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- Allopreening in the Black‐browed Albatross (Thalassarche melanophris): an exploration of patterns and possible functionsPublication . Gillies, Natasha; Guilford, Tim; Catry, PauloThe functions of display between breeding pairs of animals have been given little attention outside of sexual selection. Yet evidence suggests that display between partners is in fact most commonly observed following mate choice, and is often just as elaborate. In many bird species, allopreening, when one member of a pair preens the other, is a major component of display both pre- and post-pair formation. Despite this, there has been little investigation into its functions. Explanations that have been put forward tend to focus on its role in feather hygiene, which has limited phylogenetic support, or its function in the maintenance of the pair bond, though how this might occur or indeed what this actually represents has not been adequately explained. Phylogenetic evidence reveals that allopreening is most commonly observed in those species exhibiting high levels of partner retention and biparental care, and it appears to be functional in maintaining cooperation in parental behaviour in at least one species. In our observational study, we explored the patterns and putative functions of allopreening during the nest-relief displays of breeding pairs of Black-browed Albatrosses Thalassarche melanophris during incubation and chick-provisioning. Allopreening was an important feature of displays, constituting 30% of display time. We found that the bird returning from its foraging trip usually initiated allopreening, and preened more than its partner prior to change-over of nesting duties. We further found a positive relationship between the amount of time the pair spent in display and the duration of the subsequent foraging trip, providing tentative support for a function in maintaining cooperative parental behaviour between the parents. Although we cannot be conclusive as to its exact functions, we add to a limited literature the first exploration of functions for this conspicuous behaviour in albatrosses.
- Progressing delineations of key biodiversity areas for seabirds, and their application to management of coastal seasPublication . Handley, Jonathan; Harte, Emma; Stanworth, Andrew; Poncet, Sally; Catry, Paulo; Cleminson, Sacha; Crofts, Sarah; Dias, MariaAim: Decision-making products that support effective marine spatial planning are essential for guiding efforts that enable conservation of biodiversity facing increasing pressures. Key Biodiversity Areas (KBAs) are a product recently agreed upon by an international network of organizations for identifying globally important areas. Utilizing the KBA framework, and by developing a conservative protocol to identify sites, we identify globally importants places for breeding seabirds throughout the coastal seas of a national territory. We inform marine spatial planning by evaluating potential activities that may impact species and how a proposed network of Marine Management Areas (MMAs) overlap with important sites. Location: Southwest Atlantic Ocean. Methods: We collated a national inventory of all breeding locations for seabirds, including abundance records where available, and complementary estimates of at-sea distribution. We delineated areas of importance in coastal seas following approaches tailored to the ecology of species and assessed areas against global KBA criteria. To determine opportunities for species conservation and management, we reviewed which human activities have been documented to impact the target species globally via IUCN Red List accounts, and also assessed the overlap of important sites with a proposed MMA network. Results: We identified global KBAs for nine seabird species (Anatidae, Diomedeidae, Laridae, Procellariidae, Spheniscidae, Stercorariidae) throughout national coastal seas. Globally important areas where multiple species overlapped were only partially accounted for in key zones of the proposed MMA network. Main Conclusions: Development of a conservative protocol to identify marine sites for assessment against KBA criteria, revealed opportunities for enhancing a network of proposed Marine Management Areas in coastal seas. The framework we apply in this study has broad relevance for other systems where the design or review of management plans for the marine environment is required.
- Prey-switching to fishery discards does not compensate for poor natural foraging conditions in breeding albatrossPublication . Kuepfer, Amanda; Votier, Stephen C; Sherley, Richard; Ventura, Francesco; Matias, Rafael; Anderson, Orea; Brickle, Paul; Arkhipkin, Alexander; Catry, PauloFishery discards supplement food for many seabirds, but the impacts of declining discards are poorly understood. Discards may be beneficial for some populations but have negative impacts by increasing bycatch risk or because they are junk-food. The Falkland Islands support > 70% of global black-browed albatross Thalassarche melanophris populations, which feed on discards. However, the effect of discards on population demographics, and implications of fishery management changes, are unknown. We analysed stomach contents of black-browed albatross chicks across eight breeding seasons (2004-2020) from New Island, Falkland Islands, to assess variation in discard consumption and how this relates to foraging conditions and breeding success. Across years, 68%-98% of samples contained natural prey, whilst 23%-88% of samples contained fishery discards. Discard consumption was positively related to fishery catches of hoki Macruronus magellanicus and sea surface temperature anomalies SSTA (degrees C), and negatively related to breeding success. These results suggest a diet-switching behaviour for Falkland Islands albatrosses, whereby birds switch from preferred natural prey to suboptimal discards when environmental conditions, and hence natural feeding opportunities, are unfavourable. Crucially, this study highlights that fishery discards do not compensate for poor natural foraging conditions for breeding albatrosses in the long term.
