BEECH MAST

Source Author Year Title Quote
TV3News online 29/01/14 Simon Wong 2014 Expanded 1080 drop to curb ‘plague’ of rats “The Government will be dropping 1080 poison on an extra 500,000 hectares of forest in an effort to combat an expected “plague of mice and rats of biblical proportions””
TV3News online 29/01/14 Simon Wong 2014 Expanded 1080 drop to curb ‘plague’ of rats “Dr Smith says it is “particularly urgent” this year because there is a one-in-10 year beech mast in which beech trees will drop a million seeds in autumn. “This flood of food will trigger a plague of an additional 30 million rats and tens of thousands of stoats,” Dr Smith says. “When the seeds germinate in spring, these starved predators will annihilate populations of our endangered birds””
DoC 07/05/2014 DoC 2014 DOC code of practice for aerial 1080 in kea habitat “However stoats are a far more important predator, particularly following mast events when kea nest failure and predation of juveniles and adults are at their greatest.”
DoC 07/05/2014 DoC 2014 DOC code of practice for aerial 1080 in kea habitat “Where rodent monitoring has not been done, toxic bait application can occur when the operation includes forest or tussock in a mast (seedfall) year or in the year following (post-seedfall) as determined either by seed monitoring or by expert judgment..This standard allows mast seeding to be used as a proxy for rodent density where rodent monitoring data is not available, such as for some possum operations.”
DoC 07/05/2014 DoC 2014 DOC code of practice for aerial 1080 in kea habitat “Where standard 4 or 5 have not been met, aerial operations…can only proceed in kea habitat where rats can be scarce at the discretion of the manager…”
NPCA 2014 Battle for Our Birds “In the South Island, 23 pest control operations, covering approximately 700,000 ha of beech forest, are planned for the coming late winter and spring. If the beech mast does not reach the intensity set to trigger these operations, four operations to supplement the normal control programme are planned as a contingency…Arrangements have been made for the supply, transport and storage of the large bait quantities required, tenders have been called for helicopter and fixed wing aircraft for bait sowing, and additional or amended consents are being obtained.”
DoC Media releases 29/1/14 DoC 2014 Battle for Our Birds’ launched to save native species “It is like having a Rena disaster, which killed 2000 birds, every hour,” Dr Smith says
Scoop Independent News 22/5/14 Murray Dench 2014 Why is there an argument over 1080? “This year is a mast year and the Department has received around 12 million dollars in extra funding for aerial poisoning operations to limit rat populations (remember aerial 1080 does NOT kill mice). We know from the science that the operations are going to generate very large rat populations in the years following the poison drops. What is the difference between high rat numbers created by a mast year and high rat numbers created by the control operations themselves?”
Scoop Independent News 12/2/14 Sporting Hunters’ Outdoor Trust 2014 Expanded 1080 drop to curb ‘plague’ of rats “Laurie Collins said Nick Smith’s assumption flew in the face of historical facts. Beech trees had been seeding for millions of years in two to three year gaps between mast years according to Te Ara…Beech masting and rats have been in co-existence for almost 1000 years.”
stuff.co.nz 19/2/14 Rachel Young 2014 Rat plague puts native species at risk “New Zealand’s beech forests could become like a scene from The Pied Piper of Hamelin with a population explosion of ship rats predicted this year, a senior Department of Conservation ranger says.The population boom has the potential to wipe out local populations of vulnerable species, including mohua, long-tailed bats and kakariki.”You’ll be able to come here and walk around and you’ll see rats running across the road, you’ll see rats running through the forest in broad daylight, let alone in the evenings,” said Department of Conservation senior ranger Brad Edwards.”Effectively they are going to cover the whole valley. They will chew the milking cups out of the dairy sheds, they will chew the electrics out of people’s cars in their carports, they’ll be trying to get into the houses and they will be doing all that and more in the bush.” Climatic conditions over the past two winters – a cooler one followed by a warmer one – appear to have triggered the onset of a bumper crop of seed, or beech mast…On Monday, Tinnemans checked red beech trees in Lewis Pass National Reserve. From one sample he counted 11 seed pods – in previous years this number was usually fewer than three. “This is a lot of seed. This will definitely get the rats and mice going.”
