Friday, August 25, 2006

Offshore Islands - Ecological Restoration in New Zealand (1)

Despite the impression conveyed to the outside world, New Zealand's ample open lands did not survive colonization and successive waves of pioneer settlement in pristine condition. Even before the arrival of European explorers, fires spread by Polynesian settlers had dramatically reduced New Zealand's original forest cover. Conversion of land to agricultural uses and extinction of native species accelerated throughout the 19th and early 20th Centuries, when sheep farming transformed vast tracts of wild bush into endless blankets of green pasture. Introduced mammals and plants have devastated remaining native ecosystems. In fact, the scale of destruction and loss is truly overwhelming when you consider how quickly it has taken place. New Zealand was among the very last places on Earth to be settled by human beings. Over the course of just a few hundred years, it has gone from being a unique, isolated remnant of Gondwanaland, to a tamed and familiarized landscape.

Many of NZ's native species have been severely outcompeted or predated by introduced birds, such as magpies, and animals such as stoats, rabbits, mice, rats, cats, sheep, goats, dogs, deer, pigs, wasps and possums. The problem is severe enough to have caused the extinction of more than one third of native bird species, and to have eliminated a large number of surviving species from their original habitats on the mainland.

Faced with the enormous responsibility of preserving their rapidly disappearing native animals and plants, conservationists here have developed several intensive and highly unique approaches. These include offshore island reserves, species transfers, pest removal regimes, and the creation of so-called "mainland islands", which I will describe in good time.

Offshore island reserves have been established on dozens of islands all around New Zealand, many quite close to the mainland, but distant enough to prevent pest species from easily colonizing them. Not all islands managed to avoid the problems of the mainland. Restoration efforts have incorporated a heavy investment in livestock removal, cat, possum and stoat trapping, and poisoning to eliminate rodents. However, once eliminated, island reserves have tended to remain free of pests.

At first, these islands were the spontaneous refuge of birds, reptiles, amphibians, insects and plants pushed off the mainland by habitat destruction and predators. In recent decades, conservationists have taken the more drastic step of translocating entire populations of species on the verge of extinction (e.g. kakapo, saddlebacks, black robin, etc.) to predator-free offshore island refuges where they have never occurred naturally. Although risky, these transfers were essentially last-ditch efforts to preserve native species in the wild, and they have paid off by successfully establishing breeding populations of animals that would otherwise have been eliminated.

takahe encounterKapiti Island, located just an hour up the coast from central Wellington (pictured throughout), is among the oldest of NZ's offshore island nature reserves. Despite its proximity to the city, relatively few Wellingtonians take advantage of the opportunity to visit. Entrance is strictly controlled by a daily quota permit system and overnight camping is not allowed. Jay and I were lucky enough to accompany the Victoria University Tramping Club for a day hike there in May.

Kapiti is famous for its thriving communities of rare birds. We had the opportunity to see and record the sounds of many of them on our four-hour wander over the island. Below and at left is the takahe, a flightless member of the rail family. These birds were thought to be extinct until the 1940s, when an isolated group were discovered in the high alpine tussocks of Fiordland. They are grass-eaters, and have been primarily threatened by the spread of deer throughout their mountain habitat. (Deer are considered a pest in NZ, and hunting season on them is open year-round.) Their numbers have been added to with the aid of a captive breeding program. This particular takahe is the matriarch of the group on Kapiti Island, literally mother or grandmother to every bird present (with the exception of one new arrival). We interrupted her enjoying her afternoon tea, one carefully-chosen blade of grass at a time.


Another flightless bird in abundance on Kapiti is the weka. Weka are very well camouflaged, and their presence is mainly betrayed by copious scratching and shuffling sounds in the dead leaves of the undergrowth. In other parts of the world, such sounds would lead you to expect a squirrel or a rabbit, but in New Zealand they are invariably caused by birds. Weka are gutsy and fast-moving. They are especially skilled at targeting unattended lunches, and are said to be able thieves of shiny objects that catch their eye.