- Quantifying annual spatial consistency in chick-rearing seabirds to inform important site identificationPublication . Beal, Martin; Catry, Paulo; Phillips, Richard A.; Oppel, Steffen; Arnould, John P.Y.; Bogdanova, Maria I.; Bolton, Mark; Carneiro, Ana P.B.; Clatterbuck, Corey; Conners, Melinda; Daunt, Francis; Delord, Karine; Elliott, Kyle; Fromant, Aymeric; Granadeiro, José P.; Green, Jonathan A.; Halsey, Lewis; Hamer, Keith C.; Ito, Motohiro; Jeavons, Ruth; Kim, Jeong-Hoon; Kokubun, Nobuo; Koyama, Shiho; Lane, Jude V.; Lee, Won Young; Matsumoto, Sakiko; Orben, Rachael; Owen, Ellie; Paiva, Vitor H.; Patterson, Allison; Pollock, Christopher J.; Ramos, Jaime A.; Sagar, Paul; Sato, Katsufumi; Shaffer, Scott A.; Soanes, Louise; Takahashi, Akinori; Thompson, David R.; Thorne, Lesley; Torres, Leigh; Watanuki, Yutaka; Waugh, Susan M.; Weimerskirch, Henri; Whelan, Shannon; Yoda, Ken; Xavier, José C.; Dias, Maria P.Animal tracking has afforded insights into patterns of space use in numerous species and thereby informed area-based conservation planning. A crucial consideration when estimating spatial distributions from tracking data is whether the sample of tracked animals is representative of the wider population. However, it may also be important to track animals in multiple years to capture changes in distribution in response to varying environmental conditions. Using GPS-tracking data from 23 seabird species, we assessed the importance of multi-year sampling for identifying important sites for conservation during the chick-rearing period, when seabirds are most spatially constrained. We found a high degree of spatial overlap among distributions from different years in most species. Multi-year sampling often captured a significantly higher portion of reference distributions (based on all data for a population) than sampling in a single year. However, we estimated that data from a single year would on average miss only 5 % less of the full distribution of a population compared to equal-sized samples collected across three years (min: −0.3 %, max: 17.7 %, n = 23). Our results suggest a key consideration for identifying important sites from tracking data is whether enough individuals were tracked to provide a representative estimate of the population distribution during the sampling period, rather than that tracking necessarily take place in multiple years. By providing an unprecedented multi-species perspective on annual spatial consistency, this work has relevance for the application of tracking data to informing the conservation of seabirds.
- Deliberate poisoning of Africa's vulturesPublication . Henriques, Mohamed; Buij, Ralph; Monteiro, Hamilton; Sá, Joãozinho; Gomes Wambar, Francisco; Tavares, José Pedro; Botha, Andre; Citegetse, Geoffroy; Lecoq, Miguel; Catry, Paulo; Ogada, DarcyNão consta
- Habitat preferences, foraging behaviour and bycatch risk among breeding sooty shearwaters Ardenna grisea in the Southwest AtlanticPublication . Bonnet-Lebrun, Anne-Sophie; Catry, Paulo; Clark, Tyler J.; Campioni, Letizia; Kuepfer, Amanda; Tierny, Megan; Kilbride, Elizabeth; Wakefield, Ewan D.Pelagic seabirds are important components of many marine ecosystems. The most abundant species are medium/small sized petrels (<1100 g), yet the sub-mesoscale (<10 km) distribution, habitat use and foraging behaviour of this group are not well understood. Sooty shearwaters Ardenna grisea are among the world’s most numerous pelagic seabirds. The majority inhabit the Pacific, where they have declined, partly due to bycatch and other anthropogenic impacts, but they are increasing in the Atlantic. To evaluate the sub-mesoscale habitat preferences (i.e. the disproportionality between habitat use and availability), diving behaviour and bycatch risk of Atlantic breeders, we tracked sooty shearwaters from the Falkland Islands during late incubation and early chick-rearing with GPS loggers (n = 20), geolocators (n = 10) and time-depth recorders (n = 10). These birds foraged exclusively in neritic and shelf-break waters, principally over the Burdwood Bank, ~350 km from their colony. Like New Zealand breeders, they dived mostly during daylight, especially at dawn and dusk, consistent with the exploitation of vertically migrating prey. However, Falkland birds made shorter foraging trips, shallower dives, and did not forage in oceanic waters. Their overlap with fisheries was low, and they foraged at shallower depths than those targeted by trawlers, the most frequent fishing vessels encountered, indicating that bycatch risk was low during late incubation/early chick-rearing. Although our results should be treated with caution, they indicate that Atlantic and Pacific sooty shearwaters may experience markedly differing pressures at sea. Comparative study between these populations, e.g. combining biologging and demography, is therefore warranted.
