Kylie Scales (Plymouth Marine Laboratory, UK) and colleagues have published early view in the journal Diversity and Distributions on modelling foraging of Grey-headed Albatrosses Thalassarche chrysostoma.

The paper’s abstract follows:

“Aim

Ecological niche modelling can provide valuable insight into species' environmental preferences and aid the identification of key habitats for populations of conservation concern. Here, we integrate biologging, satellite remote-sensing and ensemble ecological niche models (EENMs) to identify predictable foraging habitats for a globally important population of the grey-headed albatross (GHA) Thalassarche chrysostoma.

Location

Bird Island, South Georgia; Southern Atlantic Ocean.

Methods

GPS and geolocation-immersion loggers were used to track at-sea movements and activity patterns of GHA over two breeding seasons (n = 55; brood-guard).  Immersion frequency (landings per 10-min interval) was used to define foraging events.  EENM combining Generalized Additive Models (GAM), MaxEnt, Random Forest (RF) and Boosted Regression Trees (BRT) identified the biophysical conditions characterizing the locations of foraging events, using time-matched oceanographic predictors (Sea Surface Temperature, SST; chlorophyll a, chl-a; thermal front frequency, TFreq; depth).  Model performance was assessed through iterative cross-validation and extrapolative performance through cross-validation among years.

Results

Predictable foraging habitats identified by EENM spanned neritic (<500 m), shelf break and oceanic waters, coinciding with a set of persistent biophysical conditions characterized by particular thermal ranges (3–8 °C, 12–13 °C), elevated primary productivity (chl-a > 0.5 mg m−3) and frequent manifestation of mesoscale thermal fronts.  Our results confirm previous indications that GHA exploit enhanced foraging opportunities associated with frontal systems and objectively identify the APFZ as a region of high foraging habitat suitability.  Moreover, at the spatial and temporal scales investigated here, the performance of multi-model ensembles was superior to that of single-algorithm models, and cross-validation among years indicated reasonable extrapolative performance.

Main conclusions

EENM techniques are useful for integrating the predictions of several single-algorithm models, reducing potential bias and increasing confidence in predictions.  Our analysis highlights the value of EENM for use with movement data in identifying at-sea habitats of wide-ranging marine predators, with clear implications for conservation and management.”

Grey-headed Albatross at sea, photograph by Kirk Zufelt

With thanks to Richard Phillips for information.

Reference:

Scales, K.L, Miller, P.I, Ingram, S.N., Hazen, E.L., Bograd, S.J. & Phillips, R.A. 2015.  Identifying predictable foraging habitats for a wide-ranging marine predator using ensemble ecological niche models.  Diversity and Distributions DOI: 10.1111/ddi.12389.

John Cooper, ACAP Information Officer, 09 November 2015

Maria Enriqueta Velarde (Instituto de Ciencias Marinas y Pesquerías, Universidad Veracruzana, Veracruz, México) and colleagues have published open-access in the journal Marine Ornithology on the discovery of the Near Threatened Black-vented Shearwater Puffinus opisthomelas breeding on Isla Rasa in the Gulf of California, Mexico.

The paper’s abstract follows:

“The endangered Black-vented Shearwater has been reported nesting at only three islands in the Mexican Pacific Ocean, one of which contains ~95% of their world population.  We report on the nesting of this species at a new site, Isla Rasa in the Gulf of California, in 2010 and 2011, and on other signs of possible nesting in 2008 and 2009.  Evidence includes a nesting burrow; a genetically identified addled egg at a burrow entrance; nest activity, indicated by tracks and photographs of the nesting individuals; and, in several years, vocalizations, which were monitored to determine prevalence.  Although the number of nests at Isla Rasa has not been determined, our observations confirm the nesting of this species, which is the first such report for the Gulf of California.  We also report on the presence of the species at Isla Partida Norte, as well as on complementary records during marine surveys in the Midriff Islands Region.  Because of the endangered status of the Black-vented Shearwater and of the presence of introduced predators at islands where it is known to breed, the confirmed record of an alternative nesting site, which has now been freed of introduced rodents, bodes well for the conservation of the species.  It will be important to explore other potential nesting sites in the Gulf of California and to promote nesting of the species at Isla Rasa through the use of artificial burrows (nest boxes), vocalization playbacks or other methods.”

