The Birds at my Table

by Darryl Jones

  The View from Tiritiri Matangi

  It is about noon and fairly warm when Josie and I decide that it is time for a lunch break. We have emerged from the forest onto a grassy headland overlooking the deep blue-black ocean on the northern part of the island. A raised embankment covered in soft, thick grass offers an ideal place to pause and extract food from our day packs. “This is a great spot,” de-clares Josie, with just a hint of mystery. Gazing out through the sea mists to the northwest I can just make out the shape of what is obviously a large, mountainous island. “Little Barrier Island!” exclaims Josie quietly, as though simply naming the place conveyed some impression of its significance. Before I can respond, however, we are confronted with an immediate and urgent bird-feeding emergency: someone has just stolen Josie’s sandwiches!

  Throughout this visit I had been expecting to see a Weka, the small dull-colored rail species that is, without doubt, the most adaptable and adroit of New Zealand’s native birds at exploiting any possible foraging opportunity. I suspect many visitors to this country can relate stories of the cunning and resourcefulness of this little rail, typically involving the stealing of food from right under their noses. Obviously, I thought, the Weka strikes again! Except, as Josie informs me, Weka do not occur on Tiritiri. . . .

  Instead, the rail that strides confidently out from the nearby dense undergrowth is not small and gray but alarmingly large, deep blue and rich green and, for me, entirely unexpected. This is a Takahē, undoubtedly one of the world’s rarest birds (total world population about 200) and one of the species I most hoped to see on Tiritiri. Josie had been circumspect about my chances, however, explaining just how unpredictable sightings could be. “After all,” she had said only a few minutes previously, “there are only 9 on the entire island. Although this particular spot is often pretty good . . .” Josie planned this potential encounter nicely, though she had not foreseen the loss of her lunch in the process.

  This is an extraordinary experience! I am lounging on a grassy bank on a beautiful island a few meters from one of the rarest birds on earth, a species on the very precipice of extinction. Despite seemingly overwhelming odds, however, this extraordinary species remains vibrantly alive, its prospects of long-term survival steadily increasing. The Takahē is a truly massive rail, at about 3 kilograms (6.6 pounds) by far the largest rail in the world. (Although the Moho, a now extinct New Zealand species (last seen in 1894), was even larger.)30 Seeing a Takahē so close, one cannot fail to be impressed by their robust, solid build, no-nonsense demeanor, and massive red industrial-strength beak, capable of snipping deftly through coarse vegetation (or fingers, I suspect) with ease. I had been aware of the rescue of the Takahē for some time, having read about the painstaking effort taken to understand its ecology and behavior, and knew it to be one of the species released on some of New Zealand’s predator-free islands.31 Yet all these facts simply had not prepared me for the living, breathing reality of the creature up close. And this stridently confident super-rail is just one example of the many species almost certainly still extant because of islands like Tiritiri Matangi.

  This particular wildlife-human interaction concludes abruptly with the Takahē disappearing suddenly into the dark undergrowth nearby, having discarded Josie’s plastic lunch box unopened. It seems that our bird, unable to procure anything edible, continued on with other pressing business elsewhere, such as ambushing unsuspecting picnickers farther along the path. If so, would these people be able to resist? “It’s just a cookie? What difference would that make?” This is an all-too familiar scenario, played out in picnic spots every day, the world over. What may seem trivial and commonplace in a suburban park, however, assumes a special pertinence here on Tiritiri. Ensuring easy access by anyone to one of New Zealand’s outstanding conservation islands has been a fundamental goal of the cus-todians of the island from its very beginning. As I had just experienced myself, encountering the living evidence of successful conservation in the form of species now effectively impossible to see in the wild can be profoundly moving. The other side of this easy accessibility, however, is the risk that visitors could become complacent about what is required to re-tain the conditions necessary for conserving the birds. As readers of this book are likely to appreciate, resisting the temptation to offer something to nibble to an eager animal can be very difficult. But feeding wild birds, like Takahē, in a place like Tiritiri Matangi—or any conservation reserve—can be a serious matter indeed. Sometimes even apparently minor changes to a bird’s diet can have a significant influence on their lives, especially when it comes to breeding.

