UPDATE:  Read of progress here.  "Some 28,000 bait stations were filled across farmed and residential areas starting 22 May, and helicopters will scatter baits over more forested and mountainous parts of the island as soon as weather permit[s]."

The Lord Howe Island Rodent Eradication Project aims to eradicate introduced Ship Rats Rattus rattus and House Mice Mus musculus from Australia’s World Heritage Lord Howe Island (14.55 km²⁾, inter alia to help protect its breeding populations of burrowing petrels and shearwaters.  The one-off eradication will distribute a cereal-based bait pellet (Pestoff 20R) containing 0.02 g/kg (20 parts per million) of the toxin Brodifacoum over the island by helicopter drop, coupled with bait stations in inhabited areas, including in and around dwellings and other buildings in the settlement area, as well as set out in a 10-m grid in pasture land.  Following years of planning and some delays and postponements (click here) implementation of the eradication exercise has recently received final approval from the Lord Howe Island Board and is now targeted for the austral winter months of June to August this year.

Lord Howe Island

At risk to rats: a globally Near Threatened Flesh-footed Shearwater Ardenna carnepeis pair on Lord Howe Island

According to information received earlier this month by ACAP Latest News from island naturalist, Ian Hutton, activities have already commenced ashore: 50 personnel have deployed no less than 24 000 empty bait stations which arrived on the island in late April.  Poison bait will be added to the stations from 20 May.  Two helicopters for aerial baiting of the non-inhabited, mountainous parts and coastal cliffs of the island are on their way to the island from Hobart and are expected to arrive on the 14th.  Aerial baiting is set to commence as soon as weather conditions will allow from 1 June, with a repeat operation planned two weeks later.

Get past that if you can: pasture land on Lord Howe Island with roofed rodent bait stations set out on a 10-m grid

A rodent bait station on Lord Howe Island

Large numbers of two species of land birds, the Lord Howe Pied Currawong Strepera graculina crissalis (120 caught), an island-endemic subspecies, and the endemic and Endangered Lord Howe Woodhen Hypotaenidia sylvestris (250), both determined to be at risk to non-target poisoning, are being taken into protective temporary housing on the island, following advice on rodent- and bait-proof enclosures and husbandry received from Sydney’s Taronga Zoo.  They will be released four months after the bait drop, when it is considered they will be no longer be at risk to poisoning.

Read recent news reports on the go-ahead here and here.

The above news was briefly mentioned under item 6.1. “Updates on management of land-based threats” at the Fifth Meeting of ACAP's Population and Conservation Status Working Group (PaCSWG5), that too place in Floreanópolis, Brazil on 9 and 10 May.

ACAP Latest News will report on the fortunes of the eradication attempt as further information comes to hand.

With thanks to Ian Hutton for information and photographs.

John Cooper, ACAP Information Officer, 09 May 2019, updated 12 May 2019 & 06 June 2019

Lauren Roman (CSIRO Oceans and Atmosphere, Hobart, Tasmania, Australia) and colleagues have published in the Marine Pollution Bulletin on plastic items found in corpses of 20 species of petrels and shearwaters beach-washed or killed by fisheries in Australasia; most were 2-10 mm in dimension.

The paper’s abstract follows:

“Pollution of the world's oceans by marine debris has direct consequences for wildlife, with fragments of plastic <10 mm the most abundant buoyant litter in the ocean.  Seabirds are susceptible to debris ingestion, commonly mistaking floating plastics for food.  Studies have shown that half of petrel species regularly ingest anthropogenic waste.  Despite the regularity of debris ingestion, no studies to date have quantified the dimensions of debris items ingested across petrel species ranging in size.  We excised and measured 1694 rigid anthropogenic debris items from 348 petrel carcasses of 20 species.  We found that although the size of items ingested by petrels scale positively with the size of the bird, 90% of all debris items ingested across species fall within a narrow “danger zone” range of 2–10 mm, overlapping with the most abundant oceanic debris size.  We conclude that this globally profuse size range of marine plastics is an ingestion hazard to petrels.”

A Flesh-footed Shearwater yields its plastic load, photograph by Ian Hutton

Read a popular article on the study here.

Reference:

Roman, L., Paterson, H., Townsend, K.A., Wilcox, C., Hardesty, B.D. & Hindell, M.A. 2019.  Size of marine debris items ingested and retained by petrels.  Marine Pollution Bulletin 142: 569-575.

John Cooper, ACAP Information Officer, 06 June 2019

Saskia Wischnewski (School of Biological, Earth and Environmental Sciences, University College Cork, Ireland) and colleagues have published in the journal Animal Behaviour on foraging strategy choice by Manx Shearwaters Puffinus puffinus feeding their young.

