Search Results - "Crawford, Robert J"

Global Seabird Response to Forage Fish Depletion—One-Third for the Birds by Cury, Philippe M., Boyd, Ian L., Bonhommeau, Sylvain, Anker-Nilssen, Tycho, Crawford, Robert J. M., Furness, Robert W., Mills, James A., Murphy, Eugene J., Österblom, Henrik, Paleczny, Michelle, Piatt, John F., Roux, Jean-Paul, Shannon, Lynne, Sydeman, William J.

“…Determining the form of key predator-prey relationships is critical for understanding marine ecosystem dynamics. Using a comprehensive global database, we…”
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Pollution, habitat loss, fishing, and climate change as critical threats to penguins by Trathan, Phil N, García‐Borboroglu, Pablo, Boersma, Dee, Bost, Charles‐André, Crawford, Robert J. M, Crossin, Glenn T, Cuthbert, Richard J, Dann, Peter, Davis, Lloyd Spencer, De La Puente, Santiago, Ellenberg, Ursula, Lynch, Heather J, Mattern, Thomas, Pütz, Klemens, Seddon, Philip J, Trivelpiece, Wayne, Wienecke, Barbara

“…Cumulative human impacts across the world's oceans are considerable. We therefore examined a single model taxonomic group, the penguins (Spheniscidae), to…”
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Phenological changes in the Southern Hemisphere by Chambers, Lynda E

“…Conducts the largest meta-analysis to date of phenological drivers and trends among Southern Hemisphere species, assessing 1208 long-term datasets from 89…”
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Bayesian inference reveals positive but subtle effects of experimental fishery closures on marine predator demographics by Sherley, Richard B., Barham, Barbara J., Barham, Peter J., Campbell, Kate J., Crawford, Robert J. M., Grigg, Jennifer, Horswill, Cat, McInnes, Alistair, Morris, Taryn L., Pichegru, Lorien, Steinfurth, Antje, Weller, Florian, Winker, Henning, Votier, Stephen C.

“…Global forage-fish landings are increasing, with potentially grave consequences for marine ecosystems. Predators of forage fish may be influenced by this…”
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Ecosystem change in the southern Benguela and the underlying processes by Blamey, Laura K., Shannon, Lynne J., Bolton, John J., Crawford, Robert J.M., Dufois, Francois, Evers-King, Hayley, Griffiths, Charles L., Hutchings, Laurence, Jarre, Astrid, Rouault, Mathieu, Watermeyer, Katherine E., Winker, Henning

“…Overfishing and human-induced climate change are putting severe pressure on marine ecosystems. In the southern Benguela, most of South Africa's commercial…”
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A space oddity: geographic and specific modulation of migration in Eudyptes penguins by Thiebot, Jean-Baptiste, Cherel, Yves, Crawford, Robert J M, Makhado, Azwianewi B, Trathan, Philip N, Pinaud, David, Bost, Charles-André

“…Post-breeding migration in land-based marine animals is thought to offset seasonal deterioration in foraging or other important environmental conditions at the…”
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A paper which influenced my practice, and the importance of peer review by Crawford, Robert J., MB ChB, FRCS, ChM

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The conservation status and population decline of the African penguin deconstructed in space and time by Sherley, Richard B., Crawford, Robert J. M., Blocq, Andrew D., Dyer, Bruce M., Geldenhuys, Deon, Hagen, Christina, Kemper, Jessica, Makhado, Azwianewi B., Pichegru, Lorien, Tom, Desmond, Upfold, Leshia, Visagie, Johan, Waller, Lauren J., Winker, Henning

“…Understanding changes in abundance is crucial for conservation, but population growth rates often vary over space and time. We use 40 years of count data…”
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Bottom-up effects of a no-take zone on endangered penguin demographics by Sherley, Richard B., Winker, Henning, Altwegg, Res, van der Lingen, Carl D., Votier, Stephen C., Crawford, Robert J. M.

“…Marine no-take zones can have positive impacts for target species and are increasingly important management tools. However, whether they indirectly benefit…”
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Defining ecologically relevant scales for spatial protection with long-term data on an endangered seabird and local prey availability by Sherley, Richard B., Botha, Philna, Underhill, Les G., Ryan, Peter G., van Zyl, Danie, Cockcroft, Andrew C., Crawford, Robert J.M., Dyer, Bruce M., Cook, Timothée R.

