Pub Date : 2022-12-06DOI: 10.20417/nzjecol.47.3510
T. Etherington, Philip O'Lyver, Leilani A. Walker
{"title":"Initiating open access licensing in the New Zealand Journal of Ecology to further promote ecological science and better align copyright with the intent of Te Tiriti o Waitangi","authors":"T. Etherington, Philip O'Lyver, Leilani A. Walker","doi":"10.20417/nzjecol.47.3510","DOIUrl":"https://doi.org/10.20417/nzjecol.47.3510","url":null,"abstract":"","PeriodicalId":49755,"journal":{"name":"New Zealand Journal of Ecology","volume":"22 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67539644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-01DOI: 10.20417/nzjecol.47.3512
J. Ogden, G. Perry
: The arrangement of plant species along elevational gradients is prominent in the debate between individualistic versus community-unit concepts in plant ecology. We obtained elevational ranges (upper and lower elevation limits) for woody species and ferns on the three highest mountains on Aotea (Great Barrier Island), Aotearoa-New Zealand. These data allowed potential species composition to be obtained for any elevation and were analysed using regression, ordination, and classification. Both woody plants and ferns demonstrated linear declines in richness with increasing elevation. The three mountains were distinct in ordination space, and their differences increased with elevation and were most marked in the fern flora. Site classifications indicated a change in composition at c. 300 m for woody plants on Hirakimata. The elevational distribution patterns of individual species differed considerably between mountains. In particular, the higher-elevation flora of the highest peak (Hirakimata) was largely absent from the other two summits, despite these being within the elevational ranges of most of the missing species. This pattern supports Steenis’s (1972) hypothesis that species will be absent from, or ephemeral on, mountains not sufficiently high to intersect their zone of permanent establishment. A second observed pattern was that widespread forest species at lower elevations often did not extend to their potential upper limits on Hirakimata. These two patterns are clear for both woody plant species and ferns. Combining Steenis’s hypothesis with inferred redistribution of elevational vegetation during the Last Glacial and Holocene periods can explain these distributional patterns
{"title":"Ranges of woody plant species and ferns on forested elevational gradients on Aotea-Great Barrier Island, New Zealand: the role of zones of permanent and temporary establishment","authors":"J. Ogden, G. Perry","doi":"10.20417/nzjecol.47.3512","DOIUrl":"https://doi.org/10.20417/nzjecol.47.3512","url":null,"abstract":": The arrangement of plant species along elevational gradients is prominent in the debate between individualistic versus community-unit concepts in plant ecology. We obtained elevational ranges (upper and lower elevation limits) for woody species and ferns on the three highest mountains on Aotea (Great Barrier Island), Aotearoa-New Zealand. These data allowed potential species composition to be obtained for any elevation and were analysed using regression, ordination, and classification. Both woody plants and ferns demonstrated linear declines in richness with increasing elevation. The three mountains were distinct in ordination space, and their differences increased with elevation and were most marked in the fern flora. Site classifications indicated a change in composition at c. 300 m for woody plants on Hirakimata. The elevational distribution patterns of individual species differed considerably between mountains. In particular, the higher-elevation flora of the highest peak (Hirakimata) was largely absent from the other two summits, despite these being within the elevational ranges of most of the missing species. This pattern supports Steenis’s (1972) hypothesis that species will be absent from, or ephemeral on, mountains not sufficiently high to intersect their zone of permanent establishment. A second observed pattern was that widespread forest species at lower elevations often did not extend to their potential upper limits on Hirakimata. These two patterns are clear for both woody plant species and ferns. Combining Steenis’s hypothesis with inferred redistribution of elevational vegetation during the Last Glacial and Holocene periods can explain these distributional patterns","PeriodicalId":49755,"journal":{"name":"New Zealand Journal of Ecology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48701929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-28DOI: 10.20417/nzjecol.47.3500
S. Horn, R. Sagar, V. Frank, Finlay Cox, Paul Jacques, James Ware, Rose Hanley-Nikolls, Estelle Leask, Norm Macdonald, Micaela Kirby-Crowe, Mark Le Lievre, K. Broome
Pub Date : 2022-11-28DOI: 10.20417/nzjecol.47.3492
K. McInnes, Micah Jenson, Inga Bolt, Pauline Howard, Sam Lee, Norma. MacDonald, Finlay Cox
