wry old time down at the river
Wry old time down at the river!
How careless we are, we humans, about our pleasures and their consequences.
When I was a lad a mate and I were fishing in the Orari River gorge near Geraldine, my home town. We were taking turns at dropping a ‘black gnat’ into the last swirl of a rapid so it drifted to where trout patrolled the junction of the shallow rill and the deep, black pool it emptied into.
It was my turn to test my skill against the cautious trout, when a duck drifted down the rapids and across my line.
Too quick to stop him, my mate picked up a rock and threw it at the bird, as 12-year-old boys are wont to do. Like so many throws that are instinctive and without thought, it was devastatingly accurate, catching the duck on the head and killing it instantly.
‘So what?’ You might ask. ‘It was just a duck and, after all, you were trying to kill a trout! What’s the difference?’
The difference is that the trout I was trying to catch are an introduced and plentiful game species. The duck was an endemic whio (blue duck – Hymenolaimus malacorhynchos) a beautiful torrent duck that, even then, I knew was rare and threatened (and it has become more so since, you no longer see them in the river gorges behind Geraldine as I did in my youth).
Of course, you can hardly condemn a boy for picking up a stone, it is an instinct that seems deeply ingrained in our psyche; and he neither had the maturity nor the knowledge to appreciate what he was doing.
But adults! Well, that’s another story.
Not so far away, as the blue duck flies, from the small Orari is a much more impressive river, the mighty Rangitata. This is one of the great rivers that emanates in the eastern flanks of the South Island’s Southern Alps and bisects the Canterbury Plains in a myriad of shingle-banked braids.
Braided rivers, coursing through alluvial shingle beds are, on a global scale, a comparatively rare and specialised environment. The rivers that are still building the Canterbury Plains of New Zealand are an internationally recognised natural feature with their own ecosystem of plants, insects and birds.
A number of unique bird species choose to raise young and/or feed in these braided channels, making nests in the bare stone. They include: the very rare kaki (black stilt Himantopus novaezelandiae) the status of which is listed as nationally critical (the most endangered ranking);
the taranui (Caspian tern Sterna caspia); and the wrybill (Anarhynchus frontalis) the only bird in the world that has a bill that curves sideways (always to the right).
The taranui and the wrybill are both classified as nationally vulnerable, the third most serious ranking.
These rare birds share their stony home with another small wader, the abundant tuturiwhatu (banded dotterel Charadrius bicinctus). Apart from the taranui, all of these species are endemic; meaning that they are found nowhere other than New Zealand.
But braided alluvial shingle river systems are under serious threat directly and indirectly, because of the actions of humans, partly, I suggest, because there is not a great deal of understanding or appreciation of shingle riverbeds as a critically important ecological resource.
We see, and welcome, a great many campaigns for protection of wetlands, the establishment of marine reserves, and the preservation of forests and mountain landscapes, but public awareness of the value of braided rivers seems poor.
We seem to take riverbeds for granted or, worse, see no real value in them. I suggest that for many people, braided shingle riverbeds are just stone and weeds, a seemingly barren playground on which to hoon around in off-road vehicles; or simply the land they must traverse to get to the water to swim, fish or jet boat.
This carelessness as to the value of braided river systems means that their threats are many.
Introduced weeds, especially lupin, gorse and broom, invade the bare shingle banks depleting the amount of nesting space available to the river nesting specialists, which require open, clean shingle to nest on. The additional vegetative cover also means that introduced predators such as feral cats and stoats can sneak up to nests more easily.
Water extraction for irrigation is another issue. Braided river systems require regular freshes of water to maintain the bare shingle islands. Low water flows allow weeds to establish and also reduce the habitat of the water-living invertebrates that the wading birds feed upon.
Ironically, more frequent heavy and unseasonal flooding is also a threat, a consequence of loss of native vegetation in the high country catchments that feed these rivers, so that rain enters the river systems quickly instead of being held by tussock and forest and released from the catchment slowly.
Of course a huge risk is the introduced predators already mentioned, especially feral cats and stoats, but also possums, hedgehogs, dogs and rats. Our indigenous birds have evolved without the presence of mammalian predators, so while their stay-still-and-rely-on-camouflage defences work well against natural aerial predators like kahu (Australasian Harrier – Circus approximans), karoro (black-backed gull – Larus dominicanus) and karearea (New Zealand falcon – Falco novaeseelandiae) they do not work any where near as well against ground predators with a sense of smell!
