Carlos Teixeira (Instituto Superior Técnico, Departamento de Engenharia Mecânica I, Área Científica de Ambiente e Energia, Lisbon, Portugal) and colleagues have published in the Journal of Sea Research on the growth pattern of the Wandering Albatross Diomedea exulans.

The paper’s abstract follows:

“The Wandering Albatross (Diomedea exulans) and other seabirds exhibit a growing pattern that includes a period of body mass decrease before fledging.  Several hypotheses have been suggested to explain it without success.  We hypothesized that: 1) chicks and adults have similar metabolic traits regulating assimilation, growth and maturation; 2) there is a difference in locomotion effort between chicks and adults, and 3) chicks are exposed to a decline in food availability before fledging.  This set of hypotheses allows for an energy surplus to be available and stored in reserve during the first months of development, explaining the mass recession that starts before fledging and the fact that adults keep a lower weight than fledglings, throughout the rest of their life span.  To test this set of hypotheses we applied the Dynamic Energy Budget (DEB) theory.  Using a small set of life-history traits and growth curves we parameterized the DEB standard model.  We confirmed this set of hypotheses and estimated the pattern of decline in food availability that explains mass recession. An assessment of the daily energy intake was also performed.  The implications related to that energy flux and diet composition are discussed based on current knowledge. The DEB model for the Wandering Albatross also provided estimates for the adult daily food ingested by adults (464.06 kJ kg^- 1d^- 1), fasting capacity (25 d), Field Metabolic Rate (4.29 W kg^- 1) and Resting Metabolic Rate (2.87 W kg^- 1).  These values are consistent with the averages obtained in the field, suggesting that DEB may be useful to provide good estimations on a broader scale.”

Wandering Albatross and chick, photograph by Genevieve Jones

Reference:

Teixeira, C.M.G.L., Sousa, T., Marques, G.M., Domingos, T. & Kooijman, S.A.L. 2014.  A new perspective on the growth pattern of the Wandering Albatross (Diomedea exulans) through DEB theory.  Journal of Sea Research  DOI: 10.1016/j.seares.2014.06.006.

John Cooper, ACAP Information Officer, 03 July 2014

The Scientific Council of the Convention on Migratory Species (CMS) will hear a report from its By-catch Working Group this week in Bonn, Germany at its 18th Meeting.

Inter alia, the council will review an assessment report (UNEP/CMS/ScC18/Inf.10.15.1) of bycatch in gill net fisheries and consider the outcomes of a technical workshop held in Christchurch, New Zealand last year to identify new operational or technical measures for reducing the risk to seabirds from gill and trawl nets (click here).

Black-browed Albatrosses gather behind a fishing trawler, photograph by Graham Parker

Management of marine debris and a draft resolution on the subject will also be discussed (click here) as will a review on the impact of invasive alien species on species protected under the Convention on Migratory Species.  In the latter document the successful Macquarie Island Pest Eradication Project (MIPEP) is treated as a case study.  The review also refers to the ACAP Conservation Guidelines document for the eradication of introduced mammals from breeding sites of ACAP-listed seabirds (click here).

See earlier ACAP Latest News reports on CMS-related activities here.

With thanks to Barry Baker, CMS Councillor for By-Catch for information.

John Cooper, ACAP Information Officer, 02 July 2014

Aurélie Goutte (Centre d'Etudes Biologiques de Chizé, Villiers-en-Bois, France) and colleagues have published in the journal Proceedings of the Royal Society B Biological Sciences on pollutants affecting Wandering Albatrosses Diomedea exulans.

“Seabirds are top predators of the marine environment that accumulate contaminants over a long life-span. Chronic exposure to pollutants is thought to compromise survival rate and long-term reproductive outputs in these long-lived organisms, thus inducing population decline.  However, the demographic consequences of contaminant exposure are largely theoretical because of the dearth of long-term datasets.  This study aims to test whether adult survival rate, return to the colony and long-term breeding performance were related to blood mercury (Hg), cadmium (Cd) and persistent organic pollutants (POPs), by using a capture–mark–recapture dataset on the vulnerable wandering albatross Diomedea exulans.  We did not find evidence for any effect of contaminants on adult survival probability.  However, blood Hg and POPs negatively impacted long-term breeding probability, hatching and fledging probabilities.  The proximate mechanisms underlying these deleterious effects are likely multifaceted, through physiological perturbations and interactions with reproductive costs.  Using matrix population models, we projected a demographic decline in response to an increase in Hg or POPs concentrations.  This decline in population growth rate could be exacerbated by other anthropogenic perturbations, such as climate change, disease and fishery bycatch.  This study gives a new dimension to the overall picture of environmental threats to wildlife populations.”

Wandering Albatross and chick, photograph by John Cooper

Reference:

Goutte, A., Barbraud, C., Meillère, A., Carravieri, A., Bustamante, P., Labadie, P., Budzinski, H., Delord, K., Cherel, Y.,Weimerskirch, H. & Chastel, O. 2014.  Demographic consequences of heavy metals and persistent organic pollutants in a vulnerable long-lived bird, the wandering albatross.  Proceedings of the Royal Society B Biological Sciences doi:10.1098/rspb.2013.3313.

John Cooper, ACAP Information Officer, 01 July 2014

Hiroshi Arima (Faculty of Medicine, Kyoto University, Kyoto, Japan) and colleagues write in the Japanese journal Ornithological Science on assigning gender to sexually monomorphic Streaked Shearwaters Calonectris leucomelas.

The paper’s abstract follows:

“Like most seabirds Streaked Shearwaters Calonectris leucomelas have sexually monomorphic plumage.  Researchers have conveniently identified gender in the field by means of two types of calls, associated with dimorphism in body size.  By molecular sexing analysis using the chromo-helicase-DNA-binding (CHD) genes, we determined the gender of Streaked Shearwaters in relation to call types and body size.  We recorded the type of calls, measured body dimensions and collected non-invasive samples (buccal cells or feathers) of Streaked Shearwaters at two breeding islands.  As obvious amplification to identify gender by polymerase chain reaction (PCR) could not be obtained at high rates using a known universal primer pair, we developed two new primer pairs to identify gender in this species; this enabled us to identify the gender of all of the samples.  Without exception all males gave high-pitched calls, whereas all females gave low-pitched calls.  Molecular evidence also confirmed morphometric differences between males and females.  We, therefore, conclude that Streaked Shearwaters exhibit sexual dimorphism in body size and call type.  Males are significantly larger than females, and males give high calls whereas females give low calls.”

Reference:

Arima, H., Oka, N., Baba, Y., Sugawa, H. & Ota, T.2014.  Gender identification by calls and body size of the Streaked Shearwater examined by CHD genes.  Ornithological Science 13: 9-17.

John Cooper, ACAP Information Officer, 30 June 2014