Nest Boxes... on the inside

It's not just birds and mammals that use the nest boxes I make. While these larger creatures are the 'target market' for most backyard wildlife homes, there are other critters roaming around which we may not even think of as being possible tenants. Today I removed one of the boxes from a tree in our backyard for some maintenance (it was very old and due for replacement), and noticed a large Huntsman Spider clinging to the inside wall. This is not the first time I've experienced this - many years ago a female huntsman reared her babies inside a box previously used by parrots. But it was when I took the box to the shed and began taking it apart that I noticed some really cool little surprises.

When I un-threaded the wire from the length of hosepipe through which it had been placed to protect the tree's bark, a small shape fell out of the hose. Closer inspection revealed a beautiful Fence Skink (Cryptoblepharus buchananii), who had been hiding inside this rubber hollow chamber for protection. This species of native lizard, quite common in the south-west of WA, is a specialist of dead rotting timber on standing and fallen trees. Large logs are its playground and it can often be seen emerging from small holes to bask in the sun and catch insects. In the human environment it readily habituates to occupying fences (hence the name), buildings, walls and wood piles, and squeezes into all sorts of tight cracks and crevices to hide from predators. What difference does it make whether your hidey-hole is a natural piece of wood or a man-made piece of hosepipe!?

After tipping the box upside down, I noticed many small cockroaches running out from the pile of sawdust on the shed floor - these had found refuge in the box's sawdust and woodchip layer which is placed on the floor of the box, replicating a natural tree hollow. Cockroaches probably feast on decaying wood debris and small insects which are found in this hidden environment. Spreading apart the contents revealed yet another surprise...

These tiny white flecks are actually eggs... lizard eggs... belonging to a species of gecko we are lucky enough to share our backyard (and house!) with. The Marbled Gecko (Christinus marmoratus, pictured at the top of the page) is another common reptile found across southern Australia. They are brilliant climbers and can be seen clinging to the walls at night, feeding on the abundance of small insects which are attracted to our porch light. We've seen quite a few of these nocturnal lizards before and about a year ago found a baby one inside our lounge room - but now we know where some of them were reared!

So, if you have a nest box in your backyard which you think 'hasn't been used by anything', then think outside the square and beyond the realm of large vertebrates before you rule it out as an empty wildlife home. You just might have a family of geckoes hidden inside.