Ryan Carle (Oikonos Ecosystem Knowledge, Valparaíso, Chile) and colleagues have published in the journal The Condor: Ornithological Applications on the overlap between ACAP-listed and globally Vulnerable Pink-footed Shearwaters Ardenna creatopus and Chilean purse-seiners.

The paper’s abstract follows:

“Understanding susceptibility of seabirds to fisheries bycatch requires quantifying overlap of seabird at-sea habitat with fisheries’ distribution and effort.  Pink-footed Shearwaters (Ardenna creatopus) are vulnerable seabirds that breed only in Chile.  Recently, high rates of Pink-footed Shearwater bycatch (i.e. >1,500 observed mortalities 2015–2017) were documented by observers in central Chilean purse-seine fisheries.  We present analysis of Pink-footed Shearwater at-sea movements and overlap with central Chilean purse-seine fleets targeting common sardine (Strangomera bentincki), Peruvian anchoveta (Engraulis ringens), and Chilean jack mackerel (Trachurus symmetricus).  To determine overlap during 2015–2017, we paired locations from 49 Pink-footed Shearwaters rearing nestlings at Isla Mocha, Chile, with locations and number of observed purse-seine sets in central Chile.  Pink-footed Shearwaters typically visited waters ≤30 km offshore throughout central Chile.  Foraging trip durations varied interannually, with longer trips in 2016, but all years revealed persistent foraging hotspots near Valdivia, the Gulf of Arauco, and Isla Mocha, Chile.  Greatest overlap between Pink-footed Shearwaters and fisheries occurred with the sardine/anchoveta fleet near Valdivia (artisanal and industrial) and the Gulf of Arauco (artisanal); overlap with the jack mackerel fleet was minimal.  Given Pink-footed Shearwater bycatch documented in these fisheries, this overlap may indicate risk of bycatch for these birds, although we did not directly quantify shearwater–fisheries interaction.  Our results can inform further fishery monitoring efforts, as well as collaboration among scientists, managers, and fishers to identify, quantify, and reduce fisheries bycatch of Pink-footed Shearwaters within Chile and internationally.”

Pibk-footed Shearwater at sea, photograph from Oikonos

Reference:

Carle, R.D., Felis, J.J., Vega, R., Beck, J., Adams, J., López, V., Hodum, P.J., González, A., Colodro, V. & Varela, T. 2019.  Overlap of Pink-footed Shearwaters and central Chilean purse-seine fisheries: implications for bycatch risk.  The Condor: Ornithological Applications doi.org/10.1093/condor/duz026.

John Cooper, ACAP Information Officer, 19 July 2019

Julio César Hernández Montoya (Centro de Investigaciones Biológicas del Noroeste, La Paz, Mexico) and colleagues have published open access in the journal Animals on aspects of the biology of Laysan Albatrosses Phoebastria immutabilis breeding on Mexico’s Guadalupe Island.

The paper’s abstract follows:

“Sexual dimorphism in the Laysan albatross (Phoebastria immutabilis) on Guadalupe Island was evaluated during the breeding seasons of 2015–2018 by measuring and comparing 10 morphological attributes: cranial length, bill length, nostril length, cranial width, bill height, bill width, tarsus length, closed wing length, opened wing length, and wingspan length in reproductive adults (n = 135). Males were larger than females across all traits (Student’s t-test, p < 0.05, p < 0.05). We created a logistic model using stepwise regression to predict sex based on morphological variables. This model indicated four significant morphological predictor variables (z < 0.05) and was able to successfully predict the sex of P. immutabilis individuals in more than 90% of the cases. Based on these predictor variables, a web app was developed to determine the sex of the Laysan albatross in the field, providing a non-invasive method for rapid data collection that reduces costs and handling times while improving conservation efforts. We tracked Laysan albatross (n = 36) during breeding seasons and found no significant differences between females and males for either trip length (GLMM, F = 0.017, DF = 1, 1, p = 0.917 > 0.05) or maximum trip distance (GLMM, F = 0.374, DF = 1, 1, p = 0.651 > 0.05). Our results suggest that both sexes show a strong preference to travel to highly productive coastal waters northeast of the breeding colony that are influenced by the California Current. The present research will serve to establish a baseline to protect this species on Guadalupe Island and highlights the importance of understanding sexual dimorphism in at-risk seabird species.”