  Understanding the detailed relationship between food and reproduction has been fundamental to some of the desperate conservation rescue stories played out in New Zealand. Perhaps the most desperate—and celebrated—of them all is the case of the Kākāpō, the famously odd parrot, an important part of which took place on the misty island our eyes are repeatedly drawn to on the northern horizon.

  Little Barrier Island is entirely different from its neighbor, Tiritiri Matangi. Where the latter has a gentle terrain and a welcoming manner and is open to all after a brief ferry trip, Little Barrier is brutally rugged, demanding, and unforgiving. Access is also stringently restricted; even for those authorized to visit, extreme fitness and resolve are necessities. I have long dreamed of making such a trip but, so far it had been just too difficult. Josie has, however, been to Little Barrier several times as part of a conservation team. As we wander slowly along the cliff-top track, the misty mass of Little Barrier just evident on the horizon, I am keen to hear her experiences. She needs little encouragement.

  “I have been over several times recently, trying to catch [Red-crowned] Kākāriki [parakeets] for translocation,” Josie explains. “Little Barrier feels so, so ancient as it looms out of the sea as you approach on the boat, feeling very much like a scene from Jurassic Park. It does not look at all inviting, with its dark, thick forest cover, steep cliffs, and the cloud cling-ing to the summit. The beach is comprised of large boulders, which makes landing a boat very hazardous, although this has probably helped to protect the island from casual visitors. And you can see and hear the birdlife before you even land: Kākā [one of the large parrots] screeching and whis-tling, Tui chasing each other, Kererū [New Zealand pigeon] performing their aerial dives. Once you are safely on the island there is a real sense of what this country must have been like before people. The forest is a bustling, busy, noisy place both day and night, full of birdlife. It is always striking to see the huge flocks of 50, 60, 70 or more Kererū foraging on the ground, something that just doesn't happen on the mainland anymore.” These are sights and experiences possible only because Little Barrier has none of the marauding mammals that have caused so much damage elsewhere in New Zealand. In their absence, as Josie has so poetically described, it is possible to maintain the ancient atmosphere of Aotearoa as well as providing a safe refuge for some special guests. Which is why this journey exploring bird feeding has brought us—metaphorically—to the resounding forests of Little Barrier Island, trying to feed a very strange parrot. It is a provocative illustration of the importance and risks of em-ploying supplementary feeding for specific purposes.

  Preparing a Smorgasbord for a Peculiar Parrot

  There are plenty of contenders for the title World’s Strangest Bird, but by any measure the Kākāpō must surely come close to the top of the list. This mossy green monster is easily the largest parrot by weight (at 3.6 kilograms (8 pounds), heavier than the biggest macaw) and is, not surprisingly, entirely flightless. It is also nocturnal, the only night-going parrot. It exudes a very strong, musky odor that has been likened variously to honey, the scent of fuchsias, and, rather imaginatively, the inside of a clarinet case.32 When it comes to reproduction, however, things get really odd. Unlike most parrots, which form close, sometimes lifelong pair bonds with their mates, Kākāpō do romance rather differently. Every evening during the long summer breeding season, the males trudge up to
the top of a prominent forested hilltop or ridge where they settle into a dusty depression that they (or their predecessors) have slowly excavated over a prolonged period, these well-worn mating grounds being known as a “track and bowl” site. Within this bowl, prone and primed, they slowly inflate their huge frontal air sacs (which expands their body into a circular pillow shape) and begin to “boom,” forcing the air out through their nostrils to produce a weird, low-frequency, and extremely unbirdlike call. These vocal displays can continue, more or less continuously, throughout the night, the strange low moaning sounds traveling far off over the surrounding landscape.33

