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Louzao M, Delord K, García D, Afán I, Arcos JM, Weimerskirch H. First days at sea: depicting migration patterns of juvenile seabirds in highly impacted seascapes. PeerJ 2021; 9:e11054. [PMID: 34026341 PMCID: PMC8121070 DOI: 10.7717/peerj.11054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 02/11/2021] [Indexed: 11/20/2022] Open
Abstract
Increasing human activities have detrimental consequences on marine ecosystems and their impact can have cumulative effects. Within marine ecosystems, seabirds respond to ecosystem variability and face multiple human pressures, especially threatened species. In long-lived species, juveniles and immatures could represent up to 50% of the total population, but their migratory movements remain largely unknown. Here, we depict the migratory patterns of juvenile Balearic shearwaters Puffinus mauretanicus, the most threatened European seabird, using miniaturised satellite transmitters. At the end of the 2012 breeding season, five tagged juveniles left the breeding colonies of Eivissa Island (western Mediterranean) the first week of July. They moved westwards to reach the Atlantic Ocean between 3 and 13 days afterwards. Juveniles showed a two-phase migratory pattern: they first travelled slower close to the breeding colonies, and then moved towards their wintering areas in the Atlantic Ocean by rapid directional movements. Environmental cues (e.g.,marine productivity, water mass distribution, frontal systems) might have a prominent role in driving the migratory patterns of juvenile Balearic shearwaters, moving from warm and poor marine areas in the Mediterranean Sea to cooler and rich non-breeding grounds in the Atlantic Ocean. Based on observational findings, we observed certain spatial overlap of juvenile Balearic shearwaters with areas of high human impact, but the relationship between flying travel speed and both fishing effort and cumulative human impacts were not statistically significant. These results suggest that more research is needed to assess whether the movement patterns of migrating juveniles are affected by human activities. Therefore, understanding the at-sea spatial ecology of juveniles should be a priority for research and conservation due to the importance of this population component in long-lived species, as well as assessing their vulnerability to multiple anthropogenic pressures.
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Affiliation(s)
- Maite Louzao
- AZTI, Marine Research, Basque Research and Technology Alliance (BRTA), Pasaia, Spain.,Centro Oceanográfico de Xixón, Instituto Español de Oceanografía, Xixón, Spain
| | - Karine Delord
- Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS/ULR, Villiers-en-Bois, France
| | - David García
- Iniciativa de Recerca de Biodiversitat de les Illes (IRBI), Pina, Balearic Islands, Spain
| | - Isabel Afán
- Estación Biológica de Doñana, Sevilla, Spain
| | | | - Henri Weimerskirch
- Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS/ULR, Villiers-en-Bois, France
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Traisnel G, Pichegru L. Boldness at the nest predicts foraging and diving behaviour of female but not male African penguins. Anim Behav 2019. [DOI: 10.1016/j.anbehav.2019.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Sherley RB, Ludynia K, Dyer BM, Lamont T, Makhado AB, Roux JP, Scales KL, Underhill LG, Votier SC. Metapopulation Tracking Juvenile Penguins Reveals an Ecosystem-wide Ecological Trap. Curr Biol 2017; 27:563-568. [PMID: 28190725 DOI: 10.1016/j.cub.2016.12.054] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Revised: 11/17/2016] [Accepted: 12/27/2016] [Indexed: 10/20/2022]
Abstract
Climate change and fisheries are transforming the oceans, but we lack a complete understanding of their ecological impact [1-3]. Environmental degradation can cause maladaptive habitat selection, inducing ecological traps with profound consequences for biodiversity [4-6]. However, whether ecological traps operate in marine systems is unclear [7]. Large marine vertebrates may be vulnerable to ecological traps [6], but their broad-scale movements and complex life histories obscure the population-level consequences of habitat selection [8, 9]. We satellite tracked postnatal dispersal in African penguins (Spheniscus demersus) from eight sites across their breeding range to test whether they have become ecologically trapped in the degraded Benguela ecosystem. Bayesian state-space and habitat models show that penguins traversed thousands of square kilometers to areas of low sea surface temperatures (14.5°C-17.5°C) and high chlorophyll-a (∼11 mg m-3). These were once reliable cues for prey-rich waters, but climate change and industrial fishing have depleted forage fish stocks in this system [10, 11]. Juvenile penguin survival is low in populations selecting degraded areas, and Bayesian projection models suggest that breeding numbers are ∼50% lower than if non-impacted habitats were used, revealing the extent and effect of a marine ecological trap for the first time. These cascading impacts of localized forage fish depletion-unobserved in studies on adults-were only elucidated via broad-scale movement and demographic data on juveniles. Our results support suspending fishing when prey biomass drops below critical thresholds [12, 13] and suggest that mitigation of marine ecological traps will require matching conservation action to the scale of ecological processes [14].