Otago Daily Times Online News 7/12/13 Rebecca Fox 2013 Beech 1080 blitz possible: Doc “Doc scientist Dr Graeme Elliot said a large mast and resulting rat plague in 2000 caught Doc by surprise and there were huge losses of birds, including the loss of a mohua population at Mt Stokes in the Marlborough Sounds and a population in the Eglinton valley in Fiordland, which was reduced from several hundred to a dozen or so birds. ‘We learnt our lesson and we’ve been practicing in the meantime, so we know what to do.'”
DoC G. Harper et. Al. 2013 Rotoiti Nature Recovery Project Annual Report 2011-12 “Two rodent control operations were carried out during 2011-12. One (in spring) was effective at reducing rat tracking indices to below 4%, but another operation (in autumn) failed, possibly because an alternative food source (beech seed) was available.”
NZ J Ecology 36: 131-140 C. O’Donnell & J. Hoare 2012 Quantifying the benefits of long-term integrated pest control for forest birds populations in a New Zealand temperate rainforest “Stoats were caught in relatively high numbers in four of the 10 years…Three of these years coincided with partial or full beech mast…but captures were low after the partial mast of 2003.”
NZ J Ecology 32: 214-218 S. McQueen, B. Lawrence 2008 Diet of ship rats following a mast event in beech (Nothofagus spp.) “Diet of 98 ship rats…was investigated…from June to December 2006….after a beech mast. Plant material was found in 43% of all stomachs, invertebrate fragments in 67%, feathers in 8%…feathers were found in one or two stomachs in every month except October.”
NZ J Ecology 29: 69-82 D. Kelly et al. 2005 Can stoat (Mustela erminea) trapping increase bellbird (Anthornis melanura) populations and benefit misteltoe (Peraxilla tetrapetala) pollination? “…satiation of predators and consequent reduced predation rates on birds is now thought to occasionally occur when mice reach extremely high densities (C.M. King, pers. comm., Waikato University, Hamilton, N.Z.).”
NZ J Ecology 29: 69-82 D. Kelly et al. 2005 Can stoat (Mustela erminea) trapping increase bellbird (Anthornis melanura) populations and benefit misteltoe (Peraxilla tetrapetala) pollination? “Several studies on other forest birds have found that trapping can reduce the high predation pressure during stoat irruptions. O’Donnell et al. (1996) found that a very intensive trapping programme significantly reduced stoat predation on breeding mohua during a stoat irruption.”
Rarebits 52 DoC 2004 Newsletter “The stoat control line in the Landsborough Valley has recently been extended down to Harper Flat…Following a beech mast in 2000 and corresponding stoat plague in 2001, stoat numbers have steadily declined in 2002/03. Seven stoats were caught over a 10 week period this year compared with 23 from the same period in 2001.”
Rarebits 54 DoC 2004 Newsletter “although it was a good beech flowering year in the Dart, there has been very little seed. He is also getting some rats turning up in the Fenn trap lines even though they are not appearing in the tracking tunnels”
Rarebits 55 DoC 2004 Newsletter “Catlins: We received money for stoat control but while in the process of preparing an operation plan, issues concerning rats arose; an observed doubling of rat abundance occurred between the start and end of October.”
NZ J. Ecology P. Dilks et al. 2003 Large scale stoat control to protect mohua (Mohoua ochrocephala) and kaka (Nestor meridionalis) in the Eglinton Valley, Fiordland, New Zealand. “Although rat numbers reached high levels during the beech mast in 1995/96…no predation was recorded on breeding mohua that were being monitored…in 1999 and 2000…rat numbers irrupted…this resulted in significant predation on mohua duing the breeding season and the following winter, an event not previously recorded in the Eglington Valley.”
