Observation of the Week, 12/29/17

Our Observation of the Week is a Middle-European weasel (and its child), seen in New Zealand by @oscarkokako!

For someone who’s only seventeen years of age, oscarkokako is already an accomplished naturalist. His interest in birds was sparked by a field trip to the Tiritiri Matangi Open Sanctuary when he was just eight years old. “I had a school teacher who was one of the founders…[and] I quickly got hooked on New Zealand’s diverse and unique array of native birds, my favourite being the Kokako (even though it took a few trips to see one),” says Oscar.

He’s already seen over 160 of New Zealand’s birds species, and was recently part of a research trip to the Chatham Islands, “to help survey their critically endangered birds, including the Shore plover, Chatham Island snipe and the Black robin.” The latter species was one of the rarest birds in the world, with a lone breeding pair in existence (and five individuals overall) by 1980. In addition to  birds, Oscar says he’s now “trying to branch out into reptiles, insects and other [taxa] to gain a better idea of the entire picture.”

Mammals, of course, would be one of those non-avian taxa, as Oscar’s fantastic photo proves. He was volunteering for Napier’s Department of Conservation and he and friend went to the estuary to look for some birds that had recently been sighted there, when

Not 100 metres down the track from where I observed them, I came across the weasel. It was maybe 20cm long and running directly at me, holding its young (which at the time I thought was a baby rabbit). I heard these creatures were fairly blind so I decided to just lie down on the path and wait for it to come closer for a photo. Better to document this event than to try and catch it, as they are rarely photographed in New Zealand.

About that last point, Oscar is definitely correct - of the 15 Middle-European weasels (in New Zealand) posted on iNat, Oscar’s is the only one that depicts a living animal (the rest are all dead ones found in traps). Weasels were introduced to New Zealand in the late 1800s, as a response to the growing rabbit overpopulation problem on the islands, and they now pose a threat to many of the island’s native organisms.

“For some context, New Zealand had no mammalian predators before humans arrived here, bringing rodents, mustelids, cats and dogs,” says Oscar.

As a result, none of our native wildlife had adapted to protect itself against threats such as these. Many of the birds even became near flightless, as they had to hide from aerial predators through camouflage. Mammals, however, hunt using smell as opposed to sight, rendering many of our species defences futile. Kakapo are said to have a musty-sweet odour, which may be why only 130 individuals remain today.

Oscar, pictured above with a Kokako perched on his head, is currently a volunteer guide at Tiritiri Matangi and working with the Auckland Zoo on their conservation efforts. He uses iNaturalist to “keep a catalogue of all the organisms I see around the country. Obviously, this is difficult to achieve with insects and plants, as they are so plentiful and harder to identify correctly. I even have trouble walking past plants now without stopping to check if I’ve uploaded it yet.

NaturewatchNZ [iNat’s partner site in New Zealand] is full of smart and helpful users ready to identify even the most indecipherable photographs of things. A few years ago I had no idea about the website, but now I find more and more of my friends joining up, or else coming to me with the organisms they cannot identify. Our community consists of over 5,000 members with 272,000 observations of 11,300 species, and is steadily increasing.

- by Tony Iwane

- Elizabeth Kolbert wrote an interesting article about New Zealand and its invasive mammal problem for The New Yorker.

- A species of fungus new to New Zealand was discovered on NatureWatchNZ.

- This short video shows a calling Kokako on Tiritiri Matangi.

Posted by tiwane tiwane, December 30, 2017 00:58



I love NZ, have friends there and spent a month in Dunedin a while ago. While looking at wildlife, I saw that many of the bird species (at least) were 'self introduced' from Australia. I would assume it might be the same for insects which can fly, but are there any data on 'self introduced' mammals (a more treacherous journey)?

Posted by mamestraconfigurata over 2 years ago (Flag)

I don't know much about New Zealand, but I'm from Hawaii and there are two mammals that are thought have to arrived in Hawaii before humans did: the Hawaiian monk seal, and the Hawaiian hoary bat.

Posted by tiwane over 2 years ago (Flag)

Spectacular observations, @oscarkokako -- people from around the world are enjoying your posts! :)

Posted by sambiology over 2 years ago (Flag)

Thank you @sambiology :) I'm enjoying posting them.

Posted by oscarkokako over 2 years ago (Flag)

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