Nature’s Corner – Late Spring to Early Summer 2006

Rata Flowers for Christmas?

Northern rata new leaves and flower buds reach for the sky

This summer we expect the first of the northern rata (Metrosideros robusta) that have been planted in the Karori Wildlife Sanctuary to flower. The young tree is on the eastern border of Round Lawn. When seated on the Rae’s Ramblers seat, it is immediately to your left. From time to time we have speculated about how many years we might have to wait before we would see it flower. Pam Fuller, our co-ordinator of guides and hosts, was the first to notice some clusters of tiny flower buds in late October. Since then more and more such clusters have become visible among the leaves. It will flower sometime in December, or possibly January, so remember to check on its progress when you visit. The flowers won’t last very long, perhaps two weeks.

Northern rata flower buds in detail Photo by Tom Lynch

The rata at Round Lawn was planted on Arbor Day 1997 by Nick Smith, then the Minister of Conservation, to mark the official opening of a plant nursery that had been established on the site by the Wellington Branch of the Royal Forest and Bird Protection Society of New Zealand. The nursery raised native plants for the Sanctuary and other local revegetation and forest restoration projects. This particular rata was grown from seed gathered from a northern rata in Victoria Street and was around three years old when planted out, making it at least twelve years old now. The present lawn picnic area was developed after the nursery relocated in 2000 to a site outside the Sanctuary.

New leaves emerge on Northern rata

The flowering of one of our planted rata is an early milestone in the long journey toward our goal of restoring the Sanctuary’s forest ecology. In the early 19th Century flowering northern rata made a spectacular show in the Karori forest in summer, but land clearance for human settlement almost eliminated them from the area. The timber’s reputation as excellent firewood meant that trees continued to be sought out and felled in bush remnants well into the 20th Century. When human consumption declined, the burgeoning possum population continued the onslaught, defoliating trees to feed an apparently insatiable appetite for their leaves and buds. Since our pest-proof fence was completed in 1999, the Sanctuary’s only surviving mature rata (thought to be about 150 years old) has been slowly recovering its foliage. You can see it from Tui Terrace, a large rather gaunt tree standing out from the bush canopy of the western scarp. It’s too distant to tell whether it too has flower buds, but maybe this will be a special year for rata in the Sanctuary. Keep it under summer surveillance.

Is it a Toy? A Mutant? A Micro Penguin?

What could this be?

No, none of the above. This ridiculously obese little figure is a fledgling welcome swallow (Hirundo tahitica neoxena) parked on the railing of the boat ramp at the southern end of Roto Kawau, our lower lake. A svelte adult swallow sitting further along the rail may have been a parent, or the parents may have been among several other swallows that were swooping about above the lake in pursuit of flying insects.

Swallow fledglings remain dependent on their parents for food for about three weeks and this one has obviously been very well fed. There will be a lean time ahead, until he perfects his own insect-catching techniques, so those fat reserves are essential. I suspect he has recently left a nest under the boat ramp. It is difficult to imagine such a roly-poly staying airborne for very long and welcome swallows have a penchant for nesting in human constructions, especially those situated close to water. It takes persistent policing to stop them taking over the valve tower at the other end of the lake.

Welcome swallows are relatively recent recruits to our native fauna. Their forebears were Australians who crossed the Tasman Sea to New Zealand and from 1958 started to settle and breed, initially in the far north. They colonised the Hutt Valley-to-Wellington area in the 1970s.

Flowers to Find

Bumble bee explores rewarewa flowers

Rewarewa (Knightia excelsa). These trees, which belong to the protea family, were flowering in November. You may still be able to find some flowers in early December at shady Rewarewa Bridge (attached to the southernmost boardwalk on Te Mahanga Track). There is a partly fallen rewarewa on the western side of the bridge and standing where bridge and boardwalk meet on 2 December I saw both crimson flower clusters and spiky, rust-coloured, flower buds. There is also a porokaiwhiri / pigeonwood with orange fruit.