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Affiliation(s)
- Richard B Sherley
- Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall TR10 9FE, UK; Bristol Zoological Society, Bristol Zoo Gardens, Bristol BS8 3HA, UK; Animal Demography Unit, Department of Biological Sciences, University of Cape Town, Rondebosch 7701, South Africa.
| | - Katrin Ludynia
- Marine Research Institute, University of Cape Town, Rondebosch 7701, South Africa
| | - Bruce M Dyer
- Oceans and Coasts Branch, Department of Environmental Affairs, Cape Town 8000, South Africa
| | - Tarron Lamont
- Marine Research Institute, University of Cape Town, Rondebosch 7701, South Africa; Oceans and Coasts Branch, Department of Environmental Affairs, Cape Town 8000, South Africa
| | - Azwianewi B Makhado
- Oceans and Coasts Branch, Department of Environmental Affairs, Cape Town 8000, South Africa
| | - Jean-Paul Roux
- Animal Demography Unit, Department of Biological Sciences, University of Cape Town, Rondebosch 7701, South Africa; Ministry of Fisheries and Marine Resources, PO Box 394, Lüderitz, Namibia
| | - Kylie L Scales
- Institute of Marine Sciences, University of California, Santa Cruz, Santa Cruz, CA 95064, USA; National Oceanic and Atmospheric Administration (NOAA) Southwest Fisheries Science Center, Environmental Research Division, 99 Pacific Street, Suite 255A, Monterey, CA 93940, USA; School of Science and Engineering, University of the Sunshine Coast, Maroochydore, QLD 4558, Australia
| | - Les G Underhill
- Animal Demography Unit, Department of Biological Sciences, University of Cape Town, Rondebosch 7701, South Africa; Marine Research Institute, University of Cape Town, Rondebosch 7701, South Africa
| | - Stephen C Votier
- Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall TR10 9FE, UK.
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Weller F, Sherley RB, Shannon LJ, Jarre A, Stewart T, Scott L, Altwegg R, Cecchini LA, Crawford RJ, Geldenhuys D, Ludynia K, Waller LJ. Penguins’ perilous conservation status calls for complementary approach based on sound ecological principles: reply to Butterworth et al. (2015). Ecol Modell 2016. [DOI: 10.1016/j.ecolmodel.2016.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Lower foraging efficiency in immatures drives spatial segregation with breeding adults in a long-lived pelagic seabird. Anim Behav 2015. [DOI: 10.1016/j.anbehav.2015.09.008] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Anguita C, Simeone A. Influence of Seasonal Food Availability on the Dynamics of Seabird Feeding Flocks at a Coastal Upwelling Area. PLoS One 2015; 10:e0131327. [PMID: 26125630 PMCID: PMC4488391 DOI: 10.1371/journal.pone.0131327] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 06/01/2015] [Indexed: 11/19/2022] Open
Abstract
The formation of multi-species feeding flocks (MSFFs) through visual recruitment is considered an important strategy for obtaining food in seabirds and its functionality has been ascribed to enhanced foraging efficiency. Its use has been demonstrated in much of the world's oceans and includes numerous species. However, there is scant information on the temporal stability of the composition and abundance of MSFFs as well as the effect of seasonal food availability on their dynamics. Between July 2006 and September 2014, we conducted monthly at-sea seabird counts at Valparaiso Bay (32°56' to 33°01'S, 71°36' to 71°46'W) within the area of influence of the Humboldt Current in central Chile. This area is characterized by a marked seasonality in primary and secondary production associated with upwelling, mainly during austral spring-summer. Based on studies that provide evidence that flocking is most frequent when food is both scarce and patchy, we hypothesized that seabird MSFF attributes (i.e. frequency of occurrence, abundance and composition) will be modified according to the seasonal availability of food. Using generalized linear models (GLMs), our results show that the contrasting seasonality in food availability of the study area (using chlorophyll-a concentration as a proxy) had no significant influence on MSFF attributes, sparsely explaining their variations (P>0.05). Rather than seasonal food availability, the observed pattern for MSFF attributes at Valparaiso Bay suggests a substantial influence of reproductive and migratory (boreal and austral migrants) habits of birds that modulates MSFF dynamics consistently throughout the whole year in this highly variable and patchy environment. We highlight the importance of visual recruitment as a mechanism by which migratory and resident birds interact. This would allow them to reduce resource unpredictability, which in turn has a major impact on structuring seabird's MSFF dynamics.
