30 research outputs found
Accounting for the low survival of the Critically Endangered northern bald ibis Geronticus eremita on a major migratory flyway
AbstractThe poor survival rate of immature northern bald ibises Geronticus eremita during their first years spent outside the natal site is driving the last known wild colony of the migratory eastern population to extinction. To inform emergency conservation action for this Critically Endangered species we investigated the distribution range and behaviour of immature birds in passage and wintering areas, and the threats to which they are subject. We integrated recent satellite telemetry data with visual observations spanning 130 years. We assessed threats across the range, using satellite tracking and field surveys. Our results show that during the years before they return to the natal site in Syria, immature northern bald ibises reside away from the recently identified adult wintering site in the central Ethiopian highlands. They occur mainly across the northernmost 70–80% of the adult migratory range. Historical records suggest that immature birds spend more time along the western Arabian Peninsula now than in the past. This range shift exposes them for longer periods to threats, such as hunting and electrocution on power lines, which are absent from the wintering site used by adult birds. We suggest that other threatened and declining bird species sharing the same flyway probably face the same threats during migration
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Further notes on the natural history of the Ethiopian Bush-crow Zavattariornis stresemanni
The Ethiopian Bush-crow Zavattariornis stresemanni is a charismatic and Endangered endemic bird of southern Ethiopia, whose general biology remains under-studied. We present field notes and observations from 2008 to 2014, covering many aspects of the species’ behaviour and morphology. Bush-crows breed co-operatively in response to both of the local rainy seasons, but group size and fidelity of helpers appears to be variable. Bush-crow nests were found for the first time on man-made structures; a low power distribution pole and a tall electricity pylon. The display of one bush-crow to another is further described. Juveniles can be identified by darker coloration around the face, bright red gapes and distinctive begging calls. Adults possess lightweight, low-density body feathers and it appears that bush-crows have a moult phenology that overlaps extensively with breeding, a trait unusual in birds. Post-breeding dispersal is often limited, although anecdotal evidence and a handful of observations suggest that some individuals cover greater distances between breeding seasons. We report the first confirmed predation of a bush-crow, and supplement this with notes on other interspecific interactions. Finally, bush-crows were found for the first time north-west of Yabello (a small range extension), and we discuss the implications of local movements and range fluctuations in the context of the species’ apparent climatic range limitation.This is the author accepted manuscript. The final version is available from African Bird Club via https://www.africanbirdclub.org/bulletins/abc-bulletin-231-march-2016/further-notes-natural-history-ethiopian-bush-cro
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Notes on the behaviour, plumage and distribution of the White-tailed Swallow Hirundo megaensis
The White-tailed Swallow Hirundo megaensis is a threatened and poorly known bird endemic to southern Ethiopia, where it is restricted to a small area of Acacia savanna. Despite the paucity of previous nest records, we found 67 nests in the years 2010–14, commonly in village huts lived in by people, and report the first confirmation of nesting (two certain records) in termite mounds. Its nests are small mud cups lined with grass and animal hair, fixed to roof joists and similar to those of its sister species, the Pearl-breasted Swallow H. dimidiata of southern Africa, although it appears to lay larger clutches (3–4 pure white eggs) and breed less frequently, producing one brood in each of its two rain-driven breeding seasons (April–June and October–November). The same nests are reportedly used in these two seasons, presumably by the same pairs. Incubation lasts 16–17 days, with some broods showing clearly smaller chicks and hence presumably asynchronous hatching. Study of nestlings in the hand and museum skins confirmed that juveniles can be determined by their shorter tails, browner heads and frequently also wings, and reduced white in the tail. Although birds are typically seen singly or in pairs, flocks of up to 50, sometimes mixed with other hirundines, can occur. The breeding range appears to be almost identical to that of the Ethiopian Bush-crow Zavattariornis stresemanni but regular sightings of White-tailed Swallows since 2005 at the Liben Plain, 120 km to the east of the core area, suggest that the birds are frequent visitors there.We are grateful to the numerous funding bodies which have supported this research over several years: