The great New Zealand lupin debate and why it matters

First we need to talk about the lupin’s favoured environment being mainily the braided rivers which drain the Southern Alps – rivers that find it impossible to run in a straight line, and be anything other than dynamic.

When in flood braided rivers carry sediment from the ever rising mountains [geologically speaking] and landslides that frequent such a young country, and at every point where the water flow slows down the carried sediment settles onto the bed of the river, thus in time raising the level of same, and the river, seeking always the path of least resistance, flows off to the side. Thus during high water levels and floods the nature of this predominately gravel environment can change in several hours

The Hunter River that flows into Lake Hawea…
Hunter River


The delightful, endemic and endangered NZ banded dotterel / tuturiwhatu is one of many birds that has evolved to breed in these river beds. Despite exhibiting a variety of seasonal movement patterns ranging from sedentary behaviour, through migration within New Zealand, to trans-Tasman migration, it is hard to not love their comical stop-start actions…
Banded Dotterel


This is typical tuturiwhatu breeding ground – also shared with wrybill and other like minded birds. OK to us humans it is pretty desolate, but keep in mind it lets them see any predators, and when they do they mimic an injury to lure rats, cats and stoats away from off-spring…
Riverbeds 2


Well meaning flower lovers of decades ago decided to brighten up the desolation, and spread the non native lupin seed. They probably never realised the above, and that each seed being coated with a type of oil to preserve it, can survive for several years sprouting only when ideal conditions exist. The perfect seed for such a dynamic bed – they of course then become impossible to get rid of, apart from annual spraying and that is not a cunning or cheap thing to do in waterways annually…
Lupins in The Ahuriri river valley


And then there are wilding pines – these ones have been sprayed. The terrain hosting cushion type vegetation is again the sort chosen for nesting…
Tasman Riverbed


No one denies the lupins look beautiful. And by-the-way after the brief flowering is over they become anything but ethereal, and more of an eyesore…
Lupins in The Ahuriri river valley


Another beautiful frequenter of the braided river environment is the black fronted tern tarapirohe. They spend hours swooping for bugs above and on the glacial silt laden blue/grey water surface, and of course breed nearby…
Tern


The natural state as another dawn breaks on a braided river in The Southern Alps…
Tasman Riverbed dawn light


If only lupins could be confined to roadsides! But even in such a place they invite suicide by flowery eyed tourists, toting cameras that are scant protection against the 110km/hr traffic that rushes by their nearby vehicles, the parking of which is more spontaneous than well thought out…
Lupins again


The two villains together on the shores of Lake Pukaki…
Lupins and a wilding pine - Lake Pukaki


The uniquely billed wrybill / ngutuparore which breeds only in braided rivers of the South Island. It is the only bird in the world with a laterally-curved bill [curved to the right], which it uses to reach insect larvae under rounded riverbed stones. Wrybills are completely dependent on the greywacke shingle of the riverbeds…
Wry bill


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