The New Zealand robin is much smaller than its North American counterparts. A tiny, gray bird with a puffed, rounded body, stubby tail and thin stilts for legs, it offers an incredibly pleasing profile. Here you can see one with a leaf beside it for comparison of scale. Robins tend to hop along unobtrusively behind trampers, often approaching very close, looking for insects stirred up by our footsteps.

The dominant sound chorusing throughout the canopy in all corners of Kapiti Island is the melodious call of the bellbird (at left). We sometimes hear these birds singing outside our windows at home, but their numbers are sparse (due to the city's high density of cats) and their presence is irregular. On the island, the trees fairly pulsed with their song. It was a small taste of what early visitors to the vast forests of this land must once have experienced. Amidst the bellbirds, we heard the calls of tieke, or saddleback, and hihi, or stitchbird, and the ever astonishing tui.

After hiking to the top of Kapiti's stark western cliffs and taking in the view over the Tasman Sea, we descended through the dense forest and back to the marshy flats near the island's seashore. In the bushes near our boat's landing site, we had a close encounter with a kereru, or NZ native wood pigeon (below). These birds may look somewhat similar to typical pigeons, but they are at least twice their size, much more lovely with their iridescent green and purple plumage, and very different in their comportment. Kereru are very silent and ponderous birds. They rarely coo, but they make an alarming racket whenever they fly, their wing feathers whistling and whirring with the strain of keeping their plump bodies aloft. The sight of such a large bird perching incongruously on a slender branch above your head never fails to give you a start. Unfortunately, although not endangered, these birds are becoming less and less common.


As we returned to the pebbled beach to watch the shadows lengthen and await our boat ride back to the coast, we passed a pair of pukeko watching from among the tussocks. These lovely birds are related to the brightly colored takahe, but they are swamp dwellers, and possess a wader's long legs. They can fly, but they do so in a very ungainly way, almost as if they were halfway to giving it up entirely.

Although our time on Kapiti was brief, the abundance of wildlife and rich biodiversity on this offshore island reserve made its conservation value immediately clear. These islands provide a measure of safety against the excesses of mainland ecological degradation and provide a supply of animals and plants for ongoing restoration efforts. More on those efforts to follow in my next dispatch...

Thursday, August 03, 2006

Wellington Pictures of the Day

Darkness had been falling by 5:00. We're glad to see daylight lingering till 6:00 these days.

Wellington Harbour looking unusually calm today




Wednesday, June 28, 2006

Mt Hector, to the north, from Wellington.



And to the south, over Cook Straight, even bigger peaks.

Saturday, June 17, 2006

Kiwi Radio - Here's your chance to check out a New Zealand-made radio documentary, co-produced by yours truly. It's about releasing captive-bred kiwi birds into the wild in an area where they have been extinct for several hundred years.

It aired today on Radio New Zealand's National Radio. It should be up on the Spectrum archive page soon. Look for the June 18th programme to appear there at the top of the list.

You won't hear me presenting the programme, so you may be wondering what I did to earn that co-producer credit? I got invited along for the field recording, on the hike into the Rimutaka Range, shadowing Jack Perkins who is one of Radio New Zealand's most veteran producers. He's been making documentaries here for over 30 years. I gave feedback throughout the editing process and contributed some of the tape I recorded in the field to help pull together the final piece. It was a great experience. Listen carefully for 3 cameo appearances from me throughout the piece (who do you suppose that girl from Minnesota is?)

Happy listening!

Thursday, June 01, 2006

Endangered sounds of New Zealand

Kokako:

The kokako is the most endangered of New Zealand's two remaining endemic wattlebirds. Wattles are brightly coloured fleshy appendages on the throat or cheeks. Part of the reason Kokakos are so intriguing is their loud, melodious song which is said to be one of purest tones in nature. Each pair sing their own distinctive duet for half an hour at dawn.
Click here to listen to a recording of the Kokako


Kiwi:

The kiwi is the closest thing to a mammal in the bird world. The kiwi's blood temperature is nearly the same as a mammal, about 2 degrees centigrade lower than other birds. And it has bone marrow, instead of air as in the bones of a bird.

