Cerren Richards (Department of Ocean Sciences, Memorial University of Newfoundland, St John’s, Canada) and colleagues have published open access in the journal PeerJ on rafting by Manx Shearwaters Puffinus puffinus around the Welsh island of Skomer.

The paper’s abstract follows:

“Before visiting or leaving their remote island colonies, seabirds often engage in a behaviour termed ‘rafting’, where birds sit, often in groups, on the water close to the colony. Despite rafting being a widespread behaviour across many seabird taxa, the functional significance of rafting remains unknown. Here we combine global positioning system (GPS) tracks, observational and wind condition data to investigate correlates of rafting behaviour in Manx shearwaters (Puffinus puffinus) at a large colony on Skomer Island, Wales. We test (1) the influence of wind direction on rafting location and (2) whether raft size changes with respect to wind speed. Our approach further allows us to describe day-night trends in (3) raft distance from shore through time; (4) the number of birds present in the nearshore waters through time; and (5) spatial patterns of Manx shearwater rafts in marine waters adjacent to the breeding colony. We find no evidence that wind direction, for our study period, influences Manx shearwater rafting location, yet raft size marginally increases on windier days. We further find rafting birds closer to the shore at night than during the day. Thus, before sunset, birds form a “halo” around Skomer Island, but this halo disappears during the night as more individuals return from foraging trips and raft nearer the colony on Skomer Island. The halo pattern reforms before sunrise as rafts move away from land and birds leave for foraging. Our results suggest that wind conditions may not be as ecologically significant for rafting locations as previously suspected, but rafting behaviour may be especially important for avoiding predators and cleaning feathers.”

Manx Shearwater on the sea surface, photograph by Nathan Fletcher

Reference:

Richards, C., Padget, O., Guilford, T. & Bates, A.E. 2019.  Manx shearwater (Puffinus puffinus) rafting behaviour revealed by GPS tracking and behavioural observations. PeerJ 7: e7863 doi.org/10.7717/peerj.7863.

John Cooper, ACAP Information Officer, 14 November 2019

Rhiannon Austin (National Oceanography Centre, Southampton, UK) and colleagues have published open access in the journal Scientific Reports on movements of Puffinus shearwaters endemic to the Mediterranean.

The paper’s abstract follows:

“Patterns of behavioural variation and migratory connectivity are important characteristics of populations, particularly at the edges of species distributions, where processes involved in influencing evolutionary trajectories, such as divergence, mutual persistence, and natural hybridization, can occur. Here, we focused on two closely related seabird species that breed in the Mediterranean: Balearic shearwaters (Puffinus mauretanicus) and Yelkouan shearwaters (Puffinus yelkouan). Genetic and phenotypic evidence of hybridization between the two species on Menorca (the eastern and westernmost island in the breeding ranges of the two shearwaters, respectively) has provided important insights into relationships between these recently diverged species. Nevertheless, levels of behavioural and ecological differentiation amongst these populations remain largely unknown. Using geolocation and stable isotopes, we compared the at-sea movement behaviour of birds from the Menorcan ‘hybrid’ population with the nearest neighbouring populations of Balearic and Yelkouan shearwaters. The Menorcan population displayed a suite of behavioural features intermediate to those seen in the two species (including migration strategies, breeding season movements and limited data on phenology). Our findings provide new evidence to support suggestions that the Menorcan population is admixed, and indicate a role of non-breeding behaviours in the evolutionary trajectories of Puffinus shearwaters in the Mediterranean.”

Comparison of the non-breeding at-sea distributions of Mallorcan (Balearic), Menorcan (hybrid) and Yelkouan Shearwater populations – from the publication

Reference:

Austin, R.E., Wynn, R.B., Votier, S.C., Trueman, C., McMinn, M., Rodríguez, A., Suberg, L., Maurice, L., Newton, J., Genovart, M., Péron, C., Grémillet, D. & Guilford, T. 2019.  Patterns of at-sea behaviour at a hybrid zone between two threatened seabirds.  Scientific Reports 9, 14720. doi:10.1038/s41598-019-51188-8.

John Cooper, ACAP Information Officer, 13 November 2019

ACAP’s Advisory Committee currently has three working groups that report to it at its meetings that normally take place two years of every three.  It most recently met (AC11) in May this year in Brazil.  The 12th meeting of the Advisory Committee is set to take place next year in Ecuador.  Each of the three working groups is led by two to four convenors appointed by the Advisory Committee for fixed terms.  These are the Taxonomy WG, Population and Conservation Status WG and the Seabird Bycatch WG.

The TWG discusses issues intersessionally at the request of the Advisory Committee; the PaCSWG and SBWG meet the week before the Advisory Committee for a total of five days, normally at the same venue.  Reports from the working groups are presented to the Advisory Committee by their convenors, which then considers their recommendations for possible action.

At AC11 it was agreed to launch the inaugural World Albatross Day next year on 19 June, the date the Agreement was signed in Canberra, Australia in 2001, with the aim of increasing awareness among the general public of the conservation crisis facing albatrosses and petrels (click here).  Welcome support for this initiative has come from ACAP working group convenors in correspondence with ACAP Latest News as set out below.

