Monday, 2 April 2018

Forest flashback

After nearly twenty years of pest control in this piece of forest we see and hear a noticeable increase in bird life. Tui, bellbird, tomtit, silvereye, grey warbler, kingfisher, shining cuckoo, fantail and morepork numbers all seem to have benefitted. However, it is sobering to imagine what we might have experienced when the largest trees in this forest were mere saplings. Prior to the arrival of humans, and rats and mustelids in particular, the forest was an astonishing place.
Deep in the forest we might have come across the two metre high Giant Moa stretching even higher to graze the vegetation. We might have caught a glimpse of a Little Bush Moa as it scurried into the dense ferns and scrub to escape the eagle eye of a circling Forbes' Harrier.
Little Bush Moa
Another possible predator would have been the flightless Adzebill, a very large, grey Takahe-like bird with a huge bill. This may have been searching for young seabirds in their nesting burrows below the higher peaks and ridges.
 Another flightless and possibly nocturnal small rail-like bird, the Snipe rail could also have been feeding amongst the forest litter.
Snipe Rail
At night calling morepork would have shared the rocky crags and larger rotten trees with another owl, the much larger Laughing Owl or Whekau. The naturalist Thomas Potts commented that "If its cry resembles laughter at all, it is the uncontrollable outburst, the convulsive shout of insanity". The Whekau spent a lot of time on the ground hunting native bats that fed in the forest litter.
An unusual nocturnal resident may have been the New Zealand owlet-nightjar which was virtually flightless and also spent time hunting insects on the forest floor.

Owlet Nightjar 
In addition to all our native song birds today we would have seen and heard many of the rare endemics now restricted to predator free islands and fenced reserves. As well as all these, we could have seen two species of flightless wren searching the forest floor for insects - the Bush wren or Matuhi and the Stout-legged wren.
Bush Wren
Finally, Huia and North Island piopio would join the chorus of Kokako, Saddleback, Robin and Stitchbird.
Much of this has gone forever. It is our responsibility to do everything we can to protect the remnant that is left - it is all we have got and it is doubly precious as a result.

Extinct species referred to:-
North Island giant moa  Dinornis novaezelandiae
Little bush moa  Anomalopteryx didiformis
Forbes' harrier  Circus teauteensis
North Island adzebill  Aptornis otidiformis

Snipe rail  Capellirallus karma
Laughing owl  Sceloglaux albifacies
New Zealand owlet-nightjar  Aegotheles novaezelandiae
Stout-legged wren  Pachyplichas yaldwyni
Bush wren  Xenicus longipes
Huia  Heteralocha acutirostris
North Island piopio  Turnagra tanager

Information on these species has been drawn from "Extinct Birds of New Zealand" by Alan Tennyson and Paul Martinson published by Te Papa Press.

Monday, 26 March 2018

Harriers and Kereru

Ex cyclone Hola recently passed east of the Peninsula only dumping 50mm of rain and packing moderate winds. It has been a wet year so far with more than 650mm of rain recorded at the house. It will have been a lot more higher up the divide. 
With continuous rain and wind I spent some time yesterday watching the forest for activity from the comfort of the living room. Flocks of silvereye feeding in the lower vegetation were blown from one spot to another and every so often a kereru would fly up into the gale to ride the buffeting wind before hurtling back into the canopy of an emergent rata. It is difficult to imagine any purpose to these sallies other than sheer enjoyment in the power of the elements and their mastery of them. 
Watching the kereru got me to thinking about one characteristic behavior we have frequently observed. Whenever a Swamp Harrier (also known as the Australasian Harrier or Harrier Hawk) drifts up the valley quartering the forest, kereru will fly up from the forest canopy and fly around apparently in some panic until it moves on. The harrier is quite a small raptor and no threat to an adult kereru. It feeds mostly on carrion and small animal prey (although no doubt given the opportunity, a harrier would take a squab from a nest). The adult kereru's response to these harrier visits seems excessive. However, the swamp harrier is a relative newcomer to New Zealand - having arrived only a few hundred years ago.

Swamp Harrier

What is fascinating is that 500 years ago or so these hillsides would have been the domain of a far larger predator that would have targeted kereru as a main source of prey. The Forbes' Harrier (Circus teauteensis ) known from fossil remains, was four times the size of our swamp harriers today. Of NZ's aerial predators only the Haast's Eagle was larger. Forbes' Harriers were formidable killers taking large prey even including small moa. They became extinct in the prehistoric period presumably as a result of human hunting although the introduction of pacific rats could have resulted in egg and chick loss.

Is it possible that todays kereru, which evolved for millennia alongside the Forbes Harrier have transferred their flight response to the smaller, but similar shaped, swamp harrier? Perhaps, deep in the kereru's DNA, the survival of the species over thousands or millions of years still drives the behavior of our birds today. 
What else that we witness in our forest is a vestige of an extraordinary lost past?
Forbes Harrier
Image from a painting by Paul Martinson in Extinct Birds of New Zealand by Alan Tennyson and Paul Martinson.

