Annette Fayet (Oxford Navigation Group, Department of Zoology, University of Oxford, UK) and colleagues have published in the Journal of Animal Ecology on the results of manipulating the length of chick-rearing periods in Manx Shearwaters Puffinus puffinus by cross fostering.

The paper’s summary follows:

Long-lived migratory animals must balance the cost of current reproduction with their own condition ahead of a challenging migration and future reproduction.  In these species, carry-over effects, which occur when events in one season affect the outcome of the subsequent season, may be particularly exacerbated.  However, how carry-over effects influence future breeding outcomes and whether (and how) they also affect behaviour during migration and wintering is unclear.

Here we investigate carry-over effects induced by a controlled, bidirectional manipulation of the duration of reproductive effort on the migratory, wintering and subsequent breeding behaviour of a long-lived migratory seabird, the Manx shearwater Puffinus puffinus.  By cross-fostering chicks of different age between nests, we successfully prolonged or shortened by ∼25% the chick-rearing period of 42 breeding pairs.  We tracked the adults with geolocators over the subsequent year and combined migration route data with at-sea activity budgets obtained from high-resolution saltwater-immersion data.  Migratory behaviour was also recorded during non-experimental years (the year before and/or two years after manipulation) for a subset of birds, allowing comparison between experimental and non-experimental years within treatment groups.

All birds cared for chicks until normal fledging age, resulting in birds with a longer breeding period delaying their departure on migration; however, birds that finished breeding earlier did not start migrating earlier.  Increased reproductive effort resulted in less time spent at the wintering grounds, a reduction in time spent resting daily and a delayed start of breeding with lighter eggs and chicks and lower breeding success the following breeding season. Conversely, reduced reproductive effort resulted in more time resting and less time foraging during the winter, but a similar breeding phenology and success compared with control birds the following year, suggesting that ‘positive’ carry-over effects may also occur but perhaps have a less long-lasting impact than those incurred from increased reproductive effort.

Our results shed light on how carry-over effects can develop and modify an adult animal's behaviour year-round and reveal how a complex interaction between current and future reproductive fitness, individual condition and external constraints can influence life-history decisions.”

Manx Shearwater at sea, photograph by Nathan Fletcher

Read more on the research here.

Reference:

Fayet, A.L., Freeman, R., Shoji, A., Kirk, H.L., Padget, O., Perrins, C.M. & Guilford, T. 2016.  Carry-over effects on the annual cycle of a migratory seabird: an experimental study.  Journal of Animal Ecology DOI:10.1111/1365-2656.12580.

John Cooper, ACAP Information Officer, 07 September 2015

Kalinka Rexer-Huber (Department of Zoology, University of Otago, Dunedin, New Zealand) and colleagues have published in the journal Polar Biology on a population survey of the ACAP-listed White-chinned Petrel Procellaria aequinoctialis on Disappointment Island in the sub-Antarctic Auckland Island group.

“The white-chinned petrel Procellaria aequinoctialis is one of the most frequently observed seabird species captured in fisheries bycatch, yet some populations remain virtually unstudied.  The size of the breeding population on the sub-Antarctic Auckland Islands, New Zealand, is unknown.  Disappointment Island is thought to be the main white-chinned petrel breeding site in the Auckland Islands, and maybe also in the New Zealand region, and has never had introduced mammalian predators.  We estimated the white-chinned petrel breeding population size taking into account the detection probability of burrows via distance sampling and the burrow occupancy rate.  Eighty line transects were distributed over the island, with a total line length of 1600 m.  Burrows were patchily distributed and most abundant in dense megaherb communities.  White-chinned petrel burrow densitywas 654 burrows/ha (95 % CI 528–809 burrows/ha), with burrow detection probability varying among vegetation communities from 0.28 ± 0.02 to 0.43 ± 0.02 (±SE). Mean burrow occupancy was 0.73 ± 0.03.  We document an estimated total of 155,500 (125,600–192,500) breeding pairs of white-chinned petrels on Disappointment Island during mid incubation in early January 2015.  The relatively high occupancy and density of burrows suggest that Disappointment Island is a key breeding site for white-chinned petrels.”

Disappointment Island, photograph by Paul Sagar

White-chinned Petrels, photograph by David Boyle

With thanks to Kalinka Rexer-Huber.

Reference:

Rexer-Huber, K., Parker, G.C., Sagar, P.M. & Thompson, D.R. 2016.  White-chinned petrel population estimate, Disappointment Island (Auckland Islands).  Polar Biology. doi:10.1007/s00300-016-2031-x.

John Cooper, ACAP Information Officer, 06 September 2016

Protection of Antarctica’s marine environment received support at the International Union for the Conservation of Nature (IUCN) World Conservation Congress being held in Honolulu, Hawaii, USA when 107 governmental members (96%) voted in favour of new Marine Protected Areas (MPAs) in Antarctica’s Southern Ocean.  Only four governmental members voted against the motion, although 45 abstained.  A total of 507 non-governmental organizations (97%) also voted in favour (click here).

The adopted IUCN Congress motion urges the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) to designate marine reserves in the Ross Sea and East Antarctica.  Both proposed MPAs will offer formal support for the more southerly-ranging ACAP-listed species, such as Light-mantled Albatross Phoebastria palpebrata and Southern Giant Petrel Macronectes giganteus, as well as for other marine biota.

Light-mantled Albatrosses, photograph by Aleks Terauds 

CCAMLR’s Scientific Committee and Commission meet in Hobart, Australia next month, when it is expected the proposed MPAs, will, once more, come up for discussion.

The IUCN represents over 1300 member organizations, including states, government agencies, scientific and academic institutions, business associates and non-governmental organizations.

Click here to read of previous progress by CCAMLR towards the new Antarctic MPAs.

A news item on the vote can be read here.

John Cooper, ACAP Information Officer, 05 September 2016

The 6th International Albatross and Petrel Conference will be held in Barcelona, Spain over 19-23 September.  The Conference Programme and Abstract Book is now available (click here).

“In the book, you will find the provisional conference programme with all the presentations and posters, including useful information for presenters as well as on the conference venue and social events.  If you are registered, you will receive a printed copy of the book at your arrival at the conference so, please, don’t print it by yourself.  If you have any query concerning the programme and abstracts, please contact us as soon as possible.”

A popular science Video Session is scheduled on the last day of the conference. Delegates with a short (5-10 min) informative video of their research and/or conservation programmes are encouraged to bring it to the conference.  Send in the title, the duration, a brief description of the video (around 50 words) and a link to download it as soon as possible.

During the Conference we have organised a number of social events for all delegates.  The last day to register for the Tarragona pelagic trip on 19 September is 15 September. The last day to register for the Cap de Creus pelagic trip and Aiguamolls de l’Empordà, to the Ebro Delta and Delta Birding Festival, to Codorniu Winery and Cellars, and for the conference dinner is Tuesday the 20th.

The final deadline to register for the Conference is 10 September.  Communicate with the conference organizers via This email address is being protected from spambots. You need JavaScript enabled to view it..

John Cooper, ACAP Information Officer, 02 September 2016