Judas pigs (Sus scrofa) will be integral to the success of the proposed Auckland Island (45 891 ha) pig eradication. Judas pigs must be permanently unable to breed and reliably retain a radio-transmitter to enable tracking and retrieval. This study tested the techniques and practical requirements to undertake the procedures required to produce a Judas pig in a remote location. Four adult female wild pigs were captured using a netgun from a helicopter and processed at a base site in the field. They were anaesthetised using intramuscular injection of one of two anaesthetic protocols (ZoletilTM, ketamine and xylazine; or medetomidine, ketamine and butorphanol). Surgical sterilisation consisted of tubal ligation and resection via a ventral midline incision. Pigs received either a subcutaneous or intra-abdominal implanted radio-transmitter and had a radio-collar and radioear tag attached. The anaesthetic was reversed prior to release close to the capture location. Radio-tracking at 10 and 104 days showed all pigs had survived and radio-tracking was effective using all the transmitter types. Pigs were humanely dispatched and necropsied on day 104. No adverse events were detected from the surgeries or radio-transmitters. All transmitter types except one subcutaneous transmitter model were shown to be secure and had an effective radio range for a Judas pig programme. Pig growth rates implicate a limited humane collaring period and ear transmitters may be at greater risk of transmitter loss. Implantable intra-abdominal radio transmitters provide the most security, but multiple transmitters are advised. Surgical sterilisation by tubal ligation and resection under general anaesthesia using an intramuscular injection containing medetomidine, butorphanol and ketamine and reversed with atipamezole was shown to be feasible in field conditions.
{"title":"A field test of the anaesthetics, surgical methods and radio-transmitters required for producing Judas pigs for an eradication programme","authors":"K. McInnes, Micah Jenson, Inga Bolt, Pauline Howard, Sam Lee, Norma. MacDonald, Finlay Cox","doi":"10.20417/nzjecol.47.3492","DOIUrl":"https://doi.org/10.20417/nzjecol.47.3492","url":null,"abstract":"Judas pigs (Sus scrofa) will be integral to the success of the proposed Auckland Island (45 891 ha) pig eradication. Judas pigs must be permanently unable to breed and reliably retain a radio-transmitter to enable tracking and retrieval. This study tested the techniques and practical requirements to undertake the procedures required to produce a Judas pig in a remote location. Four adult female wild pigs were captured using a netgun from a helicopter and processed at a base site in the field. They were anaesthetised using intramuscular injection of one of two anaesthetic protocols (ZoletilTM, ketamine and xylazine; or medetomidine, ketamine and butorphanol). Surgical sterilisation consisted of tubal ligation and resection via a ventral midline incision. Pigs received either a subcutaneous or intra-abdominal implanted radio-transmitter and had a radio-collar and radioear tag attached. The anaesthetic was reversed prior to release close to the capture location. Radio-tracking at 10 and 104 days showed all pigs had survived and radio-tracking was effective using all the transmitter types. Pigs were humanely dispatched and necropsied on day 104. No adverse events were detected from the surgeries or radio-transmitters. All transmitter types except one subcutaneous transmitter model were shown to be secure and had an effective radio range for a Judas pig programme. Pig growth rates implicate a limited humane collaring period and ear transmitters may be at greater risk of transmitter loss. Implantable intra-abdominal radio transmitters provide the most security, but multiple transmitters are advised. Surgical sterilisation by tubal ligation and resection under general anaesthesia using an intramuscular injection containing medetomidine, butorphanol and ketamine and reversed with atipamezole was shown to be feasible in field conditions.","PeriodicalId":49755,"journal":{"name":"New Zealand Journal of Ecology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45110241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-28DOI: 10.20417/nzjecol.47.3493
M. Rodríguez-Recio, R. Sagar, Lindsay Chan, Finlay Cox, Paul Jacques