Kiwis have large ear openings, long whiskers, and plumage more like hair than feathers - all physical characteristics of most mammals.

With strong stout legs and claws that are 30 percent of its' body weight, the kiwi is a powerful runner, fighter and swimmer.

The kiwi also has a keen sense of smell. It's the only bird with nostrils located at the end of its beak. Kiwis forage for insects at night by plunging their beaks into the earth and sniffing them out.

This is an excellent description of Kiwis, well worth a quick read. These funny looking birds grow dearer to us every day.

Click on the image above to get a better picture.

Click to hear a kiwi

Thursday, May 04, 2006

Antipodal Moon

Yesterday evening, Jay & I were walking along a high ridgeline in the parkland behind our house as the sun was setting. As we came around a bend, my eyes focused on the quarter moon's brilliant white semi-circle directly ahead of me, and I stopped dead in my tracks. My brain struggled to make sense of what I was seeing. The moon was facing the wrong way!

Now some of you may not understand what I mean by this. You may also wonder how it is that I've lived in NZ for over two months without ever noticing the moon. Let me explain: when I was little, I learned a handy rule for remembering the moon's phases when it is waxing and waning. "If you draw a vertical line closing the moon's crescent, it will form either a 'p' for premier - first - or a 'd' for dernier - last." As a budding francophile, I immediately learned this by heart, and I have never been at a loss to know whether I am seeing the first quarter or the last quarter of the moon.

Since arriving in NZ, I have seen moonrise in the dusky rose of sunset, with the full moon blossoming fat on the far ridges of the Rimutakas. I have noticed the increased brilliance of the city's already bright stars on the nights of the new moon. I have glimpsed the crescent moon here and there in the sky without pausing to consider its celestial context. It was only last night that I finally, viscerally, realized that I am seeing the moon from a new perspective.

[The graphic you see moving above is how I have been used to seeing the moon. In the southern hemisphere, imagine playing the film backwards. See chart at right.]

A similar experience occurred soon after I arrived here. One of the things I looked forward to with the greatest anticipation was the prospect of seeing the stars of the southern hemisphere. The New Zealand of my imagination nestled beneath strange stars, entirely unknown to me. On a first clear night, I was shocked to see familiar Orion above me, doing a handstand, upside down! For a few moments I felt entirely disoriented, not because of Orion's novel position, but because he was visible at all! I had looked at the same stars above my home in Minneapolis just a week before. Traveling all this way had failed to take me out of their sight.

This makes sense once you think about it - we see more than just the sky directly above us at 45 degrees latitude.
If you live at 40 degrees north latitude, and if you have an unobstructed view of the southern horizon, it's theoretically possible to see a star that would be overhead for someone at 50 degrees south latitude (40 + 50 = 90). From our view, such a star would be kissing the horizon. ...The point is, just because we're in the Northern Hemisphere, it doesn't mean we can't see stars in the Southern Hemisphere. We just can't see the ones that are more than about 80 degrees or so of our latitude. [source]
Our angle of view isn't so different from what we left behind, so we continue to share many of the same stars with those of you back home. However, the Big Dipper is gone, as is Cassiopeia. Perhaps you are curious to learn: What does our sky have that yours doesn't? For one thing,
All-in-all, the northern sky is rather devoid of light. By contrast, in the Southern Hemisphere, there are 11 constellations which are circumpolar and 6 first order magnitude stars! [source]
We have noticed that the stars are incredibly bright here, with the Milky Way visible even inside the central city. Whether this is due to brighter stars or cleaner air is hard to say. If you're interested, here's a link to get you started on learning the stars down under. And maybe you'll even be inspired to pack your bags to come see the antipodal sky.