DOC Science Internal Series 107: 16 pp D. Smith & I. Jamieson 2003 Movement, diet, and relative abundance of stoats in an alpine habitat “A prey switch to ground weta occurred as mice numbers declined, and not to birds, as is often expected or feared by conservation managers.”
DOC Science Internal Series 107: 16 pp D. Smith & I. Jamieson 2003 Movement, diet, and relative abundance of stoats in an alpine habitat “As mice numbers rise after beech masts, the stoat population also increases and uses mice to maintain population growth. When mouse numbers crash, stoat numbers also decline, with the small number of remaining stoats in the Murchison Mountains apparently relying primarily on ground weta for their survival.”
DOC Science Internal Series 107: 16 pp D. Smith & I. Jamieson 2003 Movement, diet, and relative abundance of stoats in an alpine habitat “…peaks in stoat activity seem to be in late summer and autumn.”
Rarebits 50 DoC 2003 Newsletter “We continue to have elevated numbers of mice in tracking tunnels and traps in the Catlins mohua areas. A number of rats have also turned up. As we did not have a beech seedfall event last autumn, the jury is out on what is happening and whether it will lead to a stoat eruption”
Conservation Advisory Notes 318, 9pp. B. Studholme 2000 Ship rat (Rattus rattus) irruptions in South Island beech (Nothofagus) forest In 1985 a remnant population of mohua (yellowhead) was discovered in silver beech (Nothofagus menziesii) forest on Mt Stokes in the Marlborough Sounds. Over recent years, intensive pest control has been carried out on the mountain for possums, stoats, weasels, goats and pigs…However, over the winter of 1999, more than half of these birds went missing. Only 32 birds could be found in October 1999…Stoats and ship rats were caught on Mt Stokes traplines in October 1999…Few ship rats had been caught in these traplines previously…this high-altitude beech forest was thought to be unsuitable habitat for ship rats…Low numbers of stoats were caught on the mountain in 1997/98…and a beech mast seedfall occurred in autumn 1999. Reduced predation pressure and an increased food supply, coupled with a mild winter, may have contributed to increased ship rat numbers on the mountain.”
Conservation Advisory Notes 318, 9pp. B. Studholme 2000 Ship rat (Rattus rattus) irruptions in South Island beech (Nothofagus) forest “It is likely that seedfall is only one of the factors regulating ship rat numbers in beech forest. There are some examples where ship rat numbers do not increase after beech seedfall. A partial mast in the Dart and Caples Valleys last autumn (1999) did not result in high rat numbers…King (1983) recorded an increase in rat numbers in the Hollyford and Eglinton valleys after seed fall in 1996 but found no increase after a beech mast in 1979.”
Conservation Advisory Notes 318, 9pp. B. Studholme 2000 Ship rat (Rattus rattus) irruptions in South Island beech (Nothofagus) forest “Elliot (1990) observed that Mohua have survived for over 100 years of rat and stoat predation in beech forest where rat abundance is generally low with only occasional peaks”
Conservation Advisory Notes 318, 9pp. B. Studholme 2000 Ship rat (Rattus rattus) irruptions in South Island beech (Nothofagus) forest “…ship rats were not an important food for stoats in the Hollyford and Eglinton Valleys even in years of relatively high rat abundance (King & Moller 1997).”