: Restoration initiatives of ecosystems transformed by human actions require optimisation of eradication measures of introduced species, particularly in fragile insular ecosystems. We studied aspects of the spatial ecology of introduced feral cats ( Felis catus ) on subantarctic Auckland Island of New Zealand to assist eradication efforts of pests from this remote, biologically rich island. Firstly, we estimated home range sizes and identified core areas of activity based on movement-rooted dynamic Brownian bridge models. Second, we used resource selection functions with generalised linear mixed models to identify seasonal patterns of space use associated to topographic, vegetation and other landscape predictors. Lastly, we quantified cats daily movement rates within home ranges. Average home range size was larger than on other offshore islands and mainland New Zealand, which might relate to lower cat densities and the abundance and predictability of food resources on the island. Cats mostly selected mosaic areas of forest, shrubs and tall tussocks near the coast, and in predominantly flat areas or nearby steep cliffs, which are all typical habitats of seabirds and terrestrial birds. Cats also selected alpine short tussocks during the cold season, likely related to the upsurge of mice ( Mus musculus ) due to tussock mast seeding and to transiting to steep cliffy areas. Male cats had home ranges that were larger, contained more core areas, and covered longer daily distances in the warm season than females, which might be associated with different breeding and reproductive behaviour. Eradication tools will need to target all habitats on Auckland Island with increased efforts in areas of identified higher use by cats. Understanding aspects of pest species’ spatial ecology on offshore islands worldwide can assist decision-makers in optimising eradication programs such as Predator Free 2050 in New Zealand.
{"title":"Spatial ecology meets eradication of feral cats on Auckland Island","authors":"M. Rodríguez-Recio, R. Sagar, Lindsay Chan, Finlay Cox, Paul Jacques","doi":"10.20417/nzjecol.47.3493","DOIUrl":"https://doi.org/10.20417/nzjecol.47.3493","url":null,"abstract":": Restoration initiatives of ecosystems transformed by human actions require optimisation of eradication measures of introduced species, particularly in fragile insular ecosystems. We studied aspects of the spatial ecology of introduced feral cats ( Felis catus ) on subantarctic Auckland Island of New Zealand to assist eradication efforts of pests from this remote, biologically rich island. Firstly, we estimated home range sizes and identified core areas of activity based on movement-rooted dynamic Brownian bridge models. Second, we used resource selection functions with generalised linear mixed models to identify seasonal patterns of space use associated to topographic, vegetation and other landscape predictors. Lastly, we quantified cats daily movement rates within home ranges. Average home range size was larger than on other offshore islands and mainland New Zealand, which might relate to lower cat densities and the abundance and predictability of food resources on the island. Cats mostly selected mosaic areas of forest, shrubs and tall tussocks near the coast, and in predominantly flat areas or nearby steep cliffs, which are all typical habitats of seabirds and terrestrial birds. Cats also selected alpine short tussocks during the cold season, likely related to the upsurge of mice ( Mus musculus ) due to tussock mast seeding and to transiting to steep cliffy areas. Male cats had home ranges that were larger, contained more core areas, and covered longer daily distances in the warm season than females, which might be associated with different breeding and reproductive behaviour. Eradication tools will need to target all habitats on Auckland Island with increased efforts in areas of identified higher use by cats. Understanding aspects of pest species’ spatial ecology on offshore islands worldwide can assist decision-makers in optimising eradication programs such as Predator Free 2050 in New Zealand.","PeriodicalId":49755,"journal":{"name":"New Zealand Journal of Ecology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49345526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-28DOI: 10.20417/nzjecol.47.3485
Derek Brown, Finlay Cox
: Cattle ( Bos taurus ) were liberated on 695 ha Enderby Island, the northernmost of the Auckland Island group, in 1894–96, after a previous liberation had died out. After reaching a peak population of c. 100 animals, they established a relatively stable population of 35–60 animals for the latter half of the 20th century. Eradication was mandated in the 1987 Auckland Islands Management Plan, but proposals for eradication were not universally supported due to the interesting traits of this long-isolated population and its adaptation to the subantarctic environment of the island. Therefore, retrieval of genetic material was permitted before the planned operation. Eradication of the cattle occurred between 1991 and 1993, with at least 47 animals shot in 3 weeks in February 1991, a further two in March–April 1991, and two in December 1991–January 1992. The only two surviving animals were removed alive in February 1993 for captive breeding. The ecological response is considered significant but unable to be completely differentiated from the effects of subsequent eradication of rabbits and mice. Attempts to preserve genetic material via ova, sperm, and live animals met with limited initial success but a small captive population has been established on mainland New Zealand.