Thunderstorms and Volcanoes


The front pages today are full of criticisms of New Zealand’s civil defense, which should have responded more efficiently to the tsunami threat yesterday morning. As it turns out, there was no tsunami, despite a powerful 7.9 magnitude earthquake about 2000 km from Auckland near the Tonga Islands. Apparently, the rest of the world had heard about our nearby quake before most of us in NZ. Word got out in the town of Gisbon, NZ when friends and family living abroad called town residents after hearing reports of the tsunami potential on the BBC. It surprises me that New Zealand’s warning systems are a bit rusty. We are located within the ring of fire, a region notorious for volcanic and seismic activity, and the country is well-equipped to monitor these conditions. (Photo above depicts a 6.6 magnitude quake that hit Edgecumbe in 1987. Photo: L. Homer)

Living in this fiery ring thing is new to me, though. I grew up in Virginia and Minnesota where the primary forces of nature to be reckoned with are thunderstorms and damaging winds. I’ve always enjoyed watching as the sky darkens; the wind gusts and the sounds of thunder grow steadily closer. I can remember countless occasions of standing out under the roiling clouds and running to cover only when the torrential downpours began. With real-time weather data now widely available on the internet I often monitored the storm’s approach and could tell exactly when it was time to head outside and watch the show.

What thrills me about thunderstorms, and strong weather in general, is the opportunity these events provide. Aside from the sheer exhilaration of physically recoiling from a deafening clap of thunder or gazing skyward to see branches of white light climb across the clouds, there's something more. Observers have the chance to understand the world in new ways. Nature puts on a demonstration, much like a professor does in a science lab. We’ve all heard the faint crackle of static electricity; how big those bolts must be to cause the ground shaking thunder we hear overhead!

I was saddened to discover, after a night of distant rumbling and occasional flashes, that Wellington sees only 2 or 3 thunderstorms a year. No snow, no thunderstorms… weather changing so quickly that keeping up with it is pointless! (What am I to do?) I’ve slept through the only tremor I was ever present for—one night when I was living in Oakland, CA, for a brief time. As I said earlier, I’m new to the restless character of the land I’m now living on. It goes without saying, then: I’ve never been frightened by an earthquake, and the same can be said for any weather related event, which is why the sound of thunder still delights me and I stay out watching the storm even when Dacia is shouting to run for cover (it’s fair to say that Minnesota has a much higher tornado potential than Virginia, and I spent most of my time growing up in VA).

I got my first inkling of what's going on down beneath the earth one evening, a few weeks ago. I was sitting against the wall in my room, reading and minding my own business. I felt a bump, as though a bus had nudged the corner of the house. My head was resting against the wall and it got a gentle knock as the entire wall moved against me. Dacia and I both looked at each other, “Did you feel that?” Whoa…Yeah...

That little grunt from deep within the earth captivated my imagination for days. I can still recall the sensation even now. My awareness traveled deep into the earth while entertaining the notion of not just our house having moved but the entire Wellington region “bumping” in that moment. It was hard to get my head around, which is the reason I’m compelled to ponder it so intently. The same fascination I have with lightning, or hail storms (how fast must the winds be blowing up above to push those hails stones higher and higher as they grow heavier?) has found an outlet in New Zealand—how far down underground did that movement of earth occur to yield such a sensation here on the surface?

I will leave it to Dacia to explain the tectonic conditions that are at work under ground here in New Zealand. I want to point out some of the fascinating earthquake information that is now freely available to NZ residents and the world at large through the Internet.

After our tremor experience we wanted to find out if there was any seismology information online. We discovered a website called Geo-Net which “provides real-time monitoring and data collection for rapid response and research into earthquake, volcano, landslide and tsunami hazards.” The site includes up to the hour images of the 4 major volcanoes and also short video clips of the steaming craters. As you can see from the map of strong motion recording sites the islands here are well monitored.