- Multispecies tracking reveals a major seabird hotspot in the North AtlanticPublication . Davies, Tammy E.; Carneiro, Ana P.B.; Tarzia, Marguerite; Wakefield, Ewan; Hennicke, Janos C.; Frederiksen, Morten; Hansen, Erpur Snær; Campos, Bruna; Hazin, Carolina; Lascelles, Ben; Anker‐Nilssen, Tycho; Arnardóttir, Hólmfríður; Barrett, Robert T.; Biscoito, Manuel; Bollache, Loïc; Boulinier, Thierry; Catry, Paulo; Ceia, Filipe R.; Chastel, Olivier; Christensen‐Dalsgaard, Signe; Cruz‐Flores, Marta; Danielsen, Jóhannis; Daunt, Francis; Dunn, Euan; Egevang, Carsten; Fagundes, Ana Isabel; Fayet, Annette L.; Fort, Jérôme; Furness, Robert W.; Gilg, Olivier; González‐Solís, Jacob; Granadeiro, J. P.; Grémillet, David; Guilford, Tim; Hanssen, Sveinn Are; Harris, Michael P.; Hedd, April; Huffeldt, Nicholas Per; Jessopp, Mark; Kolbeinsson, Yann; Krietsch, Johannes; Lang, Johannes; Linnebjerg, Jannie Fries; Lorentsen, Svein‐Håkon; Madeiros, Jeremy; Magnusdottir, Ellen; Mallory, Mark L.; McFarlane Tranquilla, Laura; Merkel, Flemming R.; Militão, Teresa; Moe, Børge; Montevecchi, William A.; Morera‐Pujol, Virginia; Mosbech, Anders; Neves, Verónica; Newell, Mark A.; Olsen, Bergur; Paiva, Vitor H.; Peter, Hans‐Ulrich; Petersen, Aevar; Phillips, Richard A.; Ramírez, Iván; Ramos, Jaime A.; Ramos, Raül; Ronconi, Robert A.; Ryan, Peter G.; Schmidt, Niels Martin; Sigurðsson, Ingvar A.; Sittler, Benoît; Steen, Harald; Stenhouse, Iain J.; Strøm, Hallvard; Systad, Geir H. R.; Thompson, Paul; Thórarinsson, Thorkell L.; Bemmelen, Rob S.A.; Wanless, Sarah; Zino, Francis; Dias, Maria P.The conservation of migratory marine species, including pelagic seabirds, is challenging because their movements span vast distances frequently beyond national jurisdictions. Here, we aim to identify important aggregations of seabirds in the North Atlantic to inform ongoing regional conservation efforts. Using tracking, phenology, and population data, we mapped the abundance and diversity of 21 seabird species. This revealed a major hotspot associated with a discrete area of the subpolar frontal zone, used annually by 2.9–5 million seabirds from ≥56 colonies in the Atlantic: the first time this magnitude of seabird concentrations has been documented in the high seas. The hotspot is temporally stable and amenable to site-based conservation and is under consideration as a marine protected area by the OSPAR Commission. Protection could help mitigate current and future threats facing species in the area. Overall, our approach provides an exemplar data-driven pathway for future conservation efforts on the high seas.