Mahoe buds and flowers

Mahoe / Whiteywood (Melicytus ramiflorus). I always associate the scent of mahoe flowers with summer holiday bush walks. A few of our trees had some flowers in November, but most wait until December. The tiny yellow flowers erupt in profusion from bare branchlets below the leaves. Mahoe are dioecious so there are male trees whose flowers produce pollen and female trees whose flowers are fertilized by the males’ pollen and then form small fruits. The flowers produce nectar and scent to entice insect visitors that will transfer pollen from males to females. These buds and partly open flowers were photographed on a tree growing on the south side of the grassy gully across the road from Alison Morton’s memorial. If conditions are favourable, there may be a second flush of flowers in April-May.

Poroporo flower

Poroporo (Solanum laciniatum). The poroporo grove at Birdsong Gully is in decline as a vigorous growth of makomako /wineberry puts it in the shade but, as predicted in the Mid to Late Spring 2005 edition, land clearance associated with the establishment of the Research Area created another site favourable to poroporo colonisation. A new grove has established in the vicinity of the Research Area gate onto the Union Mine Track and there are also intermittent bushes along one side of that track. Poroporo has been flowering throughout spring and will continue through summer provided bushes do not become too dry. New green fruit is also present. It is toxic when unripe.

Blowfly on manuka flowers © Allison Buchan

Manuka (Leptospermum scoparium). The slender young manuka beside the Sait Family seat at the entrance to Alison Morton’s memorial will soon flower for the first time. A few small white buds were showing at the end of November. More manuka grows along the Hides Loop Track where these flowers were photographed. Insect pollinators like this blowfly come to sip the nectar the flowers contain.

Ngaio flowers

Ngaio (Myoporum laetum). The dainty white flowers decorated with a pattern of reddish-purple stippling are easily seen on trees near the north end of the Valley View Track and along the Lake Road. On the latter, check out the tree above the track sign at the Morning Star junction or the two in the vicinity of bait station 23 where the road passes above the Keith Taylor wetland. Ngaio also screen the toilet block ahead.

Wharariki flower and buds

Wharariki / Coastal and mountain flax (Phormium cookianum). Tui are once again laying claim to the korari (flowering stems) and dipping into the flowers for nectar. A good place to watch is near the Weka Fence on Lake Road. The orange pollen deposited on their beaks and foreheads by protruding stamens will fertilize other wharariki flowers.

For more about summer flowers and fruit in the Sanctuary refer to the Early to Mid Summer 2005-2006 flora edition in our Archive.

Little Korimako Battler Succeeds

Korimako / Bellbird Photo by Tom Lynch

Our previous edition told of a female korimako / bellbird and her battle to nest successfully in a population consisting predominantly of bachelor males. Happily her persistence has been rewarded. She and her mate now have two fledglings. The youngsters left the nest in mid November. Their parents feed them for a period of up to two weeks while they gradually learn how to provide for themselves. They are sometimes seen in the Discovery Area, but as they get older will be more mobile. The female is now incubating her second clutch of eggs.

Some more good news: there are two female korimako in the Sanctuary, not one as feared earlier. The second female and her mate are a new pair, having fledged in the Sanctuary last year. They have already fledged two chicks and chicks in their second nest are also nearly ready to fledge.

Turning Pale then Turning Red

Kamahi flowers in transition to capsules

Kamahi (Weinmannia racemosa). Colour changes have brought the scattered specimens on the western scarp into greater prominence. Their rounded domes stand out from the surrounding bush when masses of flower spikes resembling small white bottlebrushes give them a pale whitish sheen. As the flowers wither and begin to transform into seed capsules these spikes turn a reddish colour. When interspersed with many flower spikes that are still white, a brownish-pink colouring develops. As more and more flowers die off to be replaced by capsules, the tree is tinted rusty red.