  The bizarre display is intended to advertise the presence of the males to any prospective females within earshot, who are theoretically free to choose among the various boomers available in the local vicinity. This type of mating arrangement (a “lek,” after a Swedish term for “play”), where males perform and females select, is well known among species such as bowerbirds, sage grouse, and birds of paradise, but it is practiced by only one of the 350 species of parrot.34 Should this elaborate process be successful, the birds mate (“overly vigorously,” according to one early observer) before the female departs to prepare a nest; she has no further interaction with the male. The nest site is typically located far from the male’s calling bowl and placed under a dense thicket, presumably as protection from the typically wet and windy weather. She remains at the nest for over 100 days, and because she incubates without assistance from a partner, is obliged to leave the nest and eggs unattended whenever she needs to forage.35

  Noisy, smelly, heavy, slow, flightless, remaining for prolonged periods in predictable locations, and relying on camouflage and stillness to avoid detection—it is hardly a mystery why the Kākāpō was especially vulnerable to the relentless tide of mammalian marauders, especially stoats. Having previously been found throughout the country, and often in abundance, by the 1880s the only remaining Kākāpō were restricted to remote mountainous regions and Stewart Island, the third island of New Zealand in the extreme south.36

  The Kākāpō story—the realization of catastrophic demise, the early and heroic attempts at rescue, the repeated heartbreaking failures, the pitiless pressure of the invasive predators, the ever-present likelihood of extinction, and the recent breakthroughs—all make for one of the world’s truly great if nerve-racking conservation stories. The details are far too complex and intriguing to be given justice here but have been well described elsewhere (most eloquently in William Stolzenberg’s Rat Island: Predators in Paradise and the World’s Greatest Wildlife Rescue).37 Suffice to say, despite astonishingly farsighted attempts in the 1880s to establish populations on predator-free islands (over 400 Kākāpō were moved to Resolution Island, only to have stoats reach the island within a few years) and plenty of other desperate actions, the population continued to slide. A long and devastating period of attempting to establish captive breeding facilities failed utterly, with no birds surviving longer than 4.5 years and not even a hint of reproduction. When you recall how these birds go about their courtship, this is hardly surprising.

  By the 1970s, the accelerating process of removing the mammalian invaders from various offshore islands provided opportunities for the transfer of Kākāpō from the last surviving population in the country.38 These were fraught times. At the time it was believed that only about 20 birds remained alive, all in the extremely remote and rugged mountains near Milford Sound in Fiordland on the South Island. Every aspect of this exercise was extraordinarily difficult and inherently risky: the finding of the birds, their capture, containment, transport, release—plenty could go seriously wrong at every step. Yet the risk of doing nothing meant almost certain extinction. The first transfers began in 1974, all the way to tiny Maud Island in the Marlborough Sounds at the top of the South Island. Over the following few years a total of five Fiordland Kākāpō were found, captured, and released, apparently a quarter of the entire population. Unfortunately, it was later discovered that these were all males. Reproduc-tion was not that likely.

  And then, came the startling discovery, in 1977, of an entirely unknown population of Kākāpō on Stewart Island, far to the south.39 With estimates of over 100 birds, this was wonderfully welcome news and prompted the remarkably resourceful New Zealand Wildlife Service to revise their Kākāpō conservation strategy to include both safeguarding the Stewart Island birds and continuing translocation to suitable islands. The discovery of a population of this size also provided an opportunity to conduct some fundamental research into this peculiar and very poorly understood species. In particular, little was known about the Kākāpō’s diet, a potentially critical influence on breeding activities. The fragmentary information available on Kākāpō reproduction indicated that breeding occurred erratically and was rarely annual. Surely some aspect of the food supply was implicated and could hold the key to understanding what led to breeding. Studies of the Stewart Island birds showed that they chomped their way through all manner of foliage, stems, roots, buds, fruits, and seeds—seemingly any vaguely edible part—of a wide variety of local plant species.40 While these foods were somehow capable of supplying the nutrients required for daily survival and maintenance in this bulky bird, it was unlikely that most of these items would have supplied the key resources, especially the protein, required by females to breed.