NERC, RSPB, British Birdfair, African Bird Club, British Ornithologists’ Union, Gesellschaft für Tropenornithologie, Tim Whitmore Zoology Fund, Magdalene College (Cambridge), Cambridge Philosophical Society, and BirdLife Preventing Extinctions Programme; and especially to Julian Francis. We also thank Robert Prys-Jones at the Natural History Museum (NHMUK) for access to specimens; Les Colley for his photograph used in Fig. 5; Stefanie Rick for her excellent drawings used in Fig. 9; Steve Rooke (Sunbird Tours), Bernard, Willem and Sjoerd Oosterbaan, Simon Busuttil, Merid Gabremichael and Claire Spottiswoode for providing additional information and sightings; Alazar Dakar, Abiy Dange, Birhan Dessalegn, Solomon Desta, Okotu Dida, Ali Guche, Sam Jones, Gufu Kashina, Stuart Marsden, Tesfaye Mekonnen, Samson Zelleke and many others including all the staff of Borana National Park for help with fieldwork; Angela Turner and John Atkins for their services as referees; and the Borana villagers who so kindly allowed us into their homes to study the White-tailed Swallow’s nests and without whose hospitality our knowledge of this species would be much poorer.This is the author accepted manuscript. The final version is available from African Bird Club
The global, regional, and national burden of pancreatic cancer and its attributable risk factors in 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017
Background: Worldwide, both the incidence and death rates of pancreatic cancer are increasing. Evaluation of pancreatic cancer burden and its global, regional, and national patterns is crucial to policy making and better resource allocation for controlling pancreatic cancer risk factors, developing early detection methods, and providing faster and more effective treatments. Methods: Vital registration, vital registration sample, and cancer registry data were used to generate mortality, incidence, and disability-adjusted life-years (DALYs) estimates. We used the comparative risk assessment framework to estimate the proportion of deaths attributable to risk factors for pancreatic cancer: smoking, high fasting plasma glucose, and high body-mass index. All of the estimates were reported as counts and age-standardised rates per 100 000 person-years. 95% uncertainty intervals (UIs) were reported for all estimates. Findings: In 2017, there were 448 000 (95% UI 439 000\u2013456 000) incident cases of pancreatic cancer globally, of which 232 000 (210 000\u2013221 000; 51\ub79%) were in males. The age-standardised incidence rate was 5\ub70 (4\ub79\u20135\ub71) per 100 000 person-years in 1990 and increased to 5\ub77 (5\ub76\u20135\ub78) per 100 000 person-years in 2017. There was a 2\ub73 times increase in number of deaths for both sexes from 196 000 (193 000\u2013200 000) in 1990 to 441 000 (433 000\u2013449 000) in 2017. There was a 2\ub71 times increase in DALYs due to pancreatic cancer, increasing from 4\ub74 million (4\ub73\u20134\ub75) in 1990 to 9\ub71 million (8\ub79\u20139\ub73) in 2017. The age-standardised death rate of pancreatic cancer was highest in the high-income super-region across all years from 1990 to 2017. In 2017, the highest age-standardised death rates were observed in Greenland (17\ub74 [15\ub78\u201319\ub70] per 100 000 person-years) and Uruguay (12\ub71 [10\ub79\u201313\ub75] per 100 000 person-years). These countries also had the highest age-standardised death rates in 1990. Bangladesh (1\ub79 [1\ub75\u20132\ub73] per 100 000 person-years) had the lowest rate in 2017, and S\ue3o Tom\ue9 and Pr\uedncipe (1\ub73 [1\ub71\u20131\ub75] per 100 000 person-years) had the lowest rate in 1990. The numbers of incident cases and deaths peaked at the ages of 65\u201369 years for males and at 75\u201379 years for females. Age-standardised pancreatic cancer deaths worldwide were primarily attributable to smoking (21\ub71% [18\ub78\u201323\ub77]), high fasting plasma glucose (8\ub79% [2\ub71\u201319\ub74]), and high body-mass index (6\ub72% [2\ub75\u201311\ub74]) in 2017. Interpretation: Globally, the number of deaths, incident cases, and DALYs caused by pancreatic cancer has more than doubled from 1990 to 2017. The increase in incidence of pancreatic cancer is likely to continue as the population ages. Prevention strategies should focus on modifiable risk factors. Development of screening programmes for early detection and more effective treatment strategies for pancreatic cancer are needed. Funding: Bill & Melinda Gates Foundation
Global, regional, and national incidence, prevalence, and mortality of HIV, 1980–2017, and forecasts to 2030, for 195 countries and territories: a systematic analysis for the Global Burden of Diseases, Injuries, and Risk Factors Study 2017
Background
Understanding the patterns of HIV/AIDS epidemics is crucial to tracking and monitoring the progress of prevention and control efforts in countries. We provide a comprehensive assessment of the levels and trends of HIV/AIDS incidence, prevalence, mortality, and coverage of antiretroviral therapy (ART) for 1980–2017 and forecast these estimates to 2030 for 195 countries and territories.
