Wade Doak of Riverlands Landcare in Ngunguru writes that it is biological indicators which are a true indicator of the success of pest control measures:
Since success implies that pest kill tallies will gradually reduce each year, surveys of these alone, which our neighbours in Riverlands Landcare Group have done for several years, are not a good basis to estimate pest control performance. Biological indicators are a sure sign of improvement. Where three decades ago I got 31 possums in one night, Jan and I have only caught four in the past eight months, and we operate on some neighbouring land too. We are across the highway from the DoC Crawford Reserve, at Ngunguru, a reservoir of pest invaders we also have to control.
Certain occurrences have set me thinking about the unexpected benefits that emerge as old, relatively recently severed ecological connections start to get mended. (Logging of native forest in past 150 years and ensuing livestock farming). Emergent biological indicators that we may notice day by day make an interesting list.
That dense grove of large karaka seedlings Jan and I found recently along the extended Kanuka/ Bittern track, (newly territory) near a never-before-sighted blooming, pohutukawa, set us thinking. It indicates a new influence from the time our neighbours began intensified pest control, with the much-reduced possum grazing and seed eating by rats and mice. (For many years, before neighbours arrived, pest control here was mainly done by the Doaks.)
Are the whirlwinds of native bees on the kanuka blooms, a species going extinct elsewhere, surviving well here because of a pest that threatens it? Or what influence assists them, absent elsewhere?
Our widespread army of giant kauri snails have radiated from a single, hermaphroditic releasee right over to the eastern Waiotoi River boundary; south out to Reggie’s; along the newly made Buffalo Track to the west and are seen as road kill on Ngunguru Highway to the north.
Further evidence is growing density of miromiro; of two quail species; and pheasants; the dramatic increase in tui and kereru; the great numbers of fantail and grey warblers, with so many migratory cuckoo of two species. Kiwi calls are frequent now, (male and female) and there are sightings and droppings around our homes. Increasing sightings of endangered pateke /brown teal, there are now 54 on Ngunguru River, and documentation of spotless crake, banded rail, fernbirds, and Australian bittern sightings, all indicate major improvements in our marshes. Weta galore of two species, rhinoceros beetles on our house walls (both are pollinators) and geckoes in our outbuildings, peripatus in our forests, so many orchid species, the list goes on….
Then there is the abundance of seedlings that now survive rats and can be dispersed by expanding numbers of birds: karaka, pigeonwood, taraire, nikau, kahikatea, rimu, miro, totara, Pseudopanax-two species, coprosmas, (several species: five common ones), mairehau, toropapa, Pittosporum umbellatum, mahoe (two species), mingimingi of two species), hangehange, nikau and veritable swards of possum-favoured kohekohe now crowd our paths. Then, the wind-blown seeds of kauri, tanekaha, towai, kumarahou, rangiora, hebe, tree daisy (O. furfuracea) and kanuka, are spreading vigorously, uneaten by rodents. A whole grove of fragrant mairehau bushes has been found.
Lack of plant damage is further evidence: non-nibbled foliage and uneaten fruit; even fallen black passionfruit now remain untouched; we no longer see empty macadamia nut shells, tooth drilled by rats. Our auto camera once took pictures of a possum grazing tree bark repeatedly: a blackwood. Possums once stripped a single gum tree overnight and made it impossible to raise pohutukawa: now some 200 healthy plantings head skywards, many donated by Project Crimson.
No hedgehogs have been seen for ages: a nuisance in stoat traps, predators of ground bird nests. Rabbits are expanding without predation by stoats. They become mustelid bait or promote banana growth. But we still have native hawks, kingfishers and ruru as predators.
The quality of human life in our homes, gardens and orchards has increased as our forests flourish. It’s like getting rid of fleas and body lice for home owners. It is by far the best way to enhance your land; and your neighbourhood. Our Landcare project now protects 172 hectares.
Find more of Wade’s writing