A view of Lord Howe Island, photograph by Ian Hutton

The Lord Howe Island Rodent Eradication Project has worked to eradicate introduced Ship Rats Rattus rattus and House Mice Mus musculus from Australia’s inhabited Lord Howe Island.  In 2019 after a 15-year period of discussion and planning an attempt was made to eliminate the island’s rodents by a combined aerial- and ground-baiting campaign, as reported in ACAP Latest News.  The prevailing “rule of thumb” is that two years elapse before surveying for rat presence.  This allows for any survivors to breed up to more detectable levels. Only then can the success of an island eradication operation be officially announced.  Although a check was scheduled for August 2021 with success appearing promising, shortly before the two years were up a male and a pregnant female rat were caught on the island in April this year which led to a quick reponse (click here).

The Lord Howe Island Board reported on 4 June:

“Lord Howe Island Board (LHIB) and the [New South Wales] National Parks and Wildlife Service (NPWS) field crews are working together with rodent control experts undertaking rodent baiting and monitoring in and around the settlement area and on the fringes of the Permanent Park Preserve. The team currently working on the rodent response include[s] specialists from Lord Howe Island, mainland NSW, Tasmania and New Zealand.  Locations where rats have been detected continue to be actively monitored using detection dogs and field teams checking an extensive network of monitoring stations.  This complements the permanent monitoring stations in the settlement area and the Permanent Park Preserve.  Despite vigilant monitoring, no rats have been detected in the Permanent Park Preserve.  All detections to date have been in the northern settlement area.

“The combination of detection, surveillance and removal techniques being used are proving successful.  Our Lord Howe Island based dog handlers and detection dogs have been joined by additional dogs from Port Macquarie, Tasmania and New Zealand.  These teams have been invaluable in detecting the rats and are integral to planning our response.  Detection dog handlers are targeting locations of recent rodent sightings or where monitoring stations indicate recent rodent activity.”

According to the latest weekly Rodent Response Update (No. 19, 12 August 2021) sent to the island’s householders a total of 95 rats, made up of 43 adults and 52 juveniles, has been removed since the April detection.  To achieve this, the detection dogs and their handlers have walked over 2100 km.  The effort continues with more motion-detection trail cameras shortly to arrive on the island.

Lord Howe supports breeding populations of Black-winged Pterodroma nigripennis and Providence P. solandri Petrels along with Flesh-footed Ardenna carneipes, Wedge-tailed A. pacifica and Little Puffinus assimilis Shearwaters.

With thanks to Darcelle Matassoni, Project Officer and Keith Springer, Technical Advisor, Lord Howe Island Board.

John Cooper, ACAP Information Officer, 19 August 2021

Grey-headed Albatross, artwork by  Nancy Bryant for ACAP, after a photogaph by Dimas Gianuca

Caitlin Frankish (British Antarctic Survey, Cambridge, UK) and colleagues have published in the journal Biological Conservation on tracking juvenile Grey-headed Albatrosses Thalassarche chrysostoma (globally Endangered).  The study will help inform ACAP’s Seabird Working Group in its deliberations, currently taking place virtually at its Tenth Meeting.

The paper’s abstract follows:

“Fisheries bycatch is a major threat to marine megafauna such as seabirds.  Population monitoring has revealed low survival of juvenile seabirds over recent decades, potentially because naïve individuals are more susceptible to bycatch than adults.  However, major gaps remain in our knowledge of behavior and interaction of juveniles with fisheries.  Here, we tracked juvenile grey-headed albatrosses (Thalassarche chrysostoma) from South Georgia - the largest global population of this endangered species, and in rapid decline - to investigate their at-sea distribution and assess bycatch risk.  Fledged juveniles dispersed to the northeast, overlapping with a bycatch hotspot for grey-headed albatrosses reported by the Japanese pelagic longline fleet in the southeast Atlantic Ocean.  Given adult grey-headed albatrosses use regions less exposed to fishing activity (< 40°S), the majority of birds bycaught in this area are probably juveniles, and possibly immatures, from South Georgia, likely representing a key factor explaining the sustained population decline.  Our study highlights the urgent need to uncover the ‘lost-years’ for marine megafauna to enable focused conservation efforts.”

The British Antarctic Survey writes on its Facebook page about the publication:

"Tracking juvenile seabirds confirms a new fisheries-bycatch hotspot for endangered albatross population – New research led by ecologist Dr Caitlin Frankish shows that juvenile grey-headed albatrosses tracked from South Georgia [Islas Georgias del Sur]* disperse to a region in the southeast Atlantic where the Japanese pelagic longline fishing fleet has reported a high number of bycaught (unintentionally caught) individuals of the same species. Caitlin says, “As this region isn’t used by adults, this finding suggests that these bycaught birds are likely juveniles from South Georgia, which may be a key factor in explaining the continued decline in their population size. This study highlights the importance of uncovering the distribution of albatrosses of all ages and has important implications for focusing future conservation efforts.”  Learn more about the Grey-headed Albatross Juvenile Tracking project here."

