Australia’s Macquarie Island is recovering from the ravages of now-removed introduced mammals, allowing its seabirds to breed without predation by cats and rats and habitat alteration by rabbits (click here). 

News of research on Macquarie’s small population of ACAP-listed and Vulnerable Wandering Albatrosses Diomedea exulans was reported in the island’s electronic newsletter “This week at Macquarie Island” last month by ornithological researcher currently based on the island, Kate Lawrence (click here).  It is repeated here with permission as it gives a good account of what it is like to work on a sub-Antarctic island – both in the field with the birds and at the computer in the lab.

A Male Wandering Albatross on its nest at Petrel Peak prior to egg-laying

A Wanderer pair on their nest (female in front) below Mount Haswell 

“On Saturday I returned from a great 12 days in the field 'wanderer' watching.  My purpose was to check on the seven wandering albatross nests we have here this season, to identify partners that we had not yet seen on four of the nests, and to identify any non-breeders hanging about.  So armed with my binoculars, profile pictures of birds we had already identified and my notebook, I set off for Waterfall Bay on day one, to get ahead of the Macquarie Island Pest Eradication Project (MIPEP) crowd also heading down island on the same day.

When we identify a wanderer by reading the number on the band around its leg, we take a profile picture for future reference.  The plumage on the birds is varied and unique, so having the pictures of the breeding birds previously seen meant that I could identify if that same bird was on the nest from a distance, and prevent unnecessary disturbance.  When we do need to go close to a nest or a non-breeding bird, we sneak up very carefully and slowly, staying quiet and out of sight until close.  As soon as we’ve snuck a peek at the bird’s band and snapped a quick pic, we retreat back out of sight.

Courting Wandering Albatrosses at Petrel Peak

On day two I headed cross country to Cape Star to check if the female of the pair had returned to incubate – luckily she was there.  Then it was on to the Amphitheatre to check the status of two nests there.  As we already had identification for both partners on those nests, I made a quick check to see if the adults were still happily incubating.  It was then down to Caroline Cove hut for the night.

The following day on Petrel Peak two more of the birds I needed to identify were on their nests so I was feeling super productive – just one previously unseen bird to go!  The first incubation shift on the nest taken by the male can be up to 21 days, so I spent the next week checking on the nests and hoping the last remaining bird would turn up, but to no avail.  Hopefully we will see her on our next visit!  Luckily my time was not wasted; I also obtained some re-sights of non-breeding birds on Petrel Peak, in the Amphitheatre and on Cape Star, including a courting couple on the top of Petrel Peak.

A wanderer flies over the Amphitheatre

Upon my return to station, I plugged some band numbers into our database.  Here are some interesting facts about some of our breeding birds this year:

The male incubating on the nest on Petrel Peak is a 25-year-old bird.  In the years between 1998 and 2004 he bred successfully four times with the same partner (wanderers are biennial breeders - every other year).  Then she seems to have disappeared – she has not been seen since 2005.  Sadly, this could be due to being caught on a long-line hook.  Of course we can’t know for sure but long-line fisheries are one of the major threats to a number of species of albatross, including wanderers.  The females from Macquarie Island are more vulnerable to this threat than the males because they head north to feed and are more likely to encounter fisheries than the males who head south.

If a partner dies, it can take years for the bereaved bird to find a new partner (especially given the shortage of females, but also because they can be very picky about choosing a mate!) In this case, our male took five years to find a new partner, and bred successfully with her in 2009/10 and 2011/12.  This is the nest where we have not identified the female this season, but we expect it to be the same female as in 2009/10 and 2011/12.

The nest at the base of Mt. Haswell has an 18-year-old male and female of unknown age (as she was not banded as a chick but as an adult in 2006).  From 2007 to 2010, the male built 'sits' (a sit is a pile of nest material generally smaller and less well-formed than a nest, that gets built up into a nest if a breeding attempt is made), courted and tried to call in females.  However, it wasn’t until 2011/12 that he got hitched and bred successfully with the same female as this year. In 2006/07 and 2008/09 the female bred with a different partner, unsuccessfully the first time and successfully the second.  Three years later she’d switched to her current partner.

Let’s hope that this year, the second breeding year for this partnership, is also successful!”

With thanks to Kate Lawrence for permission to reproduce her account and her photographs.

John Cooper, ACAP Information Officer, 30 March 2014

Laurie Thiers (Centre d’Études Biologiques de Chizé, Centre National de la Recherche Scientifique, Villiers en Bois, France) and colleagues write in the journal Marine Ecology Progress Series on the at-sea distribution and behaviour of Northern Macronectes halli and Southern Giant Petrels M. giganteus from the French Crozet and Kerguelen Islands.

The paper’s abstract follows:

“We studied the year-round distribution and at-sea activity patterns of the sibling species, northern giant petrel Macronectes halli and southern giant petrel M. giganteus.  Loggers combining light-based geolocators and immersion sensors were used to provide year-long data on large-scale distribution and activity of both species from the Crozet Islands (46°25’S, 51°51’E) and northern giant petrels from the Kerguelen Islands (49°19’S, 69°15’E) in the southern Indian Ocean.  Argos platform transmitter terminals (PTTs) were used to track fine-scale movements of breeding adults and juveniles.  Overall, adults remained within the Indian Ocean during and outside the breeding season, whereas juveniles dispersed throughout the Southern Ocean.  In accordance with previous studies, differences in adult distribution and behaviour were greater between sexes than species: females dispersed more widely than males and also spent more time sitting on the water, particularly during the winter.  Observed differences in distribution have important conservation implications: adults, especially males, overlap to a large extent with longline fisheries for Patagonian toothfish Dissostichus eleginoides in shelf areas within national Exclusive Economic Zones (EEZs), whereas adult females and juveniles are more likely to encounter high-sea longline fleets targeting tuna in subtropical waters.  The circumpolar wide ranging behavior of naïve juvenile birds makes them particularly susceptible to interaction with a wide range of longline fisheries.”

