Takahe fly north
It was treated like a homecoming, and there was a large and excited welcoming party to greet two flightless takahe that were flown into Tiritiri Matangi, an open island bird sanctuary in Auckland’s Hauraki Gulf in late May.
The welcoming party of over 400 included a virtual Who’s Who of the local ornithological and conservation organisations, and scores of others who had over the years helped with the reforestation of an island that until 1984 had been intensively farmed.
Over the years, more than 200,000 trees, many raised in the island’s own nursery, have been planted in Tiritiri, mostly by parties of school children. These plantings have allowed such birds as saddleback, bellbird, stitchbird, whitehead and red crown parakeets to be reintroduced from other sanctuaries, to take their places alongside the tui and kereru that have crossed over from the mainland.
Of course, not all native birds like dense bush, and the island planting programme has made provision for the possible introduction of species that enjoy open grasslands by leaving some former pasture areas untouched.
When takahe were rediscovered in 1948, scientists were astounded. The heavy-bodied flightless rails had been recorded only four times in the previous hundred years. The last of those sightings had been in 1898, 50 years before, so it had been reasonable to believe that the takahe had become extinct.
When Dr G.B. Orbell came across a small population of takahe in an out-of-the-way valley of the Murchison Mountains (west of Lake Te Anau in south-west Southland), it was hailed as the bird discovery of the century.
Subsequent expeditions into the area established that about 200 pairs of takahe were living above the beech forest tree line, at about 1000m above sea level, in the high tussock grasslands. There they fed mainly on hardy tussocks, but also on other grasses, mountain daisies and sedges. With their large and powerful bills they could easily pull out tussock shoots and then, holding each one dextrously between their toes, strip away the dry outer leaf sheath and snip off the succulent white base beneath.
It was easy to make a case for these birds being particularly well adapted for life in these upland tussock meadows. How ever, subsequent finds of sub-fossil takahe bones throughout the South and North Islands, right up to North Cape, indicated that these birds had once been widespread throughout New Zealand.
While they can pull, strip and nip off the edible bases of tussock shoots throughout the day, at the rate of six per minute, they also pull up the rhizomes of ferns, snip away at soft herbs and can delicately glean the seeds from an ear of grass. They are clearly well adapted to a general browsing habit suited to the whole range of natural grasslands, and the alpine “homeland” far from being typical, evidently represents only their last retreat.
The disappearance of takahe from more accessible open spaces was very probably related to early human settlement and hunting.
Although in 1949 it was estimated that there was a fairly healthy population of up to 200 pairs of takahe, and the remote Murchison Mountain valleys seemed to be a safe refuge, a subsequent decline in their numbers was soon noted. Stoats had finally reached these back-blocks and the population of feral red deer, originally released for sport hunting, was multiplying and spreading. The deer are arguably a worse threat than stoats, for they have eaten the heart out of the highland forest undergrowth which was found to be vital winter forage when the tussock was covered by deep snow in winter.
From the late 1960s, a decade of deer culling at a rate of 1000 deer a year helped to arrest the natural forest decline, and programmes of artificial breeding at Burwood (near Te Anau) and the Mount Bruce Native Bird Reserve (in Wairarapa) were set up.
Later, transfer to predator-free islands commenced.
It had long been appreciated that offshore predator-free islands were the best bet for the long term survival of this brilliantly coloured species and other vulnerable birds. Takahe have survived well on Mana and Kapiti Islands north of Wellington and on Maud Island in the Marlborough Sounds, and the transfer of two takahe from the latter sanctuary to Tiritiri is just the latest step in the island colonisation programme.
The two birds, known as Mr Blue and Stormy, are both males, and must be regarded as pioneers on a mission to establish how well South Island takahe take to Tiritiri Matangi Island and to Northland’s different climate.
Takahe are strongly territorial, with territory sizes ranging from a couple to over 50 hectares, depending on the quality and quantity of the forage. On Tiritiri, some 80 hectares of grassland have been excluded from the tree planting programme, but it is uncertain how many birds this area would support. It is hoped that if Stormy and Mr Blue settle in well and thrive on their Hauraki Gulf island, females will be introduced in about a year, and the following year, chicks may be hatched.
Whatever happens, the touchdown of these two birds on May 26 after an epic flight from Blenheim is reminiscent of an earlier pioneering flight. Perhaps as Stormy took his first confident step on Tiritiri he was saying to Mr Blue, and the rest of the world, “A large step for takahe,” (for they have very big feet) “a giant leap for conservation.”