Vets guardians of lush bush retreat
Exotic trees grow alongside a 20ha stand of native bush on retired vets’ small farm, writes Rob Tipa.
After 34 years working at the cutting edge of international research into deer farming, veterinary scientist Dr Colin Mackintosh has swapped his stethoscope for a pruning saw as a guardian of a block of exotic forest and native bush on the Otago coast.
Mackintosh and his wife Dr Marjorie Orr, also a veterinarian, bought a bush-clad block of land on the seaward side of Saddle Hill, south of Dunedin, nearly 30 years ago. They loved the wildness of their bush retreat just 10 minutes east of AgResearch’s Invermay Research Centre, where they both worked as research and diagnostic veterinary scientists for more than three decades.
The couple placed a Queen Elizabeth II Trust covenant on part of their original bush block and seven years ago bought a neighbouring property with an extensive range of exotic forest trees and a patch of regenerating native bush. The previous owner had already placed a QEII covenant over this bush so protective covenants now cover close to 20 hectares of contiguous native bush. Successive owners have planted a range of podocarps - including to¯ tara, rimu, kahikatea, miro and matai – reinforcing the dominant ka¯ nuka cover typical of this dry coastal Otago location. ‘‘This is our retirement property,’’ Mackintosh explains. ‘‘With the QEII covenant, we feel we are guardians of this land. Once you put a covenant on it, it is there for good and it will just get better and better as the podocarps grow. You don’t really own it as much as look after it for future generations,’’ he says. ‘‘We love sharing it with people so we have walkways and bridges all through it.’’
Within three years of fencing stock out of the native bush, the undergrowth recovered quickly. QEII staff have returned to document that recovery with a series of photographs taken from key points.
Bird life has improved with a broad range of fantails, tomtits, bellbirds, tuis and wood pigeons commonly spotted in their bush. Mackintosh is concerned about the effects of introduced pests on nesting birds so he is trapping rats and possums to control numbers.
The couple were delighted when an entomologist from the Otago Museum discovered good numbers of peripatus, or ‘‘velvet worm’’, living in rotten logs in their protected patch of bush. This is a species that does not differ much from its ancient ancestor that was present around 500 million years ago. They also inherited the previous owner’s passion for a ‘‘licorice allsorts’’ collection of exotic timber trees, including several eucalyptus species, macrocarpas, Tasmanian blackwoods, redwoods, yeogi poplars and alders to name a few.
‘‘Farm forestry has become a real interest because we are trying to nurture the trees,’’ Mackintosh says. They have harvested one block of pines and have replanted with Cupressus lusitanica, macrocarpas and pines.
They hosted a farm forestry field day on their 40ha property last month and welcomed advice from experienced farm foresters on pruning and thinning their trees. They have seen signs of canker in their macrocarpa plantings and have decided to thin out the worst of their diseased trees in the hope that the rest will recover. On their original block of land, they found mud bricks and discovered records of early settlers who cleared bush on the flanks of Saddle Hill in 1880 and built a small house and cow byre made of mud bricks. The family planted oats and took a crop of grain off the land in their first year, but the virgin soils had little humus or fertility and subsequent crops were poor. ‘‘They grew very good bush, but not very good crops,’’ Mackintosh says.
The settler’s family continued farming this block during the 1930s and a subsequent owner remembered cutting ka¯ nuka, loading a horse-drawn wagon and carting it into Dunedin to sell as firewood because that was their only source of income during the Depression. Both Mackintosh and Orr trained as veterinarians in Palmerston North and in Scotland, respectively. They met and married when Mackintosh was studying for his doctorate on leptospirosis at Massey University and Orr was working as a relieving lecturer there.
‘‘In 1981 we both finished [at Massey] and were looking around for jobs,’’ Mackintosh says. They were lucky to get two jobs working together, Orr in Invermay’s diagnostic laboratory and Mackintosh as a research veterinarian in the deer unit.
He became part of a team responsible for ground-breaking research into farming deer commercially. ‘‘For me that was very exciting getting into a whole new ball game with a blank sheet of paper, because there was not a lot known about deer health in those days,’’ he says.
Initially Mackintosh developed a reversal agent for the anaesthetic xylazine, a drug that was widely used in the deer industry at the time for antler removal, velveting or calving.
The drug was registered and revolutionised the handling of farmed deer. In the early days of the deer unit, he also worked on parasite research into the effective use of anthelmintics to control worms in farmed deer herds.
He also worked closely with colleagues in the development of Yersiniavax, a vaccine against the deer-specific disease Yersiniosis pseudotuberculosis. Invermay researchers developed a range of tests, starting with a blood test that was later refined to an accurate antibody test. As the Tb research work tapered off the team turned their attention to developing a test to identify Johne’s disease, which is closely related to Tb. When research started, outbreaks of Johne’s disease commonly killed up to 20 per cent of weaners in affected herds within their first 12 months. The test they developed identified the disease early and accurately, virtually controlling the problem.
Both Mackintosh and Orr have a busy lifestyle looking after their piece of paradise on the flanks of Saddle Hill, along with a menagerie of horses, goats and dogs. Mackintosh has retained an interest in deer research as a consultant veterinarian and Orr as an SPCA educator, website columnist and an advocate on animal health and welfare issues.
You don't really own it as much as look after it for future generations
Colin Mackintosh