108 research outputs found
Effects of Individual Pre-Fledging Traits and Environmental Conditions on Return Patterns in Juvenile King Penguins
Despite the importance of early life stages in individuals' life history and population dynamics, very few studies have focused on the constraints to which these juvenile traits are subjected. Based on 10 years of automatic monitoring of over 2500 individuals, we present the first study on the effects of environmental conditions and individual pre-fledging traits on the post-fledging return of non-banded king penguins to their natal colony. Juvenile king penguins returned exclusively within one of the three austral summers following their departure. A key finding is that return rates (range 68â87%) were much higher than previously assumed for this species, importantly meaning that juvenile survival is very close to that of adults. Such high figures suggest little juvenile dispersal, and selection occurring mostly prior to fledging in king penguins. Pre-fledging conditions had a strong quadratic impact on juvenile return rates. As expected, cohorts reared under very unfavourable years (as inferred by the breeding success of the colony) exhibited low return rates but surprisingly, so did those fledged under very favourable conditions. Juvenile sojourns away from the colony were shorter under warm conditions and subsequent return rates higher, suggesting a positive effect of climate warming. The longer the post-fledging trip (1, 2 or 3 years), the earlier in the summer birds returned to their natal colony and the longer they stayed before leaving for the winter journey. The presence of juveniles in the colony was more than twice the duration required for moulting purposes, yet none attempted breeding in the year of their first return. Juvenile presence in the colony may be important for acquiring knowledge on the social and physical colonial environment and may play an important part in the learning process of mating behaviour. Further studies are required to investigate its potential implications on other life-history traits such as recruitment age
Ornamental colors reveal age in the king penguin
We investigated whether delayed plumage maturation occurred in king penguins (Aptenodytes patagonicus). Therefore we examined the relationships between age and sex on spectral properties and size of two colored plumage patches and a UV-reflective beak spot, using known-age cohorts. Unlike the colored patch on the breast, we found age differences in ear and beak coloration. These results suggest that head ornaments in king penguins could signal sexual maturity or social status. No sex differences were found in the intensity of colored ornaments, which can result from mutual mate choice or genetic correlation between sexes. Size of colored patches did not relate to age or sex
Juvenile emperor penguin range calls for extended conservation measures in the Southern Ocean
To protect the unique and rich biodiversity of the Southern Ocean, conservation measures such as marine protected areas (MPAs) have been implemented. Currently, the establishment of several additional protection zones is being considered based on the known habitat distributions of key species of the ecosystems including emperor penguins and other marine top predators. However, the distribution of such species at sea is often insufficiently sampled. Specifically, current distribution models focus on the habitat range of adult animals and neglect that immatures and juveniles can inhabit different areas. By tracking eight juvenile emperor penguins in the Weddell Sea over 1 year and performing a meta-analysis including previously known data from other colonies, we show that conservation efforts in the Southern Ocean are insufficient for protecting this highly mobile species, and particularly its juveniles. We find that juveniles spend approximately 90% of their time outside the boundaries of proposed and existing MPAs, and that their distribution extends beyond (greater than 1500 km) the species' extent of occurrence as defined by the International Union for Conservation of Nature. Our data exemplify that strategic conservation plans for the emperor penguin and other long-lived ecologically important species should consider the dynamic habitat range of all age classes
No evidence of microplastic ingestion in emperor penguin chicks (Aptenodytes forsteri) from the Atka Bay colony (Dronning Maud Land, Antarctica)
Microplastic (500 ÎŒm using Attenuated Total Reflection Fourier-transform Infrared (ATR-FTIR) spectroscopy. A total of 85 putative particles, mostly in the shape of fibers (65.9 %), were sorted. However, none of the particles were identified as MP applying state-of-the-art methodology. Sorted fibers were further evidenced to originate from contamination during sample processing and analyses. We find that MP concentrations in the local food web of the Weddell Sea and Dronning Maud Land coastal and marginal sea-ice regions; the feeding grounds to chick-rearing emperor penguin adults, are currently at such low levels that no detectable biomagnification is occurring via trophic transfer. Being in contrast to MP studies on other Antarctic and sub-Antarctic penguin species, our comparative discussion including these studies, highlights the importance for standardized procedures for sampling, sample processing and analyses to obtain comparable results. We further discuss other stomach contents and their potential role for MP detection, as well as providing a baseline for the long-term monitoring of MP in apex predator species from this region
Cryptic speciation in gentoo penguins is driven by geographic isolation and regional marine conditions: Unforeseen vulnerabilities to global change
The conservation of biodiversity is hampered by data deficiencies, with many new species and subspecies awaiting description or reclassification. Population genomics and ecological niche modelling offer complementary new tools for un-covering functional units of phylogenetic diversity. We hypothesize that phyloge-netically delineated lineages of gentoo penguins (Pygoscelis papua) distributed across Antarctica and sub-Antarctic Islands are subject to spatially explicit ecological con-ditions that have limited gene flow, facilitating genetic differentiation, and thereby speciation processes
Antarctica and the Strategic Plan for Biodiversity 2011â2020
The Strategic Plan for Biodiversity, adopted under the auspices of the Convention on Biological Diversity, provides the basis for taking effective action to curb biodiversity loss across the planet by 2020âan urgent imperative. Yet, Antarctica and the Southern Ocean, which encompass 10% of the planetâs surface, are excluded from assessments of progress against the Strategic Plan. The situation is a lost opportunity for biodiversity conservation globally. We provide such an assessment. Our evidence suggests, surprisingly, that for a region so remote and apparently pristine as the Antarctic, the biodiversity outlook is similar to that for the rest of the planet. Promisingly, however, much scope for remedial action exists
Reviews and syntheses: A framework to observe, understand and project ecosystem response to environmental change in the East Antarctic Southern Ocean
Abstract. Systematic long-term studies on ecosystem dynamics are largely
lacking from the East Antarctic Southern Ocean, although it is well
recognized that they are indispensable to identify the ecological impacts
and risks of environmental change. Here, we present a framework for
establishing a long-term cross-disciplinary study on decadal timescales. We
argue that the eastern Weddell Sea and the adjacent sea to the east, off
Dronning Maud Land, is a particularly well suited area for such a study,
since it is based on findings from previous expeditions to this region.
