The Wedge-tailed Shearwater Puffinus pacificus is the only seabird currently known to breed within the James Campbell National Wildlife Refuge on the Hawaiian island of Oahu.  Reproductive success is unknown but predation is reported as a limiting factor.  An intensive, year-round predator control programme aims to reduce the impact of invasive predators.

Several other seabird species have been identified for introduction by the refuge’s 2011 conservation plan because of their habitat preferences at other breeding sites in Hawaii that resemble the conditions at the Refuge.  These include Laysan Albatross Phoebastria immutabilis and Black-footed Albatross P. nigripes.  These species are currently observed along the Refuge coastline and in the general vicinity.  Laysan Albatrosses have attempted to breed near the Refuge in the past but were thought to have been killed by domestic dogs; introduced albatrosses would thus need to be protected by a predator-proof fence.

“As rising sea levels begin to negatively impact important seabird nesting sites in more vulnerable remote Pacific islands, nesting sites on the main Hawaiian Islands (which are generally higher in elevation) will become increasingly important,” including for Laysan Albatrosses.

Laysan Albatrosses, photograph by Ross Wanless

One possible source for founders of a new seabird colony could be Laysan Albatross eggs from the exchange programme at the Pacific Missile Range Facility Barking Sands on Kauai where eggs are removed to reduce risks of bird air strikes (click here).  The chicks from these eggs could then be hand reared at the refuge and allowed to fledge from the colony site.

Reference:

O‘ahu National Wildlife Refuge Complex 2011.  James Campbell National Wildlife Refuge Draft Comprehensive Conservation Plan and Environmental Assessment.  Honolulu: U.S. Fish & Wildlife Service.  283 pp.

John Cooper, ACAP Information Officer, 18 August 2014

Last month, ACAP Latest News reported on plans to rid New Zealand’s Great Mercury Island of its alien rats and cats (click here).

Great Mercury Island

News is in from the Department of Conservation that two aerial bait drops were successfully completed on Great Mercury last week (click here).  Time will tell –in about two years’ time - whether the island has become rat free, helping its breeding Grey-faced Petrels Pterodroma macroptera gouldi.

The Mercury Islands are a group of seven islands eight kilometres off the north-east coast of the North Island of New Zealand.  The six smaller islands in the group are rodent free after eradication operations between 1987 and 1997 removed Pacific Rats Rattus exulans.  They have been identified as an Important Bird Area by BirdLife International because they support up to 3000 breeding pairs of Pycroft's Petrels Pterodroma pycrofti, as well as Little Shearwaters Puffinus assimilis.  Removing rats from Great Mercury will help with biosecurity for the rest of the island group: all rat-free seabird islands.

“Removing the rats and feral cats from the island involved precisely targeted aerial applications of bait using specially designed buckets carried by helicopter.  The helicopter pilots use satellite navigation (GPS) technology to ensure the bait is spread only where intended.”

This year marks 50 years since the first New Zealand island was made pest free.  Ruapuke/ Maria Island was declared pest free in 1964 after the successful removal of Norway Rats Rattus norvegicus.

Read more on the Great Mercury operation here.

John Cooper, ACAP Information Officer, 17 August 2014

Predation by the Black Rat Rattus rattus threatens the World’s largest population of Yelkouan Shearwaters Puffinus yelkouan on Italy’s Tavolara Island off the north-east coast of Sardinia.  Tavolara falls within the Punta Coda Cavallo Marine Preserve but its shearwaters (and its Mediterranean Storm Petrels Hydrobates pelagicus melitensis) can only breed successfully in caves in rat-free cliffs.  In addition Scopoli’s Shearwater Calonectris diomedea breeds in small numbers.

The island’s population of 9991 to 13 424 pairs of Yelkouan Shearwaters (a potential candidate for ACAP listing) is to be protected by EU LIFE Project Puffinus Tavolara NAT/IT/000416 that aims to eradicate both Black Rats and House Mice Mus musculus over the period 2103 to 2017.  Rodenticide baits will be distributed from the air on Tavolara and on three small islets - except along the coast and in the few inhabited areas (click here).  The project aims to increase the number of fledging shearwaters post rats to 5000 to 8000 a year.

Yelkouan Shearwater, photograph by Matthew Borg Cardona

The project will also attempt to eradicate two species of invasive plants, a 40% reduction of the island’s feral goats Capra aegagrus hircus and establish improved biosecurity measures.

John Cooper, ACAP Information Officer, 16 August 2014

Back in 2012 ACAP Latest News reported on the Kellian Line Setter, an underwater setting device initially developed by New Zealander Dave Kellian to mitigate seabird bycatch in demersal (bottom) longline fisheries (click here).

Sea trials on board a 10-m bottom longliner have been taking place since then as reported earlier this year to the New Zealand Department of Conservation’s Conservation Services Programme.  Trials were conducted off New Zealand and have led to further suggestions for improvement to the device: “[t]he developments outlined … may be best achieved by taking the setter back to the Australian Maritime College where modifications could be made and subsequent performance assessed in the flume tank.  Ideally the setter could then be briefly taken to sea in Australia to confirm that the results from the flume tank can be then be achieved behind a vessel at speeds of 5 ‐ 6 knots.  Further development in the flume tank would also provide the opportunity to fine tune the funnel shape and paravane settings to optimise performance, prior to continuing further sea trials in New Zealand where operational performance and workability of the setter can be assessed under normal fishing conditions.”

Grey Petrel at sea - and at risk to longliners, photograph by Peter Ryan

Reference:.

Baker, G.B., Goad, D., Kiddie, B. & Frost, R. 2014. Kellian Line Setter Sea Trials Initial Performance Testing.  Report prepared for Department of Conservation Contract 4529  [Kettering]: Latitude 42 Environmental Consultants Pty Ltd.  7 pp. 

John Cooper, ACAP Information Officer, 15 August 2014