Jorge Pereira (MARE – Marine and Environmental Sciences Centre, University of Coimbra, Portugal) and colleagues have published in the journal Marine Biology on sexual segregation in  globally Vulnerable Wandering Albatrosses Diomedea exulans while foraging.

The paper’s abstract follows:

“Sexual segregation in foraging habitat occurs in many marine predators and is usually attributed to competitive exclusion, different parental roles of each sex or niche specialisation associated with sexual size dimorphism. However, relatively few studies have attempted to understand the patterns and underlying drivers of local-scale sexual segregation in marine predators. We studied habitat use, diet and feeding ecology of female and male wandering albatrosses Diomedea exulans, fitted with GPS and stomach-temperature loggers during the chick-rearing period (austral winter) at South Georgia in 2009. During this period, when oceanographic conditions were anomalous and prey availability was low in waters near the breeding colony, the tracked wandering albatrosses showed high consistency in their foraging areas at a large spatial scale, and both males and females targeted sub-Antarctic and subtropical waters. Despite consistency in large-scale habitat use, males and females showed different foraging behaviours in response to oceanographic conditions at a smaller scale. Males appeared to be more opportunistic, scavenging for offal or non-target fish discarded by fishing vessels in less productive, oceanic waters. They exhibited sinuous movements, feeding mostly on large prey and consuming similar amounts of food during the outbound and return parts of the foraging trip. In contrast, females targeted natural productivity hotspots, and fed on a wide variety of fish and cephalopods. They commuted directly to these areas; most prey were ingested on the outbound part of the trip, and they often started their return after ingesting large prey at the farthest point from the colony. Together, these results indicate that sexual segregation in core foraging areas of wandering albatrosses is driven by sex-specific habitat selection due to the low availability of prey in local Antarctic waters. This segregation results in different feeding behaviour at local scales which may be explained by differing breeding roles and degree of parental investment by each sex, with females investing more than males in reproduction. Further investigations are necessary to confirm the existence of this pattern through time under contrasting environmental conditions and to identify the drivers responsible for local-scale sexual segregation in wandering albatrosses.

Wandering Albatross at sea, photograph by John Chardine

With thanks to Richard Phillips.

Reference:

Pereira, J.M., Paiva, V.H., Phillips, R.A. & Xavier, J.C. 2018. The devil is in the detail: small-scale sexual segregation despite large-scale spatial overlap in the wandering albatross. Marine Biology 165: 55.  doi.org/10.1007/s00227-018-3316-0.

John Cooper, ACAP Information Officer, 01 March 2018

The project “Sustainable Management of Tuna Fisheries and Biodiversity Conservation in the Areas Beyond National Jurisdiction (ABNJ)”, (also known as the “Common Oceans Tuna Project”) aims to achieve responsibility, efficiency and sustainability in tuna production and biodiversity conservation in the ABNJ. The Food and Agriculture Organization of the United Nations (FAO) is the overall implementing agency of the project, and BirdLife International, through its local partner, BirdLife South Africa, is implementing the seabird bycatch component. This component has a number of separate, but aligned, areas of work. These include increasing awareness and capacity of observer programmes regarding seabird bycatch mitigation, and building capacity of national scientists from key countries in the areas of bycatch data collection and analysis, and facilitating a collaborative approach to the assessment of seabird bycatch. The first stage of the seabird bycatch assessment process involved two regional pre-assessment workshops, one in South Africa in March 2017, and the second in Vietnam in April 2017 (click here).

Attendees at the ABNJ workshop in Cusco, photograph courtesy of BirdLife South Africa

Building on the outcomes of these regional workshops, and to progress planning for the collaborative assessment of bycatch associated with southern hemisphere tuna fisheries, country representatives, and members of BirdLife and ACAP participated in a data preparation workshop from 20-24 February this year in Cusco, Peru. Discussions at the workshop focused on the data that are available for estimating seabird bycatch and assessing the effectiveness of mitigation measures, how best to address data gaps, and methodological approaches for estimating seabird bycatch in southern hemisphere tuna fisheries. An Action Plan was developed to help guide further work in preparation for the final assessment workshop, which is planned for February 2019. ACAP was represented at the workshop by Anton Wolfaardt, ACAP Seabird Bycatch Working Group Co-convenor.

Yellowfin Tuna

Anton Wolfaardt, Co-Convenor, ACAP Seabird Bycatch Working Group, 28 February 2018

Ewan Wakefield (Institute of Biodiversity, University of Glasgow, United Kingdom) and colleagues have published a grant report in the Seabird Group Newsletter (and on the grants page on the group’s website) on a study of the numbers and at-sea movements of globally Near Threatened Sooty Shearwaters Ardenna grisea at the Falkland Islands/Islas Malvinas*.

The authors report an estimate of “well in excess of 100,000 pairs” on Kidney Island, a population thought to be increasing in numbers. Birds tracked at sea from Kidney Island showed “the vast majority” foraged south of the island group in a region partly within an Argentinian Marine Protected Area (MPA).

Sooty Shearwater, photograph by John Graham

Reference:

Wakefield, E., Clark, T.J., Bonnet-Lebrun, A.-S., Campioni, L. & Catry, P. 2018. Seabird Group Grant Report – Surveying and tracking sooty shearwaters in the Falkland Islands. Seabird Group Newsletter 137: 8-9.

John Cooper, ACAP Information Officer, 27 February 2018

*A dispute exists between the Governments of Argentina and the United Kingdom of Great Britain and Northern Ireland concerning sovereignty over the Falkland Islands (Islas Malvinas), South Georgia and the South Sandwich Islands (Islas Georgias del Sur y Islas Sandwich del Sur) and the surrounding maritime areas.

At an estimated 67 years of age, Wisdom the globally Near Threatened Laysan Albatross Phoebastria immutabilis, the world’s oldest known breeding bird, hatched her latest egg (click here) on 6 February this year. Wisdom and her mate Akeakamai of 12 years breed on Midway Atoll in the North Pacific; both are colour-banded to aid in identification.

Wisdom with her 2018 chick, photograph by Bob Peyton, U.S. Fish & Wildlife Service

Wisdom has been breeding on Midway Atoll since at least 1956, when she was first banded by the late Chandler Robbins.

She has successfully raised an estimated 30-36 albatross chicks over the course of her life to date.

Visit Wisdom’s USFWS and Facebook pages for more information and photographs.  Read the latest news here and access the many ACAP Latest News postings on Wisdom here.

John Cooper, ACAP Information Officer, 26 February 2018