Comparative population genomics reveals key barriers to dispersal in Southern Ocean penguins.

The mechanisms that determine patterns of species dispersal are important factors in the production and maintenance of biodiversity. Understanding these mechanisms helps to forecast the responses of species to environmental change. Here, we used a comparative framework and genomewide data obtained through RAD-Seq to compare the patterns of connectivity among breeding colonies for five penguin species with shared ancestry, overlapping distributions and differing ecological niches, allowing an examination of the intrinsic and extrinsic barriers governing dispersal patterns. Our findings show that at-sea range and oceanography underlie patterns of dispersal in these penguins. The pelagic niche of emperor (Aptenodytes forsteri), king (A. patagonicus), Adélie (Pygoscelis adeliae) and chinstrap (P. antarctica) penguins facilitates gene flow over thousands of kilometres. In contrast, the coastal niche of gentoo penguins (P. papua) limits dispersal, resulting in population divergences. Oceanographic fronts also act as dispersal barriers to some extent. We recommend that forecasts of extinction risk incorporate dispersal and that management units are defined by at-sea range and oceanography in species lacking genetic data.

Dispersal in the sub-Antarctic: king penguins show remarkably little population genetic differentiation across their range.

BACKGROUND: Seabirds are important components of marine ecosystems, both as predators and as indicators of ecological change, being conspicuous and sensitive to changes in prey abundance. To determine whether fluctuations in population sizes are localised or indicative of large-scale ecosystem change, we must first understand population structure and dispersal. King penguins are long-lived seabirds that occupy a niche across the sub-Antarctic zone close to the Polar Front. Colonies have very different histories of exploitation, population recovery, and expansion. RESULTS: We investigated the genetic population structure and patterns of colonisation of king penguins across their current range using a dataset of 5154 unlinked, high-coverage single nucleotide polymorphisms generated via restriction site associated DNA sequencing (RADSeq). Despite breeding at a small number of discrete, geographically separate sites, we find only very slight genetic differentiation among colonies separated by thousands of kilometers of open-ocean, suggesting migration among islands and archipelagos may be common. Our results show that the South Georgia population is slightly differentiated from all other colonies and suggest that the recently founded Falkland Island colony is likely to have been established by migrants from the distant Crozet Islands rather than nearby colonies on South Georgia, possibly as a result of density-dependent processes. CONCLUSIONS: The observed subtle differentiation among king penguin colonies must be considered in future conservation planning and monitoring of the species, and demographic models that attempt to forecast extinction risk in response to large-scale climate change must take into account migration. It is possible that migration could buffer king penguins against some of the impacts of climate change where colonies appear panmictic, although it is unlikely to protect them completely given the widespread physical changes projected for their Southern Ocean foraging grounds. Overall, large-scale population genetic studies of marine predators across the Southern Ocean are revealing more interconnection and migration than previously supposed.

The accuracy of the Alvarado score in predicting acute appendicitis in the black South African population needs to be validated.

BACKGROUND: The Alvarado score is the most widely used clinical prediction tool to facilitate decision-making in patients with acute appendicitis, but it has not been validated in the black South African population, which has much wider differential diagnosis than developed world populations. We investigated the applicability of this score to our local population and sought to introduce a checklist for rural doctors to facilitate early referral. METHODS: We analyzed patients with proven appendicitis for the period January 2008 to December 2012. Alvarado scores were retrospectively assigned based on patients' admission charts. We generated a clinical probability score (1-4 = low, 5-6 = intermediate, 7-10 = high). RESULTS: We studied 1000 patients (54% male, median age 21 yr). Forty percent had inflamed, nonperforated appendices and 60% had perforated appendices. Alvarado scores were 1-4 in 20.9%, 5-6 in 35.7% and 7-10 in 43.4%, indicating low, intermediate and high clincial probability, respectively. In our subgroup analysis of 510 patients without generalized peritonitis, Alvarado scores were 1-4 in 5.5%, 5-6 in 18.1% and 7-10 in 76.4%, indicating low, intermediate and high clinical probability, respectively. CONCLUSION: The widespread use of the Alvarado score has its merits, but its applicability in the black South African population is unclear, with a significant proportion of patients with the disease being potentially missed. Further prospective validation of the Alvarado score and possible modification is needed to increase its relevance in our setting.

