Show simple item record

dc.contributor.authorWissel Silkeen
dc.date.accessioned2009-06-02T20:17:04Z
dc.date.issued2008en
dc.identifier.urihttps://hdl.handle.net/10182/1082
dc.description.abstractPoison operations are a widely used technique for rodent control in the indigenous forests of New Zealand. This study examined the bait-take and rat monitoring data obtained for continuous poison operations at Boundary Stream Mainland Island (BSMI), Hawke’s Bay, between 1996 and 2007. Since the beginning of the Mainland Island project at BSMI in 1996, 800 ha of indigenous forest have been treated with an ‘Integrated Pest Management’ approach, in which rodents (primarily ship rats) have been targeted by consecutive ground poison operations. The aim of the intensive pest control was to allow the ecosystem to recover and provide a safe environment for threatened native bird species to recover or be re-introduced. Another important aim of this pest control is to provide experience and expert knowledge in management techniques especially applicable to the protection of indigenous habitat on the New Zealand mainland. This research study had two main aims: to identify spatial patterns of the rodent population at BSMI and to determine the efficacy of the different rodenticides applied for their control. The distribution of the rodent population was investigated by spatial analysis of bait-take across the reserve and through time. Visualisation of high and low bait-take areas revealed that there was a noticeable reinvasion from adjacent unmanaged native forests, but not markedly from exotic forest or pasture. Reinvasion from small and isolated adjacent forests ceased to be noticeable consistently after approximately four years of the poison operation, while a large scenic native reserve, as well as a narrow part of the treatment area surrounded by many native bush patches, were continuously affected by reinvasion through the entire project time. Bait-take was visibly higher after the bait had either been removed, or left in the field unserviced, over winter. No consistent areas of no bait-take were identified. Further statistical analysis of bait-take data revealed that bait-take was higher in bait stations within 150 m of the treatment edge than interior bait stations. Bait-take in broadleaf/tawa/podocarp forest was significantly higher than in kamahi/kanuka/rewarewa, beech and cloud-cap forest. The second aim of the study was to determine the efficacy of the various bait types with different active ingredients used during the operation. Rat monitoring data, namely rat tracking indices (RTI) obtained from tracking tunnels, were statistically modelled using Generalised Linear Models. Diphacinone cereal pellets (Pestoff® 50D, 0.05g/kg diphacinone) obtained the lowest RTI, followed by pindone cereal pellets (Pindone Pellets®, 0.5g/kg pindone), brodifacoum cereal pellets (Pestoff® 20p and Talon®, 0.02 g/kg brodifacoum), coumatetralyl paste (Racumin®, 0.375 g/kg) and diphacinone bait blocks (Ditrac®, 0.05 g/kg). Cereal pellet baits worked better than any other bait type used at this location. Season had no statistically significant effect on either RTI or bait-take estimates. The overall goal of the poison operation to decrease rat numbers, and to maintain low levels, has been met. However, the results of this study suggest that baiting needs to be done continuously and over the entire treatment area. Edge bait stations – particularly next to adjacent native forests – should be prioritised to target reinvading rodents. Poisons presented in cereal pellet baits should be preferred to other bait types. Both pindone and brodifacoum showed very good results, as well as diphacinone in cereal pellet baits.en
dc.language.isoenen
dc.publisherLincoln Universityen
dc.subjectmainland islandsen
dc.subjectrodentsen
dc.subjectship ratsen
dc.subjectRattus rattusen
dc.subjectnative foresten
dc.subjectconservationen
dc.subjectpest controlen
dc.subjectground controlen
dc.subjectbait stationsen
dc.subjectbait efficacyen
dc.subjectbrodifacoumen
dc.subjectpindoneen
dc.subjectdiphacinoneen
dc.subjectcoumatetralylen
dc.subjectwarfarinen
dc.subjectcholecalciferolen
dc.subject1080en
dc.titleSpatial distribution of the rodent population at Boundary Stream Mainland Island and determination of the efficacy of different baits used for rodent controlen
dc.typeThesis
thesis.degree.grantorLincoln Universityen
thesis.degree.levelMastersen
thesis.degree.nameMaster of International Nature Conservationen
dc.subject.marsdenFields of Research::300000 Agricultural, Veterinary and Environmental Sciencesen
dc.subject.marsdenFields of Research::270000 Biological Sciencesen
lu.contributor.unitLincoln Universityen
lu.contributor.unitBio-Protection and Ecologyen
pubs.organisational-group/LU
pubs.organisational-group/LU/BPEC
pubs.publication-statusPublisheden


Files in this item

Default Thumbnail

This item appears in the following Collection(s)

Show simple item record