Browsing by Author "Thompson, David R."
Now showing 1 - 8 of 8
Results Per Page
Sort Options
- A framework for mapping the distribution of seabirds by integrating tracking, demography and phenologyPublication . Carneiro, Ana Paula B.; Pearmain, Elizabeth J.; Oppel, Steffen; Clay, Thomas A.; Phillips, Richard A.; Bonnet‐Lebrun, Anne‐Sophie; Wanless, Ross M.; Abraham, Edward; Richard, Yvan; Rice, Joel; Handley, Jonathan; Davies, Tammy E.; Dilley, Ben J.; Ryan, Peter G.; Small, Cleo; Arata, Javier; Arnould, John P. Y.; Bell, Elizabeth; Bugoni, Leandro; Letizia, Campioni; Catry, Paulo; Cleeland, Jaimie; Deppe, Lorna; Elliott, Graeme; Freeman, Amanda; Gonzalez-Solis, Jacob; Granadeiro, José Pedro; Grémillet, David; Landers, Todd J.; Makhado, Azwianewi; Nel, Deon; Nicholls, David G.; Rexer‐Huber, Kalinka; Robertson, Christopher J. R.; Sagar, Paul M.; Scofield, Paul; Stahl, Jean‐Claude; Stanworth, Andrew; Stevens, Kim L.; Trathan, Philip N.; Thompson, David R.; Torres, Leigh; Walker, Kath; Waugh, Susan M.; Weimerskirch, Henri; Dias, Maria P.1. The identification of geographic areas where the densities of animals are highest across their annual cycles is a crucial step in conservation planning. In marine environments, however, it can be particularly difficult to map the distribution of species, and the methods used are usually biased towards adults, neglecting the distribution of other life-history stages even though they can represent a substantial proportion of the total population. 2. Here we develop a methodological framework for estimating populationlevel density distributions of seabirds, integrating tracking data across the main life-history stages (adult breeders and non-breeders, juveniles and immatures). We incorporate demographic information (adult and juvenile/immature survival, breeding frequency and success, age at first breeding) and phenological data (average timing of breeding and migration) to weight distribution maps according to the proportion of the population represented by each life-history stage. 3. We demonstrate the utility of this framework by applying it to 22 species of albatrosses and petrels that are of conservation concern due to interactions with fisheries. Because juveniles, immatures and non-breeding adults account for 47%–81% of all individuals of the populations analysed, ignoring the distributions of birds in these stages leads to biased estimates of overlap with threats, and may misdirect management and conservation efforts. Population-level distribution maps using only adult distributions underestimated exposure to longline fishing effort by 18%–42%, compared with overlap scores based on data from all lifehistory stages. 4. Synthesis and applications. Our framework synthesizes and improves on previous approaches to estimate seabird densities at sea, is applicable for data-poor situations, and provides a standard and repeatable method that can be easily updated as new tracking and demographic data become available. We provide scripts in the R language and a Shiny app to facilitate future applications of our approach. We recommend that where sufficient tracking data are available, this framework be used to assess overlap of seabirds with at-sea threats such as overharvesting, fisheries bycatch, shipping, offshore industry and pollutants. Based on such an analysis, conservation interventions could be directed towards areas where they have the greatest impact on populations.
- Genomics detects population structure within and between ocean basins in a circumpolar seabird: The white‐chinned petrelPublication . Rexer-Huber, Kalinka; Veale, Andrew; Catry, Paulo; Cherel, Yves; Dutoit, Ludovic; Foster, Yasmin; McEwan, John C.; Parker, Graham C.; Phillips, Richard; Ryan, Peter G.; Stanworth, Andrew J.; Van Stijn, Tracey; Thompson, David R.; Waters, Jonathan; Robertson, BruceThe Southern Ocean represents a continuous stretch of circumpolar marine habitat, but the potential physical and ecological drivers of evolutionary genetic differentiation across this vast ecosystem remain unclear. We tested for genetic structure across the full circumpolar range of the white-chinned petrel (Procellaria aequinoctialis) to unravel the potential drivers of population differentiation and test alternative population differentiation hypotheses. Following range-wide comprehensive sampling, we applied genomic (genotyping-by-sequencing or GBS; 60,709 loci) and standard mitochondrial-marker approaches (cytochrome b and first domain of control region) to quantify genetic diversity within and among island populations, test for isolation by distance, and quantify the number of genetic clusters using neutral and outlier (non-neutral) loci. Our results supported the multi-region hypothesis, with a range of analyses showing clear three-region genetic population structure, split by ocean basin, within two evolutionary units. The most significant differentiation between these regions confirmed previous work distinguishing New Zealand and nominate subspecies. Although there was little evidence of structure within the island groups of the Indian or Atlantic oceans, a small set of highly-discriminatory outlier loci could assign petrels to ocean basin and potentially to island group, though the latter needs further verification. Genomic data hold the key to revealing substantial regional genetic structure within wide-ranging circumpolar species previously assumed to be panmictic.