Fruit to Go

Ripe porokaiwhiri fruit Photo by Tom Lynch

Porokaiwhiri / Pigeonwood (Hedycarya arborea). By late November fruit was starting to ripen to orange on some trees. Look for it at the first hairpin bend on the gentle Beech Track after leaving Lake Road, or opposite fencepost 192 on the Union Mine Track. Soon it will be showing up on many more trees, but not on all of them because this is another dioecious species and only the female trees bear fruit.

Kereru: 'I would prefer something else' Photo by Tom Lynch

Both the Maori and English names imply an association with the kereru / New Zealand pigeon (Hemiphaga novaeseelandiae). There are some early accounts of kereru flocking to eat the fruit in great numbers and, on the strength of this, books about native plants sometimes state that the fruit is a favourite of the kereru, but modern research into their diet has shown that other fruits are preferred and porokaiwhiri fruit has a very minor place on the kereru menu. However we must remember that today’s kereru population is small in comparison with what existed in the 19th Century. I suspect that back then some flocks would have been pushed into marginal habitats and that competition for food resources would be such that at times they would exhaust the supply of preferred fruits and be forced to resort to the less nutritious porokaiwhiri fruit until something better came on stream. Forest fires, bush felling, and an occasional crop failure or light crop of a preferred fruit would also have that effect. To conclude: pigeonwood is not a pigeon favourite; they will only eat it if they really must.

Hihi Herald

Female Hihi Photo by Tom Lynch

The breeding frenzy that followed the introduction of hihi / stitchbirds (Notiomystis cincta) to the Sanctuary is not being repeated this year. Spring has been cold and wet with strong gales, heavy downpours and hail showers at times. The difficult conditions meant that the birds took longer to build up to breeding condition and then, when nesting seemed to be taking off, it was disrupted by a wintry blast at Labour Weekend that caused some females to abandon their nests. The supplementary feeding stations had a sudden surge in popularity as cold and stressed birds recovered from that event.

In the first week in December, fourteen nests were being monitored, seven of which contained chicks. One female had produced a clutch of six fertile eggs, thought to be a new hihi record. The usual clutch is 3-5. Twenty-three chicks had been banded for the season and all have subsequently fledged. The first one left its nest on 14 November. Some fledglings are already making use of the supplementary feeding stations. They can be distinguished by their cohort combination of a white band above a metal band on one leg. The coloured bands on the opposite leg allow individual identification. The first second-clutch egg of the season was laid on 6 December.

• For last season’s hihi news refer to our Mid to Late Spring 2005 Bird News edition and our Mid to Late Autumn 2006 edition.
• More about hihi.

What Will I Be?

One type of kaihua seedling

There is no mistaking a kawakawa seedling. It may have only three leaves but they are heart-shaped miniatures of adult kawakawa leaves. There are other New Zealand species, however, in which there are no obvious clues to link parent and child. We just have to learn that this will eventually transform into that. This curious plant, with its narrow brown leaves scalloped at intervals, is a young kaihua / New Zealand jasmine (Parsonsia heterophylla) that was photographed near Alison Morton’s memorial.

One form of adult kaihua foliage

Kaihua grows as a vine, using a neighbour as climbing frame to get up into the canopy where there is more sunlight. In its adult form it has conventionally shaped, smooth-edged, leathery, green leaves that are shiny on the upper surface and paler below. Juvenile leaves might be heavily disguised to protect them from herbivores, perhaps invertebrates that would eat or lay eggs on them. The seedling seemed to be camouflaged to blend into the surrounding ground litter of dead leaves and sticks, but it later blew its cover and my theory by sprouting some bright green leaves!

Juvenile kaihua leaves in four different shapes

The word heterophylla means ‘other’ or ‘different’ leaves and kaihua certainly lives up to that specific name. Apart from differing juvenile and adult foliage, there can be marked differences between individual plants. Not all seedlings have brownish leaves. Some have only green leaves, and some have a mixture. Juvenile leaves may be straight sided with pointed tips, culminate in rounded lobes, or be a variety of other shapes. Most curious of all, leaves of diverse shape can occur right next to each other on the same plant. Adult leaves also vary between vines or on the same vine, especially in their breadth and length, but their shape shifting is not as extreme. Some changes may be influenced by the amount of light available to different parts of the vine. The seedlings and juvenile vines are the most diverse, but once you know what to look for you will find lots of examples along the margins of bush tracks.

