#Subantarctic Islands: diary of a #plantgeek

Campbell Is.

The giant carrot… Anisotome latifolia among the tussocks.

The natural history of New Zealand’s remote Subantarctic Islands is as intriguing as the islands’ history of human endeavour. Scattered across the Roaring Forties and Furious Fifties, these remote volcanic outcrops are home to an extraordinary array of flora and fauna. Discovered between 1791 and 1810, the profligate harvest of seals, whales and penguins followed. Numerous attempts at settlement and farming were made well into the 20th century while during WW2, coastwatchers scanned inlets for foreign vessels. Latterly, scientific expeditions have removed previously introduced animal species while ongoing research continues to untangle the complex ecology of these islands. Then there are people like me who want to gain insight into the plant life and see megaherbs flourishing in their natural environment…

Snares

The sheer number of birds on the Snares group is said to be greater than the total number of birds found in the UK.

First, the Snares

I joined a group of 46 passengers to board the Russian polar expedition vessel the Professor Kromov/Spirit of Enderby. We left the calm waters of Bluff Harbour to venture into ocean swells that sent the ship bucking and heaving throughout the day and into the night. A storm-rattled morning revealed the Snares, a group of islands renowned for the abundance of sea birds – mainly sooty shearwater/titi, common diving petrel and mottled petrel. Despite gusts of 70 knot winds (nearly 100 km/hour) shattering the surface waters, thousands of birds reeled and dived finely tuned to each change in pressure, wind direction and strength. Researchers are among the few permitted to land on these islands. Honeycombing the peat underneath the dense cover of coastal tree daisies (Olearia lyallii), are countless seabird burrows that could easily collapse under the weight of human footfalls.

  • The Snares group covers c.328 ha and is located 100km SW of Stewart Is
  • 22 vascular plants (20 indigenous)
  • Birds include the Snares crested penguin, mollymawks, shearwaters and petrels, as well as 3 endemic species: Snares Is fernbird, tomtit and snipe
  • The islands are remarkably free of introduced mammals (including mice)

We continued south, folk like me falling under the weather, staying prone, then supine as an attempt to quash creeping sea sickness. My cabinmate supplied me with Russian anti-nausea fare: white bread, a stack of pickled gherkins, and a plate of sliced lemon generously coated in sugar. I declined and promptly fell asleep.

Enderby Is.

Sandy Bay, strewn with sea lions. Huts for visiting researchers are nearby. Photo credit: Heritage crew.

Next, Enderby and Auckland Island

In the small hours, the boat anchored in the calm waters of Sandy Bay, Enderby Is. (710 ha). Traversing the 12,000 yr BP layer of peat that covers much of the island (see McGlone 2002), we encountered carpets of yellow-flowering Bulbinella rossii. Extravagantly flowered, large-leaved megaherbs are a unique feature of the Subantarctic Islands, but the origins of the four genera (Bulbinella, Stilbocarpa, Pleurophyllum, Anisotome) are debated. They could be relicts of an ancient flora pre-dating the ice ages and their large, hairy leaves an adaptation to typically cool, cloudy and wet weather conditions.

Enderby Flora

Compact heads of and endemic gentian and the large, yellow cones of Bulbinella rossii; coastal grass re-colonising following release from grazing by cattle and the giant carrot, Anisotome latifolia.

The diversity of birdlife was impressive – first albatrosses, chattering red crowned kakariki, rare yellow-eyed penguins tucked amongst coastal shrubs, tui and bellbirds in the rata forest, Auckland Is. shags on the coast and ubiquitous pipits. The birders were happy. Very happy.

Most botanically fascinating were the lush swathes of Macquarie Is. cabbage (Stilbocarpa polaris) underneath the tangle of low growing rata forest. Firstly, the extraordinary juxtaposition of colour and texture but the experience of being in an intact, weed-free coastal forest – so very rare on mainland New Zealand (even rarer on the east coast). Returning to the beach, male sea lions postured, gruffly exhaling while lunging at each other in territorial displays. The smaller females fended off their advances, prioritizing feeding their 3-day old pups. Opportunistic skua scavenged around the colony, one tugging persistently at an umbilical cord still attached to a pup.

Stilbocarpa_Rata

Lush carpets of Macquarie Is. cabbage, Stilbocarpa polaris underneath stunted southern rata, Metrosideros umbellata.