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Affiliation(s)
- Cristóbal Anguita
- Departamento de Ecología y Biodiversidad, Facultad de Ecología y Recursos Naturales, Universidad Andrés Bello, Santiago, Chile
| | - Alejandro Simeone
- Departamento de Ecología y Biodiversidad, Facultad de Ecología y Recursos Naturales, Universidad Andrés Bello, Santiago, Chile
- * E-mail:
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Sherley RB, Waller LJ, Strauss V, Geldenhuys D, Underhill LG, Parsons NJ. Hand-rearing, release and survival of African penguin chicks abandoned before independence by moulting parents. PLoS One 2014; 9:e110794. [PMID: 25337698 PMCID: PMC4206437 DOI: 10.1371/journal.pone.0110794] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 09/12/2014] [Indexed: 11/19/2022] Open
Abstract
The African penguin Spheniscus demersus has an 'Endangered' conservation status and a decreasing population. Following abandonment, 841 African penguin chicks in 2006 and 481 in 2007 were admitted to SANCCOB (Southern African Foundation for the Conservation of Coastal Birds) for hand-rearing from colonies in the Western Cape, South Africa, after large numbers of breeding adults commenced moult with chicks still in the nest. Of those admitted, 91% and 73% respectively were released into the wild. There were veterinary concerns about avian malaria, airsacculitis and pneumonia, feather-loss and pododermatitis (bumblefoot). Post-release juvenile (0.32, s.e. = 0.08) and adult (0.76, s.e. = 0.10) survival rates were similar to African penguin chicks reared after oil spills and to recent survival rates recorded for naturally-reared birds. By December 2012, 12 birds had bred, six at their colony of origin, and the apparent recruitment rate was 0.11 (s.e. = 0.03). Hand-rearing of abandoned penguin chicks is recommended as a conservation tool to limit mortality and to bolster the population at specific colonies. The feasibility of conservation translocations for the creation of new colonies for this species using hand-reared chicks warrants investigation. Any such programme would be predicated on adequate disease surveillance programmes established to minimise the risk of disease introduction to wild birds.
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Affiliation(s)
- Richard B. Sherley
- Animal Demography Unit and Marine Research Institute, University of Cape Town, Rondebosch, Western Cape, South Africa
- Bristol Zoological Society, Bristol Zoo Gardens, Bristol, United Kingdom
- * E-mail:
| | - Lauren J. Waller
- Animal Demography Unit and Marine Research Institute, University of Cape Town, Rondebosch, Western Cape, South Africa
- CapeNature, Hermanus, Western Cape, South Africa
| | - Venessa Strauss
- Southern African Foundation for the Conservation of Coastal Birds, Bloubergrant, Western Cape, South Africa
| | | | - Les G. Underhill
- Animal Demography Unit and Marine Research Institute, University of Cape Town, Rondebosch, Western Cape, South Africa
| | - Nola J. Parsons
- Southern African Foundation for the Conservation of Coastal Birds, Bloubergrant, Western Cape, South Africa
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Weller F, Cecchini LA, Shannon L, Sherley RB, Crawford RJ, Altwegg R, Scott L, Stewart T, Jarre A. A system dynamics approach to modelling multiple drivers of the African penguin population on Robben Island, South Africa. Ecol Modell 2014. [DOI: 10.1016/j.ecolmodel.2014.01.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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