Miguel Ferrer (Applied Ecology Group, Estación Biológica de Doñana, Seville, Spain) and colleagues have published in the journal Waterbirds on sexing Black-browed Albatrosses Thalassarche melanophrys by bill measurements.

The paper’s abstract follows:

“To provide an easy and reliable work tool to identify the sex of individuals, adult Black-browed Albatrosses (Thalassarche melanophrys) (n = 31) were weighed and measured, and the sex determined using DNA analyses.  Stepwise discriminant analysis showed upper bill depth and weight to be the best predictor variables for sex determination.  This model classified correctly 95.0% of the males and 81.8% of the females (overall success was 90.3%).  Additionally, a single measure discriminant analysis of upper bill depth was developed that is able to separate sexes using a threshold upper bill depth of 29.87 mm, with values above this point being males and values below it being females.”

Black-browed Albatrosses engage in preening, photograph by Aleks Terauds

Reference:

Ferrer, M., Morandini, V., Perry, L. & Bechard, M. 2016.  Sex determination by morphological measurements of Black-browed Albatrosses (Thalassarche melanophrys) Using Discriminant Analysis.  Waterbirds 39: 295-299.

John Cooper, ACAP Information Officer, 28 October 2016

Benoit Gineste (UMR ENTROPIE, Saint-Denis Messag, France) and colleagues  have published in the Journal of Ornithology on the effects of light pollution on Tropical Shearwaters Puffinus bailloni on Reunion.

The paper’s abstract follows:

“Seabirds are exposed to numerous threats at sea and on land, and they are among the most endangered birds worldwide.  Procellariids are attracted by artificial light, and this causes massive fallout at various places of the world.  In Reunion Island, Tropical Shearwaters Puffinus bailloni are heavily impacted by light pollution.  To assess the population trends of this species, we conducted two large-scale acoustic surveys across the island (in 1996/1997 and in 2013/2015) and analysed the numbers of birds attracted by lights and rescued by the local wildlife rescue center between 1996 and 2015.  We detected 220 colonies in 2013/2015, including 124 colonies previously surveyed in 1996/97 and 96 newly discovered colonies.  The average vocal activity recorded at colonies was similar during the two surveys suggesting no marked change in population size.  Some 13,200 Tropical Shearwaters were found grounded since 1996 due to light attraction, of which 88 % were successfully released.  The number of reported grounded birds increased 19-fold between 1996 and 2015.  This increase was due to a combination of factors that are difficult to disentangle: (1) increasing public awareness; (2) increasing light pollution; and (3) the absence of population collapse.  Indeed, both acoustic surveys and the number of rescued birds indicate that the Tropical Shearwater population of Reunion Island did not decline between 1996/1997 and 2013/2015.  We suggest that the rescue campaigns conducted annually strongly contributed to this stability.  Thus, we recommend maintaining the rescue operations, but also to reduce light pollution.”

Tropical Shearwater 

Reference:

Gineste, B., Souquet, M., Couzi, F.-X., Giloux, Y., Philippe, J.-B., Hoarau, C., Tourmetz, J., Potin, G. & Le Corre, M. 2016.  Tropical Shearwater population stability at Reunion Island, despite light pollution.  Journal of Ornithology  doi: 10.1007/s10336-016-1396-5.

John Cooper, ACAP Information Officer, 27 October 2016

William Mackin (Guilford College, Greensboro, North Carolina, USA ) has published in the journal The Condor: Ornithological Applications on the reduced populations of Audubon’s Shearwaters Puffinus lherminieri in the Caribbean.

The paper’s abstract follows:

“Cryptic species are often difficult to count and thus protect.  Audubon's Shearwater (Puffinus lherminieri) is a cryptic seabird that has disappeared from many colonies, but knowledge of the population's status is incomplete.  This paper reviews the survey methods in detail and assesses the status.  This species nests or once nested on at least 154 islands in the Caribbean and remains on 137 today, with most habitat just above sea level.  Remaining colonies represent 1% of the former breeding area and are remote, with 98 sites lacking any estimate of density.  In 16 plots searched on multiple nights using playback, the probability of detection of defended nests was 79 ± 5% (57 of 72 defended nests) in a single night of searching. Pairs were attempting to breed in 54 ± 6% (39 of 72) of defended nests.  Average densities, adjusted for missed detections, ranged from 0.6 to 246 defended nests ha−1 (n = 21 colonies, median = 18.5 ha−1, area-weighted mean = 104 ha−1).  Using the best data from every colony, at least 13,600 defended nests (7,400 breeding pairs) remain.  If conservative densities from surveyed colonies occur on unsurveyed colonies, then about 37,900 defended nests (20,500 breeding pairs) should exist.  Assuming shearwaters nested on the known extirpated sites in lower densities compared to surveyed colonies, populations were at least 446,000 and potentially >2,000,000 defended nests.  Uncertainty in current population estimates could be reduced by surveying the largest unsurveyed colonies first.   Audubon's Shearwater could be used as an indicator of island and marine ecosystem health with the caveat that the population is a small fraction of its former size. Conservation recommendations include continuing standardized monitoring, surveying large unsurveyed sites, limiting the rise of sea level, and removing invasive species from colonies.”

Audubon's Shearwater at sea

Reference:

Mackin, W.A. 2016.  Current and former populations of Audubon's Shearwater (Puffinus lherminieri) in the Caribbean region.  The Condor: 118: 655-673.

John Cooper, ACAP Information Officer, 26 October 2016

Junichi Sugishita (Department of Zoology, University of Otago, Dunedin, New Zealand) and colleagues have published in the New Zealand Journal of Ecology on recording meal sizes of Northern Royal Albatross Diomedea sanfordi chicks with an automatic weighing system.

The paper’s abstract follows:

“Periodic weighing of seabird chicks is labour-intensive and repeated handling can cause high levels of disturbance to chicks.  Although automatic weighing systems using a fibreglass nest have been designed for albatross species with a pedestal nest made of mud, this approach is inappropriate for great albatross species (genus Diomedea) whose nests consist of a low mound of soil and vegetation.  We developed an automatic weighing technique, using a digital scale beneath a natural nest, to remotely measure meal size in great albatrosses.  To illustrate the system’s capability when used coupled with time-lapse cameras, we present sample data by comparing meal sizes fed to chicks by male and female parents of northern royal albatross (Diomedea sanfordi).  Our weighing system is not only applicable to other great albatross species, but can also be modified to allow automatic weighing of other terrestrial breeders.”

Junichi Sugishita adjusts his weighing balance underneath a watching Northern Royal Albatross chick

Reference:

Sugishita, J., McKenzie, M. Torres, L.G. & Seddon, P.J. 2017.  Automated techniques for measuring meal size in great albatrosses.  New Zealand Journal of Ecology 41(1). DOI: https://doi.org/10.20417/nzjecol.41.6.

John Cooper, ACAP Information Officer, 25 October 2016