The ACAP-listed White-chinned Petrel Procellaria aequinoctialis is the bird most commonly recorded as fisheries bycatch by longline and trawl fisheries in the Southern Ocean.  Although currently listed as globally Vulnerable, it has been suggested that limited population trend data provide some grounds for uplisting the species to Endangered, with the decision dependent largely on better information from South Georgia (Islas Georgias del Sur)*, which is believed to hold more than half of the World’s population.  At Bird Island, there was a decrease of 28% (equivalent to 2% per year) in nesting burrow occupancy from the late 1970s to the late 1990s.

Based on existing tracking data, the greatest overlap between adult birds and fisheries, and therefore the greatest risk of bycatch, occurs on the Patagonian Shelf during the pre-laying period, and on the Patagonian Shelf and off southern Chile during the non-breeding period.  However, non-breeders (10 birds) have been tracked in only one year, and stable isotope analysis of feathers from a larger sample suggests that a small proportion also spend the winter in the Benguela Upwelling region off the west coast of southern Africa.  Nothing is as yet known about the movements of newly-fledged birds.

To remedy this gap in knowledge, 13 chicks were fitted with small satellite transmitters (PTTs, made by Telonics) last month on Bird Island and are being tracked in near real-time using the Argos system.  The tagging will enable monitoring of the routes they take as they search for food sources.  Their movements are being added to a map which is updated daily (click here).

The greatest risk to these birds lies on the Patagonian Shelf where most of them appear to be heading.  The distances covered in the first few weeks after fledging are already in excess of 9000 kilometres.  The tracking is part of a wider study that involves attaching geolocators to birds to track non-breeding movements and at-sea activity patterns of adults in the South Atlantic.

White-chinned Petrels on Bird Island, photographs by Andy Wood 

With thanks to Andy Wood, British Antarctic Survey, Cambridge, UK for information and photographs.

Selected literature:

Phillips, R.A., Silk, J.R.D., Croxall, J.P. & Afanasyev, V. 2006.  Year-round distribution of white-chinned petrels from South Georgia: relationships with oceanography and fisheries.  Biological Conservation 129: 336-347.

Mackley, E.K., Phillips, R.A., Silk, J.R.D., Wakefield, E.D., Afanasyev, V. & Furness, R.W. 2011.  At-sea activity patterns of breeding and nonbreeding white-chinned petrels Procellaria aequinoctialis from South Georgia.  Marine Biology 158: 429-438.

Martin, A. R., Poncet, S., Barbraud, C., Foster, E., Fretwell, P. & Rothery, P. 2009.  The white-chinned petrel (Procellaria aequinoctialis) on South Georgia: population size, distribution and global significance.  Polar Biology 32: 655-661.

Phillips, R.A., Bearhop, S., McGill, R.A.R. & Dawson, D.A. 2009.  Stable isotopes reveal individual variation in migration strategies and habitat preferences in a suite of seabirds during the nonbreeding period.  Oecologia 160: 795-806.

John Cooper, ACAP Information Officer, 29 May 2015

*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.

Graeme Elliott (Science and Capability Group, Department of Conservation, Nelson, New Zealand) and colleagues have published a report in the New Zealand Department of Conservation’s DOC Research and Development Series on research conducted preparatory to the planned attempt to eradicate House Mice Mus musculus on Antipodes Island next year.