{"title":"The eradication of cattle from Enderby Island and subsequent ecological response","authors":"Derek Brown, Finlay Cox","doi":"10.20417/nzjecol.47.3485","DOIUrl":"https://doi.org/10.20417/nzjecol.47.3485","url":null,"abstract":": Cattle ( Bos taurus ) were liberated on 695 ha Enderby Island, the northernmost of the Auckland Island group, in 1894–96, after a previous liberation had died out. After reaching a peak population of c. 100 animals, they established a relatively stable population of 35–60 animals for the latter half of the 20th century. Eradication was mandated in the 1987 Auckland Islands Management Plan, but proposals for eradication were not universally supported due to the interesting traits of this long-isolated population and its adaptation to the subantarctic environment of the island. Therefore, retrieval of genetic material was permitted before the planned operation. Eradication of the cattle occurred between 1991 and 1993, with at least 47 animals shot in 3 weeks in February 1991, a further two in March–April 1991, and two in December 1991–January 1992. The only two surviving animals were removed alive in February 1993 for captive breeding. The ecological response is considered significant but unable to be completely differentiated from the effects of subsequent eradication of rabbits and mice. Attempts to preserve genetic material via ova, sperm, and live animals met with limited initial success but a small captive population has been established on mainland New Zealand.","PeriodicalId":49755,"journal":{"name":"New Zealand Journal of Ecology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46253704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-28DOI: 10.20417/nzjecol.47.3496
A. Glen, S. Howard, Paul Jacques, R. Sagar, Finlay Cox
: As a major threat to New Zealand’s biodiversity, feral cats ( Felis catus ) are the subject of planned eradications on a number of offshore islands, including Rakiura Stewart Island. We used camera traps to estimate population density of feral cats on the north-east coast of Rakiura, and to investigate their movement behaviour and detection probability. We also used camera footage to compare the consumption of two types of non-toxic sausage baits (chicken and rabbit) with a view to future use of toxic baits. Population density of feral cats was likely between 1 and 2 cats per km 2 . Non-target species (rats and possums) removed more than half the baits, greatly reducing bait availability for feral cats. Deer and birds (including kiwi) encountered baits but did not eat them. Cats had an apparent preference for chicken over rabbit baits, although small sample sizes prevent firm conclusions. Both bait types appeared to decline rapidly in palatability, and no baits were consumed by cats more than 5 days after deployment. Future trials and baiting regimes should consider ways to improve bait availability. Increased bait density, exclusion of rats and possums and/or more frequent replacement of baits will likely increase encounter rates by feral cats.
