Goannas can jump! They are smart and learnt as we adapted our chicken pen to try to keep them out.
One of the delights of living in the bush is to live in such close proximity to the wildlife. We don't have dogs or cats so their is no threat to the wildlife and they literally live around us. Goannas, ours are lace monitors (Varanus Varius), routinely wander along the verandah like the ducks, swamp hens, snakes and wallabies.
Goanna or lace monitor wanders by
We do keep chooks* though. The chooks live comfortably with all the wildlife, sometimes with heart stopping moments when they wander up to a red-bellied black snake but in general they know what is dangerous and keep a distance. Fully grown chooks are too big for most predators except dogs or a large feral cat, especially during the day.
Night however is another matter. Snakes, foxes, dingos, feral dogs or cats and even quolls will take a chook at night if they are big enough. Our chooks have a secure pen where they are locked in every night. They know to return at the end of each day, sometimes with a little coaxing for a slow learner.
The chooks are released each morning to roam freely around the property. They return to the coop for food or to lay their eggs.
Goannas love eggs too. Leaving the door open so the chooks can get in and out is an invitation to a wandering goanna. An invitation taken on a number of occasions.
So begins the battle of the wits with these dinosaur like creatures.
Our initial solution was to build a hatch door about a metre off the ground in the main chook pen door. The chooks quickly learnt, well most of them, to fly or jump through the hatch to get in and out of the pen and return there in the evenings. Goannas went around the pen and couldn't find the opening. We also added a smooth surface on each side of the entrance so that they couldn't climb up the sides.
This worked well, for a while. The goannas just walked past the door, until one goanna worked it out. It was the end of summer last year when we found we had a security breach and lost eggs.
Our largest, we think male, goanna was caught inside the pen. But how did it get in? We set up a wildlife camera to follow the comings and goings and sure enough our friend was caught on video, jumping up to the hatch.
Goanna jumping through the hatch
This big fellow, he is well over 1.5m long, knew the eggs were there and persisted until he worked out how to get in.
Adaptation in living things is amazing. We found we suddenly had to adapt or he would raid us throughout the summer. We decided on a long flap made of metal in front of the hatch so that when he jumped up he would slide off.
That worked ... for a moment. You can see how the big fella is trying to get in after the addition of a flap at the front to try to stop him jumping through the hatch.
He then just went up the side and came into the hatch from there. We added metal on each side as well as longer sides. He came from roof then!
Our final adaptation has been to extend the roof over the door and replace the metal on the sides with single sheets as he even managed to find a claw hole when there were a couple of sheets side by side. It's like he was abseiling in.
To date we have had no further security breaches. We'll let you know if the wise old goanna has worked out our latest adaptation.
*chooks - Australian slang for chicken