Cruel poi­sons won’t re­turn bird­song

Fiona McQueen re­sponds to a re­cent opin­ion ar­ti­cle de­cry­ing those who chal­lenge the use of 1080.

Waikato Times - - News - Dr Fiona McQueen, a con­sul­tant rheuma­tol­o­gist, is the author of The Quiet For­est: The case against ae­rial 1080.

Dave Hans­ford has launched yet an­other at­tack against those op­posed to pest con­trol in the Brook Waimarama Sanc­tu­ary, near Nel­son. This sanc­tu­ary has just re­opened, sur­rounded by a 14km pest-proof fence. It will be stocked with kiwi, ka¯ ka¯ riki and ka¯ ka¯ .

The nasty part is that brod­i­fa­coum, a poi­son graded 8/10 for its abil­ity to cause an­i­mal suf­fer­ing, needed to be in­tro­duced first to kill pests in­side the fence. It also killed na­tive birds in­clud­ing weka and pukeko.

Do the ends jus­tify the means? A hu­man equiv­a­lent would be if a rul­ing party de­cided to ex­ter­mi­nate all un­wanted peo­ple and re­stock with dif­fer­ent peo­ple who are rep­re­sen­ta­tives of a ‘‘cho­sen race’’. Wait a minute, hasn’t that been done be­fore?

An­drea Mid­gen, chief ex­ec­u­tive of the SPCA, re­cently spoke out about the as­so­ci­ated an­i­mal cru­elty, say­ing, ‘‘1080 (and other poi­sons) causes in­tense, pro­longed suf­fer­ing to an­i­mals and there­fore we can­not sup­port its use’’.

Suf­fer­ing is not men­tioned to those who en­joy our eco­sanc­tu­ar­ies. Should it be?

Hans­ford then segues into a tirade against pro­test­ers who op­pose the drop­ping of 1080 over vast swaths of na­tive for­est (about 1000 tonnes an­nu­ally, 80 per cent of to­tal world pro­duc­tion).

He skims over the fact that these ar­eas of na­tive bush do not have preda­tor-proof fences. Con­se­quently, af­ter 1080 has cleared all the rats and na­tive fauna (yes, it can def­i­nitely kill an ar­ray of na­tive birds, in­sects and aquatic life), the for­est re­mains very quiet for a while.

But na­ture ab­hors a vac­uum and the place is re­pop­u­lated from the edges by those that re­pro­duce rapidly, pro­duc­ing

post-1080 rat plagues.

One pub­li­ca­tion showed rat num­bers bounc­ing back to more than dou­ble their base­line lev­els,

12 months af­ter a 1080 drop. These are young, ac­tive rats, hun­gry for na­tive birds.

What about the ev­i­dence then that 1080 boosts bird pop­u­la­tions? Does it re­ally ‘‘bring back the bird­song’’?

That de­pends on who you be­lieve. Kea are at high risk of death by 1080, be­cause they are nat­u­rally cu­ri­ous and at­tracted to baits. Of the 150 kea that have been for­mally mon­i­tored, 12 per cent died of 1080 poi­son­ing (found in their stom­achs and mus­cle tis­sue). Tomtits, robins, more­pork and fern­birds have all been proven to have died 1080 deaths and there are ac­counts of tu¯ ı¯, wood pi­geons and even kiwi found dead on the ground af­ter poi­son­ing op­er­a­tions.

Deaths in non-tar­get species (in­clud­ing birds such as the Amer­i­can ea­gle) was one of the rea­sons the En­vi­ron­men­tal Pro­tec­tion Agency banned 1080 from wide­spread use in the United States in 1985.

The ko¯ kako has been held up as the ‘‘poster-bird’’ of 1080’s suc­cess. Its num­bers tre­bled af­ter eight years of pest con­trol in Ma­para, near Te Kuiti, ac­cord­ing to a 1999 study. But there were sci­en­tific flaws in that study. Ma­para has a unique geog­ra­phy, be­ing an ‘‘is­land of for­est in a sea of pas­ture’’, which might de­ter re­coloni­sa­tion by rats (the Achilles heel of all poi­son­ing op­er­a­tions).

It could not mean­ing­fully be com­pared with con­trol ar­eas. The in­crease in bird num­bers was largely due to brod­i­fa­coum, not 1080, but that poi­son is kept in DOC’s back cup­board as it is not only ugly in terms of an­i­mal suf­fer­ing but very slow to de­grade.

Dr Quinn Whit­ing-O’Keefe, a clin­i­cal tri­als spe­cial­ist, said: ‘‘The prin­ci­ples of good re­search de­sign are well es­tab­lished, and . . . have not been fol­lowed by DOC in the re­search sup­port­ing their as­ser­tions on the use of ae­rial 1080 . . . If health­care used this stan­dard of ev­i­dence, we would likely still be bleed­ing pa­tients as a cure for pneu­mo­nia.’’

What about TB? Hans­ford raises the spec­tre of hordes of tu­ber­cu­lous pos­sums pour­ing down to in­fect in­no­cent dairy cows as they graze in their pad­docks. The re­al­ity is rather dif­fer­ent. New Zealand is re­garded in­ter­na­tion­ally as ‘‘TBfree’’, that is < 0.2 per cent of our dairy herds are in­fected by bovine TB. Ac­tu­ally our level is < 0.003 per cent.

Ev­i­dence for pos­sum-to-cow trans­fer of TB is flimsy at best and this can be pre­vented by sim­ple trap­ping at the edges of pad­docks. Many farm­ers ar­gue that bovine TB is most of­ten trans­ferred from other in­fected cows. This can be min­imised by good farm­ing prac­tices.

What are the al­ter­na­tives to ae­rial 1080? We could stim­u­late the fur trade and re­duce dam­age to forests by trap­ping pos­sums. Multi-use traps have also been de­vel­oped for rats. The new CRISPR gene-drive tech­nol­ogy could elim­i­nate rats but this prospect has been omi­nously de­scribed as ‘‘ex­tinc­tion on de­mand’’; and is a dan­ger­ous path for eth­i­cal and bi­o­log­i­cal rea­sons.

Per­haps it is time for us to ‘‘step away from the ecosys­tem’’. The fledg­ling science of in­va­sion bi­ol­ogy in­di­cates that na­ture has its own ways of ex­ert­ing con­trol over species that pro­lif­er­ate too much. Some hu­man el­ders re­mem­ber a time be­fore 1080 when there were more na­tive birds in the bush. Let’s lis­ten to what they have to say. Poi­son­ing can only do harm.


Kea are at high risk of death by 1080, be­cause they are at­tracted to baits, says McQueen.

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