BirdLife International has announced its 'Pacific Petrels in Peril' initiative to address the conservation problems facing the smaller procellariiform species that occur in the tropical Pacific.

 “Sprinkled across the tropical Pacific, the innumerable islands of Oceania are home to some of the most unusual bird communities on the planet.  The Pacific Ocean is the petrel capital of the world, but these traditional companions of travellers and fishermen are in trouble in the region.”

Priority will be given to find the breeding sites of the little-known Critically Endangered Fiji Petrel Pseudobulweria macgillivrayi, Critically Endangered Beck's Petrel P. becki and Vulnerable Heinroth's Shearwater Puffinus heinrothi.  Overall, 18 procellariiform species have been identified for attention, including a number of threatened gadfly petrels Pterodroma spp. and storm petrels.

“Most islands in Oceania have not had systematic surveys performed of breeding seabirds. While there are some threats at sea for petrels breeding in the region, the primary threats are on land.  Until we can eliminate predation pressure and the degradation of nesting and roosting sites, and establish them as secure areas, there will be no improvement in their conservation status.”

BirdLife intends to work with other organisations to “develop networks for improved communication, resource sharing, capacity building and further project development”.

Read more here.

Birdlife set up a Gadfly Petrel Conservation Group in 2008/09 with the aim of improving knowledge and conservation status of the 32 species of Pseudobulweria and Pterodroma petrels, but it has been seemingly inactive for some time.

John Cooper, ACAP Information Officer, 13 October 2015

Marie Hale (Department of Biological Sciences, University of Canterbury, Christchurch, New Zealand) and colleagues have published in the New Zealand journal Notornis on how similar genetically are the two remaining populations of Hutton’s Shearwaters Puffinus huttoni.

The paper’s abstract follows:

“Hutton’s shearwater (Puffinus huttoni) currently breeds only in 2 colonies in the Seaward Kaikoura mountains, South Island, New Zealand.  Conservation measures now include re-locating young to establish a new low altitude colony.  To assess the genetic similarity of birds breeding in the 2 colonies as a basis for decisions on sourcing recruits to the present and potentially other new colonies, we genotyped 9 microsatellite loci, with 3-13 alleles, in 30 birds from the Kowhai River catchment colony and 29 from Shearwater Stream.  There was no significant population genetic differentiation between the 2 sampling locations.  Our results suggest that there would be little genetic risk to mixing birds from both relict colonies in newly established colonies.  Future analyses of the former distributions of Hutton’s shearwater, the fluttering shearwater (P. gavia), and the extinct Scarlett’s shearwater (P. spelaeus) will require an analysis of the levels of genetic similarity between birds from the relict colonies and those of former, widely separated colonies.”

Hutton's Shearwater

Reference:

Hale, M., Harrow, G., Bradfield, P., Cubrinovska, I. & Holdaway, R.N. 2015.  Genetic similarity of Hutton’s shearwaters (Puffinus huttoni) from two relict breeding populations.  Notornis 62: 130-134.

John Cooper, ACAP Information Officer, 12 October 2015

Rocío Moreno (British Antarctic Survey, Cambridge, UK) and colleagues have published in the Journal of Animal Ecology on the trophic structure of a sub-Antarctic seabird community over time.

The paper’s summary follows:

1. Understanding interspecific interactions, and the influences of anthropogenic disturbance and environmental change on communities, are key challenges in ecology.  Despite the pressing need to understand these fundamental drivers of community structure and dynamics, only 17% of ecological studies conducted over the past three decades have been at the community level.
2. Here, we assess the trophic structure of the procellariiform community breeding at South Georgia, to identify the factors that determine foraging niches and possible temporal changes.  We collected conventional diet data from 13 sympatric species between 1974 and 2002, and quantified intra- and inter-guild, and annual variation in diet between and within foraging habits.  In addition, we tested the reliability of stable isotope analysis (SIA) of seabird feathers collected over a 13-year period, in relation to those of their potential prey, as a tool to assess community structure when diets are diverse and there is high spatial heterogeneity in environmental baselines.
3. Our results using conventional diet data identified a four-guild community structure, distinguishing species that mainly feed on crustaceans; large fish and squid; a mixture of crustaceans, small fish and squid; or carrion.  In total, Antarctic krill Euphausia superba represented 32%, and 14 other species a further 46% of the combined diet of all 13 predators, underlining the reliance of this community on relatively few types of prey.  Annual variation in trophic segregation depended on relative prey availability; however, our data did not provide evidence of changes in guild structure associated with a suggested decline in Antarctic krill abundance over the past 40 years.
4. Reflecting the differences in δ15N of potential prey (crustaceans vs. squid vs. fish and carrion), analysis of δ15N in chick feathers identified a three-guild community structure that was constant over a 13-year period, but lacked the trophic cluster representing giant petrels which was identified using conventional diet data.
5. Our study is the first in recent decades to examine dietary changes in seabird communities over time.  Conventional dietary analysis provided better resolution of community structure than SIA.  However, δ15N in chick feathers, which reflected trophic (level) specialization, was nevertheless an effective and less time-consuming means of monitoring temporal changes.

Wandering Albatross, photograph by Linda Clokie

Reference:

Moreno, R., Stowasser, G., McGill, R.A.R, Bearhop, S.& Phillips, R.A.2015.  Assessing the structure and temporal dynamics of seabird communities: the challenge of capturing marine ecosystem complexity.  Journal of Animal Ecology DOI: 10.1111/1365-2656.12434.

John Cooper, ACAP Information Officer, 11 October 2015

The Vulnerable Pink-footed Shearwater Puffinus creatopus is the most recent addition to the ACAP “family”, having been listed in May this year (click here).  A breeding endemic to Chile, it migrates to the northern hemisphere as far as Canadian waters after breeding.  Over recent years the species’ trans-equatorial migration route along the eastern Pacific seaboard has been studied by the use of solar-powered satellite transmitters.  Ten transmitters were placed on breeding Pink-footed Shearwaters in April this year on Isla Mocha in Chile (click here).

Pink-footed Shearwater, photograph by Peter Hodum

The tagged shearwaters are now heading home to Chile after their trans-equatorial sojourn.  One satellite-tagged bird has flown nearly 21 000 kilometres in total during its migration so far, and is currently heading south (orange dots) toward its breeding site on Isla Mocha.

Click here to read of the Pink-foots' progress north towards the Canadian border earlier in the year.

The tracking study is a project of the U.S. Geological Survey and Oikonos Ecosystem Knowledge.

John Cooper, ACAP Information Officer, 10 October 2015