May 2017 – Tracking tunnels and discovering geckos

Auckland green gecko

You have to be lucky to see a native gecko in the forest. The little lizards are rare because rats, cats, dogs, stoats, pigs and possums eat them. So it was a red letter day four years ago when a volunteer putting out rat bait came face to face with a gecko. It was a brown and grey forest gecko, an endemic species, which means it is native only to NZ.

Then two years ago on a guided walk led by the Aongatete Trust an observant participant saw a green gecko, just as another walker trod on its tail! Fortunately the gecko ran off – without its tail but otherwise unscathed. This was our first record of the Auckland green gecko, and another one was seen this summer on the swimming hole track.

Rat monitoring tunnel inspection

Last week we found another gecko, not the actual animal but its footsteps. Volunteers had been doing a monitoring exercise in the forest using tracking tunnels. Inside each tunnel they slipped an ink-covered card dobbed with peanut butter.

Everybody loves peanut butter. Overnight, big and small animals crept through the tunnels to eat the peanut butter, crossing the ink pad and leaving their footprints on the white card margins. The next day the volunteers gathered up the numbered cards. All sorts of footprints were recorded, a few rats and mice, a smudged possum print, lots of tiny weta footprints, snail trails and, on one card, the unmistakable tracks of a green gecko!

These tracking cards help us to work in the dark. Most of the introduced predators that have invaded our native forests hunt in the night-time. Overnight the cards can record the inky footprints of rats, possums, stoats and cats out hunting our native birds, lizards and insects.

This is the way we learn what is going on in the forest. Are the rat footprints increasing to a level where we need to ask our volunteers to re-fill the bait stations? Do we have masses of insect foot prints, evidence of fewer rats? And sometimes a shy gecko will reveal its presence by leaving its foot prints on a monitoring card.

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