 Black-vented Shearwater

Reference:

Velarde, E., Ruiz, E.A., Aguilar, A. & Gallo, J.P. 2015.  Black-vented Shearwater Puffinus opisthomelas nesting in the Gulf of California: a major extension of breeding range.  Marine Ornithology 43: 249-254.

John Cooper, ACAP Information Officer, 08 November 2015

Eric Vanderwerf (Pacific Rim Conservation, Honolulu, Hawaii, USA) and colleagues have published on-line, open-access in the journal Marine Ornithology on aspects of the demography of Christmas Shearwater Puffinus nativitatis (Least Concern) on Kure Atoll in the Northwestern Hawaiian Islands.

The paper’s abstract follows:

“The Christmas Shearwater Puffinus nativitatis is a small (350 g) Procellariiform seabird that nests on remote islands in the tropical and subtropical Pacific Ocean.  Little is known about its demography or conservation needs.  We banded and recaptured 1120 Christmas Shearwaters on Kure Atoll, the northwestern-most of the Hawaiian Islands, on 60 occasions during a 20-year period, 1995–2014.  To provide demographic information that is lacking for this species, we used robust design mark-recapture models to estimate apparent annual survival, emigration, capture probabilities, and size of the study population.  Annual survival of residents was 0.864 SE 0.034, which is typical for seabirds this size.  The oldest known bird was at least 17 years and 1 month old.  Of birds banded as chicks, the average age of first recapture was 3.9 years.  Among birds captured, 11% appeared to be transients.  The annual emigration rate was 0.249 SE 0.096.  Thirteen shearwaters captured on Kure originally were banded on Midway Atoll; three of [which] were captured multiple times and presumably were breeding on Kure, indicating there is exchange between the colonies on those two islands.  The size of the study population averaged 358 birds, with an increasing trend and an estimate of 480 birds in the last two years.  The primary reason for the population increase was eradication of Polynesian rats Rattus exulans in 1995, which has resulted in a 10-fold increase in shearwater population size since the last estimate in the 1980s.  The high survival rate and increasing number of birds indicate that the Kure Christmas Shearwater population is robust.”

Christmas Shearwater

Reference:

Vanderwerf, E.A, Smith, D.G., Vanderlip, C., Marie, A., Saunter, M., Parrish, J. & Worcester, N. 2015.  Status and demographic rates of the Christmas Shearwater Puffinus nativitatis on Kure Atoll.  Marine Ornithology 43: 199-205.

John Cooper ACAP Information Officer, 07 November 2015

Alex Bond (Centre for Conservation Science, Royal Society for the Protection of Birds, Sandy, UK) and Jen Lavers have published in the journal Canadian Field-Naturalist on the occurrence of Flesh-footed Shearwaters Puffinus carneipes in the northern Pacific Ocean.

The paper’s abstract follows:

“Flesh-footed Shearwaters (Puffinus carneipes) breed in Australia and New Zealand, but spend the non-breeding season in the north Pacific Ocean.  They are rare compared with most non-breeding pelagic seabirds that occur in the northeastern Pacific.  Recent surveys at breeding colonies have indicated a significant population decline since the 1970s.  We compiled records of Flesh-footed Shearwaters off the Pacific coast of Canada and Alaska from 1937 to 2013.  Flesh-footed Shearwaters were recorded from May to October, with most sightings in August and September.  Flocks of more than 20 birds have not been recorded since the 1940s, and most sightings have been of single birds, although some key areas (e.g., Goose Island Bank) have not been surveyed in recent years and previous surveys are confounded by fishing activity.  Given the significant population declines at breeding colonies, the conservation status of Flesh-footed Shearwaters should be revisited.”

Flesh-footed Shearwater at sea, photograph by Tim Reid

Reference:

Bond, A.L. & Lavers, J.L. 2015.  Flesh-footed Shearwaters (Puffinus carneipes) in the northeastern Pacific Ocean: summary and synthesis of records from Canada and Alaska.  Canadian Field-Naturalist 129: 263-267.

John Cooper, ACAP Information Officer, 06 November 2015