Monday, 26 February 2018

Summer 2018

This is my first blog since 2015. So much has happened up here in the forest in the past few years. Many of our discoveries and observations have been posted on the Mahakirau Facebook page, on the Mahakirau website or on Nature Watch. However, a number of people have asked that I continue to post on my blog as it does provide another (personal) record of what goes on in our fabulous piece of paradise. So where do I start?
Metrosideros fulgens
I am looking out from the house over the valley towards the east coast. The forest appears to be extremely healthy. Every shade of green, with subtle differences of colour, form and texture enabling the observant viewer to identify many of the more than fifty species of tree we have in our forest. This spring and summer have been excellent for all the flowering trees and climbers and the green on green has been punctuated by other splashes of colour. At the moment the scarlet of the climbing rata (Metrosideros fulgens) is spectacular and follows a fine and prolongued season for the magnificent emergent crimson northern rata (Metrosideros robusta).
From our bedroom we look into the canopy of one of the tall rata in the valley below. As it came into flower the resident tui became increasingly defensive and belligerent. Prolonged singing was punctuated by aerial chases after other tuis, bellbirds and silvereyes if they dared enter the canopy.
The tui's world has calmed down at the moment following a very good breeding season. We had a nest in the tawa (Beilschmiedia tawa) above the house but I never managed to work out how many young they successfully fledged although we regularly had young birds pestering their parents for food. Many species seem to have had a particularly good breeding season this year with bellbirds successfully raising numerous young and more than one brood. The young bellbird's incessant squeaking contact call takes on a 'dripping tap' dimension. Once you are aware of the call it drives you to distraction. Such constant calling might at first seem counter intuitive as it provides an obvious target for predators. However if you attempt to find the source of the call you soon realize what ventriloquists they are. Even when you can see the bird the call seems to come from everywhere.
Silvereye are another species that has had a good breeding season. Flocks of at least thirty birds have been feeding in the low canopy around the house often bringing fantail, grey warbler, tomtit and bellbird with them. Five finger berries, and the insects they attract, are a favourite target and at times the bushes have been alive with juvenile silvereye calling and vibrating their wings in anticipation of their parents providing food.
One of our resident moreporks
For the past few nights our family of morepork have been busy around the house. They have at least three young that have been flying in a somewhat ungainly fashion, landing on the ends of mamaku fronds which collapse under their weight so that they end up hanging upside down endeavoring to look nonchalant. The young morepork call is very un-owl-like. A sort of soft trill that is more insect like than bird (described in the literature as a gentle high-pitched cricket-like trill). They don't begin to sound like adult morepork until they are about five months old.
The forest this spring and summer has been a far cry from the silent bush of the past. I will cover our recent experiences of predator control and successes with our rare endemics in future blog posts.

Sunday, 8 February 2015

Gecko central

Coromandel Striped Gecko 

The most exciting news since the start of summer has been the discovery of three geckos on the estate. Two of these, discovered and photographed by Sara Smerdon, were Coromandel Striped Gecko – possibly the rarest Gecko in the world. The species was discovered on the Coromandel at the end of the 1990s and only a handful has been seen since. We are awaiting further information from scientists and DoC experts but most or all previous records have been from the 309 road north to Moehau. Sara’s records may extend the known range of the species. This is a beautiful and quite large gecko. Both the individuals Sara photographed had previously dropped, and were regrowing, their tails. Reviewing photographs on the internet I see that this is also true of other individuals. It will be interesting to know if this is the case with all gecko species or if these geckos are particularly vulnerable to predation.
Second Coromandel Striped Gecko
The other Gecko was found and photographed by Kevin and Cynthia and looks like a forest gecko. These photographs have also been sent away for verification.
It is important to know that it is illegal to handle or keep in captivity any of the native lizards. All are especially vulnerable to predation by cats and rats. These gecko records further illustrate the incredible diversity of rare species that we live alongside at Mahakirau.

Around the house there have been a number of Copper and Blue Butterflies as well as visits from the occasional Red Admiral and Painted Lady. The lack of cicadas is noticeable and we have seen fewer puriri moths than usual. Apparently cicada numbers are low across the country. This is a consequence of what was going on five years ago when they would have started their life cycles.

In the hot dry January we have just enjoyed, the bush has been relatively quiet as far as birds are concerned. We have several families of silvereye, fantail, tomtit and bellbird in the bush around us and kingfisher have been noisy at times. A lone kaka flew over the house in mid January – but they seem to spend time at  more elevated parts of the estate, only occasionally visiting us at 300masl.  Two Black backed gulls flew over the estate in December – a surprisingly rare occurrence. Californian Quail appear to have had a bumper breeding season with several parties of more than twenty chicks. The number of well grown young suggests that stoat and weasel numbers must be low – a tribute to the pest control team.