Rarebits 38 DoC 2000 Newsletter “Various stoat control research projects have been carried out in the Eglinton Valley since 1990…1999 was a beech mast year, and a stoat population irruption occurred during the following summer in response to the huge increase in rodent numbers. Kaka: The beech forest seeded heavily in 1999 and in 2000, and kaka breeding was widespread. Kaka in the Eglinton Valley generally start nesting in January when stoats are most abundant. Overall we monitored 25 kaka nests by 13 different females. Twenty nests successfully fledged 55 young. One female double brooded in 1999 rearing 5 then 2 chicks. In 1999 two nests failed at the chick stage owing to predation by either a stoat or possum but both females survived. This season we lost three nests, one with eggs and two with chicks, and 2 females were killed probably by a stoat. All five nests that have been lost were the most distant from the trapline. An unusual feature of this breeding season was the high level of predation by ship rats – unrecorded in the Eglinton in previous 6 years of intensive nest monitoring. Effectiveness of stoat control: It appears that stoat control carried out at this low intensity provides sufficient protection to markedly reduce stoat predation on breeding mohua and kaka…This summer we may not have lost any nests to stoats, but the huge increase in rat numbers and the associated rat predation is a major concern. The Te Anau area has had two mild winters and there is some suggestion that this results in high rat populations in beech forest. High rat numbers have been recorded elsewhere in South Island beech forests this past summer – in areas where no stoat control has been undertaken. If a permanently higher rat population were a result of continual stoat trapping, there would be serious consequences for many bird species. It could be suggested that stoat trapping be initiated only following beech mast years, but for kaka, at least, stoat control would need to occur during the previous summer when beech flowering initiates widespread breeding. If some kaka breeding occurs in all years then continual stoat control is preferable, because we knew of no successful kaka nests in the Eglinton Valley before we initiated stoat control. To keep the stoat population at a low level with a low density of traps probably requires continual trapping. Further work is needed here on rat population dynamics in beech forests to determine whether lack of predators means a larger irruption in mast years or if climate is the major influence.”
Rarebits 38 DoC 2000 Newsletter “quarterly mouse tracking lines and beech seed fall in the Caples and Dart Valleys have been completed. Both indices are up with mouse tracking rates averaging 43% in the Caples Valley and 73% in the Dart. Beech seed fall in the Dart is tapering off after reaching 3968 seed per square metre in March and 2336 in May this year. This is the third year that large numbers of beech seeds have been produced in the Dart.”
Rarebits 39 DoC 2000 Newsletter “Mohua/predator control: Rat captures in the Makarora and Dart Valleys are up on previous years, and rodents now appear to be a permanent feature of these permanent trap lines. Also, in the Dart stoat numbers are increasing as a result of the mast event last spring. This is the third season in a row for high stoat numbers in the Dart. In the Catlins the post irruption survey for mohua has been started, and results so far are showing good numbers of mohua in the core.”
NZ J Ecology 23: 95-100 N.C. Alterio et al. 1999 Trappability and densities of stoats (Mustela erminea) and ship rats (Rattus rattus) in a South Island Nothofagus forest, New Zealand “Fluctuations in trap success suggest that stoats become very numerous in the summer and autumn following heavy seedfall, but remain at low abundance in the intervening times.”
NZ J Ecology 23: 95-100 N.C. Alterio et al. 1999 Trappability and densities of stoats (Mustela erminea) and ship rats (Rattus rattus) in a South Island Nothofagus forest, New Zealand “Rodent capture rates fluctuate widely in Nothofagus forest in relation to infrequent and irregular seedfalls.”
NZ J Ecology 37: 41-50 N.C. Alterio et al. 1999 Trappability and densities of stoats (Mustela erminea) and ship rats (Rattus rattus) in a South Island Nothofagus forest, New Zealand “Long-term intensive trapping of mustelid and rodent populations through beech seedfall events would be valuable and are overdue.”
NZ J Ecology 23: 95-100 N.C. Alterio et al. 1999 Trappability and densities of stoats (Mustela erminea) and ship rats (Rattus rattus) in a South Island Nothofagus forest, New Zealand “Mice may also prey on eggs and the role of weasels in killing adult and young birds is unknown. Accordingly, predator control operations should target all these predators to minimise predation risks to native wildlife, at least until the relative impacts of each species has been discerned”
WWF-NZ Final Report 1 August 1999 64pp G. Elliot & J. Kemp 1999 Conservation ecology of kea (Nestor notabilis) “Nest predation did not increase in the breeding season following full beech mast-seeding in 1995, when stoat (Mustela erminea) numbers were beginning to rise”
WWF-NZ Final Report 1 August 1999 64pp G. Elliot & J. Kemp 1999 Conservation ecology of kea (Nestor notabilis) “In the autumn and winter following an irruption stoat numbers slowly return to low levels until the next beech mast (King 1983).”
