Macquarie Island and eradication efforts have attracted media attention.
Below are two scientific papers that might provide useful perspective. Note
that the vegetation paper presents data only up to 2011 when rabbit
eradication began. Caution might be advised regarding media reports of
effects since then.--David Duffy

Robinson, S. A. and Copson, G. R. (2014), *Eradication of cats (Felis
catus) from subantarctic Macquarie Island.*Ecological Management &
Restoration, 15: 34–40. doi: 10.1111/emr.12073

*Keywords*: cage trap;cat;eradication;Felis catus;leg-hold trap;Macquarie
Island

*Summary*
The feral Cat (Felis catus) population on Macquarie Island was targeted for
eradication between 1996 and 2002, with 761 cats captured during this
period. After 22 years of cat control from 1974 integrated with control
programmes for other pests, effort intensified for 2 years before a
dedicated eradication programme began in 1998. The primary knock-down for
the eradication used cage trapping and shooting, with most surviving cats
captured with leg-hold traps. A total of 6298 field days and 216 574 trap
nights were recorded in this operation. Factors contributing to the success
of the programme included extensive planning, increased staff numbers at
critical times, better access to remote areas of the island, introduction
of leg-hold traps, sufficient operational funding and good collaboration
between government agencies operating on the island. The programme would
have benefited from earlier deployment of detector dogs and better
posteradication monitoring of a broader range of native species impacted by
cats. The successful eradication of cats from Macquarie Island, being the
second largest achieved to date, provides valuable experience for cat
eradication attempts on other large remote islands. This programme relied
on ground-based techniques with minimal use of poisons and provides
possible options for sites where broad-scale poisoning, or where aerial
distribution of poisons, cannot be used.
------------------------------
Whinam, J., Fitzgerald, N., Visoiu, M. and Copson, G. (2014), *Thirty years
of vegetation dynamics in response to a fluctuating rabbit population on
sub-Antarctic Macquarie Island.* Ecological Management & Restoration, 15:
41–51. doi: 10.1111/emr.12076

*Keywords:* conservation management;disturbance;ecosystem processes;island
management;pest animals;World Heritage Areas

*Summary*
Australia's sub-Antarctic Macquarie Island is presently undergoing one of
the most ambitious vertebrate pest eradication programmes ever undertaken.
The anticipated success of this programme will release the island's
tundra-like vegetation from well over a century of grazing and disturbance
from House Mouse (Mus musculus), Ship Rat (Rattus rattus) and most
significantly European Rabbit (Oryctolagus cuniculus). This study describes
results from 30 years of vegetation quadrat monitoring (prior to the most
recent and comprehensive pest eradication programme) when lower level pest
animal control programmes were underway. Plant species were assigned to one
of five distinct functional plant groups: Indigenous short-lived
perennials, Introduced short-lived perennials, Indigenous perennials rarely
grazed by rabbits, Indigenous perennials occasionally grazed by rabbits and
Indigenous long-lived perennials heavily grazed by rabbits, with one
species, Agrostis magellanica, analysed as a sixth monospecific group.
Results from monthly rabbit counts were used to compare changes in
abundance of these six groups under different rabbit populations. It was
found that there were three distinct phases of rabbit activity during the
study period, indicated by (i) an initial very high count year in
1980–1981, followed by (ii) 20 years of low counts ending in 2001–2002
after which (iii) counts rose to medium/high until the commencement of the
eradication programme in 2010–2011. Vegetation composition and progression
were distinct for these three rabbit count phases. The first four of the
plant functional groups decreased under lower count periods and increased
in cover under higher rabbit count periods. Agrostis magellanica appears to
respond primarily to interspecies competition and is disadvantaged under
extended periods of low rabbit numbers. Indigenous long-lived perennials
heavily grazed by rabbits, which includes the large tussocks and megaherbs,
is inversely related to rabbit numbers. During the study period, there has
also been an overall decline in plant species richness with average species
count per quadrat falling by between 0.6 and 2.7 taxa. This study attempts
to address the observed vegetation change from this long-term monitoring,
to discuss other potential contributing factors and to use the results to
predict likely future vegetation changes after eradication of vertebrate
pests

-- 

Pacific Cooperative Studies Unit
Botany
University of Hawaii
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