Methods
We determined a modelling strategy for each country on the basis of the availability and quality of data. For countries and territories with data from population-based seroprevalence surveys or antenatal care clinics, we estimated prevalence and incidence using an open-source version of the Estimation and Projection Package—a natural history model originally developed by the UNAIDS Reference Group on Estimates, Modelling, and Projections. For countries with cause-specific vital registration data, we corrected data for garbage coding (ie, deaths coded to an intermediate, immediate, or poorly defined cause) and HIV misclassification. We developed a process of cohort incidence bias adjustment to use information on survival and deaths recorded in vital registration to back-calculate HIV incidence. For countries without any representative data on HIV, we produced incidence estimates by pulling information from observed bias in the geographical region. We used a re-coded version of the Spectrum model (a cohort component model that uses rates of disease progression and HIV mortality on and off ART) to produce age-sex-specific incidence, prevalence, and mortality, and treatment coverage results for all countries, and forecast these measures to 2030 using Spectrum with inputs that were extended on the basis of past trends in treatment scale-up and new infections.
Findings
Global HIV mortality peaked in 2006 with 1·95 million deaths (95% uncertainty interval 1·87–2·04) and has since decreased to 0·95 million deaths (0·91–1·01) in 2017. New cases of HIV globally peaked in 1999 (3·16 million, 2·79–3·67) and since then have gradually decreased to 1·94 million (1·63–2·29) in 2017. These trends, along with ART scale-up, have globally resulted in increased prevalence, with 36·8 million (34·8–39·2) people living with HIV in 2017. Prevalence of HIV was highest in southern sub-Saharan Africa in 2017, and countries in the region had ART coverage ranging from 65·7% in Lesotho to 85·7% in eSwatini. Our forecasts showed that 54 countries will meet the UNAIDS target of 81% ART coverage by 2020 and 12 countries are on track to meet 90% ART coverage by 2030. Forecasted results estimate that few countries will meet the UNAIDS 2020 and 2030 mortality and incidence targets.
Interpretation
Despite progress in reducing HIV-related mortality over the past decade, slow decreases in incidence, combined with the current context of stagnated funding for related interventions, mean that many countries are not on track to reach the 2020 and 2030 global targets for reduction in incidence and mortality. With a growing population of people living with HIV, it will continue to be a major threat to public health for years to come. The pace of progress needs to be hastened by continuing to expand access to ART and increasing investments in proven HIV prevention initiatives that can be scaled up to have population-level impact
Mapping geographical inequalities in childhood diarrhoeal morbidity and mortality in low-income and middle-income countries, 2000–17 : analysis for the Global Burden of Disease Study 2017
Background
Across low-income and middle-income countries (LMICs), one in ten deaths in children younger than 5 years is attributable to diarrhoea. The substantial between-country variation in both diarrhoea incidence and mortality is attributable to interventions that protect children, prevent infection, and treat disease. Identifying subnational regions with the highest burden and mapping associated risk factors can aid in reducing preventable childhood diarrhoea.
