Saturday, 2 April 2011

Tiritiri Matangi Island

Yesterday (or the UK's today...kinda) we ventured out on the 9am ferry to Tiritiri Matangi Island, a open science reserve about 30km from Central Auckland.

Tiritiri Matangi (Maori: 'tossed by the wind') is an entire island devoted to maintaining populations of endangered bird species. There are several islands like this in NZ, but I think Tiri is the only one open to the public.

When NZ split from the main continent 60 million years ago no land mammals had yet evolved. Only bird and reptile life existed on the islands, and there were no predators. As a consequence the native life did not adapt the neccessary evolutionary mechanisms to protect them from predators, and lost the ability to fly. When Polynesian (and later white Europeans) settled and brought land mammals with them, such as rats, mice and stoats, almost 50% of the species native to the country were wiped out. The rest of the species became severely endangered.

Around 600 years ago the Maori made their way to Tiri, followed by the British in 1840 (the British set it up as a lighthouse station, which they had made in England and then shipped over to NZ). Then followed a period of intense farming, and 94% of the original bush was wiped out.

When the impact of human activities on NZ wildlife was realised, a big drive to restore populations of species began, and in 1970 Tiri became a science reserve. Predators were irradicated, volunteers planted 280,000 native trees, and birds were rounded up and introduced to the island when it was felt the conditions could support them. Tiri was selected for this as it is 3km away from the nearest land, and rats can only swim 2km.

Since then the island and it's wildlife has florished, though there are some difficulties. The Takahe is a flightless bird that resembled a cross between a chicken and a parrot, and was thought to be extinct until a small population of around 250 was found on the South Island. 60 years later there are still only around 300 in the country - inbreeding and the shrinking of the gene pool has led to a high rate of genetic mutations and thus infertility and miscarriage.

Because of the significance of this island biosecurity is very important, and the guidebooks and leaflets forewarn of the impact of bringing pests with you. So, after hastily throwing our pet hamsters and armies of mongooses over the side of the ferry, we set off to Tiri.

We decided to get the guided tour, a bargain of $5 (£2.50) on top of the ferry price of $66 (£33), which is done by a volunteer. Ours was called S, and worked at Starship during the week. She took us on a 2.5hr tour, pointing out all the birds which I completely failed to take pictures of. Turns out I'm not very good at taking pictures of birds - either I've taken too long setting up the shot, or my camera zoom isn't good enough. For example, this picture theoretically contains a bird, but it's like a game of Where's Wally:


Fortunately, one of our party said I could steal some of his pictures, as he was more successful, so here is one of a Takahe:


As well as birds, we also saw some other interesting wildlife. The Kohekohe tree is unusual as it is the only tree outside of the Amazon rainforest to grow it's berries on little shoots directly out of the main trunk. Usually this feature evolves due to the dense canopy in the rainforest, so animals can still get to the berries. Why this feature has evolved in NZ is a mystery.

Also on Tiri is a Tuatara (Maori: 'peaks on the back'), a reptile which is different from all other reptiles in the world: it is the sole remaining member of a family that has been unchanged since dinosaur times 225 million years ago. Sadly we did not see one as they are nocturnal.

The scenery on Tiri was astonishing, and we took loads of photos. Sadly, they don't do them justice. The sight of a palm tree against the blue sea with a volcanic island in the background cannot be captured on a basic camera, but here is an attempt of a beach:


After several hours walking round the (very hilly!) island, we returned to Auckland and decided to have a BBQ. I won't bore you with that, but here is a picture I took on the way to the supermarket. It turns out in NZ they don't cut down trees to make way for telephone wires:


1 comment:

  1. Wow. You certainly learned a lot about evolution and plants! Really interesting. Glad you're having fun.

    Ambrose

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