  • Enderby and the Auckland Is. group lie 460 km south of Bluff
  • With 235 taxa (202 taxa are native), the Auckland Is. group contains the richest vascular flora of all Subantarctic Islands
  • Over 120 species of bird have been recorded including 40 species of seabird which breed on the islands
  • Cats and pigs still roam Auckland Is. Short horn cattle, French blue rabbits and mice were eradicated from Enderby Is in the 1990s, one of a series of ill-fated attempts at farming

Crossing to Auckland Is. (50,990 ha), a Zodiac trip into Musgrave Inlet revealed cluster after cluster of rockhopper penguins. Perched on the granite boulders, they looked as if debating whether to launch into the kelp, and who should go first. With their low centre of gravity, they are perfectly adapted to waddling and bouncing from boulder to boulder, flippers used for balance. It’s almost impossible not to anthropomorphise them, let alone be struck by the ‘cuteness’ of their sock-like bodies.

Musgrave Inlet

The boulder-strewn coast is home to southern rockhopper penguins. They next among dense Hebe elliptica shrubs, safe from predatory skua.

We travelled further along the eastern coast and turned into Carnley Harbour, the eroded and flooded remains of an ancient volcano. Venturing inland through more rata forest and then into dracophyllum forest, we poked among the ruined home of a WW2 coastwatcher before stepping into the tiny space where they spent hours scanning the harbour. Thankfully, the lonely job attracted staff with a bent for natural history – their descriptions of the islands’ geology, landforms, flora, fauna and climate have greatly enriched our knowledge of these islands.

Auckland Is

Restored coastwatcher’s hut and derelict home; deep inside Carnely Harbour and a pig skull on the shore.

Last, Campbell Island

Campbell Is. (11,300 ha) lies 700 km south of Bluff, and like Auckland Is., has a long, sheltered harbour. We ranged all over the island for most of one day and half of the next.

Campbell flora

The button-like heads of Pleurophyllum criniferum and the showy P. speciosum; signage and rasp fern.

At lower altitudes, there was densely branched forest, up to 5m high in sheltered places (Dracophyllum cockayneanum, Myrsine divericata, Coprosma ciliata), with sturdy clumps of rasp fern (Polystichum vestitum) making up the understory. At higher altitudes, the landscape was open: fields of megaherbs and tussocks (see Nicholls 2000). Megaherbs earn their title by their sheer size – pink flowering heads of giant carrot (Anisotome antipoda, A. latitfolia) and purple flowering Pleurophyllum species easily reach a metre or more in height. Each species is an extravagant piece of plant architecture, structurally complex and incredibly beautiful. Although the genera of Bulbophyllum and Anisotome exist on mainland NZ, the plants come nowhere near the dimensions of those found in the Southern Ocean. Nesting southern royal albatross were scattered throughout the open tussocks, their white feathers in stark contrast to the dun vegetation.

Campbell royal

Southern royal albatross nesting among tussocks on Campbell Is.

Along the western clifftops, we unexpectedly encountered a couple of sealions. For creatures that look so unwieldy on land, they can move very quickly and across surprisingly rough terrain and for long distances. They can be aggressive, lunging and sharply exhaling. With males up to 400kg, and females roughly half that, they are intimidating, but can be fended off by using a day pack as a shield… best left to the guide.

Veg plot

Vegetation and photopoint marker: ongoing research to measure change following the eradication of introduced animals on Campbell Is.

  • Owing to the size of Campbell Is., the successful 2001 rodent eradication project was considered the most ambitious in the world at the time.
  • Almost the entire population of southern royal albatross are held on Campbell Is.
  • The island is the sole nesting ground of the Campbell albatross, and the critically endangered Campbell Is. teal.
  • Diminutive Campbell Is. snipe, thought to be extinct owing to predation by rats and cats, was rediscovered in 1997 on nearby Jaquemart Is. They have now re-established on Campbell Is.
Campbell Is

An unexpectedly mild morning in Perseverance Harbour, Campbell Is.

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One response to “#Subantarctic Islands: diary of a #plantgeek

  1. great photographie, I would love to see the amazing fauna and flora but the rough crossing would put me off, so it is great to be able to read about it !

    Like

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