{"title":"Feral cats on Rakiura Stewart Island: population attributes and potential eradication tools","authors":"A. Glen, S. Howard, Paul Jacques, R. Sagar, Finlay Cox","doi":"10.20417/nzjecol.47.3496","DOIUrl":"https://doi.org/10.20417/nzjecol.47.3496","url":null,"abstract":": As a major threat to New Zealand’s biodiversity, feral cats ( Felis catus ) are the subject of planned eradications on a number of offshore islands, including Rakiura Stewart Island. We used camera traps to estimate population density of feral cats on the north-east coast of Rakiura, and to investigate their movement behaviour and detection probability. We also used camera footage to compare the consumption of two types of non-toxic sausage baits (chicken and rabbit) with a view to future use of toxic baits. Population density of feral cats was likely between 1 and 2 cats per km 2 . Non-target species (rats and possums) removed more than half the baits, greatly reducing bait availability for feral cats. Deer and birds (including kiwi) encountered baits but did not eat them. Cats had an apparent preference for chicken over rabbit baits, although small sample sizes prevent firm conclusions. Both bait types appeared to decline rapidly in palatability, and no baits were consumed by cats more than 5 days after deployment. Future trials and baiting regimes should consider ways to improve bait availability. Increased bait density, exclusion of rats and possums and/or more frequent replacement of baits will likely increase encounter rates by feral cats.","PeriodicalId":49755,"journal":{"name":"New Zealand Journal of Ecology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46383972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-28DOI: 10.20417/nzjecol.47.3482
J. Russell, S. Horn, K. Broome
: New Zealand manages five island groups in the Southern Ocean New Zealand subantarctic region: The Snares (Tini Heke), Bounty Islands, Antipodes Islands, Auckland Islands (Motu Maha or Maungahuka) and Campbell Island / Motu Ihupuku. Charted by Europeans in the late 18th and early 19th centuries, their preservation commenced in the early 20th century and restoration in the late 20th century. Since 1984, eradications of six introduced mammal species (cattle Bos taurus , sheep Ovis aries , goats Capra hircus , rabbits Oryctolagus cuniculus , Norway rats Rattus norvegicus , and mice Mus musculus ) across five islands (Campbell, Antipodes, Auckland, Enderby and Rose) have taken place. The only introduced mammal species remaining in the New Zealand subantarctic region are pigs ( Sus scrofa ), cats ( Felis catus ) and mice on the main Auckland Island. Building on previous eradication work, from 2018 to 2020 the Department of Conservation undertook research and development to determine the feasibility and cost of a multi-species eradication programme on Auckland Island. The outcomes of the research programme not only inform eradication on Auckland Island, but have wider applicability to other eradication programmes throughout the Southern Ocean.
{"title":"Restoration of New Zealand subantarctic islands","authors":"J. Russell, S. Horn, K. Broome","doi":"10.20417/nzjecol.47.3482","DOIUrl":"https://doi.org/10.20417/nzjecol.47.3482","url":null,"abstract":": New Zealand manages five island groups in the Southern Ocean New Zealand subantarctic region: The Snares (Tini Heke), Bounty Islands, Antipodes Islands, Auckland Islands (Motu Maha or Maungahuka) and Campbell Island / Motu Ihupuku. Charted by Europeans in the late 18th and early 19th centuries, their preservation commenced in the early 20th century and restoration in the late 20th century. Since 1984, eradications of six introduced mammal species (cattle Bos taurus , sheep Ovis aries , goats Capra hircus , rabbits Oryctolagus cuniculus , Norway rats Rattus norvegicus , and mice Mus musculus ) across five islands (Campbell, Antipodes, Auckland, Enderby and Rose) have taken place. The only introduced mammal species remaining in the New Zealand subantarctic region are pigs ( Sus scrofa ), cats ( Felis catus ) and mice on the main Auckland Island. Building on previous eradication work, from 2018 to 2020 the Department of Conservation undertook research and development to determine the feasibility and cost of a multi-species eradication programme on Auckland Island. The outcomes of the research programme not only inform eradication on Auckland Island, but have wider applicability to other eradication programmes throughout the Southern Ocean.","PeriodicalId":49755,"journal":{"name":"New Zealand Journal of Ecology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43489838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-28DOI: 10.20417/nzjecol.47.3484
Derek Brown, Finlay Cox
: Cattle ( Bos taurus ) were introduced to 11 268 ha Campbell Island/Motu Ihupuku in 1902 as part of a short-lived farming venture that was abandoned by 1931. The cattle were left to fend for themselves and a small feral population of 10–20 animals persisted for 53 years. The population was largely limited to a small area (c. 440 ha) of the island noted for its limestone geology. Ecological damage was pronounced with churning of the soil, damage to vegetation and probable impact on seabird nesting. Eradication was proposed for 1984 as a precursor to the fencing subdivision of the island for subsequent sheep eradication. Three cattle were shot in January 1984 and although 1–2 animals were known to have survived the cull, for unknown reasons these survivors died out shortly after, and no cattle were seen after winter 1984. Extreme weather events, poor recruitment, and competition with an increasing sheep population may have been partly responsible for the decline to local extinction. The ecological response has been significant but cannot be fully differentiated from the response to subsequent sheep and rat removal.
