often much larger than the owl.

• Tits generally use natural holes but some, such as willow tits, may dig their own in rotten wood.
• Blue and great tits use holes in trees or walls from ground level upwards. The hole is often only a crack through which the bird squeezes, with no obvious sign other than slightly worn bark around the hole.