Once we found Geo-Net we were able to locate the report on the particular tremor we experienced—note the big spike, which was the bump we felt. If your explore the site further you’ll find real-time seismograph records, magnitude, depth and epicenter information, as well as fascinating seismic history reports that date back to the 1400’s. GeoNet even offers a "Felt Earthquake Report" link that Dacia used to submit her account of the April 17th tremor.

We decided to investigate the earthquake history of the Wellington region. Using the QuakeSearch feature we identified all quakes over 5 on the Richter scale. Whoa…too many to know what to do with. We raised the bar to show quakes over a 7. Yikes—still a lot. We kept raising the limit until we got to 8 and above. Now there were only 2 earthquakes shown on the map. Can you guess where they were?

It’s well known that Wellington is situated directly on top of a significant fault line. New Zealand is full of fault lines, actually. Never-the-less, the fact that in the past 600 years there have been two major earthquakes right here in Wellington… it’s a bit concerning. The continued tremors, however, are signs that all is well beneath our feet. Slight movements indicate that the colliding plates are moving together smoothly. A major earthquake occurs when friction builds up between the plates and releases all at once. Let’s all hope we feel some more rumblings soon.

Eruption of Mount Ruapehu, 1945. Source: Matapihi

Tuesday, April 25, 2006

The Wairarapa

On recommendation from a classmate we decided to spend a weekend exploring the Wairarapa region of New Zealand. The area covers the south eastern tip of the North Island and is named after Lake Wairarapa, a large shallow lake ringed with wetlands. The region is known for beautiful coastline, forest parks, wine making,
and lots and lots of sheep. All this only 90 minutes away from the heart of Wellington. We hired a car and I got my first chance to drive on the left side of the road--thanks for the help Dacia! Having no idea about distances we weren’t sure whether we’d be able to keep to our planned itinerary. At the end of it all we had witnessed a whole spectrum of weather, saw amazing countryside and coastline and survived an embarrassing (and frightening) off road situation that nearly left us stranded.

After an eventful overnight at the Greytown Hotel, NZ's oldest pub (which has survived into the modern day through its ability to faithfully attract a loud, enthusiastic crowd of drinkers -- not the greatest for a restful night's sleep!) we drove on until we reached the Pacific coast at Castlepoint. We're getting used to the weather in NZ, but on this day we encountered something new -- a brilliant sunny day with gale-force winds. This means that our day at the beach included intermittent clouds of stinging sand that pelted us as we walked along (at the end of the day we had sand just about everywhere -- ears, nose, shoes, pockets…) We didn't let it stop our fun though, just took off up the highest neighboring peak and made the best of it. On our hike up Castle Rock the wind was at our backs making the steep climb somewhat easier. Conversely, the way down meant that we had to lean into the wind and downhill—kind of scary when you see how steep Castle Rock is. We tried to capture the experience of being on that summit in several photos, but they somehow fail miserably to show the chaos of the situation. We had to shout to one another even though just a few feet apart. Our jackets and pants flapped as though we were standing up on the back of a pickup truck going down the highway. I kept checking my pockets to make sure my wallet and keys were still there, it seemed anything not actually attached was going to fly away, over the edge of the cliff.

We fought the wind all the way to our car and beat a hasty retreat back to the relative safety of the inland hills. It was totally exhausting being out in those conditions, like we had spent an entire day hiking when, in fact, it was just over an hour.

