Kidney only covers about 80 acres, but despite its small size it is home to around 100,000 breeding pairs of Sooty Shearwaters, white-chinned petrels (1000 pairs), rockhopper penguins (500 pairs), Magellanic penguins, southern sea lions and the endemic Cobb’s wren, flightless steamer duck and camel cricket. This abundance of life is largely due to what is not found on Kidney – rats and mice.Biosecurity is essential when visiting an island like this, because it would be really easy for a new pest, disease or invasive species to establish on the island and disturb the delicate balance of the ecosystem. Everybody is required to thoroughly check their clothes and belongings for seeds, insects and of course rats & mice, before going ashore.
There is a small tin hut hidden amongst the tussac which was put there years ago as a shelter for the people who would visit the island and cut tussac to take back to Stanley as fodder for livestock. Now the island is protected and the tussac cutters hut is used as a field shelter for scientists or for the occasional visitor to take shelter in if the weather turns nasty.
Although biosecurity is strict for people going to Kidney, any stowaway earwigs arriving there would most likely establish first in the hut. So we placed an ‘earwig hotel’ nearby, which should be an irresistible place for any earwigs to hide in if they are present, and an easy place to monitor for them.
The hut is very basic, with some bunks made from rough sawn wood, and a trestle table. There is an old stove in the corner, which would have kept the tussac cutters toasty, but it’s days of use have long since past. Visiting the hut brought back memories of my last visit to Kidney Island a few years ago, when I stayed for 5 days to help deploy GLS trackers on sooty shearwaters, but that’s another story.
We checked the rodent bait stations around the island. In each box is a waxy block of bait which, if anything chews on it, leaves tell-tale tooth marks in the wax, and as such gives their presence away. Happily all the blocks were intact with no signs of being chewed on by rodents.Once the work was done there was still time to take in the amazing wildlife on the island. First we visited the rockhopper penguins, who for millenia have chosen to make their nest on this virtually smooth slab of rock at a toe curling 45 degree slope, at the bottom of which the waves froth and foam. The rockies seem undetererd by the smooth slope and after negotiating the breaking waves below, hop up the slope with ease. Near the cliff top the penguin chicks wait for their feed of regurgitated fish, squid or krill. It’s a miracle that these birds manage to lay an egg, incubate it, hatch it, and brood and rear a chick to maturity without them tumbling to their death below. Presumably a few do roll off the edge, but most survive to return another year. On the way back to the landing beach we passed through Dix’s Cove where the sea lions lurk. Negotiating through the 7ft high tussac we almost stumbled into a few on the way, but on the beach itself there were only a couple of bulls resting among the boulders.
By the time we got back to the landing beach the sun was setting, and the greatest spectacle that Kidney offers was about to begin, indeed we were set for one of nature’s great spectacles which happens here every night during the breeding season. Just off shore huge rafts of sooty shearwaters were gathering. The surface of the sea for as far as vision allowed began to flicker with the wing flashes of sooty shearwaters in the evening light. Their numbers increased and they flew ever closer to the coast until before we knew it they were circling right over head in their hundreds of thousands.
The entire sky was filled with swirling shearwaters, the occasional white-chinned petrel wheeling among them. After about 30 minutes of this spectacle they began to land, thudding down into the tussac with none of the acrobatic ability that they had shown on the wing. While we sat and watched this spectacle we were joined by a curious magellanic penguin who watched us, as we watched the shearwaters.
During the time the shearwaters are in flight they are mainly quiet except for the noise of their feathers whistling through the air, but once they land they begin to call to their chicks who sit in their underground burrows. The island is a honeycomb of burrows, and at the bottom of each awaits a hungry chick.The light faded and still the shearwaters swarmed overhead and thudded down in the tussac all around us, but it was time to leave. We motored back to Stanley in darkness with all the stars of the Southern sky overhead, and the blinking of Cape Pembroke lighthouse marking the direction home.