43 research outputs found
The influence of biotic and abiotic factors on the bacterial microbiome of gentoo penguins ( Pygoscelis papua ) in their natural environment
The microbiome is a key factor in the health, well-being, and success of vertebrates, contributing to the adaptive capacity of the host. However, the impact of geographic and biotic factors that may affect the microbiome of wild birds in polar environments is not well defined. To address this, we determined the bacterial 16S rRNA gene sequence profiles in faecal samples from pygoscelid penguin populations in the Scotia Arc, focusing on gentoo penguins. This mesopredatory group breeds in defined colonies across a wide geographic range. Since diet could influence microbiome structure, we extracted dietary profiles from a eukaryotic 18S rRNA gene sequence profile. The bacterial microbiome profiles were considered in the context of a diverse set of environmental and ecological measures. Integrating wide geographic sampling with bacterial 16S and eukaryotic 18S rRNA gene sequencing of over 350 faecal samples identified associations between the microbiome profile and a suite of geographic and ecological factors. Microbiome profiles differed according to host species, colony identity, distance between colonies, and diet. Interestingly there was also a relationship between the proportion of host DNA (in relation to total 18S rRNA gene signal) and the microbiome, which may reflect gut passage time. Colony identity provided the strongest association with differences in microbiome profiles indicating that local factors play a key role in the microbiome structure of these polar seabirds. This may reflect the influence of local transfer of microbes either via faecal-oral routes, during chick feeding or other close contact events. Other factors including diet and host species also associate with variation in microbiome profile, and in at least some locations, the microbiome composition varies considerably between individuals. Given the variation in penguin microbiomes associated with diverse factors there is potential for disruption of microbiome associations at a local scale that could influence host health, productivity, and immunological competence. The microbiome represents a sensitive indicator of changing conditions, and the implications of any changes need to be considered in the wider context of environmental change and other stressors
Pan-Antarctic analysis aggregating spatial estimates of Adélie penguin abundance reveals robust dynamics despite stochastic noise
© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Nature Communications 8 (2017): 832, doi:10.1038/s41467-017-00890-0.Colonially-breeding seabirds have long served as indicator species for the health of the oceans on which they depend. Abundance and breeding data are repeatedly collected at fixed study sites in the hopes that changes in abundance and productivity may be useful for adaptive management of marine resources, but their suitability for this purpose is often unknown. To address this, we fit a Bayesian population dynamics model that includes process and observation error to all known AdĂ©lie penguin abundance data (1982â2015) in the Antarctic, covering >95% of their population globally. We find that process error exceeds observation error in this system, and that continent-wide âyear effectsâ strongly influence population growth rates. Our findings have important implications for the use of AdĂ©lie penguins in Southern Ocean feedback management, and suggest that aggregating abundance across space provides the fastest reliable signal of true population change for species whose dynamics are driven by stochastic processes.H.J.L., C.C.-C., G.H., C.Y., and K.T.S. gratefully acknowledge funding provided by US National Aeronautics and Space Administration Award No. NNX14AC32G and U.S. National Science Foundation Office of Polar Programs Award No. NSF/OPP-1255058. S.J., L.L., M.M.H., Y.L., and R.J. gratefully acknowledge funding provided by US National Aeronautics and Space Administration Award No. NNX14AH74G. H.J.L., C.Y., S.J., Y.L., and R.J. gratefully acknowledge funding provided by U.S. National Science Foundation Office of Polar Programs Award No. NSF/PLR-1341548. S.J. gratefully acknowledges support from the Dalio Explore Fund
Multi-modal survey of Adélie penguin mega-colonies reveals the Danger Islands as a seabird hotspot