Southern Giant Petrel at sea, photograph by Warwick Barnes

With thanks to Deborah Pardo, ACAP European News Correspondent for information.

Reference:

Thiers, L., Delord, K., Barbraud, C., Phillips, R.A., Pinaud, D. & Weimerskirch, H. 2014.  Foraging zones of the two sibling species of giant petrels in the Indian Ocean throughout the annual cycle: implication for their conservation.  Marine Ecology Progress Series 499:233-248.

John Cooper, ACAP Information Officer, 29 March 2014

Sarah Wong (Department of Biology, Acadia University, Wolfville, Nova Scotia, Canada) and colleagues have published in the Journal of Geophysical Research: Oceans on seabird makeup and numbers in the North American Arctic.

The paper’s abstract follows:

“The distribution and thickness of sea ice in the Arctic is changing rapidly, resulting in changes to Arctic marine ecosystems.  Seabirds are widely regarded as indicators of marine environmental change, and understanding their distribution patterns can serve as a tool to monitor and elucidate biological changes in the Arctic seas.  We examined the at-sea distribution of seabirds in the North American Arctic in July and August, 2007-2012, and marine areas of high density were identified based on bird densities for four foraging guilds.  Short-tailed shearwaters (Puffinus tenuirostris) were the most abundant species observed.  Northern fulmars (Fulmarus glacialis), thick-billed murres (Uria lomvia) and dovekies (Alle alle) were also sighted in large numbers.  Few birds were sighted between Dolphin and Union Strait and King William Island.  Areas of high density over multiple years were found throughout the entire western portion of the study area (Bering Sea, Bering Strait, Chukchi Sea), Lancaster Sound, Baffin Bay, Davis Strait and the low-arctic waters off Newfoundland.  These waters are characterized by high primary productivity.  This study is the first to document the marine distribution of seabirds across the entire North American Arctic within the same time period, providing a critical baseline for monitoring the distribution and abundance of Arctic seabirds in a changing Arctic seascape.”

Short-tailed Shearwater at sea,  Photograph by Kirk Zufelt

Reference:

Wong, SN.P., Gjerdrum, C., Morgan, K.H. & Mallory^, M.L. 2014.  Hotspots in cold seas: The composition, distribution, and abundance of marine birds in the North American Arctic.  Journal of Geophysical Research: Oceans DOI: 10.1002/2013JC009198.

John Cooper, ACAP Information Officer, 28 March 2014

Alex Bond (Department of Biology, University of Saskatchewan, Saskatoon, Canada) and Jennifer Lavers write in the journal Global Change Biology on evidence that the Flesh-footed Shearwaters Puffinus carneipes has changed its diet historically from 1936.

The paper’s abstract follows:

“Changes in the world's oceans have altered nutrient flow, and affected the viability of predator populations when prey species become unavailable.  These changes are integrated into the tissues of apex predators over space and time and can be quantified using stable isotopes in the inert feathers of historical and contemporary avian specimens.  We measuredδ¹³C andδ¹⁵N values in Flesh-footed Shearwaters (Puffinus carneipes) from Western and South Australia from 1936-2011.  The Flesh-footed Shearwaters more than doubled their trophic niche (from 3.91 ± 1.37 ‰²to 10.00 ± 1.79 ‰²), and dropped an entire trophic level in 75 years (predictedδ¹⁵N decreased from +16.9 ‰ to +13.5 ‰, andδ¹³C from –16.9 ‰ to –17.9 ‰) – the largest change inδ¹⁵N yet reported in any marine bird, suggesting a relatively rapid shift in the composition of the Indian Ocean food web, or changes in baselineδ¹³C andδ¹⁵N values.  A stronger El Niño-Southern Oscillation results in a weaker Leeuwin Current in Western Australia, and decreased Flesh-footed Shearwaterδ¹³C andδ¹⁵N.  Current climate forecasts predict this trend to continue, leading to increased oceanic ‘tropicalisation’ and potentially competition between Flesh-footed Shearwaters and more tropical sympatric species with expanding ranges.  Flesh-footed Shearwater populations are declining, and current conservation measures aimed primarily at bycatch mitigation are not restoring populations.  Widespread shifts in foraging, as shown here, may explain some of the reported decline.  An improved understanding and ability to mitigate the impacts of global climactic changes is therefore critical to the long-term sustainability of this declining species.”

Flesh-footed Shearwater, photograph by Tim Reid

With thanks to Jenn Lavers for information.

Reference:

Bond, A.L. & Lavers, J.L. 2014.  Climate change alters the trophic niche of a declining apex marine predator.  Global Change Biology DOI: 10.1111/gcb.12554.

John Cooper, ACAP Information Officer, 27 March 2014