NZ J Ecology 23: 95-100 E.C. Murphy & J.E. Dowding 1995 Ecology of the stoat in Nothofagus forest: Home range, habitat use and diet at different stages of the beech mast cycle “When we compared stoat diet in the high-density year with that in the following two years, there were no significant differences in the frequencies of occurrence of birds or invertebrates in stoat guts…King (1983) showed that there was little change in the number of birds eaten per stoat at a wide range of mouse densities, but noted that a greater absolute number of birds would be eaten in a season of high mouse density simply because of the greater number of stoats present.”
NZ J Ecology 23: 95-100 E.C. Murphy & J.E. Dowding 1995 Ecology of the stoat in Nothofagus forest: Home range, habitat use and diet at different stages of the beech mast cycle “Seedfall in Nothofagus forest is synchronous and periodic. Following seedfall, mouse density rises dramatically, followed by a sharp rise in stoat numbers. It has been suggested that mice feed on the abundant seed and that stoats in turn increase because of the large numbers of mice available to them. We suggest that the situation is more complex and that increases in not only mouse, but also bird (and possibly invertebrate) densities may contribute to the high productivity of stoats in the year following a Nothofagus seedfall.”
NZ J Ecology 23: 95-100 E.C. Murphy & J.E. Dowding 1995 Ecology of the stoat in Nothofagus forest: Home range, habitat use and diet at different stages of the beech mast cycle “Stoats did not eat birds less frequently when mice were abundant, a result also found by King (1983).”
NZ J Ecology 23: 95-100 E.C. Murphy & J.E. Dowding 1995 Ecology of the stoat in Nothofagus forest: Home range, habitat use and diet at different stages of the beech mast cycle “In addition, stoats may pose a threat without heavy beech seedfall. Mouse and stoat numbers can rise after poor mast years…so assessing potential impacts on threatened species may require a better predictor than heavy beech seeding alone.”
Joural of Animal Ecology 52: 141-166 C. King 1983 The relationship between beech (Nothofagus sp.) seedfall and populations of mice (Mus musculus), and the demographic and dietary responses of stoats (Mustela erminea) in three New Zealand forests “There was a significant relationship between seedfall and populations of mice in all forests studied. Good seedfalls were followed by increases in density of mice and changes in population structure not seen in years when the seedfall failed. Predictability of these changes decreased with increasing diversity of forest composition. (2) Stoats responded both numerically and functionally to increases in mice. There was a significant relationship between the densities of mice and of stoats in summer in two forests. (In a third, this relationship was modified by the presence nearby of many lagomorphs, an important alternative prey for stoats.) The numerical response was due to increased survival, in the uterus or the nest, of young stoats born in spring when mice were abundant, not to increased fecundity of adult female stoats. In all three forests, stoats ate significantly more mice in the summers that mice were abundant. (3) Ship rats (Rattus rattus (L.)) were most abundant in the most diverse of the three forests. The density index for R. rattus increased there after the 1976 seedfall, but not after that of 1979. A few kiore (R. exulans (Peale)) coexisted with R. rattus in this forest. (4) Stoats did not eat significantly fewer birds when there were plenty of mice, either in summer or autumn, but nevertheless there was a significant negative correlation between the proportions of birds and mice in the diet in autumn. In summer this correlation was very weak and probably non-existent. (5) A `bird predation index’, which takes into account both the numbers of stoats present and what they ate, suggests that more birds are eaten in summers of peak numbers of mice and stoats, because of the strong numerical response by stoats to mice and lack of `buffering’ of birds by mice. In autumn this effect is weakened by a regular seasonal switch by stoats from birds to mice, especially in the autumn of a mouse peak year. (6) The indirect effects of mouse irruptions on populations of forest birds in New Zealand should be further examined. Control of stoats in mouse peak summers could prevent a temporary increase in predation on birds by stoats during the highest risk period, though whether this would benefit the birds is unknown.”