The report’s abstract follows

“The eradication of house mice (Mus musculus) from subantarctic Antipodes Island is likely to present many challenges, but of particular concern is the potential impact on resident non-target terrestrial and marine bird species.  Therefore, the likely impacts of the proposed eradication operation were examined in July 2013.  Non-toxic baits containing the biotracer pyranine were distributed over 6 ha of the island at a density of 16 kg/ha.  The density of mice and levels of bait uptake were then measured on three trapping grids, two within and one external to the bait distribution area.  All mice that were captured in the two trapping grids in the baited area at Reef Point returned positive results for pyranine.  In contrast, 1 snipe (Coenocorypha aucklandica meinertzhagenae), 9 pipits (Anthus novaeseelandiae steindachneri), 17 Reischek’s parakeets (Cyanoramphus hochstetteri) and 16 Antipodes Island parakeets (Cyanoramphus unicolor) that were captured within the Reef Point study area showed no signs of having eaten the baits.  Pyranine was, however, found in bird faeces collected within the bait distribution area, which predominantly originated from blackbirds (Turdus merula) and song thrushes (Turdus philomelos), along with small numbers of pipits. Pipits were also observed eating small quantities of bait and producing faeces containing the biotracer.  Scavenging species such as brown skua (Catharacta antarctica lonnbergi), kelp gulls (Larus dominicanus) and northern giant petrels (Macronectes halli) appeared to show no interest in the baits or, in the case of northern giant petrels, dead mice.  Bait persistence trials were also conducted, and population monitoring of mice, parakeet species, pipits, snipe and invertebrates are reported on, along with captive husbandry techniques and observations of the diet of parakeets.  Finally, a list of recommendations for minimising non-target impacts and carrying out monitoring prior to and following mouse eradication is provided.”

An Antipodean Albatross pair on the Antipodes, photograph by Erica Sommer

Winter in the Subantarctic is a short film recorded on the 2013 expedition which describes the research then undertaken in preparation for the eradication of mice and restoration of the island.

Reference:

Elliott, G.P., Greene, T.C., Nathan, H.W. & Russell, J.C. 2015.  Winter bait uptake trials and related field work on Antipodes Island in preparation for mouse (Mus musculus) eradication.  DOC Research and Development Series No. 345.  34 pp.

John Cooper, ACAP Information Officer, 28 May 2015

The National Marine Fisheries Service (NMFS) of the United States has reported the incidental take of a globally Vulnerable Short-tailed Albatross Phoebastria albatrus in the logline fishery of the Bering Sea/Aleutian Islands Management Area (BSAI).  The bird was taken on 16 December 2014.

The albatross take was not reported to the NMFS observer on the vessel, nor was the bird retained by the vessel crew.  The bird was later identified by NMFS as a Short-tailed Albatross with the assistance of seabird experts who reviewed video of the bird taken onboard the vessel. The last two documented Short-tailed Albatross fatalities from a longline fishing vessel were recorded in Alaskan waters in September 2014 (click here).

Short-tailed Albatrosses gather off the Aleutians, photograph by Rob Suryan

“The short-tailed albatross is protected in Alaska waters by the Endangered Species Act (ESA).  As a result of consultation with the US Fish and Wildlife Service (USFWS) under the ESA, USFWS issued an incidental take statement of four birds during each two-year period for the BSAI and Gulf of Alaska (GOA) hook and-line groundfish fisheries. In instances where the amount or extent of incidental take is exceeded, reinitiation of formal ESA consultation is required.  This is the third take in the two-year period that began on September 16, 2013. To-date, the incidental take levels have not been reached during the current or any previous Biological Opinions.

The NMFS Alaska Regional Office, NMFS North Pacific Groundfish Observer Program, and the USFWS are actively coordinating efforts and communicating with each other in response to this take incident and are complying to the fullest extent with ESA requirements to protect this species.  NMFS is also working closely with the freezer longline fleet in which the bird was taken, to evaluate what additional actions can be taken by the fleet to avoid further takes.  To assist in this coordinated effort, NMFS reminds operators of hook-and-line vessels in the BSAI and GOA that they are required to employ multiple seabird avoidance measures.  NMFS encourages vessel operators to consider not deploying gear amidst congregations of endangered birds; if possible, move on to a location where you don’t see the short-tailed albatross.

Ed Melvin, a seabird mitigation gear researcher and specialist from Washington Sea Grant, reiterated that in order to keep birds from baited hooks in windy conditions that the streamer line on the windward side should be maintained to windward of the groundline and with a minimum of 200 feet of the line with streamers in the air. This configuration can be achieved by maintaining sufficient drag using a skid buoy with a 10-pound weight fixed at the nose of the buoy. It is this aerial extent of the streamer line with streamers attached that scares birds. The use of round buoys for this purpose should be avoided, as their position astern can be erratic. Also, individual streamers should be long enough to extend to the water. Given that all vessels are different, he recommends that each vessel purchase extra tubing to adjust streamer length as necessary and to make repairs if streamers are damaged. Each crew should have one person in the setting crew responsible for bird avoidance. Additionally, when short-tailed albatross are around the vessel, an additional crew member at the roller may be helpful. NOAA Fisheries also reminds vessel operators that when an observer is on-board, any short-tailed albatross caught by hook-and-line gear be retained and reported immediately to the NMFS observer.” (click here).