Moreover, since climate and environmental change have so far been
comparatively muted in this area, as in the eastern Antarctic in general, a
systematic long-term study of its environmental and ecological state can
provide a baseline of the current situation, which will be important for an
assessment of future changes from their very onset, with consistent and
comparable time series data underpinning and testing models and their
projections. By establishing an Integrated East Antarctic Marine
Research (IEAMaR) observatory, long-term changes in ocean dynamics,
geochemistry, biodiversity, and ecosystem functions and services will be
systematically explored and mapped through regular autonomous and ship-based
synoptic surveys. An associated long-term ecological research (LTER)
programme, including experimental and modelling work, will allow for
studying climate-driven ecosystem changes and interactions with impacts
arising from other anthropogenic activities. This integrative approach will
provide a level of long-term data availability and ecosystem understanding
that are imperative to determine, understand, and project the consequences
of climate change and support a sound science-informed management of future
conservation efforts in the Southern Ocean.
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Reviews and syntheses: A framework to observe, understand, and project ecosystem response to environmental change in the East Antarctic Southern Ocean
Systematic long-term studies on ecosystem dynamics are largely lacking for the East Antarctic Southern Ocean, although it is well recognized that such investigations are indispensable to identify the ecological impacts and risks of environmental change. Therefore, here we develop a framework for establishing a long-term cross-disciplinary study and argue why the eastern Weddell Sea and the easterly adjacent sea off Dronning Maud Land (WSoDML) is a well suited area for such an initiative. As in the Eastern Antarctic in general, climate and environmental change have so far been comparatively muted in this area. A systematic long-term study of its environmental and ecological state can thus provide a baseline of the current situation, an assessment of future changes, and sound data can act as a model to develop and calibrate projections. Establishing a long-term observation (LTO) and long-term ecological research (LTER) programme now would allow the study of climate-driven ecosystem changes and interactions with impacts arising from other anthropogenic activities, from their very onset. Through regular autonomous and ship-based LTO activities, changes in ocean dynamics, geochemistry, biodiversity and ecosystem functions and services can be systematically explored and mapped. This observational work should be accompanied by targeted LTER efforts, including experimental and modelling studies. This approach will provide a level of long-term data availability and ecosystem understanding that are imperative to determine, understand, and project the consequences of climate change and support a sound science-informed management of future conservation efforts in the Southern Ocean
Sustained Antarctic Research: A 21st Century Imperative
The view from the south is, more than ever, dominated by ominous signs of change. Antarctica and the Southern Ocean are intrinsic to the Earth system, and their evolution is intertwined with and influences the course of the Anthropocene. In turn, changes in the Antarctic affect and presage humanity's future. Growing understanding is countering popular beliefs that Antarctica is pristine, stable, isolated, and reliably frozen. An aspirational roadmap for Antarctic science has facilitated research since 2014. A renewed commitment to gathering further knowledge will quicken the pace of understanding of Earth systems and beyond. Progress is already evident, such as addressing uncertainties in the causes and pace of ice loss and global sea-level rise. However, much remains to be learned. As an iconic global âcommons,â the rapidity of Antarctic change will provoke further political action. Antarctic research is more vital than ever to a sustainable future for this One Earth
Stratégies d'histoire de vie d'un oiseau longévif : le manchot royal (Aptenodytes patagonicus)
Le compromis entre la reproduction en cours et les chances de survivre et de se reproduire ultérieurement est un élément clef des études sur l'évolution des traits d'histoire de vie. Ce travail de doctorat relatif au Manchot royal (Aptenodytes patagonicusAn evaluation of how animals optimize their lifetime reproductive success is a crucial step for defining their life history strategy. We investigated the trade-off between current reproductive effort, and future survival and breeding attempts to test th
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