With thanks to Richard Phillips, Brirish Antarctic Survey

Reference:

Frankish, C.K., Cunningham, C., Manica, A., Clay, T.A., Prince, S. & Phillips, R.A. 2021.  Tracking juveniles confirms fisheries-bycatch hotspot for an endangered albatross.  Biological Conservation  261. doi.org/10.1016/j.biocon.2021.109288.

John Cooper, ACAP Information Officer, 18 August 2021

*A dispute exists between the Governments of Argentina and the United Kingdom of Great Britain and Northern Ireland concerning sovereignty over the Falkland Islands (Islas Malvinas), South Georgia and the South Sandwich Islands (Islas Georgias del Sur y Islas Sandwich del Sur) and the surrounding maritime areas.

A Laysan Albatross tends its chick, artwork by Anne Lyon for ACAP, after a photograph by Laurie Smaglick Johnson

As for nearly all international meetings affected by the COVID-19, the Twelfth Meeting of ACAP’s Advisory Committee (AC12) and of two its working groups will be virtual ones.  This year’s meetings - delayed from last year by the pandemic - are now being held from 16/17 August to 1/2 September (depending on where you are in the world).  Meetings of the Seabird Bycatch Working Group and the Population and Conservation Status Working Group will precede AC12; SBWG10 from 16/17 to 18/19 August, and PaCSWG6 from 23/24 to 24/25 August.  AC12 will meet from 30/31 August to 1/2 September.

SBGW10 is being chaired by its Convenor, Igor Debski from New Zealand, with the support of Vice-convenors Juan Pablo Seco Pon of Argentina  and Sebastián Jiménez of Uruguay; the working groups full membership may be viewed by scrolling down from here.  Nineteen Documents (including an Annotated Agenda, SBWG10 Doc 02) and 23 Information Papers have been tabled for consideration, leading to a busy meeting over the three days allotted.  All these documents can be downloaded from this website but note that some are password protected and so only their abstracts are available to be read.

 Further information is available in AC12 Circular 5 in the three official ACAP languages of English, French and Spanish lengths on timing at different localities and lengths of the three meetings.  Congress Rental has been chosen to manage the technical aspects of the meeting, using the Interprefy platform.  Interprefy enables “relay interpretation” (involving multiple languages – three in the case of ACAP).  Congress Rental is providing technical advice to Chairs, Convenors, Secretariat, interpreters and to other participants.

John Cooper, ACAP Information Officer, 17 August 2021

 Black-footed and Laysan Albatrosses, photograph from the Kure Atoll Conservancy

Sayaka Nakatsuka (Fisheries Resource Institute, Japan Fisheries Research and Education Agency, Shizuoka, Japan) and colleagues have published in the Japanese journal Ornithological Science on stomach contents of Laysan Albatross Phoebastria immutabilis and Black-footed Albatross P. nigripes caught by pelagic longliners in the western North Pacific.

The paper’s abstract follows:

“The stomach contents (food and ingested plastics) of Laysan Albatross Phoebastria immutabilis and Black-footed Albatross P. nigripes were examined by necropsy analysis of birds caught as bycatch in the pelagic longline fisheries in the Western North Pacific. The contents were classified separately for the proventriculus and gizzard. Undigested fish and cephalopods were found in the proventriculus, while hard objects such as cephalopod beaks, plastics, and pebbles were found in the gizzard. This indicates that the retention time of soft tissues in fish or cephalopods differs from that for hard objects. The main prey of both albatrosses consisted of mesopelagic cephalopods such as Cranchiidae, Gonatidae, Histioteuthidae, and Onychoteuthidae species. Laysan Albatrosses also foraged on small teleosts (Japanese Anchovy Engraulis japonicus and some Myctophidae fishes) as major prey items. The estimated dorsal mantle length of cephalopods preyed upon by the albatrosses was below 200 mm, which was smaller than the mature sizes of those cephalopods and the size class mainly preyed upon by cetaceans. This implies that the albatrosses may forage on immature cephalopods floating in the surface layer. Ingested plastics were found in 71.8% of Laysan and 31.8% of Black-footed Albatrosses and plastic fragments were the most abundant.”

Reference:

Nakatsuka, S., Ochi, D., Inoue, Y., Ohizumi, H., Niizuma, Y. & Minami, H, 2021.  The diet composition and ingested plastics of Laysan and Black-footed Albatrosses incidentally captured by the pelagic longline fishery in the western North Pacific.  Ornithological Science 20: 29-140.

John Cooper, ACAP Information Officer, 16 August 2021