 Guadalupe Island, with a Laysan Albatross family, photographs by Ross Wanless

Reference:

Hernández Montoy, J.C., Juárez-Rodríguez, M., Méndez-Sánchez, F., Aguirre-Muñoz, A., Rojas-Mayoral, E., Íñigo-Elias, E., Galina-Tessaro, P., Arnaud, G. & Ortega-Rubio, A. 2019. Sexual dimorphism and foraging trips of the Laysan Albatross (Phoebastria immutabilis) on Guadalupe Island.  Animals 9(6), 364 https://doi.org/10.3390/ani9060364.

John Cooper, ACAP Information Officer, 18 July 2019

Simon Gorta (Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia) and colleagues have published in the journal Biological Conservation on changes over 17 years in numbers of pelagic seabirds off south-eastern Australia, including of nine species of ACAP-listed albatrosses and petrels.

The paper’s abstract follows:

“Many seabird communities are declining around the world, a trend frequently linked to climate change and human impacts on habitat and prey. Time series observations of seabirds away from breeding colonies are generally rare, which limits our understanding of long-term changes for conservation actions. We analysed a dedicated citizen science dataset of pelagic seabird abundance (86 species-30 used for modelling analysis-from 385 trips) from two locations over 17 years (2000-2016) and a third for seven years, over the continental shelf and slope of southeastern Australia. To estimate temporal trends and environmental drivers, we used generalised additive modelling and species archetype modelling for groups. Almost half (43%) of the most abundant seabird species declined in our study area over the 17 years. The declines may be associated with human-induced ecosystem change and represent poleward shifts in distribution out of our study area, changes in population abundance, or both. Winter-dominant groups, primarily species rarely frequenting warmer water, were often negatively associated with SST anom, while summer-dominant groups, composed of species more tolerant of temperate and tropical environments, were generally positively associated with SST anom. Widespread local declines in seabird populations are of increasing concern. Understanding the extent to which these observed declines represent real declines in abundance, or range shifts, should be a priority. Changing sea temperatures are probably contributing to both. These results from the coast of southeastern Australia need to be placed in the context of the highly mobile study organisms and the vast spatial scale of the ocean. Long-term citizen science observations, from an array of locations around the world, promise to provide valuable insights into seabird ecology, playing a key part in seabird conservation.”

Wandering Albatross at sea, photograph by Kirk Zufelt

With thanks to Simon Gorta.

Read a popular article on the publication.

Reference:

Gorta, S., Smith, J.A., Everett, J.D., Kingsford, R.T., Cornwell, W.K., Suthers, I., Epstein, H., McGovern, R., McLachlan, G., Roderick, M., Smith, L., Williams, D. & Callaghan, C.T. 2019.  Pelagic citizen science data reveal declines of seabirds off south-eastern Australia.  Biological Conservation 235: 226-235.

John Cooper, ACAP Information Officer, 17 July 2019

Robert Flood (FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch, South Africa) and Ashley Fisher have published in the journal British Birds giving criteria to separate three shearwater species at sea; one being the dark-plumaged form of the ACAP-listed and Critically Endangered Balearic Shearwater Puffinus mauretanicus.

The paper’s abstract follows:

“Short-tailed Shearwater Ardenna tenuirostris is an abundant species of the Pacific Ocean. We reviewed records for the Indian and Atlantic Oceans and suggest that a regular pattern of movement in these oceans is hitherto unrecognised.  It follows that the vagrancy potential of Short-tailed Shearwater to the North Atlantic probably is greater than suggested by the few documented records.  Short-tailed may have been overlooked or confused with the similar-looking Sooty Shearwater A. grisea and, in the northeast Atlantic, dark-plumaged Balearic Shearwater Puffinus mauretanicus.  Criteria for the separation of these three species at sea are presented in a bid to establish a clearer picture of the status of Short-tailed Shearwater in the North Atlantic.  Separation of Short-tailed from Sooty Shearwater builds on existing criteria; characters for separation from dark-plumaged Balearic Shearwater are new.”

Short-tailed Shearwater at sea, photograph by Peter Ryan

Reference:

Flood, R.[K.] & Fisher, A.  2019.  Identification of Short-tailed Shearwater in the North Atlantic Ocean.  British Birds 112: 250-263.

John Cooper, ACAP Information Officer, 16 July 2019