- Global political responsibility for the conservation of albatrosses and large petrelsPublication . Beal, Martin; Dias, Maria P.; Phillips, Richard A.; Oppel, Steffen; Hazin, Carolina; Pearmain, Elizabeth J.; Adams, Josh; Anderson, David J.; Antolos, Michelle; Arata, Javier; Arcos, José Manuel; Arnould, John P. Y.; Awkerman, Jill; Bell, Elizabeth; BELL, Mike; Carey, Mark; Carle, Ryan; Clay, Thomas A.; Cleeland, Jaimie; Colodro, Valentina; Conners, Melinda; Flores, Marta Cruz; Cuthbert, Richard; Delord, Karine; Deppe, Lorna; Dilley, Ben J.; Dinis, Herculano; Elliott, Graeme; De Felipe, Fernanda; Felis, Jonathan; Forero, Manuela G.; Freeman, Amanda; Fukuda, Akira; González-Solís, Jacob; Granadeiro, J. P.; Hedd, April; Hodum, Peter; Igual, Jose Manuel; Jaeger, Audrey; Landers, Timothy; Le Corre, Matthieu; Makhado, Azwianewi; Metzger, Benjamin; Militão, Teresa; Montevecchi, William A.; Pujol, Virginia Morera; Herrero, Leia Navarro; Nel, Deon; Nicholls, David; Oro, Daniel; Ouni, Ridha; Ozaki, Kiyoaki; Quintana, Flavio; Ramos, Raül; Reid, Tim; Reyes-González, José Manuel; Robertson, Christopher; Robertson, Graham; Romdhane, Mohamed Salah; Ryan, Peter G.; Sagar, Paul; Sato, Fumio; Schoombie, Stefan; Scofield, Richard; Shaffer, Scott; Shah, Nirmal Jivan; Stevens, Kim L.; Surman, Christopher; Suryan, Robert M.; Takahashi, Akinori; Tatayah, Vikash; Taylor, Graeme; Thompson, David R.; Torres, Leigh; Walker, Kath; Wanless, Ross; Waugh, Susan M.; Weimerskirch, Henri; Yamamoto, Takashi; Zajkova, Zuzana; Zango, Laura; Catry, PauloMigratory marine species cross political borders and enter the high seas, where the lack of an effective global management framework for biodiversity leaves them vulnerable to threats. Here, we combine 10,108 tracks from 5775 individual birds at 87 sites with data on breeding population sizes to estimate the relative year-round importance of national jurisdictions and high seas areas for 39 species of albatrosses and large petrels. Populations from every country made extensive use of the high seas, indicating the stake each country has in the management of biodiversity in international waters. We quantified the links among national populations of these threatened seabirds and the regional fisheries management organizations (RFMOs) which regulate fishing in the high seas. This work makes explicit the relative responsibilities that each country and RFMO has for the management of shared biodiversity, providing invaluable information for the conservation and management of migratory species in the marine realm.
- High occurrence of jellyfish predation by black-browed and Campbell albatross identified by DNA metabarcodingPublication . McInnes, Julie C.; Alderman, Rachael; Lea, Mary-Anne; Raymond, Ben; Deagle, Bruce E.; Phillips, Richard A.; Stanworth, Andrew J.; Thompson, David R.; Catry, Paulo; Weimerskirch, Henri; Suazo, Cristián G.; Gras, Michaël; Jarman, Simon NeilGelatinous zooplankton are a large component of the animal biomass in all marine environments, but are considered to be uncommon in the diet of most marine top predators. However, the diets of key predator groups like seabirds have conventionally been assessed from stomach content analyses, which cannot detect most gelatinous prey. As marine top predators are used to identify changes in the overall species composition of marine ecosystems, such biases in dietary assessment may impact our detection of important ecosystem regime shifts. We investigated albatross diet using DNA metabarcoding of scats to assess the prevalence of gelatinous zooplankton consumption by two albatross species, one of which is used as an indicator species for ecosystem monitoring. Black-browed and Campbell albatross scats were collected from eight breeding colonies covering the circumpolar range of these birds over two consecutive breeding seasons. Fish was the main dietary item at most sites; however, cnidarian DNA, primarily from scyphozoan jellyfish, was present in 42% of samples overall and up to 80% of samples at some sites. Jellyfish was detected during all breeding stages and consumed by adults and chicks. Trawl fishery catches of jellyfish near the Falkland Islands indicate a similar frequency of jellyfish occurrence in albatross diets in years of high and low jellyfish availability, suggesting jellyfish consumption may be selective rather than opportunistic. Warmer oceans and overfishing of finfish are predicted to favour jellyfish population increases, and we demonstrate here that dietary DNA metabarcoding enables measurements of the contribution of gelatinous zooplankton to the diet of marine predators.