Click here for detailed information on seabird avoidance measures in US longline fisheries.

John Cooper, ACAP Information Officer, 27 May 2015

Barry Baker (Latitude 42 Environmental Consultants) and colleagues have produced a report for the Conservation Services Programme of New Zealand's Department of Conservation on the results of an aerial survey of Salvin’s Albatross Thalassarche salvini on the Western Chain, Snares Islands (click here).

The report’s Executive Summary follows:

“Salvin’s albatrosses Thalassarche salvini is an abundant albatross species in New Zealand, breeding mainly on the Bounty Islands and the Western Chain of The Snares.  The species roams widely in winter, moving eastwards across the South Pacific to the waters off the west coast of South America.  In September 2014 we completed an aerial survey of the Western Chain, The Snares, and photographed all albatross colonies we observed.  Salvin’s albatross was breeding on two (Rima and Toru) of the five islets in the Western Chain archipelago.  The photographs were used to compile photo-montages of each colony, and these images were used to count birds on each islet.  Ground counts of nesting Salvin’s albatrosses were also undertaken on Toru Islet on the day that aerial photography was undertaken.  We estimated the total number of Salvin’s albatrosses ashore in the Western Chain in 17 September 2014 to be 2,307 (95% CI 2,211 — 2,403. Of these, 675 (CI 623 — 727) were on Rima Islet, and 1,632 (CI 1,551 — 1,713) were on Toru Islet.  Ground counts at Toru Islet showed that of 171 birds ashore, 100 (58.5%) were incubating, 14 (8.2 %) were on empty nests, and 57 (33.3 %) were loafing.  ‘Close up’ photographs taken using a large telephoto lens to assess the proportion of breeding and loafing birds were not useful for this purpose because we were unable to determine if most of the birds visible were clearly associated with a nest.  Raw counts of birds ashore were adjusted to account for the presence of loafers.  This provided an estimate of 1,486 (95% CI 1,409 — 1,563) annual breeding pairs in 2014/15, which was 32% higher than the ground counts undertaken on the same day of the aerial survey.  Aerial survey proved to be an effective method of rapidly assessing the population size of Salvin’s albatross in the Western Chain, The Snares.  Despite the difference between the aerial and ground counts, it should not be assumed at this stage that one survey methodology is more accurate than the other, as there is potential for error using both methods.  The use of close up aerial photographs has proven useful in correcting raw counts to estimate the number of annual nesting pairs at other albatross colonies, but their utility for this purpose at the Western Chain, would appear to be limited.  Ground counts indicated the proportion of loafing birds in colonies (33.3%) was high, but consistent with that observed at the Bounty Islands (25.8%) in 2013.  These values exceed those previously recorded for other Thalassarche albatrosses during the early to mid-incubation period, but may be normal for Salvin’s albatross because of the nature of their nesting sites where egg loss appears to be very high.  The cause of many nest failures appeared to be a combination of the lack of substrate with which to construct a nest, and interference from birds attending the colony. If population size (annual breeding pairs) is to be regularly estimated using aerial photography, it would appear more appropriate to use the correction factor derived by the 2014 ground count to adjust raw counts each year, noting that this correction factor will likely be dependent on the time of the breeding season that the count is undertaken.  Further ground-truthing undertaken concurrently with aerial photography would be of use to refine the correction factor.  Alternatively, aerial photography could be used to simply assess the number of birds ashore and use this as an index of abundance to assess population trend over time.”

Salvin's Albatross on the Snares, photograph by Paul Sagar

With thanks to Barry Baker.

Reference:

Baker, B.G., Jensz, K., Sagar, P. 2015.  2014 Aerial survey of Salvin's albatross at The Snares, Western Chain.  Final Report prepared for Department of Conservation Project POP2014-02 Objective 2A.  [Kettering]: Latitude 42 Environmental Consultants Pty Ltd.  9 pp.

John Cooper, ACAP Information Officer, 26 May 2015