Independent scientific reviews

and official documents on 1080

Observer interference

Observer interference has probably caused the low success rates recorded for monitored bird nests

date	authors	source	name	quote
2005	King, C., Murphy, E.	pp 204-221. In King, C.M. (Ed.). The Handbook of New Zealand Mammals (2nd Edition). Oxford University Press, Melbourne. 610 pp.	Stoat	“Prey are detected by sight (especially if moving), sound or smell.”
1996	O’Donnell, C.F.J. & Elliot, G.P.	NZ Journal of Zoology. 23:279-286	Control of a stoat (Mustela erminea) population irruption to enhance mohua (yellowhead) (Mohoua ochrocephala) breeding success in New Zealand	“These techniques enabled us to reach [mohua] nests up to 32 m above the ground. The contents of nest holes were checked every 3-4 days. All nests that fledged chicks were detected.”
2010	T. Rawlence	Report submitted at Univeristy of Otago for Dipl. Wild. Mgt. (Supervisor G. Elliot, DoC)	Can a landscape predator control regime be emplyed to ensure sustainable recruitment in endangered mohua (Mohua ochrocephala) populations, South Island New Zealand	“Once the nest is located the tree is climbed to confirm that it is indeed a nest…a ring of sticky string is placed around the base…the nest is then visited every 3-5 days to see if the nest is still active”
2015	Ellenberg, U., Edwards, E., Mattern, T., Hiscock, J.A., Wilson, R. & Edmonds, H.	NZ Journal of Ecology 39(2): 231-244	Assessing the impact of nest searches on breeding birds – a case study on Fiordland crested penguins (Eudyptes pachyrhynchus)	“Predators may learn to follow humans and profit from the distraction they cause (author’s personal experiences with stoats in New Zealand, kelp gulls Larus dominicanus in Chile, and polar foxes Vulpes lagopus in Spitsbergen).”
2015	Ellenberg, U., Edwards, E., Mattern, T., Hiscock, J.A., Wilson, R. & Edmonds, H.	NZ Journal of Ecology 39(2): 231-244	Assessing the impact of nest searches on breeding birds – a case study on Fiordland crested penguins (Eudyptes pachyrhynchus)	“In almost a third of all nests [of prenguins] both first and second searches caused temporary next abandonment that lasted up to 4.5 h, creating considerable predation opportunities”
2015	Ellenberg, U., Edwards, E., Mattern, T., Hiscock, J.A., Wilson, R. & Edmonds, H.	NZ Journal of Ecology 39(2): 231-244	Assessing the impact of nest searches on breeding birds – a case study on Fiordland crested penguins (Eudyptes pachyrhynchus)	“It is imperative to minimise the effects of nest-search related disturbance, not only to minimise impact on breeding success, but also to gather accurate long-term monitoring data.”
2015	Ellenberg, U., Edwards, E., Mattern, T., Hiscock, J.A., Wilson, R. & Edmonds, H.	NZ Journal of Ecology 39(2): 231-244	Assessing the impact of nest searches on breeding birds – a case study on Fiordland crested penguins (Eudyptes pachyrhynchus)	“Stressful events may redirect an individual’s behaviour towards survival rather than reproduction (Watanuki et al. 1993) consequently leading to temporary or even permanent nest abandonment (Wingfield et al. 1997). This creates predation opportunities and exposes the nest contents to the elements which can affect embryo development.”
1990	Major, R.E.	Ibis 132 (4): 608-612	The effect of human observers on the intensity of nest predation	“Disused nests containing eggs from aviary birds were used to determine the effect of human observers on the intensity of nest predation. Nest predation was significantly higher for nests visited daily than for nests visited only at the end of an incubation period. Care should be taken by nest observers to minimise the number of visits to nests of ground-nesting birds.
1996	Hein, E.W., Hein, W.S.	Journal of Field Ornithology 67 (4): 604-611	Effect of flagging on predation of artificial duck nests	“Nest markers are used commonly to identify and mark locations of nests…flagged nests had a higher mortality rate than unflagged nests between day 8 and 14…flagging may increasingly influence predation as nests age. We recommend that nests not be marked with flagging and that natural objects are used to aid in nest relocation.”
2015	Kemp, J., Cunninghame, F., Barrett, B., Makan, T., Fraser, J., Mosen, C.	Released under the Official Information Act (unpublished)	Effect of an aerial 1080 operation on the productivity of the kea (Nestor notabilis) in a West Coast rimu forest	“The radio tagged {kea} females were tracked repeatedly, at intervals of 2-3 weeks, from July to December, to detect the onset of nesting.”
2015	Innes, J., King, C., Bartlam, S., Forrester, G., & Howitt, R.	NZ Journal of Ecology 39(2): 245-253	Predator control improves nesting success in Waikato forest fragments	“We monitored each nest until it either fledged young or was destroyed. Video cameras recording 24 hours a day (under infrared light during darkness) were placed 1-3 m from 10 of the 11 nests, to identify predators…We visited nest areas twice per week to check nest survival”
1984	King, C.	Oxford University Press	Immigrant Killers. Introduced Predators and the conservation of birds in New Zealand	“The standard Wildlife Service technique of finding these secretive birds in thick vegetation is to play tape-recordings of their calls, to which the birds often respond in kind, or even in person. There are three recorded instances where the tapes attracted, not crakes, but mustelids, which undoubtedly expected to find spotless crakes after hearing their calls.”
2015	Kemp, J., Cunninghame, F., Barrett, B., Makan, T., Fraser, J., Mosen, C.	Released under the Official Information Act (unpublished)	Effect of an aerial 1080 operation on the productivity of the kea (Nestor notabilis) in a West Coast rimu forest	“We located kea (for radio tagging) by cruising the landscape, intermittently broadcasting recorded kea calls, until kea were seen or heard…The keas were attracted to the catch site by recorded kea calls and lured for capture in nooses and net guns. Stuffed kea decoys were often used to attract keas into nooses. As the study progressed, additional captures were made at previously-known nest sites, sometimes to change an existing radio tag for one with a fresh battery, sometimes to fit a radio tag for the first time”