ACAP Latest News has been reporting on the innovative efforts by Pacific Rim Conservation to establish a new breeding colony of Laysan Albatrosses Phoebastria immutabilis by artificially hatching eggs and then hand-rearing the chicks (click here).

The project aims to create a new breeding site on the Hawaiian island of Oahu, where the birds will not have to face the deleterious effects of sea-level rise that are predicted for the species’ main breeding sites on the low-lying atolls of the North Western Hawaiian Island chain.  Here are the latest updates of progress with rearing the chicks, courtesy of Pacific Rim Conservation.

4 March

“The translocation release site for the albatross chicks was outfitted with decoys and a speaker system playing albatross calls to not only attract adult birds, but so that the chicks know what an albatross looks and sounds like.  Amazingly, we've already had some adults checking out the site- this bird spent over an hour on the ground yesterday.  His leg banded indicated he is from Tern Island in the North Western Hawaiian Islands.  A great example of social attraction working it's magic.”

Decoys on the left; Tern Island visitor on the right next to a speaker 

12 March

“Today was another important milestone in the Laysan Albatross translocation project- we moved the chicks outside, from the garage to the fenced area.  Below is a photo from today showing 6 of the 9 chicks inside the small A-frame houses that we built for them to provide shade and prevent (we hope) overheating.  And yes, in addition to the decoys in the background there are 2 adult albatross visitors.  One of them landed about 10 minutes after we put the first chicks outside.  They never really approached the chicks, and we can’t be sure they actually saw them, but it is an encouraging sign.  The chicks began building their own nest cups almost right away by picking grass stems with their beak and scraping with their feet. The move outside will be good for them in many ways- sunlight, more exercise, natural substrate, and exposure to real adult albatross.  We have cat and mongoose traps just outside the fence.  We caught quite a few mongoose around the abandoned house, but none near the fence.  The chicks are getting 15-20% of their body weight in food each day, and are showing consistently good weights gains.  The oldest chick is 43 days old and the heaviest chick now weighs 2600 grams.  We expect their weight to begin leveling off at about 3000-3500 g, after which their feather growth should accelerate.”

13 March

“We had two adults hanging out and literally snuggling with the chicks today which is awesome- they are being visited daily by wild adults which is very exciting.”

The restoration project is supported by the U.S. Fish and Wildlife Service, American Bird Conservancy, US Navy, the National Fish and Wildlife Foundation and the David and Lucile Packard Foundation.

With thanks to Lindsay Young, Pacific Rim Conservation for text and photographs.

John Cooper, ACAP Information Officer, 15 March 2015

Henri Weimerskirch (Centre d’Etudes Biologiques de Chizé, Villiers en Bois, France) and colleagues have published in the online and open-access journal Scientific Reports on differing migratory strategies of two populations of Wandering Albatrosses Diomedea exulans.

The paper’s abstract follows:

“Migratory behavior, routes and zones used during the non-breeding season are assumed to have been selected to maximize fitness, and can lead to genetic differentiation.  Yet, here we show that migration strategies differ markedly between and within two genetically similar populations of wandering albatross Diomedea exulans from the Crozet and Kerguelen archipelagos in the Indian Ocean.  Wandering albatrosses usually breed biennially if successful, and during the sabbatical year, all birds from Kerguelen migrate to the Pacific Ocean, whereas most from Crozet are sedentary.  Instead of taking the shortest routes, which would involve a return against headwinds, migratory birds fly with the westerly winds, requiring detours of 10,000s km.  In total, migrants circumnavigate Antarctica 2 to 3 times, covering more than 120,000 km in a single sabbatical year.  Our results indicate strong links between migratory behavior and fitness; all birds from Kerguelen breed biennially, whereas a significant proportion of those from Crozet, especially females, are sedentary and breed in consecutive calendar years.  To breed annually, these females temporarily change mate, but return to their original partner in the following year.  This extreme variation in migratory behavior has important consequences in term of life history evolution and susceptibility to climate change and fisheries."