© The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Scientific Reports 8 (2018): 3926, doi:10.1038/s41598-018-22313-w.Despite concerted international effort to track and interpret shifts in the abundance and distribution of Adélie penguins, large populations continue to be identified. Here we report on a major hotspot of Adélie penguin abundance identified in the Danger Islands off the northern tip of the Antarctic Peninsula (AP). We present the first complete census of Pygoscelis spp. penguins in the Danger Islands, estimated from a multi-modal survey consisting of direct ground counts and computer-automated counts of unmanned aerial vehicle (UAV) imagery. Our survey reveals that the Danger Islands host 751,527 pairs of Adélie penguins, more than the rest of AP region combined, and include the third and fourth largest Adélie penguin colonies in the world. Our results validate the use of Landsat medium-resolution satellite imagery for the detection of new or unknown penguin colonies and highlight the utility of combining satellite imagery with ground and UAV surveys. The Danger Islands appear to have avoided recent declines documented on the Western AP and, because they are large and likely to remain an important hotspot for avian abundance under projected climate change, deserve special consideration in the negotiation and design of Marine Protected Areas in the region.We gratefully acknowledge the financial support of the Dalio Foundation, Inc. through the Dalio Explore Fund,
which provided all the financing for the Danger Island Expedition. We would like to thank additional
support for analysis from the National Science Foundation (NSF PLR&GSS 1255058 - H.J.L. and P.M.; NSF PLR
1443585 â M.J.P.) and the National Aeronautical and Space Administration (NNX14AC32G; H.J.L. and M.S.).
Geospatial support for the analysis of high resolution satellite imagery provided by the Polar Geospatial Center
under NSF PLR awards 1043681 & 1559691
Wild zebra finches choose neighbours for synchronized breeding
Organisms should aim to time their reproduction to match the optimal ecological conditions and thus maximize their fitness. However, social cues have been identified as determinants of reproductive decisions and might also be involved in coordinating the timing of reproduction. Breeding synchronously with other individuals can bring several advantages, including a reduced individual predation risk and an increased opportunity for social foraging. The behavioural mechanisms underlying reproductive synchrony are versatile and not well understood, particularly in species inhabiting unpredictable environments. In contrast to highly seasonal environments, more variable and unpredictable environments can support periods of extended breeding with lower levels of synchronous breeding overall, but opportunities for individuals to breed synchronously at a finer temporal and spatial scale. Zebra finches, Taeniopygia guttata, are a highly social species, naturally inhabiting the ecologically unpredictable arid zone of Australia. In the wild, reproduction at a broad population level is not highly synchronized and, at any time during a period of breeding activity, reproductive attempts can be found at different stages. However, previous work has suggested that at a finer spatial scale neighbours tend to breed at approximately the same time. Using nestboxes, we tested whether wild zebra finches preferentially seek to settle and initiate a breeding attempt adjacent to conspecifics at an early stage of breeding (nest building), as opposed to others at later stages of breeding and with which the opportunity to breed synchronously was reduced or absent. Pairs were more likely to initiate egg laying in nestboxes close to conspecifics at an early stage of breeding, suggesting that they do try to maximize the level of synchronicity with neighbours. Our results indicate the importance of social effects on both the phenology and spatial distribution of breeding
Priorities for synthesis research in ecology and environmental science
ACKNOWLEDGMENTS We thank the National Science Foundation grant #1940692 for financial support for this workshop, and the National Center for Ecological Analysis and Synthesis (NCEAS) and its staff for logistical support.Peer reviewedPublisher PD
Priorities for synthesis research in ecology and environmental science
ACKNOWLEDGMENTS We thank the National Science Foundation grant #1940692 for financial support for this workshop, and the National Center for Ecological Analysis and Synthesis (NCEAS) and its staff for logistical support.Peer reviewedPublisher PD
Reproductive performance and diving behaviour share a common sea-ice concentration optimum in Adélie penguins (Pygoscelis adeliae)