“…Human activities are important drivers of marine ecosystem functioning. However, separating the synergistic effects of fishing and environmental variability on…”
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Behavioural inertia places a top marine predator at risk from environmental change in the Benguela upwelling system by Pichegru, Lorien, Ryan, Peter G, Crawford, Robert J. M, van der Lingen, Carl D, Grémillet, David

“…In variable environments, organisms are bound to track environmental changes if they are to survive. Most marine mammals and seabirds are colonial,…”
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Using behavioural and state variables to identify proximate causes of population change in a seabird by Lewis, Sue, Grémillet, David, Daunt, Francis, Ryan, Peter G, Crawford, Robert J.M, Wanless, Sarah

“…Changes in animal population size are driven by the interactions between intrinsic processes and extrinsic forces, and identifying the proximate mechanisms…”
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The influence of food availability on breeding success of African penguins Spheniscus demersus at Robben Island, South Africa by Crawford, Robert J.M., Barham, Peter J., Underhill, Les G., Shannon, Lynne J., Coetzee, Janet C., Dyer, Bruce M., Leshoro, T. Mario, Upfold, Leshia

“…From 1989 to 2004, the breeding success of African penguins Spheniscus demersus at Robben Island, South Africa was significantly related to estimates of the…”
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Confidence intervals and sample size for estimating the prevalence of plastic debris in seabird nests by Tavares, Davi Castro, Moura, Jailson Fulgêncio, Acevedo-Trejos, Esteban, Crawford, Robert J.M., Makhado, Azwianewi, Lavers, Jennifer L., Witteveen, Minke, Ryan, Peter G., Merico, Agostino

“…Evidence is accumulating about the impacts of plastics on marine life. The prevalence of plastics in seabird nests has been used as an indicator of levels of…”
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Food habits of an endangered seabird indicate recent poor forage fish availability off western South Africa by Crawford, Robert J M, Sydeman, William J, Thompson, Sarah Ann, Sherley, Richard B, Makhado, Azwianewi B

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Growth and decline of a penguin colony and the influence on nesting density and reproductive success by Sherley, Richard B., Barham, Peter J., Barham, Barbara J., Crawford, Robert J. M., Dyer, Bruce M., Leshoro, T. Mario, Makhado, Azwianewi B., Upfold, Leshia, Underhill, Les G.

“…Colonial breeding is characteristic of seabirds but nesting at high density has both advantages and disadvantages and may reduce survival and fecundity…”
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Habitat preferences of Phoebetria albatrosses in sympatry and allopatry by Bentley, Lily K., Phillips, Richard A., Carpenter‐Kling, Tegan, Crawford, Robert J. M., Cuthbert, Richard J., Delord, Karine, Dilley, Ben J., Makhado, Azwianewi B., Miller, Peter I., Oppel, Steffen, Pistorius, Pierre A., Ryan, Peter G., Schoombie, Stefan, Weimerskirch, Henri, Manica, Andrea

“…Aim Competition is often proposed to drive niche segregation along multiple axes in speciose communities. Understanding spatial partitioning of foraging areas…”
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Habitat modelling of tracking data from multiple marine predators identifies important areas in the Southern Indian Ocean by Reisinger, Ryan R., Raymond, Ben, Hindell, Mark A., Bester, Marthán N., Crawford, Robert J. M., Davies, Delia, de Bruyn, P.J. Nico, Dilley, Ben J., Kirkman, Stephen P., Makhado, Azwianewi B., Ryan, Peter G., Schoombie, Stefan, Stevens, Kim, Sumner, Michael D., Tosh, Cheryl A., Wege, Mia, Whitehead, Thomas Otto, Wotherspoon, Simon, Pistorius, Pierre A.

“…Aim: The distribution of marine predators is driven by the distribution and abundance of their prey; areas preferred by multiple marine predator species should…”
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Correction to 'Bayesian inference reveals positive but subtle effects of experimental fishery closures on marine predator demographics' by Sherley, Richard B, Barham, Barbara J, Barham, Peter J, Campbell, Kate J, Crawford, Robert J M, Grigg, Jennifer, Horswill, Cat, McInnes, Alistair, Morris, Taryn L, Pichegru, Lorien, Steinfurth, Antje, Weller, Florian, Winker, Henning, Votier, Stephen C

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A junk-food hypothesis for gannets feeding on fishery waste by Grémillet, David, Pichegru, Lorien, Kuntz, Grégoire, Woakes, Anthony G., Wilkinson, Sarah, Crawford, Robert J. M., Ryan, Peter G.

“…and of their feeding environment in the Benguela upwelling zone. The natural prey of Cape gannets (pelagic fishes) is depleted and birds now feed extensively…”
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