Mike Double of the Australian Antarctic Division and Vice-convenor, Taxonomy Working Group writes: “To misquote Robert Cushman Murphy, everyone today and in the future deserves the chance to join the higher cult of mortals by seeing an albatross.  I will never forget the day I did and my life was better for it.  I thank all those around world fighting to save albatrosses, you make the world a richer place.”

Argentinian Marco Favero, ACAP’s second Executive Secretary from 2016 to 2018, and now Co-convenor of the Population and Conservation Status Working Group says “Albatrosses are globally threatened birds that require our urgent attention.  Governments and decision makers must understand this urgency and strengthen conservation actions that reverse the negative effects on these species and their habitats.”

Richard Phillips, albatross researcher at the British Antarctic Survey, past Co-convenor and current Vice-convenor of the Population and Conservation Status Working Group offers his support: “Albatrosses are some of the most iconic of birds, and, sadly, amongst the most threatened.  World Albatross Day is an excellent way to increase awareness of their conservation.”

Patricia Pereira Serafini, National Center for Bird Conservation and Research, Brazil serves as Co-convenor of the PaCSWG.  She writes to ACAP Latest News:  “The future of albatrosses and petrels depends on people.  Public awareness of the conservation situation facing albatrosses and petrels can drive people all over the world to encourage fishers and fishery managers to take necessary steps to reduce seabird bycatch.  Albatrosses and petrels are among the most thrilling birds on the planet; they are impossible not to fall in love with when you get to know them.  World Albatross Day has the potential to make the world know them better."

"Mark Tasker from the UK, an ACAP veteran from the beginning of the Agreement, is currently Convenor of the Taxonomy Working Group: “Albatrosses are one of the pinnacles of evolution in harnessing the winds to search much of the world’s oceans for food.  Sadly, human activities are putting them at risk of extinction.  I hope that World Albatross Day will highlight their plight and encourage a greater focus globally on their conservation.”

Anton Wolfaardt, based in South Africa, is the current Co-convenor of the Seabird Bycatch Working Group.  His view follows:  “Albatrosses are truly remarkable birds, highly adept at soaring effortlessly in the stormy expanses of the oceans, where they spend the majority of their time.  Unfortunately, these birds are facing a conservation crisis; they are threatened by human activities both at sea and at their breeding colonies.  World Albatross Day will help raise awareness of this crisis and galvanise action to address it.  This is essential if we are to improve the conservation status of these wonderful birds.”

Within the ACAP community support for a World Albatross Day has also come from past office holders; several of whom are still active within the agreement in various ways (click here).

John Cooper, ACAP Information Officer, 16 November 2019

Caitlin Kroeger (Department of Ocean Sciences, Long Marine Lab, University of California, Santa Cruz, California, USA) and colleagues have published in the journal Physiological and Biochemical Zoology on a hormonal study of Campbell Thalassarche impavida and Grey-headed T. chrysostoma Albatrosses from Campbell Island, New Zealand

The paper’s abstract follows:

“Corticosterone (CORT) is a glucocorticoid hormone that maintains energy balance and can modulate foraging behaviors in seabirds.  However, CORT responses are not always predictable under similar biophysical conditions and do not necessarily influence the same behaviors across breeding stages and species.  To enhance our understanding of CORT’s role as a proximate determinant of foraging behavior and energy maintenance, we examined the relationships between body condition, CORT, foraging behavior, and foraging success between two sympatric breeding albatross species with differing foraging strategies and life histories, the Campbell albatross (Thalassarache [sic] impavida) and the gray-headed albatross (Thalassarache chrysostoma), from Campbell Island, New Zealand.  Pre- and postforaging CORT did not differ between species or stage, potentially as a result of behavioral plasticity or different functional roles of CORT across stages.  Unexpectedly, body condition did not correlate with preforaging CORT during incubation, although a negative correlation was observed in Campbell albatrosses during the guard stage.  Furthermore, CORT mediated foraging success in both species and stages, but CORT mediated foraging behavior only in incubation-stage Campbell albatrosses that had shorter foraging ranges with higher pretrip CORT. Additionally, CORT positively correlated with mass gain and the time elapsed since the last feeding event in guard-stage albatrosses.  Our results highlight the complexity of CORT in mediating energy balance in free-ranging animals.  Our results also support that if CORT is to be usefully interpreted, breeding stage must be considered because the physiological and behavioral functionality of CORT may differ across stages, with enhanced sensitivity to energy reserves during chick rearing.”

A Campbell Albatross preens its downy chick on Campbell Island, photograph by David Evans

Reference:

Kroeger, C., Crocker, D.E., Thompson, D.R., Torres, L.G., Sagar, P. & Shaffer, S.A. 2019.  Variation in corticosterone levels in two species of breeding albatrosses with divergent life histories: responses to body condition and drivers of foraging behaviour.  Physiological and Biochemical Zoology 92: 223-238.

John Cooper, ACAP Information Officer, 11 November 2019.