Wandering Albatross at sea, photograph by John Chardine

With thanks to Richard Phillips for information.

Reference:

Henri Weimerskirch, H., Delord, K., Guitteaud, A., Phillips, R.A. & Pinet, P.  2015.  Extreme variation in migration strategies between and within wandering albatross populations during their sabbatical year, and their fitness consequences.  Scientific Reports 5, No. 8853.  doi:10.1038/srep08853.

J. Cooper, ACAP Information Officer, 14 March 2015

Maite Louzao (Centro Oceanográfico de Gijón/Xixón, Spain) and colleagues have published early-view in the journal Marine Ornithology on krill regurgitated by a ACAP-listed and Critically Endangered Balearic Shearwater Puffinus mauretanicus during the chick-rearing season.

“In this study, we report observations that, during breeding season, the diet of the endemic Balearic Shearwater includes macrozooplankton, specifically the krill Nyctiphanes couchii.  Further research in needed to accurately assess the importance of euphausiids in the diet of the Balearic Shearwater.”

Balearic Shearwater, photograph by Daniel Oro 

Reference:

Louzao, M., García, D., Rodríguez, B. & Abelló, P. 2015.  Evidence of krill in the diet of Balearic Shearwaters Puffinus mauretanicus.  Marine Ornithology 43: 49-51.

John Cooper, ACAP Information Officer, 13 March 2015

Leigh Torres (Marine Mammal Institute, Department of Fisheries and Wildlife, Oregon State University, Newport, Oregon, USA) and colleagues have published in the open-access, online journal PloS ONE on modelling at-sea distribution of ACAP-listed Grey Petrels Procellaria cinerea from three different populations.

The paper’s abstract follows:

“Species distribution models (SDMs) are increasingly applied in conservation management to predict suitable habitat for poorly known populations.  High predictive performance of SDMs is evident in validations performed within the model calibration area (interpolation), but few studies have assessed SDM transferability to novel areas (extrapolation), particularly across large spatial scales or pelagic ecosystems.  We performed rigorous SDM validation tests on distribution data from three populations of a long-ranging marine predator, the grey petrel Procellaria cinerea, to assess model transferability across the Southern Hemisphere (25-65°S).  Oceanographic data were combined with tracks of grey petrels from two remote sub-Antarctic islands (Antipodes and Kerguelen) using boosted regression trees to generate three SDMs: one for each island population, and a combined model.  The predictive performance of these models was assessed using withheld tracking data from within the model calibration areas (interpolation), and from a third population, Marion Island (extrapolation).  Predictive performance was assessed using k-fold cross validation and point biserial correlation.  The two population-specific SDMs included the same predictor variables and suggested birds responded to the same broad-scale oceanographic influences.  However, all model validation tests, including of the combined model, determined strong interpolation but weak extrapolation capabilities.  These results indicate that habitat use reflects both its availability and bird preferences, such that the realized distribution patterns differ for each population.  The spatial predictions by the three SDMs were compared with tracking data and fishing effort to demonstrate the conservation pitfalls of extrapolating SDMs outside calibration regions.  This exercise revealed that SDM predictions would have led to an underestimate of overlap with fishing effort and potentially misinformed bycatch mitigation efforts.  Although SDMs can elucidate potential distribution patterns relative to large-scale climatic and oceanographic conditions, knowledge of local habitat availability and preferences is necessary to understand and successfully predict region-specific realized distribution patterns.”

Grey Petrel at sea, photograph by Peter Ryan

Reference:

Torres, L.G., Sutton, P.J.H., Thompson, D.R., Delord, K., Weimerskirch, H., Sagar, P.M., Sommer, E., Dilley, B.J., Ryan, P.G. & Phillips, R.A. 2015.  Poor transferability of species distribution models for a pelagic predator, the Grey Petrel, indicates contrasting habitat preferences across ocean basins.  PloS ONE  DOI: 10.1371/journal.pone.0120014.

John Cooper, ACAP Information Officer, 12 March 2015