Methods
We used Bayesian model-based geostatistics and a geolocated dataset comprising 15 072 746 children younger than 5 years from 466 surveys in 94 LMICs, in combination with findings of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, to estimate posterior distributions of diarrhoea prevalence, incidence, and mortality from 2000 to 2017. From these data, we estimated the burden of diarrhoea at varying subnational levels (termed units) by spatially aggregating draws, and we investigated the drivers of subnational patterns by creating aggregated risk factor estimates.
Findings
The greatest declines in diarrhoeal mortality were seen in south and southeast Asia and South America, where 54·0% (95% uncertainty interval [UI] 38·1–65·8), 17·4% (7·7–28·4), and 59·5% (34·2–86·9) of units, respectively, recorded decreases in deaths from diarrhoea greater than 10%. Although children in much of Africa remain at high risk of death due to diarrhoea, regions with the most deaths were outside Africa, with the highest mortality units located in Pakistan. Indonesia showed the greatest within-country geographical inequality; some regions had mortality rates nearly four times the average country rate. Reductions in mortality were correlated to improvements in water, sanitation, and hygiene (WASH) or reductions in child growth failure (CGF). Similarly, most high-risk areas had poor WASH, high CGF, or low oral rehydration therapy coverage.
Interpretation
By co-analysing geospatial trends in diarrhoeal burden and its key risk factors, we could assess candidate drivers of subnational death reduction. Further, by doing a counterfactual analysis of the remaining disease burden using key risk factors, we identified potential intervention strategies for vulnerable populations. In view of the demands for limited resources in LMICs, accurately quantifying the burden of diarrhoea and its drivers is important for precision public health
Global, regional, and national burden of stroke, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016
Summary
Background Stroke is a leading cause of mortality and disability worldwide and the economic costs of treatment and
post-stroke care are substantial. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a
systematic, comparable method of quantifying health loss by disease, age, sex, year, and location to provide information
to health systems and policy makers on more than 300 causes of disease and injury, including stroke. The results
presented here are the estimates of burden due to overall stroke and ischaemic and haemorrhagic stroke from
GBD 2016.
Methods We report estimates and corresponding uncertainty intervals (UIs), from 1990 to 2016, for incidence,
prevalence, deaths, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years
(DALYs). DALYs were generated by summing YLLs and YLDs. Cause-specific mortality was estimated using an
ensemble modelling process with vital registration and verbal autopsy data as inputs. Non-fatal estimates were
generated using Bayesian meta-regression incorporating data from registries, scientific literature, administrative
records, and surveys. The Socio-demographic Index (SDI), a summary indicator generated using educational
attainment, lagged distributed income, and total fertility rate, was used to group countries into quintiles.
Findings In 2016, there were 5·5 million (95% UI 5·3 to 5·7) deaths and 116·4 million (111·4 to 121·4) DALYs due to
stroke. The global age-standardised mortality rate decreased by 36·2% (–39·3 to –33·6) from 1990 to 2016, with
decreases in all SDI quintiles. Over the same period, the global age-standardised DALY rate declined by 34·2%
(–37·2 to –31·5), also with decreases in all SDI quintiles. There were 13·7 million (12·7 to 14·7) new stroke cases in
2016. Global age-standardised incidence declined by 8·1% (–10·7 to –5·5) from 1990 to 2016 and decreased in all SDI
quintiles except the middle SDI group. There were 80·1 million (74·1 to 86·3) prevalent cases of stroke globally in
2016; 41·1 million (38·0 to 44·3) in women and 39·0 million (36·1 to 42·1) in men.
