What do rabbits have to do with saving a rare seabird?
asserted
rabbits → have → seabird
On a small island off the coast of New South Wales, their presence was damaging the very habitat Gould’s petrels needed to survive.
asserted
petrels → damage → habitat
Getting rid of them became an important part of a much larger conservation effort.
asserted
rid → rid → effort
In 1997, conservationists successfully eradicated rabbits from Cabbage Tree Island as they worked to protect the seabird and its breeding grounds.
asserted
they → eradicate → seabird
According to the New South Wales National Parks and Wildlife Service, conservationists worked to restore Gould’s petrel habitat and establish a second breeding colony on nearby Boondelbah Island.
uncertain
conservationists → accord → Island
By 2000, the island was home to more than 800 breeding pairs, producing over 400 young annually.
asserted
island → produce → young
The turnaround showed how removing an invasive species, alongside other conservation measures, could help a threatened seabird recover.
uncertain
seabird → show → measures
How rabbits became a problem for Gould’s petrel
Cabbage Tree Island, near Port Stephens in New South Wales, is an important breeding site for Gould’s petrel, a seabird native to Australia.
asserted
Island → become → Australia
But the island’s vegetation faced a problem after European rabbits were introduced in 1906.
asserted
rabbits → face → 1906
As the animals fed on plants and seedlings, they made it harder for the forest to regenerate.
asserted
forest → feed → plants
Cabbage tree palms and other plants formed part of the habitat that supported the petrels during their breeding season.
asserted
that → form → season
When rabbits ate seedlings before they could mature, the island’s natural vegetation struggled to replace itself.
uncertain
vegetation → eat → itself
Surveys carried out between 1989 and 1992 recorded an average of about 220 breeding pairs on Cabbage Tree Island.
asserted
Surveys → carry → Island
Annual production was low, with fewer than 50 young reported in the early 1990s.
asserted
young → report → 1990s
Pied currawongs preyed on the birds, while the sticky fruits of birdlime trees could trap petrels.
uncertain
fruits → prey → petrels
With several problems affecting the colony at once, conservationists realised that protecting the bird would require more than one intervention.
asserted
protecting → affect → intervention
The programme addressed the threats to the birds while also tackling the damage being done to their habitat.
asserted
programme → address → habitat
The operation that removed the rabbits
The rabbit eradication campaign reached its decisive stage in 1997.
asserted
campaign → remove → 1997
A research paper published in Biological Conservation in 2000 by David Priddel, Nicholas Carlile and Robert Wheeler documented how the operation unfolded.
asserted
operation → publish → Priddel
Rather than relying on a single method, the team used a sequence of measures to bring the rabbit population under control.
asserted
team → rely → control
Myxomatosis spread naturally across the island between May and July 1997, reducing the estimated population from around 250 rabbits to 100.
Rabbit haemorrhagic disease was released in August 1997 and reduced the rabbit population by a further 55%.
uncertain
disease → spread → %
In September, conservationists used aerial baiting to deal with the remaining animals.
asserted
conservationists → use → animals
The bait contained brodifacoum, an anticoagulant poison.
asserted
bait → contain → brodifacoum
The team also tracked rabbits fitted with monitoring devices to assess the effectiveness of the campaign.
asserted
team → track → campaign
Within 13 days of the baiting operation, the remaining rabbits had been eliminated.
asserted
rabbits → remain → operation
Checks over the following six months found no survivors.
asserted
Checks → follow → survivors
The operation did have unintended consequences.
asserted
operation → have → consequences
Researchers recorded the deaths of two buff-banded rails and one pied currawong.
asserted
Researchers → record → rails
Even so, the removal of rabbits eliminated a major source of damage to the island’s vegetation and gave conservationists a better chance of restoring the breeding habitat.
asserted
removal → eliminate → habitat
By 2000, the numbers told a different story
The improvement in the petrel colony was substantial.
asserted
improvement → tell → colony
By 2000, Cabbage Tree Island had more than 800 breeding pairs, and the birds were producing over 400 young each year.
asserted
birds → have → young
This was a marked change from the low breeding numbers recorded in the early 1990s.
asserted
This → record → 1990s
Removing rabbits helped ease pressure on the vegetation, but it was part of a broader recovery programme.
asserted
it → remove → programme
Conservationists were also managing predators and addressing hazards associated with birdlime trees.
asserted
Conservationists → manage → trees
Together, these efforts helped create more favourable conditions for the birds to breed.
asserted
birds → create → conditions
Still, a growing colony did not mean the species was completely out of danger.
asserted
species → grow → danger
Having a large share of the population concentrated on one small island left it vulnerable to events such as severe storms, fires and the arrival of new predators.
asserted
share → have → predators
That concern led to another important step: establishing a second breeding colony.
asserted
concern → lead → colony
Why conservationists moved chicks to another island
The New South Wales National Parks and Wildlife Service worked to establish a new colony on nearby Boondelbah Island.
asserted
Service → move → Island
The idea was to give Gould’s petrels another breeding location, reducing the risks associated with depending so heavily on a single island.
asserted
idea → give → island
…and 14 more, not listed.
The Aporia