{"title":"The hunting-assisted demise of Campbell Island cattle","authors":"Derek Brown, Finlay Cox","doi":"10.20417/nzjecol.47.3484","DOIUrl":"https://doi.org/10.20417/nzjecol.47.3484","url":null,"abstract":": Cattle ( Bos taurus ) were introduced to 11 268 ha Campbell Island/Motu Ihupuku in 1902 as part of a short-lived farming venture that was abandoned by 1931. The cattle were left to fend for themselves and a small feral population of 10–20 animals persisted for 53 years. The population was largely limited to a small area (c. 440 ha) of the island noted for its limestone geology. Ecological damage was pronounced with churning of the soil, damage to vegetation and probable impact on seabird nesting. Eradication was proposed for 1984 as a precursor to the fencing subdivision of the island for subsequent sheep eradication. Three cattle were shot in January 1984 and although 1–2 animals were known to have survived the cull, for unknown reasons these survivors died out shortly after, and no cattle were seen after winter 1984. Extreme weather events, poor recruitment, and competition with an increasing sheep population may have been partly responsible for the decline to local extinction. The ecological response has been significant but cannot be fully differentiated from the response to subsequent sheep and rat removal.","PeriodicalId":49755,"journal":{"name":"New Zealand Journal of Ecology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41432384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-28DOI: 10.20417/nzjecol.47.3491
Finlay Cox, Norma. MacDonald
: A feasibility study for removing feral pigs ( Sus scrofa ) from Auckland Island trialled feeders monitored by trail cameras to determine their effectiveness for detecting and attracting feral pigs. Ten automatic feeders were installed during January–February 2019 (summer) and again in August–September 2019 (winter) on Auckland Island. They delivered kibbled maize daily for a period ranging from 25 to 37 days. Sites selected for feeder installation needed to be of appropriate relief and area to allow feeder and trap installation, as would occur during an eradication operation. Feeder success varied across sites during the trial. Site selection where there was evidence of fresh pig presence improved the rate of visitation. Feeders offer significant efficiencies to lethal techniques such as trapping by automatically dispensing feed to allow constant supply over a long period. This automation reduces operator effort, but is also advantageous as consistent feed times train pigs to condition their visits so they can be more effectively targeted. In this trial, most visiting pigs returned to the feeder daily from around 15 days after installation. Automated feeders will be an integral component of the proposed methodology for Auckland Island pig eradication to target nocturnal individuals and family groups, and, importantly, reduce the risk of education through non-lethal engagement.
{"title":"Use of automatic feeders to attract feral pigs on Auckland Island","authors":"Finlay Cox, Norma. MacDonald","doi":"10.20417/nzjecol.47.3491","DOIUrl":"https://doi.org/10.20417/nzjecol.47.3491","url":null,"abstract":": A feasibility study for removing feral pigs ( Sus scrofa ) from Auckland Island trialled feeders monitored by trail cameras to determine their effectiveness for detecting and attracting feral pigs. Ten automatic feeders were installed during January–February 2019 (summer) and again in August–September 2019 (winter) on Auckland Island. They delivered kibbled maize daily for a period ranging from 25 to 37 days. Sites selected for feeder installation needed to be of appropriate relief and area to allow feeder and trap installation, as would occur during an eradication operation. Feeder success varied across sites during the trial. Site selection where there was evidence of fresh pig presence improved the rate of visitation. Feeders offer significant efficiencies to lethal techniques such as trapping by automatically dispensing feed to allow constant supply over a long period. This automation reduces operator effort, but is also advantageous as consistent feed times train pigs to condition their visits so they can be more effectively targeted. In this trial, most visiting pigs returned to the feeder daily from around 15 days after installation. Automated feeders will be an integral component of the proposed methodology for Auckland Island pig eradication to target nocturnal individuals and family groups, and, importantly, reduce the risk of education through non-lethal engagement.","PeriodicalId":49755,"journal":{"name":"New Zealand Journal of Ecology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42999668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：