Michelle Kappes (Department of Fisheries and Wildlife, Oregon State University, Corvallis, USA) and colleagues have published in the journal Movement Ecology on foraging patterns of Laysan Phoebastria immutabilis and Black-footed P. nigripes Albatrosses.

The paper’s abstract follows:

“Background: The spatiotemporal distribution of animals is dependent on a suite of factors, including the distribution of resources, interactions within and between species, physiological limitations, and requirements for reproduction, dispersal, or migration. During breeding, reproductive constraints play a major role in the distribution and behavior of central place foragers, such as pelagic seabirds.  We examined the foraging behavior and marine habitat selection of Laysan (Phoebastria immutabilis) and black-footed (P. nigripes) albatrosses throughout their eight month breeding cycle at Tern Island, Northwest Hawaiian Islands to evaluate how variable constraints of breeding influenced habitat availability and foraging decisions.  We used satellite tracking and light-based geolocation to determine foraging locations of individuals, and applied a biologically realistic null usage model to generate control locations and model habitat preference under a case–control design.  Remotely sensed oceanographic data were used to characterize albatross habitats in the North Pacific.

Results: Individuals of both species ranged significantly farther and for longer durations during incubation and chick-rearing compared to the brooding period.  Interspecific segregation of core foraging areas was observed during incubation and chick-rearing, but not during brooding.  At-sea activity patterns were most similar between species during brooding; neither species altered foraging effort to compensate for presumed low prey availability and high energy demands during this stage.  Habitat selection during long-ranging movements was most strongly associated with sea surface temperature for both species, with a preference for cooler ocean temperatures compared to overall availability.  During brooding, lower explanatory power of habitat models was likely related to the narrow range of ocean temperatures available for selection.

Conclusions: Laysan and black-footed albatrosses differ from other albatross species in that they breed in an oligotrophic marine environment.  During incubation and chick-rearing, they travel to cooler, more productive waters, but are restricted to the low-productivity environment near the colony during brooding, when energy requirements are greatest.  Compared to other albatross species, Laysan and black-footed albatrosses spend a greater proportion of time in flight when foraging, especially during the brooding period; this strategy may be adaptive for locating dispersed prey in an oligotrophic environment.”

Laysan and Black-footed Albatrosses in flight at Midway Atoll, photograph by Eric Vanderwerf

Reference:

Kappes, M.A., Shaffer, S.A., Tremblay, Y., Foley, D.G., Palacios, D.M., Bograd, S.J. & Costa, D.P. 2015.  Reproductive constraints influence habitat accessibility, segregation, and preference of sympatric albatross species.  Movement Ecology 3: 34.  10.1186/s40462-015-0063-4.

John Cooper, ACAP Information Officer, 25 December 2015

ACAP Secretariat, 24 December 2015

The Endangered Hutton’s Shearwater Puffinus huttoni, endemic to the vicinity of Kaikoura, South Island, New Zealand, is fortunate to have a champion in the form of the Hutton’s Shearwater Charitable Trust to help with its conservation (click here).

The species breeds in the Seaward Kaikoura Range at elevations from 1200-1800 m in two remaining colonies.  These colonies are under threat from feral pigs Sus scrofa and Stoats Mustela erminea and from natural hazards such as avalanches and earthquakes.  The New Zealand Department of Conservation and the Trust have undertaken a translocation project whereby chicks were moved from the Kowhai mountain colony to the Kaikoura Peninsula within a predator-proof fence where they were hand-fed until fledging in an attempt to establish a third breeding colony.

Hutton's Shearwater fledgling, photograph by the Hutton's Shearwater Charitable Trust

Latest news on the translocation exercise is that the peninsula colony contains 11 breeding pairs with three chicks and eight eggs this season.  In addition to these, one egg was recently lost and two eggs are not being incubated regularly, which could be attributed to young inexperienced birds returning as first-time breeders.

The Trust has made a funding application to purchase six trail cameras to record shearwater activity at night, as well as 10 geolocators that can be deployed on departing chicks and retrieved up to five years later (as chicks could have very different migration patterns to adults).

An annotated bibliography for Hutton’s Shearwater is available on the Trust’s website (click here).

The activities of the Hutton's Shearwater Charitable Trust demonstrate how a local community can come together to successfully address a local conservation issue.

John Cooper, ACAP Information Officer, 23 December 2015

Mike Dunn and colleagues (British Antarctic Survey, Cambridge, UK) have published online in the journal Polar Biology on population changes of Southern Giant Petrels Macronectes giganteus breeding on Signy Island in the South Orkney Islands.  “A fifty year study of the charismatic seabird, the southern giant petrel, on the Antarctic island of Signy shows its population has halved and its breeding success has declined in the last 10-20 years.”

The paper’s abstract follows:

“The southern giant petrel (Macronectes giganteus) has a circumpolar distribution and breeds on subantarctic islands and a few continental Antarctic sites.  Although this species has recently been down-listed to “Least Concern” by the World Conservation Union (IUCN), there are strong fluctuations in abundance and variable long-term trends recorded at different sites.  Systematic, long-term monitoring is essential to determine drivers underlying its population dynamics.  Here, we examine long-term changes in population size and productivity of southern giant petrels at Signy Island, South Orkney Islands.  Comparing estimated numbers of breeding pairs over the whole island in 2000/2001, 2005/2006, 2009/2010 and 2014/2015 with historical data revealed several phases of population change: a 64 % decline (6.2 % per annum) from 1968/1969 to 1984/1985, a 162 % increase (6.2 % per annum) to 2000/2001, stability until 2005/2006, a 56 % decline (18.3 % per annum) to 2009/2010 and stability until 2014/2015. This represents a 1.8 % decline per annum between 1968/1969 and 2014/2015.  Annual counts within focal study areas suggested a more rapid increase from 1996/1997 to 2006/2007, but the same downward trend from 2006/2007 to present, underlining potential pitfalls in inferring trends from part-island counts.  There was also a 20 % decline in breeding success from 1996/1997 to 2014/2015.  Our results indicate substantial fluctuations in southern giant petrel abundance at Signy Island over 4–5 decades and a recent decline in breeding numbers and success.  As the southern giant petrels breeding at the South Orkney Islands represents [sic] ~5–10 % of the global population, continuation of these declines would be of high conservation concern.”

Read a press release on the publication.

Southern Giant Petrel on Signy Island, photograph by Mike Dunn

With thanks to Richard Phillips for information.

Reference:

Dunn, M.J., Jackson, J.A., Adlard, S. & Phillips, R.A. 2015.  Population size and trends of southern giant petrels (Macronectes giganteus) nesting at Signy Island, South Orkney Islands.  Polar Biology doi:10.1007/ s00300-015-1855-0.

John Cooper, ACAP Information Officer, 22 December 2015