And now I return to the opening theme of this article, the carelessness of humans and the threat that our self-absorption presents to the survival of native species.
For, in addition to being the source of the weeds, irrigation and mammalian predators that impact on our bird numbers, our own activities directly impact on the survival of our river, beach and sand-bank nesting species. Our love affair with motorized cross-country transport – the four-wheel drive, beach buggy, quad bike, trail bike etc – is a real threat to ground nesting species, whose nests are impossible to see from a moving vehicle. Numerous nesting birds and/or their eggs or chicks simply get run over.
The trouble is, precious few authorities make any large-scale or concerted attempts to regulate against, restrict or confine, the activities of our off-roaders. And even where such regulations do exist there are few if any resources to actually police it. In most cases there is simply an occasional sign warning of the presence of nesting birds and prohibiting or limiting access; signs which, in my experience, are often ignored by adults who, unlike my youthful companion all those years ago, should know better
I have personally witnessed deliberate flouting of vehicle restrictions on braided rivers, beaches and estuaries; restrictions set up to protect wrybill, terns and other vulnerable species. And it’s not the young hoons in powerful vehicles of popular infamy who are the main problem. It’s almost always mature adults; frequently salmon fishermen, surf fishers or whitebaiters, whose priorities seem not to include consideration of native birds when a run is on and they need to get vehicles close to the fishing spot as quickly as possible.
I have witnessed drivers deliberately target marked dotterel nests (ironically put there by volunteers to try to warn drivers away from the eggs) because they resent the limitations imposed on their ‘freedom’ because of the birds’ presence. I have heard people loudly boast of encouraging their dogs to sniff out the nests and eat the eggs. Their reasoning is that if the birds can be got rid of, the limitations on their recreational activities will be lifted.
And I have personally been threatened with violence when I have remonstrated with drivers taking their vehicles into protected bird areas.
For the seeker of recreational fish species – or merely the thrill of high speed off-roading – it seems nothing should be allowed to limit their pleasures!
Let me acknowledge that not all baiters and fishers, nor even all recreational off-roaders, behave this way, but the numbers that do – whether through ignorance or the deliberate flouting I have described – is significant, yet records show very few are caught let along prosecuted or otherwise penalised. The sad fact is that most off-roaders who knowingly flout the law on vehicle access in bird seasons, do so knowing their chances of getting caught are almost zero!
Recently, at Kaitorete Spit on the seaward edge of Lake Ellesmere, I photographed dotterel eggs where tyre tracks passed within five centimeters of the nest; a nest, incidentally, only 30 metres inside a prohibited vehicle area marked by a large sign.
Less than a week later, hoping to get photographs of hatched chicks, I went back, and found instead crushed eggs and the sad remnants of an adult bird that must have stayed, camouflaged and frozen to the nest, as the quad bike bore down!
Organisations like the Department of Conservation (DOC), Forest and Bird and local conservation volunteers do their best and their efforts should be celebrated. But the truth is that the resources for conservation, in so-called ‘clean green New Zealand” are woefully inadequate. DOC is seriously under-funded and territorial local authorities, for the most part, seem unaware even of the need, or are facing demands from government and ratepayers to “stick to their knitting” of roads, water and sewerage systems. Money spent on conservation issues can be resented and seen as not the province of local authorities but something ‘government should do’ despite the fact that, plainly, government frequently will not, or cannot because of a lack of funding.
New Zealand’s braided rivers are unique, as are the species that depend on these fragile ecosystems for survival. Greater awareness, more education and better resources are needed, or our unenviable list of extinctions will continue, to the detriment of us all!
All photos in this blog are my own unless otherwise stated.
I don’t have any decent photos of whio (blue duck) yet, but check out these beautiful photos by my photographer friend Tim Rumble. http://www.flickr.com/photos/timrumble/sets/72157625733932216/with/5739587468/
More on blue ducks here: http://www.doc.govt.nz/conservation/native-animals/birds/wetland-birds/blue-duck-whio/
More on wrybill here: http://www.nzbirds.com/birds/wrybill.html
More on black stilt here: http://www.doc.govt.nz/conservation/native-animals/birds/wetland-birds/black-stilt-kaki/
More on Caspian tern here: http://nzbirds.com/birds/caspiantern.html
More on the banded dotterel here: http://nzbirds.com/birds/bandeddotterel.html