- Metapopulation distribution shapes year‐round overlap with fisheries for a circumpolar seabirdPublication . Rexer‐Huber, Kalinka; Clay, Thomas A.; Catry, Paulo; Debski, Igor; Parker, Graham; Ramos, Raül; Robertson, Bruce C.; Ryan, Peter G.; Sagar, Paul M.; Stanworth, Andrew; Thompson, David R.; Tuck, Geoffrey N.; Weimerskirch, Henri; Phillips, Richard A.Although fisheries bycatch is the greatest threat to many migratory marine megafauna, it remains unclear how population exposure to bycatch varies across the global range of threatened species. Such assessments across multiple populations are crucial for understanding variation in impacts and for identifying the management bodies responsible for reducing bycatch. Here, we combine extensive biologging data from white‐chinned petrel (Procellaria aequinoctialis) populations (representing >98% of their global breeding population) with pelagic and demersal longline and trawl fishing effort to map the global distribution and fisheries‐overlap hotspots for the most bycaught seabird in the Southern Hemisphere. We tracked the year‐round movements of 132 adults in 2006–2018 and examined spatial overlap among seven populations comprising three genetically distinct groupings (metapopulations). Foraging areas during the nonbreeding season were more concentrated than during breeding, with birds from all populations migrating to continental shelf or upwelling zones, but with low spatial overlap among metapopulations. Fisheries overlap differed more among than within metapopulations, underlining that these should be considered separate management units. Overlap with pelagic longline fisheries was greatest for Indian Ocean populations, and from the fleets of South Africa, Japan, Taiwan, and Spain, off southern Africa and in the High Seas. Overlap with demersal longline and trawl fisheries was greatest for Indian and Atlantic Ocean populations, within the Exclusive Economic Zones of South Africa, Namibia, and Argentina, and with the South Korean demersal longline fleet in the High Seas. The high overlap with South Korean longliners in the southwest Atlantic Ocean is of particular concern as demersal fishing in this region is not covered by any Regional Fisheries Management Organization (RFMO). We also identified fisheries‐overlap hotspots within RFMOs where there are no seabird‐bycatch mitigation requirements (1.5%–53.1% of total overlap within the area of competence of each RFMO), or where current mitigation regulations need to be strengthened. Our recommendations are that management bodies target the high‐priority fisheries we have identified for improved bycatch monitoring, mandatory best‐practice bycatch mitigation, and close monitoring of compliance, given the conservation concerns for white‐chinned petrels and other threatened seabirds. Biologging, Bycatch mitigatio, Geolocator, Longline fisheries, Migratory connectivity, Regional Fisheries Management Organization, Trawl fisheries, White-chinned petrel
- 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.
- 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 A.; Owen, Ellie; Paiva, Vitor H.; Patterson, Allison; Pollock, Christopher J.; Ramos, Jaime A.; Sagar, Paul; Sato, Katsufumi; Shaffer, Scott; 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 areabased 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.
- Seabird migration strategies: Flight budgets, diel activity patterns, and lunar influencePublication . Bonnet-Lebrun, Anne-Sophie; Dias, Maria P.; Phillips, Richard; Granadeiro, José P.; Brooke, M. de L.; Chastel, Olivier; Clay, Thomas A.; Fayet, Annette; GILG, Olivier; González-Solís, Jacob; Guilford, Tim; Hanssen, Sveinn Are; Hedd, April; Jaeger, Audrey; Krietsch, Johannes; Lang, Johannes; Le Corre, Matthieu; Militão, Teresa; Moe, Børge; Montevecchi, William A.; Peter, Hans-Ulrich; Pinet, Patrick; Rayner, Matt J.; Reid, Tim; Reyes-González, José Manuel; Ryan, Peter G.; Sagar, Paul M.; Schmidt, Niels M.; Thompson, David R.; van Bemmelen, Rob; Watanuki, Yutaka; Weimerskirch, Henri; Yamamoto, Takashi; Catry, PauloEvery year, billions of birds undertake extensive migrations between breeding and nonbreeding areas, facing challenges that require behavioural adjustments, particularly to flight timing and duration. Such adjustments in daily activity patterns and the influence of extrinsic factors (e.g., environmental conditions, moonlight) have received much more research attention in terrestrial than marine migrants. Taking advantage of the widespread deployment in recent decades of combined light-level geolocator-immersion loggers, we investigated diel organisation and influence of the moon on flight activities during the non-breeding season of 21 migrant seabird species from a wide taxonomic range (6 families, 3 orders). Migrant seabirds regularly stopped (to either feed or rest) migration, unlike some terrestrial and wetland birds which fly non-stop. We found an overall increase for most seabird species in time in flight and, for several species, also in flight bout duration, during migration compared to when resident at the non-breeding grounds. Additionally, several nocturnal species spent more of the day in flight during migration than at non-breeding areas, and vice versa for diurnal species. Nocturnal time in flight tended to increase during full moon, both during migration and at the nonbreeding grounds, depending on species. Our study provides an extensive overview of activity patterns of migrant seabirds, paving the way for further research on the underlying mechanisms and drivers.