Amsterdam Albatross by Lea Finke, Artists & Biologists Unite for Nature

Adrien Pajot (Centre d'Etudes Biologiques de Chizé, Villiers‐en‐Bois, France) and colleagues have written in the Journal of Avian Biology on development of foraging activity in juvenile Amsterdam Diomedea amsterdamensis and Wandering D. exulans Albatrosses.

The paper’s abstract follows:

“The first year of life is a period of high mortality in animals. Reduced foraging capacities of naive individuals might be the primary cause of their mortality. These capacities are supposed to be progressively acquired during the first months of life. In this study, we investigate the ontogeny of flight capacities, by day and night, of first‐year individuals, and compare it with adults from two closely related species of great albatrosses: Amsterdam Diomedea amsterdamensis and wandering Diomedea exulans albatrosses which forage in different environmental conditions. We used 71 tracks of 71 juvenile birds and 141 of 116 incubating adults to compare both age categories. In order to explore the effect of moon light on night activity, we elaborated a new formula which improves the precision of the proxy of moon illumination. By day, we found that juveniles of both species reach some adult foraging capacities in less than two months. By night, albatrosses have reduced activity increasing during the first weeks at sea for juveniles and changing in accordance with moon illumination for both juveniles and adults. A peak of flight activity at dawn and dusk was apparent for both species. Interspecific comparison underlined that Amsterdam albatrosses were more active than wandering albatrosses, suggesting a difference in food and foraging strategy. Overall, we highlighted how life history traits, environmental conditions and time of the day affect the foraging activity of two related species of seabirds.”

Reference:

Pajot, A., Corbeau, A., Jambon, A. & Weimerskirch, H. 29021.  Diel at‐sea activity of two species of great albatrosses: the ontogeny of foraging and movement behaviour. Journal of Avian Biology  doi.org/10.1111/jav.02597.

John Cooper, ACAP Information Officer, 15 March 2021

Cory's Shearwater, photograph by Paulo Catry

Marie Claire Gatt (Centro de Estudos do Ambiente e do Mar, Universidade de Lisboa, Portugal) and colleagues have published in the Journal of Avian Biology on the temperament of breeding Cory's Shearwaters Calonectris borealis (Least Concern).

The paper’s abstract follows:

“Inter‐individual variation in behaviour has been recognised as a major driver of population ecology, but its relationship to migratory strategy has been ill‐explored. Here, we investigated whether male migrant and resident Cory's shearwaters Calonectris borealis, a long‐lived partially migratory seabird, are distinguishable by their temperament at the colony. We tracked a large number of individuals over two winters using GLS devices and assessed whether exploratory behaviour and reaction to extraction from the nest corresponded to migratory strategy over this period. While exploratory behaviour was unrelated to migratory strategy, birds that were resident were more likely to be unreactive towards extraction from the nest. This difference in behavioural stress response, together with previous findings that migrants display higher physiological stress over winter, suggests that migrants and residents may be distinguishable by their stress threshold.”

Reference:

Gatt, M.-C., Granadeiro, J.P. & Catry, P. 2021.  Migrants and residents of a long‐lived seabird differ in their behavioural response to a stressor.  Journal of Avian Biology 52(2) . doi.org/10.1111/jav.02589.

John Cooper, ACAP Information Officer, 14 March 2021

A Wandering Albatross lands behind a fishing vessel; artwork by Maureen Bennetts, after a photograph by Dimas Gianuca

Can Zhou (Texas A&M University, College Station, USA) and Nigel Brothers have published in the journal Bird Conservation International on assessing bycatch in pelagic longline fisheries by recording seabird interactions.

The paper’s abstract follows:

“The incidental mortality of seabirds in fisheries remains a serious global concern. Obtaining unbiased and accurate estimates of bycatch rates is a priority for seabird bycatch mitigation and demographic research. For measuring the capture risk of seabird interactions in fisheries, the rate of carcass retrieval from hauled gear is commonly used. However, reliability can be limited by a lack of direct capture observations and the substantial pre-haul bycatch losses known to occur, meaning incidence of seabird bycatch is underestimated. To solve this problem, a new measure (bycatch vulnerability) that links an observed interaction directly to the underlying capture event is proposed to represent the capture risk of fishery interactions by seabirds. The new measure is not affected by subsequent bycatch loss. To illustrate how to estimate and analyse bycatch vulnerability, a case study based on a long-term dataset of seabird interactions and capture confirmation is provided. Bayesian modelling and hypothesis testing were conducted to identify important bycatch risk factors. Competition was found to play a central role in determining seabird bycatch vulnerability. More competitive environments were riskier for seabirds, and larger and thus more competitive species were more at risk than smaller sized and less competitive species. Species foraging behaviour also played a role. On the other hand, no additional effect of physical oceanic condition and spatio-temporal factors on bycatch vulnerability was detected. Bycatch vulnerability is recommended as a replacement for the commonly used bycatch rate or carcass retrieval rate to measure the capture risk of an interaction. Combined with a normalized contact rate, bycatch vulnerability offers an unbiased estimate of seabird bycatch rate in pelagic longline fisheries.”

Read a related paper by the same authors.

With thanks to Nigel Brothers.

Reference:

Zhou, C. & Brothers, N. 2021.  Seabird bycatch vulnerability in pelagic longline fisheries based on modelling of a long-term dataset.  Bird Conservation International  doi.org/10.1017/S0959270921000046.

https://www.tamu.edu/John Cooper, ACAP Information Officer, 13 March 2021

Whenua Hou Diving Petrel 

Johannes Fischer (School of Biological Sciences, Victoria University of Wellington, New Zealand) and colleagues have published in the journal Marine Progress Report Series on at-sea activities of the Critically Endangered (and recently described) Whenua Hou Diving Petrel Pelecanoides whenuahouensis that breeds only on predator-free Codfish Island (Whenua Hou), New Zealand.

The paper’s abstract follows:

“Without insights into the threats affecting species across their distributions and throughout their annual cycles, effective conservation management cannot be applied. The Whenua Hou diving petrel Pelecanoides whenuahouensis (WHDP) is a Critically Endangered small seabird whose offshore habits and threats are poorly understood. We tracked WHDPs year-round in 2015/16, 2017/18, and 2018/19 using global location-sensing immersion loggers to identify offshore distribution, movements, behaviour, and overlap with commercial fishing effort. During the breeding period, WHDPs ranged from southern Aotearoa (New Zealand) to Maukahuka (Auckland Islands). After breeding, WHDPs migrated southwest towards the Polar Front south of Australia, exhibited clockwise movements, and returned to their breeding grounds via the Subantarctic Front. During the non-breeding period, WHDPs exhibited extreme aquatic behaviour and spent >95% of their time on, or under, water. The core areas used consistently during breeding and non-breeding periods warrant listing as Important Bird and Biodiversity Areas. Spatiotemporal overlap of commercial fishing effort with breeding distributions was considerable, in contrast with non-breeding distributions. Spatiotemporal management of anthropogenic activity around the breeding colony during the breeding period could help protect WHDPs, but such measures should be subjected to a structured decision-making framework. Our results illustrate the importance of year-round studies to inform conservation of marine species.”

Follow research conducted on the Whenua Hou Diving Petrel on the Flying Penguin Force Facebook page.

Reference:

Fischer, J.H., Debski, I., Spitz, D.B., Taylor, G.A. &. Wittmer, H.U. 2021.  Year-round offshore distribution, behaviour, and overlap with commercial fisheries of a Critically Endangered small petrel.  Marine Progress Report Series 660: 171-187.

John Cooper, ACAP Information Officer, 12 March 2021