Interpretation Although age-standardised mortality rates have decreased sharply from 1990 to 2016, the decrease in
age-standardised incidence has been less steep, indicating that the burden of stroke is likely to remain high. Planned
updates to future GBD iterations include generating separate estimates for subarachnoid haemorrhage and
intracerebral haemorrhage, generating estimates of transient ischaemic attack, and including atrial fibrillation as a
risk factor
The nest, eggs and chicks of the White-winged Flufftail Sarothrura ayresi
Volume: 124Start Page: 233End Page: 23
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Research data supporting ''Climatic change and extinction risk of two globally threatened Ethiopian endemic bird species''
Abstract: Climate change is having profound effects on the distributions of species globally. Trait-based assessments predict that specialist and range-restricted species are among those most likely to be at risk of extinction from such changes. Understanding individual species’ responses to climate change is therefore critical for informing conservation planning. We use an established Species Distribution Modelling (SDM) protocol to describe the curious range-restriction of the globally threatened White-tailed Swallow (Hirundo megaensis) to a small area in southern Ethiopia. We find that, across a range of modelling approaches, the distribution of this species is well described by two climatic variables, maximum temperature and dry season precipitation. These same two variables have been previously found to limit the distribution of the unrelated but closely sympatric Ethiopian Bush-crow (Zavattariornis stresemanni). We project the future climatic suitability for both species under a range of climate scenarios and modelling approaches. Both species are at severe risk of extinction within the next half century, as the climate in 68–84% (for the swallow) and 90–100% (for the bush-crow) of their current ranges is predicted to become unsuitable. Intensive conservation measures, such as assisted migration and captive-breeding, may be the only options available to safeguard these two species. Their projected disappearance in the wild offers an opportunity to test the reliability of SDMs for predicting the fate of wild species. Monitoring future changes in the distribution and abundance of the bush-crow is particularly tractable because its nests are conspicuous and visible over large distances.
Methods:
We collated all available geo-referenced records of White-tailed Swallows and their nests, and Ethiopian Bush-crows and their nests, collected by various observers between 2005 and 2011. Between 2012 and 2015, we conducted 266 walked 1-km transects at locations across, and outside, the Ethiopian Bush-crow's core range, additionally surveying for White-tailed Swallows on 255 of them. Bush-crows or their nests were recorded on 102 of these 1-km transects. White-tailed Swallows were recorded on 19 transects. Additionally, in 2014, swallow nest records were documented in the north-west of the species’ range as part of an intensive breeding study. We also collected GPS locations for all ad-hoc Ethiopian Bush-crow and White-tailed Swallow observations throughout this period. This yielded a total of 2,921 presence locations for the bush-crow, and 574 presence locations for the swallow.
We repeatedly drove the road network in and around the Bush-crow’s range between 2008 and 2014 with at least two experienced observers in the vehicle searching for nests. Bush-crow nests are large, robust and conspicuous structures, made from thick twigs, often projecting above the canopy of the bush or tree in which they are built, and can last for several years. They can be detected at distances of up to one kilometre from a moving vehicle and most stretches of road were driven several times by different observers. Hence, we assumed that stretches of roads with no records of birds or nests on any survey represented Bush-crow absences. We divided the driven road network into 1-km segments, and took the mid-point of each segment without a bird or nest record within one kilometre of the route as an absence point, thus all absence points had a precision of one kilometre. In addition to the absences from walked transects, this gave us a total of 1,905 absence locations for the bush-crow.
For the White-tailed Swallow, we took the mid-point of the 236 1-km transect legs on which swallows had not been recorded. Unlike for the bush-crow, we did not use the lack of observations from stretches of road transects as true absence points because, unlike the bush-crow and its highly visible nests, White-tailed Swallows are much more difficult to detect reliably from a moving vehicle.
To increase the range of environmental variables on which the models were built, we took a random sample of 4,764 pseudo-absences (for the swallow) and 3,095 pseudo-absences (for the bush-crow) from a region stretching from 1.86°–6.87°N and 33.17°–43.67°E. We restricted these points to be at least 10 km from any presence location for the species concerned. When combined with the known absence records for each species, this gave a total of 5,000 points treated as absences in the analysis.
For model validation purposes, the White-tailed Swallow’s range was divided radially into five geographic segments, and the Ethiopian Bush-crow's range was divided radially into eight geographic segments.
The data files are as follows:
"Bush-crow+nest_records_2005-2015" contains data on all verified records of the Ethiopian Bush-crow Zavattariornis stresemanni and its nests, collected by various observers between 2005 and 2015. Data comes from a mix of walked and driven transects across the species' range, and all ad-hoc records made during fieldwork.