CONTEXTE: Le score d'Alvarado est l'outil de prédiction clinique le plus couramment utilisé pour faciliter la prise de décision chez les patients présentant une appendicite aiguë, mais il n'a pas été validé dans la population noire sud-africaine chez qui le diagnostic différentiel est beaucoup plus vaste que dans les populations des pays industrialisés. Nous avons exploré l'applicabilité de ce score à notre population locale et tenté de présenter une liste de vérification aux médecins ruraux pour accélérer les demandes de consultation. MÉTHODES: Nous avons analysé les dossiers de patients atteints d'une appendicite avérée pendant la période allant de janvier 2008 à décembre 2012. Les scores d'Alvarado ont été assignés rétrospectivement selon les dossiers d'admission des patients. Nous avons généré un score de probabilité clinique (1­4 = faible, 5­6 = intermédiaire, 7­10 = élevé). RÉSULTATS: Nous avons ainsi étudié 1000 patients (54 % de sexe masculin, âge médian 21 ans). Quarante pour cent présentaient des appendices enflammés non perforés et 60 % des appendices perforés. Les scores d'Alvarado se situaient à 1­4 chez 20,9 %, à 5­6 chez 35,7 % et à 7­10 chez 43,4 %, correspondant à une probabilité clinique faible, intermédiaire et élevée, respectivement. Dans notre analyse de sous-groupes sur 510 patients indemnes de péritonite généralisée, les scores d'Alvarado se situaient à 1­4 chez 5,5 %, à 5­6 chez 18,1 % et à 7­10 chez 76,4 %, correspondant à une probabilité clinique faible, intermédiaire et élevée, respectivement. CONCLUSION: L'utilisation répandue du score d'Alvarado a ses mérites, mais son applicabilité dans la population noire d'Afrique du Sud est indéterminée, la maladie risquant de passer inaperçue chez une proportion significative de patients. Il faudra procéder à une validation prospective plus approfondie du score d'Alvarado et le modifier peut-être si l'on veut en accroître la pertinence dans notre contexte.

A concept paper: using the outcomes of common surgical conditions as quality metrics to benchmark district surgical services in South Africa as part of a systematic quality improvement programme.

The fourth, fifth and sixth Millennium Development Goals relate directly to improving global healthcare and health outcomes. The focus is to improve global health outcomes by reducing maternal and childhood mortality and the burden of infectious diseases such as HIV/AIDS, tuberculosis and malaria. Specific targets and time frames have been set for these diseases. There is, however, no specific mention of surgically treated diseases in these goals, reflecting a bias that is slowly changing with emerging consensus that surgical care is an integral part of primary healthcare systems in the developing world. The disparities between the developed and developing world in terms of wealth and social indicators are reflected in disparities in access to surgical care. Health administrators must develop plans and strategies to reduce these disparities. However, any strategic plan that addresses deficits in healthcare must have a system of metrics, which benchmark the current quality of care so that specific improvement targets may be set.This concept paper outlines the role of surgical services in a primary healthcare system, highlights the ongoing disparities in access to surgical care and outcomes of surgical care, discusses the importance of a systems-based approach to healthcare and quality improvement, and reviews the current state of surgical care at district hospitals in South Africa. Finally, it proposes that the results from a recently published study on acute appendicitis, as well as data from a number of other common surgical conditions, can provide measurable outcomes across a healthcare system and so act as an indicator for judging improvements in surgical care. This would provide a framework for the introduction of collection of these outcomes as a routine epidemiological health policy tool.

Seabird and reef conservation must include coral islands.

Tropical seabirds exert key roles in reef ecosystems but face growing threats from climate change, especially on coral reef islands (CRIs). Therefore, we advocate for a more comprehensive, global data exchange on CRIs and CRI-dependent seabirds and outline steps for improving their study and conservation.

Acute appendicitis in a developing country.