Shining Cuckoo are still calling occasionally. At the end of December we had an interesting experience when about ten cuckoos spent an hour or more in the mature Tawa tree immediately beside the house - calling incessantly. They were very agitated displaying to each other with outstretched and quivering wings and tail. Every so often there would be wild chases through the tree canopy and at other times they could be seen feeding on caterpillars. After they flew from the tree I heard them continuing to call about 100 meters away. The next day a smaller number of birds returned to the Tawa and began calling again. According to the Handbook of Australian, New Zealand and Antarctic Birds these communal displays may involve up to a dozen birds although I have not seen more than six birds together before.
Forest Gecko

Finally, it was a good spring and summer for many of the flowering forest trees. Hinau and Rata had particularly impressive seasons and now white rata are flowering well.

Wednesday, 12 November 2014

Lancewood and diving petrel - November 2014

It has been a frustrating spring. Just when the weather appears to be improving there is another wintery blast from the far south. The few still warm days have been glorious but they do seem to have been few and far between.
This year we have had high pest numbers to contend with. Rat numbers were exceptionally high in our pre-control monitoring. This followed a major seed drop earlier in the year. In the past month or so several stoats, a weasel and two ferrets have been trapped. More rabbits have appeared on the un-forested parts of the estate and these may have attracted the ferrets. Our pest control contractor has been working on the possums and rats and I have recently seen young bellbird and tui, so some birds have successfully raised a first brood.

This has been an exceptional year for seeds and flowering in the forest. At present, Quintinia is looking impressive and white rata are in full flower. 

One of the white rata species Metrosideros perforata
which is currently flowering prolifically
A strange phenomenon has been the shedding of leaves by many Lancewoods – a common small tree throughout the estate. They had an impressive flowering and the flocks of kereru and tuis then targeted their clusters of berries. At first, I assumed the carpets of leaves below the trees to be collateral damage from the kereru and perhaps possums. However, many trees have now lost all their leaves. In the last couple of weeks some completely denuded trees have begun to put on new growth so I am hopeful that this may be a natural phenomenon and that many will recover.  Olearia rani  plants, that escaped the catastrophic dieback after its phenomenal flowering two years ago, are now looking reasonably healthy, so maybe these major diebacks are just a part of the forest ecology.
Fallen Lancewood leaves on the forest floor
Several people have commented how the bush seems to be less dense than it was. From our near ground human perspective the adjacent forest does seem to have opened up but I think that this is simply the forest moving towards maturity.
A magnificent Kauri just over the Waiparuparu Stream
So far this year I have completed sixty-four 5 minute bird counts within the estate. This is the only way of providing a direct comparison of the bird numbers year on year. Numbers of all the native species appear to be consistent with previous years. This year I first heard Shining Cuckoo on the estate on the 18th September – nine days earlier than last year. As with last year a kiwi called near the house in late September. It is difficult to know whether this is a consequence of kiwis moving within the estate or simply reflects the warmer evenings and the fact that we spend more time on the decks. Sara and Rogier recorded Kaka on the upper estate most evenings for a period in spring.
The most exciting and unusual bird record on the estate was seen and photographed by Jude Hooson.  In misty conditions a Diving Petrel was attracted to the house lights at night. Jude was able to photograph it as it fluttered around on the deck. Unfortunately the mobile phone photograph at night through the ranch slider is not clear enough to reproduce here, but is just adequate for identification purposes! The Common Diving Petrel (kuaka) is a small seabird (20cm) which breeds off the NZ east coast including the Mercury Islands and spends most of its time in adjacent waters. It is the most aquatic of all petrels. It flies with a whirring flight close to the surface of the sea. Strangely, Jude said it appeared to be attracted to the moths fluttering against the window. This was probably a response to their movement not as a source of food. Diving Petrels feed mostly on small krill and copepods, swimming underwater using their wings and legs for propulsion. A fascinating record for the estate! It just shows that almost anything can turn up. It also reinforces the importance of taking photographs. Had Jude told me she had watched a Diving Petrel chasing moths on her deck 475metres above sea level I would have suggested she should be certified! With photographic evidence, Jude has made a most extraordinary ornithological record.

Diving Petrel (from 'Seabirds' by Peter Harrison)

Tuesday, 19 August 2014

First signs of spring 2014

Following a period of southerlies the wind has changed to the north and we now have low cloud and warm rain. The days are noticeably drawing out and forest growth is evident. Epiphytic Brachyglottis kirkii is flowering down in the Waiparuparu stream valley and is in bud near the house. On the 17th August, within the estate, we found the first flowering native clematis of the year. In previous years flowering has occurred further down the 309 long before first flowering on the estate, which has been at the end of August or early September.  Beside our drive there is a single dark red tubular flower of the shrub Alseuosmia macrophylla
Again, flowering is earlier than last year. Judi has found a new species of fern for the estate, which on initial examination she thinks is – Polystichum richardii.