Kaihua flowers

At present there is an easily seen, smallish, adult vine festooning a dead branch on the east side of Lake Road just south of Birdsong Gully. Like other kaihua growing along Lake Road, it flowered in November. A more impressive adult vine can be seen when ascending the gentle Beech Track, about 55 paces up from the from the first hairpin bend, high on a tree that leans across to the right. On the Valley View Track, between the Weka Fence and the junction with the Union Mine Track, kaihua twines through the pate tree above fencepost 327 and more can be seen in the Research Area from fencepost 329. About 37-38 paces north of the Weka Fence on the same track there is another vine on the western side where some late flowers may linger. By January all vines should have slender green seedpods.

Brackets that Grow

Pycnoporus coccineus

Bracket fungi are so-called because their fruiting bodies look like those small rounded shelves that are attached to walls with brackets. Pycnoporus coccineus is a bracket fungus often seen on logs that are lying on the ground in open situations. Look for it in the Research Area when standing on Lake Road near fencepost 105. Only the reproductive part of the entire fungus is visible. Out of our sight a mass of threadlike hyphae will be digesting the dead wood by secreting enzymes that break the tissues down to release simple compounds that can then be absorbed in solution. That is how the fungus feeds. The purpose of the reddish orange brackets is spore production. When the spores are ripe they are released through many tiny pores on the undersides of the brackets. It will be interesting to see how long these particular brackets will last. They have been visible for at least a year. There are perennial bracket fungi that carry on producing spores year after year for a very long time but I think their brackets are much harder and tougher than these ones.

Californian Couple Opts for Karori Lifestyle Block

My first sight of Mr Quail

California quail (Callipepla californica) have been in New Zealand since the 19th Century when they were introduced to provide game for hunters. They are sighted or heard from time to time in the Karori Wildlife Sanctuary, especially in the exotic conifer plantations and towards the southern end of the valley. However there has been a sudden surge in quail encounters since late October. They have been regularly seen along Lake Road from Tui Terrace to just north of the Weka Fence and also on the Union Mine Track. Whether all these sightings relate to one pair or several pairs is uncertain.

I was descending the Union Mine Track on 24 November when I sighted this male perched atop the entrance to the Research Area, a handy vantage point from which to survey his surroundings and broadcast messages. ‘Vic, Vic. Vic, Vic. Vic Vercoe! Vic Vercoe!’ he exclaimed suddenly. Victor Vercoe was apparently out of earshot, because there was no response. Mr Quail flew down onto the track and I realised I was not his only listener. His wife was there. Perhaps he had been warning her of my approach. As I advanced they kept a safe distance ahead of me, walking along, occasionally pausing to peck at something, and taking a short whirring flight whenever they felt I was getting too close.

Mrs and Mr Quail wonder what I am doing

Eventually they flew up onto the Research Area fence and regarded me with an anxious air, ready to take flight if I showed predatory intentions. But it was only their image I was hunting and, once acquired, I left them puzzling over my strange behaviour. When I looked back, they had relaxed again. Mrs Quail was having a dust bath in a hollow in the track. Mr Quail remained on the fence, acting as lookout. They looked very much at home, as if they were quite decided that this was the lifestyle block for them. The koreke / New Zealand quail (Coturnix novaezealandiae) is extinct, so perhaps we can grant them residency.

This edition of Nature's Corner was written by Sanctuary volunteer Allison Buchan on 29-30 November and 6-7 December 2006. Information relating to korimako and hihi was provided by Sanctuary conservation staff. Thanks to Gary James and Julia White for answering questions about the rata. Unless otherwise indicated, photographs are taken by Allison Buchan and are © Karori Wildlife Sanctuary. Clicking on photos will take you to a larger version.

Published 11 December, 2006.