"White-tailed_Swallow+nest_records_2005-2015" contains data on all verified records of the White-tailed Swallow Hirundo megaensis and its nests, collected by various observers between 2005 and 2015. Data comes from a mix of walked and driven transects across the species' range, and all ad-hoc records made during fieldwork.
"Bush-crow_true_absences" contains data on known locations within the range of the Ethiopian Bush-crow Zavattariornis stresemanni where the species does not occur. This includes the centre points of walked 1-km transects where no birds or nests were recorded, and the centre point of each 1-km stretch of regularly driven road on which no birds or nests were recorded within 1 km.
"White-tailed_Swallow_true_absences" contains data on known locations within the range of the White-tailed Swallow Hirundo megaensis where the species does not occur. These are derived from the centre points of walked 1-km transects where no birds or nests were recorded.
"Bush-crow_background_points" contains a set of randomly sampled locations drawn from within a tile stretching from 1.86°–6.87°N and 33.17°–43.67°E, but restricted to be at least 10 km away from the nearest record of an Ethiopian Bush-crow Zavattariornis stresemanni bird or nest.
"White-tailed_Swallow_background_points" contains a set of randomly sampled locations drawn from within a tile stretching from 1.86°–6.87°N and 33.17°–43.67°E, but restricted to be at least 10 km away from the nearest record of an White-tailed Swallow Hirundo megaensis bird or nest.
"Bush-crow_segments" contains a set of polygons covering a tile stretching from 1.86°–6.87°N and 33.17°–43.67°E which were used for dividing up the Bush-crow presence, absence and background data for model validation purposes.
"White-tailed_Swallow_segments" contains a set of polygons covering a tile stretching from 1.86°–6.87°N and 33.17°–43.67°E which were used for dividing up the swallow presence, absence and background data for model validation purposes.This work was supported by a PhD studentship grant to AJB from the Natural Environment Research Council (award 1210186), with additional funding from the Royal Society for the Protection of Birds, British Birdfair/RSPB Fund for Endangered Species, African Bird Club Expedition Awards, British Ornithologists’ Union Small Grants Scheme, Cambridge Philosophical Society, Department of Zoology Tim Whitmore Fund, Cambridge, Worts Travelling Scholars Fund, Cambridge, and Magdalene College, Cambridge
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Climatic change and extinction risk of two globally threatened Ethiopian endemic bird species
Funder: Royal Society for the Protection of BirdsFunder: British Birdfair/RSPB Fund for Endangered SpeciesFunder: African Bird Club; funder-id: http://dx.doi.org/10.13039/100014663Funder: British Ornithologists’ Union; funder-id: http://dx.doi.org/10.13039/100008023Funder: Cambridge Philosophical Society; funder-id: http://dx.doi.org/10.13039/100013858Funder: Tim Whitmore FundFunder: Worts Travelling Scholars FundFunder: Magdalene College, University of Cambridge; funder-id: http://dx.doi.org/10.13039/501100000653Climate change is having profound effects on the distributions of species globally. Trait-based assessments predict that specialist and range-restricted species are among those most likely to be at risk of extinction from such changes. Understanding individual species’ responses to climate change is therefore critical for informing conservation planning. We use an established Species Distribution Modelling (SDM) protocol to describe the curious range-restriction of the globally threatened White-tailed Swallow (Hirundo megaensis) to a small area in southern Ethiopia. We find that, across a range of modelling approaches, the distribution of this species is well described by two climatic variables, maximum temperature and dry season precipitation. These same two variables have been previously found to limit the distribution of the unrelated but closely sympatric Ethiopian Bush-crow (Zavattariornis stresemanni). We project the future climatic suitability for both species under a range of climate scenarios and modelling approaches. Both species are at severe risk of extinction within the next half century, as the climate in 68–84% (for the swallow) and 90–100% (for the bush-crow) of their current ranges is predicted to become unsuitable. Intensive conservation measures, such as assisted migration and captive-breeding, may be the only options available to safeguard these two species. Their projected disappearance in the wild offers an opportunity to test the reliability of SDMs for predicting the fate of wild species. Monitoring future changes in the distribution and abundance of the bush-crow is particularly tractable because its nests are conspicuous and visible over large distances