Alseuosmia macrophylla
The dawn chorus is now composed of both native and exotic songsters with tui, bellbird, tomtit, grey warbler and silvereye being joined by blackbird, song thrush, dunnock and chaffinch. In the years we have lived up here we have never seen the numbers of tui and kereru that are around the estate at the moment. Tuis are singing everywhere and in fine still weather there are almost constant aerial chases through the bush around the house.  I am not certain if these are territorial disputes or simply related to competition for food. I have seen flocks of more than twenty birds. As many as seven tuis at a time are apparently feeding on honeydew from sooty mould that covers the upper branches of a mature pukatea beside the drive. Elsewhere tuis are busy feeding on lancewood berries, which are prolific this year. In fine weather several tuis have been making aerial sallies after flying insects.
Numerous kereru have been feeding in the taraires, which is good for forest sustainability, as the big fat purple berries need to pass through the pigeon’s digestive system if they are to germinate. Harriers have been displaying high above the forest. When they fly low over the bush they spook the kereru and this is a good opportunity to estimate numbers. Although we have seen a flock of more than twenty birds and groups of half a dozen are common, these numbers pale in comparison to a flock of nearly 200 birds in the Whenuakite kiwi management area near Tairua.
In other bird news, swallows have returned to hawk around the house and three were present yesterday. This morning I had to release a starling from the fireplace. Starlings are only seen occasionally on the estate so this bird must have been prospecting for nest sites and fell down the chimney. The only other bird that has done this was a swallow. They don’t seem to be any the worse for their experience! A lone kaka has been flying over the estate in the last few days and today two spur-winged plovers were mobbing a harrier over the grass paddock. Previously, I have heard plovers calling at night over the estate (on the acoustic kiwi call recordings) but they are rarely around during daytime. It will be interesting to see if they stay and attempt to breed.
Next month I will begin the fifth year of 5 minute bird counts through the estate. These give a direct comparison of bird numbers year by year. It will be fascinating to see if the high winter counts of native species is reflected in the spring survey.

Thursday, 22 May 2014

Kereru flocks

Today has been another glorious autumnal day – still, mild and sunny. With the exception of a week or so of cold and wet weather the summer feels like it has gone on and on.
Friends who visited at the weekend marveled at the wealth of bird life on the estate. Fantails, grey warblers, silvereye, tomtit, bellbirds and tuis surrounded us. It is so easy to forget how silent some forests have become. Our friends are seasoned trampers so it was an interesting observation.
For the first time since we have been living up here we have seen flocks of Kereru on the estate. Yesterday a flock of about twenty birds flew down the picnic area valley landing in a rata above the waterfall. It looked as if some of the birds at least were then feeding in the canopy of a miro. Four days ago I saw a flock of a dozen or so kereru near the entrance to lot 2 so these may be the same birds. Through the telescope, I watched about a dozen birds, several feeding on lancewood berries. These birds may have come from within the estate or more likely from elsewhere, as our resident birds were still around. Also the flocking birds were more wary than our regulars, which are very trusting.
I have also noted a number of small groups of tui flying over the bush. One flock of ten birds was the largest group that I have seen since being up here. Tuis had been very quiet during much of April but in the past fortnight they have reappeared. Both tuis and bellbirds are now singing well.
At times the bush is seething with flocks of many tens of silvereyes and the sound of their high-pitched calls can be quite deafening in the early morning. Every so often a bird will burst into song. Several tomtits have been calling and in the last few days I have heard the occasional singing.
In the evening light I was scanning the bush with binoculars. Pairs of fantails were everywhere, presumably hunting for insects flying just above the canopy. The sun was catching their pale fan tails and undersides as they pirouetted above the trees. These dancing pairs were visible all down the valley.  They do appear to have had a good breeding season.
Of the exotic species on the estate, song thrushes are singing strongly.  They are shy birds here and rarely seen in the open. It is interesting how wary most of the introduced species are, in comparison with many of the natives. Pheasant, rosellas, greenfinch, blackbirds and thrushes all fly as soon as a person appears whereas the native species can be extremely confiding.  It is easy to see how devastating to birdlife the introduction of predators such as rats and stoats must have been.

Thankfully, with slightly cooler nights, wasp numbers have reduced to normal levels. There is still some cricket activity heard at night but the only insect of note was another Painted Lady butterfly - in the first week of April.

Judi has recorded a single plant of the small tree ‘Raukawa’, Pseudopanax edgerleyi, a new species for the estate.