- An ontogenetic perspective on migratory strategy of a long-lived pelagic seabird: Timings and destinations change progressively during maturationPublication . Letizia, Campioni; Dias, Maria P.; Granadeiro, José Pedro; Catry, PauloThe processes that drive the ontogeny of migratory strategies in long-lived animals with slow maturation remain enigmatic. While some short-lived migrants are known or believed to repeat the same migratory patterns throughout their lives, little is known on the time required for immature long-lived migrants to progressively acquire adult-like migratory behaviours, or which aspects take longer to refine during the maturation process. Here, we studied the ontogeny of long-distance migratory strategies and related patterns of spatial distribution in a long-lived seabird species during the annual cycle. To do so, we deployed light-level geolocators on 4- to 9-year-old immature Cory's shearwaters (Calonectris borealis) and on breeding adults. We revealed that migratory timings and destinations of young shearwaters progressively changed with age. The effect of ageing was remarkably evident on spring migratory performance and phenology. Birds gradually shortened the duration of the non-breeding period by advancing departure date and reducing travelling time, which resulted in a sequential arrival at the colony of the various age contingents. Ageing immatures gradually changed from a more exploratory strategy to a more conservative way of exploiting resources, reducing both their year-round spatial spread across oceanic domains and the total distance travelled. Immatures always performed a trans-equatorial migration to the Southern Hemisphere, contrasting with 17% of the adults which remained in the North Atlantic year-round. Finally, during the breeding season immatures were widely dispersed through the North Atlantic reducing their overlap with breeding adults. Our long-term study provides empirical support to the hypothesis that in long-lived species, the refinement of migratory behaviour and year-round spatial distribution is a progressive process mediated by age and experience, where life stage constraints and competition for resources may also play a role. The emerging pattern suggests that for some avian taxa, the ontogeny of migratory strategy is a prolonged, complex and dynamic process.
- First census of the green turtle at Poilão, Bijagós Archipelago, Guinea-Bissau: the most important nesting colony on the Atlantic coast of AfricaPublication . Catry, Paulo; Barbosa, Castro; Indjai, Bucar; Almeida, Amadeu; Godley, Brendan J.; Vié, Jean-ChristopheThe island of Poilão in the Bijagós Archipelago, Guinea-Bissau, is known to be an important nesting site for the green turtle Chelonia mydas, but until recently there were no quantitative estimates of the number of clutches deposited annually. In 2000 a survey was carried out to assess the magnitude of nesting, and an estimated 7,400 green turtle clutches were deposited. Four nesting hawksbill turtles Eretmochelys imbricata were also encountered. This study confirmed that Poilão is one of the most important nesting sites for green turtles in the Atlantic, and the largest known nesting colony on the west coast of Africa. Traditionally Poilão has been regarded as a sacred site by the Bijagós people, and this has contributed to the conservation of these turtles. However, the development of fisheries in this region is an emerging threat. To conserve this site a National Marine Park was designated in August 2000.
- Fine-scale foraging segregation in a green turtle (Chelonia mydas) feeding ground in the Bijagós archipelago, Guinea BissauPublication . Madeira, Fernando Miguel; Rebelo, Rui; Catry, Paulo; Neiva, João Guilherme; Barbosa, Castro; Regalla De Barros, Aissa; Patrício, Ana RitaGreen turtles (Chelonia mydas) are highly dependent on neritic foraging areas throughout much of their life. Still, knowledge of recruitment dynamics, foraging habits, and habitat use in these areas is limited. Here, we evaluated how the distribution and food preferences of green sea turtles from different life stages varied within a foraging aggregation. We focused on two islands in Guinea-Bissau, Unhocomo and Unhocomozinho, using water captures and survey dives to record habitat use and characteristics, and stable isotopes to infer diet. Additionally, we used stable isotopes to infer their diet. Two habitat types were sampled: deeper (2.26 ± 0.4 m) rocky sites fringed by mangrove with macroalgae, and sandy shallows (1.37 ± 0.12 m) surrounded by rocky reefs with macroalgae and seagrass. The two benthic communities were similar isotopically and in terms of species composition, except for the presence or absence of seagrass, which had unique signatures. We captured 89 turtles ranging from 35 cm to 97 cm in curved carapace length (i.e., juvenile to adult stages). Size distribution was habitat-dependent, with most smaller turtles present in sandy shallows and larger turtles favoring slightly deeper rocky sites. Turtle isotopic signatures differed between the habitat of capture, regardless of size, revealing a marked dichotomy in foraging preference. All turtles fed primarily on macroalgae, mostly rhodophytes. However, individuals captured in sandy habitats had evident seagrass skewed isotopic signatures. Larger turtles may be unable to use the more diverse shallower foraging sites due to increased vulnerability to predation. Despite the proximity of the sampled foraging sites (2.7 km apart), the two foraging subgroups seem to maintain consistently different feeding habits. Our study highlights how heterogeneous green turtle foraging habits can be within populations, even at small geographic scales.