This study was financially supported by the following institutions: the WWF-UK through R. Downie, the Japanese Mombukagakusho and the Japanese Society for the Promotion of Science, the Zone Atelier Antarctique et Subantarctique âLTER France of the CNRS.The Southern Ocean is currently experiencing major environmental changes, including in seaâice cover. Such changes strongly influence ecosystem structure and functioning and affect the survival and reproduction of predators such as seabirds. These effects are likely mediated by reduced availability of food resources. As such, seabirds are reliable ecoâindicators of environmental conditions in the Antarctic region. Here, based on 9 years of seaâice data, we found that the breeding success of AdĂ©lie penguins (Pygoscelis adeliae) reaches a peak at intermediate seaâice cover (ca. 20%). We further examined the effects of seaâice conditions on the foraging activity of penguins, measured at multiple scales from individual dives to foraging trips. Analysis of temporal organisation of dives, including fractal and bout analyses, revealed an increasingly consistent behaviour during years with extensive seaâice cover. The relationship between several dive parameters and seaâice cover in the foraging area appears to be quadratic. In years of low and high seaâice cover, individuals adjusted their diving effort by generally diving deeper, more frequently and by resting at the surface between dives for shorter periods of time than in years with intermediate seaâice cover. Our study therefore suggests that seaâice cover is likely to affect the reproductive performance of AdĂ©lie penguins through its effects on foraging behaviour, as breeding success and most diving parameters share a common optimum. Some years, however, deviated from this general trend, suggesting that other factors (e.g. precipitation during the breeding season) might sometimes become preponderant over the seaâice effects on breeding and foraging performance. Our study highlights the value of monitoring fitness parameters and individual behaviour concomitantly over the longâterm to better characterize optimal environmental conditions and potential resilience of wildlife. Such an approach is crucial if we want to anticipate the effects of environmental change on Antarctic penguin populations.PostprintPeer reviewe
Priorities for synthesis research in ecology and environmental science
Synthesis research in ecology and environmental science improves understanding, advances theory, identifies research priorities, and supports management strategies by linking data, ideas, and tools. Accelerating environmental challenges increases the need to focus synthesis science on the most pressing questions. To leverage input from the broader research community, we convened a virtual workshop with participants from many countries and disciplines to examine how and where synthesis can address key questions and themes in ecology and environmental science in the coming decade. Seven priority research topics emerged: (1) diversity, equity, inclusion, and justice (DEIJ), (2) human and natural systems, (3) actionable and use-inspired science, (4) scale, (5) generality, (6) complexity and resilience, and (7) predictability. Additionally, two issues regarding the general practice of synthesis emerged: the need for increased participant diversity and inclusive research practices; and increased and improved data flow, access, and skill-building. These topics and practices provide a strategic vision for future synthesis in ecology and environmental science
Same data, different conclusions: Radical dispersion in empirical results when independent analysts operationalize and test the same hypothesis
In this crowdsourced initiative, independent analysts used the same dataset to test two hypotheses regarding the effects of scientistsâ gender and professional status on verbosity during group meetings. Not only the analytic approach but also the operationalizations of key variables were left unconstrained and up to individual analysts. For instance, analysts could choose to operationalize status as job title, institutional ranking, citation counts, or some combination. To maximize transparency regarding the process by which analytic choices are made, the analysts used a platform we developed called DataExplained to justify both preferred and rejected analytic paths in real time. Analyses lacking sufficient detail, reproducible code, or with statistical errors were excluded, resulting in 29 analyses in the final sample. Researchers reported radically different analyses and dispersed empirical outcomes, in a number of cases obtaining significant effects in opposite directions for the same research question. A Boba multiverse analysis demonstrates that decisions about how to operationalize variables explain variability in outcomes above and beyond statistical choices (e.g., covariates). Subjective researcher decisions play a critical role in driving the reported empirical results, underscoring the need for open data, systematic robustness checks, and transparency regarding both analytic paths taken and not taken. Implications for organizations and leaders, whose decision making relies in part on scientific findings, consulting reports, and internal analyses by data scientists, are discussed