  A major breakthrough (well, confirmation really, as these insights had been first made by naturalists in the early 1900s) came when it became clear that the periodic breeding activities of Kākāpō on Stewart Island almost always coincided with the masting events of two of the predominant tree species on the island.41 Known as Rimu and Pink Pine, these large podocarp trees produced huge crops of seed every 3 or 4 years, which showered the forest floor beneath the trees. The crude protein levels of these seeds provided a diet with almost twice that of the birds’ regular intake.42 Although the trees produced some seeds annually, it appeared that the birds needed the protein in bulk to get their reproductive systems moving as well as supporting chick rearing.

  Meanwhile, the number of Kākāpō known to be alive continued to decline, including the vital residual population on Stewart Island, due to predation by feral cats and the birds’ naturally low breeding rate. By the late 1980s, with only about 40 birds left, the monumental decision was made to relocate all of the remaining Stewart Island Kākāpō to suitable and safe, predator-free islands. Effectively, this was the end of truly wild Kākāpō; all populations of the species would be, to a large extent, “managed” from now on.43

  And so we return to Little Barrier Island, one of the most important places in the story of New Zealand conservation but for Kākāpō in particular. The first Kākāpō were transferred to Little Barrier from Stewart in 1982—nine females and thirteen males—and so too was Ralph Powlesland, more or less. Ralph was one of the small team of scientists who had painstakingly studied the newly discovered Kākāpō on Stewart Island and had been involved in every aspect of the subsequent debates and decisions about the bird’s future, including the huge call to move the lot to other islands.44 Although three other islands were used, Little Barrier was by far the largest and least disturbed. It was, however, much farther away—fully 1300 kilometers (807 miles) to the north—and would therefore provide a rather different climate and habitat compared to the bird’s original home of Stewart Island. It was imperative that the translocated birds were followed carefully to assess how they were coping in their new home. To do so, all the birds were fitted with tiny radio transmitters and their movements monitored intensively for the first few years. Subse-quently, tracking was less intensive and less invasive, involving indirect surveys using trained dogs.

  To everyone’s enormous relief, Kākāpō were found to be remarkably resilient, coping with the trauma of being captured, transported in boxes, and then released into an entirely new world. “Stoic” is the word Ralph uses. “They survived the drama of the transfer and nearly all went on to live long, normal lives on Little Ba
rrier.” The dedicated scientists tracking the birds found that some males soon formed their own “track and bowl” structures and that courtship booming was heard at several sites by the second year. Over the years that followed, almost all the males present were heard calling during most years; courtship by one sex at least was definitely under way. The problem was that the females did not seem to responding. Despite all that booming, there was absolutely no evidence of breeding for the first 7 years. Not even mating (as evidenced by a characteristic circular pattern of scattered feathers near the booming bowls) let alone nests, eggs, or nestlings.45 This was a frustrating situation for Ralph and his colleagues, who were now spending half their lives—2 to 3 weeks at a time—on Little Barrier Island with their charges, enduring the rain, cold, and isolation. “The problem now was not survival,” recalls Ralph. “It was them getting around to reproducing.”

  As one of the people to have made the link between the masting of podocarps and the breeding of Kākāpō on Stewart Island, Ralph soon realized that enhancing the protein content of the Little Barrier birds may be required. Neither of the two Stewart Island podocarp trees were present on Little Barrier, and although another tree species—the Kauri— producing potentially suitable seeds did occur there, its supply of seed was far more limited. Supplementary feeding with protein-rich foods was obviously worth trying, although just what to use was less clear. Furthermore, this was not a regular small bird that might visit a typical seed feeder; just how do you provision a large, nocturnal, ground-dwelling parrot that has apparently always perceived “food” as something that looks like vegetation? And another thing: it’s often wet and there were rats (in this case, Kiore, the only remaining mammal on the island), which are likely to steal the food as well as being potential nest predators that you really don’t want to benefit.