BACKGROUND: This prospective audit of appendicitis at a busy regional hospital reviews the spectrum and outcome of acute appendicitis in rural and peri-urban South Africa. METHOD: We conducted a prospective audit from September 2010 to September 2011 at Edendale Hospital in Pietermaritzburg, South Africa. RESULTS: Over the year under review, a total of 200 patients with a provisional diagnosis of acute appendicitis were operated on at Edendale Hospital. There were 128 males (64 %) in this cohort. The mean duration of illness prior to seeking medical attention was 3.7 days. Surgical access was by a midline laparotomy in 62.5 % and by a Lanz incision in 35.5 %. Two percent of patients underwent a laparoscopic appendicectomy. The operative findings were as follows: macroscopic inflammation of the appendix without perforation in 35.5 % (71/200) and perforation of the appendix in 57 % (114/200). Of the perforated appendices, 44 % (51/114) were associated with localised intra-abdominal contamination and 55 % (63/114) had generalised four-quadrant soiling. Thirty percent (60/200) required temporary abdominal closure (TAC) with planned repeat operation. Major complications included hospital-acquired pneumonia in 12.5 % (25/200), wound dehiscence in 7 % (14/200), and renal failure in 3 % (6/200). Postoperatively 89.5 % (179/200) were admitted directly to the general wards, while 11 % (21/200) required admission to the intensive care unit. The overall mortality rate was 2 % (4/200). CONCLUSIONS: The incidence of acute appendicitis amongst African patients seems to be increasing. Although it is still lower than the reported incidence amongst patients in the developed world, it is a common emergency that places a significant burden on the South African health service. The disease presents late and is associated with a high incidence of perforation which translates into significant morbidity and even mortality.

Author Correction: Important At-Sea Areas of Colonial Breeding Marine Predators on the Southern Patagonian Shelf.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Important At-Sea Areas of Colonial Breeding Marine Predators on the Southern Patagonian Shelf.

The Patagonian Shelf Large Marine Ecosystem supports high levels of biodiversity and endemism and is one of the most productive marine ecosystems in the world. Despite the important role marine predators play in structuring the ecosystems, areas of high diversity where multiple predators congregate remains poorly known on the Patagonian Shelf. Here, we used biotelemetry and biologging tags to track the movements of six seabird species and three pinniped species breeding at the Falkland Islands. Using Generalized Additive Models, we then modelled these animals' use of space as functions of dynamic and static environmental indices that described their habitat. Based on these models, we mapped the predicted distribution of animals from both sampled and unsampled colonies and thereby identified areas where multiple species were likely to overlap at sea. Maximum foraging trip distance ranged from 79 to 1,325 km. However, most of the 1,891 foraging trips by 686 animals were restricted to the Patagonian Shelf and shelf slope, which highlighted a preference for these habitats. Of the seven candidate explanatory covariates used to predict distribution, distance from the colony was retained in models for all species and negatively affected the probability of occurrence. Predicted overlap among species was highest on the Patagonian Shelf around the Falkland Islands and the Burdwood Bank. The predicted area of overlap is consistent with areas that are also important habitat for marine predators migrating from distant breeding locations. Our findings provide comprehensive multi-species predictions for some of the largest marine predator populations on the Patagonian Shelf, which will contribute to future marine spatial planning initiatives. Crucially, our findings highlight that spatially explicit conservation measures are likely to benefit multiple species, while threats are likely to impact multiple species.

Behaviourally mediated predation avoidance in penguin prey: in situ evidence from animal-borne camera loggers.

Predator dietary studies often assume that diet is reflective of the diversity and relative abundance of their prey. This interpretation ignores species-specific behavioural adaptations in prey that could influence prey capture. Here, we develop and describe a scalable biologging protocol, using animal-borne camera loggers, to elucidate the factors influencing prey capture by a seabird, the gentoo penguin (Pygoscelis papua). From the video evidence, we show, to our knowledge for the first time, that aggressive behavioural defence mechanisms by prey can deter prey capture by a seabird. Furthermore, we provide evidence demonstrating that these birds, which were observed hunting solitarily, target prey when they are most discernible. Specifically, birds targeted prey primarily while ascending and when prey were not tightly clustered. In conclusion, we show that prey behaviour can significantly influence trophic coupling in marine systems because despite prey being present, it is not always targeted. Thus, these predator-prey relationships should be accounted for in studies using marine top predators as samplers of mid- to lower trophic-level species.