The roads here in New Zealand can best be described as curvy, narrow and just about empty. In an earlier post I mentioned that the max speed limit on the island is 100 kph (62 mph). This sounded a bit slow to me at the time (I’m coming from the flat plains of the midwest where 75-80 mph is not uncommon). At that point I was assuming that the main roads would be something like freeways. But I was wrong. As soon as you get outside Wellington the main roads become basic two-laners with an occasional passing lane. This means that the majority of the roads on the map, the little ones shown in white that criss-cross the countryside, are basically dirt or gravel. When it occurred to me that all these tiny, windy little roads carried the same 100 kph speed limit I soon realized this wasn’t slow at all. Many of the turns are so tight it would be difficult to take them at 30, and only a fraction of these turns have any kind of warning sign to prepare you for what's ahead. We marveled at false encouragement given by 100 speed limit signs that immediately preceded a drop into a steep valley or down a series of tortured switch backs. Driving these roads was great fun for me though, and I kept my eyes on the road while Dacia enjoyed the scenery and held on tight.


I did pretty well for my first time behind the wheel of a right hand drive automobile. Sure I got in on the wrong side half the time and I don’t think there was any danger in reaching for the seatbelt over my left shoulder (only to grope in the air) and I’m sure no one was confused when I indicated my lane changes with the wipers instead of my turn indicator… I only drove on the wrong side of the road once and that was because we did a U turn and I took it to the left which had the effect of resetting my sense of direction (you would take a U turn to the right here). Dacia noticed about 45 seconds later and luckily there were no cars on the road ahead for us to frighten.

Cape Palliser sits at the south east tip of the North Island. The road on the way to the lighthouse follows a dramatic coastline that is desolate and empty, except for a small fishing village called Ngawi. On the way we crossed Te Humenga Point. Te Humenga has been identified as one of the earliest settlement sites of New Zealand. Ancient stone walls can be seen that date back to the 12th century. Without a modern building in sight it’s easy to imagine how the land might have looked back then. Further along we reach the lighthouse which sits atop a rocky cliff. A climb up the 258 stairs offers views up and down the coast. The rocky shore is composed of lumpy ‘pillow lava’ that erupted on the sea floor over 100 million years ago. One particular outcropping is home to the only successful breeding colony of fur seals on the North Island. During our exploration of the rocks we came across hundreds of seals. Just as you might expect with puppies, the young seal pups, though timid, were also very inquisitive and friendly. After getting used to us being around they eventually approached us, sniffed us with their long, wet whiskers and even allowed us a brief pet of sleek seal fur.

The trip was almost over, but we decided there was still time for an extra adventure. According to our map, there was a 4x4 route around Cape Turakirae that would save us from crossing back over the steep and winding Rimutaka Mountains. We were tempted by the thought of a coastal drive and, given that we had a four-wheel-drive vehicle we decided to give it a shot. Four hours later, with the adrenalin slowly draining from our veins, we were back where we’d started—back on the paved roads, headed back up into the Rimutakas and thankful that at least this way there would be guard rails along the steeps.

The turn around point came a couple hours of very slow going past the last town, after the 'road' had dwindled to a narrow shelf in a pile of landslide rubble several hundred feet above the ocean. In this particular section it dipped down around a rocky cliff back to sea level and spilled us out onto the beach. Driving in sand feels like you’re trying to run on water—there is a sinking feeling, both in the pit of your stomach and in the car as its wheels spin faster and faster and bury themselves in sand. Both of us had taken turns panicking, so we decided to scout the road ahead to see if the walking helped calm our wits, and to see if the way forward might look even worse than the way back. We were in the middle of nowhere. The only other people we had encountered on the road were two angry looking teenagers on dirt bikes who came speeding past us—obviously not willing to offer any help or even sympathy. We had stopped just short of rounding a point and we walked ahead to get a glimpse of the lighthouse that would indicate the start of the paved road. Instead we saw about another 10 miles of desolate shoreline with no lighthouse in sight. Directly ahead, the trail seemed to climb vertically up a hill before disappearing completely into a recent landslide. We paused to enjoy this utterly empty stretch of coast that offered stunning views of Cape Palliser and the bay. I don't expect we'll be passing that way again anytime soon! The rest of the Wairarapa however, will definitely be seeing more of us.

You can watch a slideshow or view pictures from the trip.