This is the female chaffinch (Fringilla coelebs gengleri). She’s not as obvious as the rust-coloured male, and it’s easy to mistake her for a sparrow. Female chaffinches are a little bit smaller than sparrows, though, and have that grey swoop behind the ears that the male has. Another not-a-sparrow giveaway is the white on the wing, which are more obvious in flight.
One of the signs of spring coming is these guys brightening up. The male chaffinch (Fringilla coelebs gengleri) is always this rusty colour with the grey hood, but in spring the rusty colour gets really intense. Chaffinches are native to Europe and North Africa and were introduced to New Zealand in the late 1800s.
Mosses and liverworts feature among the many small plants of the beech forest on Mt Arthur. Growing on the forest floor and on trees as they do, they break down dead material, collect water and provide habitats for insects, which is, of course, of intense interest to the insect-eating rifleman.
One of the things I love about the beech forest on Mt Arthur is the abundance of small plants on the forest floor. One of the many different mosses found on the mountain is this haircap moss, of the genus Polytrichum. It forms beds that look like tiny plantations of pine trees reaching for the sky.
This Dr Seuss tree (official name: mountain neinei, scientific name: Dracophyllum traversii) has tangled, twisted branches, as though its unsure just what direction it should grow in. The wild-haired clusters of leaves terminating each branch are typical of the mountain neinei, and the small cluster lower down on the tree has quite reddish leaves, which seems to be the colour assumed by younger trees. As you can see from the orange leaves all over the ground, the mountain neinei gives the cabbage tree a good run for its money in terms of making a leafy mess. In the summer, the mountain neinei grows spiky, conical flowers, which give the tree its other name, the pineapple tree. In low cloud, walking through a grove of these tufted, twisted trees can be an eerie experience, especially when the misty quiet is broken by the heckling call of an unseen kea. Mountain neinei grow at high altitude, towards the bush line, which on Mt Arthur is kea country.
On the walk up to the Mt Arthur hut, the track goes along a ridge. Here the beech trees mix with mountain neinei trees; there’s a large mountain neinei on the right-hand side of the track in the photo. Dracophyllum traversii is also called the pineapple tree. My first thought on seeing them was “Dr Seuss trees!” and they really do look like the real-life version of the Truffula tree, with their twisted branches and tufts of grassy leaves.
This photo was taken from the track going from the Flora carpark to the Mt Arthur hut. The forest on the slopes of Mt Arthur is classic New Zealand beech forest. Southern beech species (family Nothofagaceae) do well in cool, low fertility environments like Mt Arthur. Beech trees don’t flower every year, but occasionally there’s a summer when a whole lot of beech trees will flower. So much seed (called mast) is produced that introduced mammals such as rats and mice are able to have a bumper year offspring-wise, and then the large numbers of rats and mice keep the stoat population far too healthy over winter. When spring arrives and there isn’t enough beech seed to feed the rats and mice, they turn to the birds and their nests. Soon after, the stoat population explodes, and they decimate the native bird population. Masting is predictable – it’s triggered by a summer that’s warmer than the last one – so predator control can be intensified for mast years.
The best-known Māori name of the rifleman (Acanthisitta chloris) is titipounamu. The titi probably refers to its squeaky, high-pitched call and the pounamu to the green colouring of the males. You can see this striking colouring if you look closely at this photo, as the tiny bird’s back and head pretty closely match the colour of the surrounding beech tree leaves.
Another Māori name is momo-tawai, which means ‘beech tree species’. The riflemen photographed for this story were part of a fairly large group (regiment? company?) hanging around in the beech forest on the track to the Mt Arthur hut, in the Kahurangi National Park.
It’s the green head and back of the male rifleman that gained the species its European name. British rifle regiments wore dark green uniforms with low-visibility black insignia, and this tiny New Zealand forest bird reminded 19th century settlers of a rifleman’s garb.
The rifleman is one of New Zealand’s smallest birds. Weight-wise, it’s about the same as the grey warbler; males are 6 grams, females around 7. But lengthwise the rifleman is definitely the smallest, at 8 cm compared to the grey warbler’s 11 cm. The rifleman packs as much weight into its 8 cm frame as the grey warbler does into 11 cm; yes, your average rifleman is quite rotund. The grey warbler gets some extra length from having a longer tail, whereas the rifleman’s tail kind of gets lost among its wingtips when it’s sitting on a branch or rock.
The female rifleman is slightly larger than the male, by a gram. Females also have different colouring, lacking the green back and shoulders.
As you can see in the photo above, the female is more brown and speckled. Sometimes, when seeing a rifleman from below, it can be difficult to tell whether you’re looking at the male or the female. This one’s a female, you can just see the brown speckling on the top of her head.
Riflemen feed exclusively on insects. They browse native forests, going up and down trees, systematically hunting down their tiny prey. This rifleman has taken an interest in what’s inhabiting the mosses and lichens on the underside of a branch.
Both the male and the female have this pearly-white chest and belly, along with the fierce white eye stripes and the yellow sweat stains under their wings.
This somewhat unusual angle shows off the rifleman’s pearly white belly, not to mention its acrobatic skills.
Young birds are more mottled on their chests, and the pearly chest and white brow seem to come in as the birds mature. This rifleman is possibly a young female; she still has a bit of speckling on her chest and her white eye stripe isn’t very strong.
Riflemen are monogamous and the male and female will stick close together throughout the year, even outside of the breeding season. Older offspring will stay near the parents and help out with the feeding of chicks in later broods. This is why when you’re in the forest and hear the high-pitched zeet-zeet of the rifleman, it’s rare to see just one. They’re calling to each other, keeping in touch, as they search up and down the forest trees for insects.
The female rifleman (Acanthisitta chloris) is slightly larger than the male, weighing in at a whopping 7 grams, versus his 6. Females also have different colouring than the males, lacking the green back and shoulders. The female is more brown and speckled, though she has the same pearly-white chest and belly, the white eye stripe and the sweat-stained underarms. I suspect this rifleman is a young female, as it still has a bit of speckling on its chest and the white eye stripe isn’t very strong.
When I was going through the photos from this trip up to the Mt Arthur hut, my brain struggled to make sense of this one. Yes, it is actually the right way up, as you can see from the ones I posted Monday and Tuesday, which immediately precede this one. When you weigh just 6 grams, does gravity really matter?
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