The paper’s abstract follows:

“Parental care can lead to a conflict of interest between parents and offspring.  For central place foragers, conflict is expected to be particularly intensive in species that feed on relatively inaccessible, distant food resources. Some pelagic seabirds use distinct foraging strategies when provisioning young versus self-feeding: short trips near the colony versus long trips far away. Limited empirical evidence suggests that the strategy used by parents depends on their own state and that of their young, suggesting that dynamic optimization may help reduce conflict.  Tests of this hypothesis, however, are scarce.  Using a combination of GPS tracking and nest monitoring, we examined whether foraging strategy choice by Manx shearwaters, Puffinus puffinus, is explained by the body condition of parents and offspring before trip departure, and whether choice affects condition upon return.  When chick body condition was poor prior to departure, subsequent foraging trips by adults were significantly shorter and faster, and chick condition upon return improved.  When chick condition was good prior to departure, the reverse happened.  There was no evidence that adult condition affected subsequent trip choice, but adults returning from slow, long-duration trips were in comparatively better condition.  Thus, although the trips that were good for offspring were different to those that were favourable for adults, trip choice was only dependent on chick condition, which may explain why there was no evidence for a trade-off between adult and chick condition during individual trips.  Our results suggest that spatiotemporal variation in foraging strategies is driven by the conflicting needs of parents and offspring, but that the parents can reduce the conflict, resulting in no detectable trade-off under these conditions.  This link between parental care and space use is likely to be widespread in central place foragers but remains largely unexplored in most systems.”

Manx Shearwater, photograph by Nathan Fletcher

Reference:

Wischnewski, S., Arneill, G.E., Bennison, A.W., Dillan, E., Poupart, T.A., Hinde, C.A., Jessopp, M.J. & Quinn, J.L. 2019.  Variation in foraging strategies over a large spatial scale reduces parent–offspring conflict in Manx shearwaters.  Animal Behaviour 151: 165-176.

John Cooper, ACAP Information Officer, 05 June 2019

The Royal Society for the Protection of Birds (RSPB) is leading the eradication of introduced House Mice Mus musculus from the United Kingdom’s Gough Island in the South Atlantic in the austral winter of next year as a key component of the Gough Island Restoration Programme.  Mice on Gough attack and kill many seabirds, including chicks of several ACAP-listed species, most notably the Critically Endangered and near-endemic Tristan Albatross Diomedea dabbenena, as well as of burrowing petrels, such as the Endangered McGillivray’s Prion Pachyptila mcgillivrayi, only recently discovered to be breeding on the island.

Tristan Albatrosses display on Gough Island, photograph by Tom McSherry

The operation to eradicate the mice by the aerial distribution of poison bait will be undertaken in three main phases:

March – May 2020.  Establishment of baiting and aviculture infrastructure by the Avicultural Team.  Capture and holding of populations of the endemic and Critically Endangered Gough Bunting or Finch Rowettia goughensis and the Vulnerable Gough Moorhen Gallinula comeri, both of which studies have shown will be at risk to non-target poisoning.

May – August 2020.  Arrival of the Baiting Team, bait, helicopters etc.  Baiting undertaken and demobilisation of baiting team.  Ongoing captive holding of finches and moorhens.

September – December 2020.   Staged release of the captive finches and moorhens.

The baiting operation will involve the aerial application of c. 200 tonnes of cereal bait approximately 20 persons is required for the Baiting Team.  The team will leave Cape Town on South Africa’s Antarctic research and supply vessel, the S.A. Agulhas II, in mid-May and return to Cape Town at the end of August.  Accommodation while on Gough Island will be in shared bedrooms in the South African weather station or in a Weatherhaven portable shelter.

The primary role for the Baiting Team will be to load manually 25-kg bags of bait (up to 36 bags per load) into the helicopter spreader buckets in rapid succession.  All the team members must be able to lift 25-kg bags up to one metre high for most of a day at one of two loading sites operating simultaneously.  Having additional technical skills (e.g. radio communication, mechanical, electrical, engineering, construction) will be seen as a decided advantage in choosing successful applicants.

Other tasks that the team will be required to undertake include training, assisting with unloading and reloading the ship, establishing and maintaining a remote field camp, setting up loading sites for each operational day, disposing of empty bags and bait storage pods, assisting with hand baiting around the base and domestic duties including cleaning and assisting with cooking.

Read more details of requirements to be a bait loader and how to apply here or contact This email address is being protected from spambots. You need JavaScript enabled to view it..

If you have avicultural experience and are interested in a role with the Aviculture Team contact This email address is being protected from spambots. You need JavaScript enabled to view it..

The RSPB is the lead organization in delivering the Gough Island Restoration Programme, working in close partnership with the Tristan da Cunha Council and Government, BirdLife South Africa, the (recently renamed) South African Department of Environment, Forestry and Fisheries and Island Conservation.  The programme is part-funded by the RSPB, the UK Government, the National Fish and Wildlife Foundation and other individuals and organisations.  The Gough Island Restoration Programme may also be followed on Facebook.

Read previous posts in ACAP Latest News on the depredations of Gough’s “killer’ mice here.

With thanks to Andrew Callender, Carol Jacobs and Pete McClelland.

John Cooper, ACAP Information Officer, 04 June 2019

A wounded Tristan Albatross chick is dying in a Gough study colony following nocturnal attacks by House Mice

Photograph by Karen Bourgeois and Sylvain Dromzee