7 research outputs found
Habitat preferences of Phoebetria albatrosses in sympatry and allopatry
Aim: Competition is often proposed to drive niche segregation along multiple axes in speciose communities. Understanding spatial partitioning of foraging areas is particularly important in species that are constrained to a central place. We present a natural experiment examining variation in habitat preferences of congeneric Southern Ocean predators in sympatry and allopatry. Our aim was to ascertain consistency of habitat preferences within species, and to test whether preferences changed in the presence of the congener.
Location: Southern Hemisphere.
Taxon:
Multiple colonies of both species within the genus Phoebetria (sooty albatrosses).
Methods:
The two Phoebetria albatrosses breed on islands located from ~37â55°S â sooty albatrosses (P. fusca) in the north and light-mantled albatrosses (P. palpebrata) in the south â with sympatric overlap at locations ~46â49°S. We analysed GPS and PTT tracks from 87 individuals and multiple remotely sensed environmental variables using GAMs, to determine and compare the key factors influencing habitat preference for each species at each breeding colony.
Results
While foraging habitat preferences are consistent in light-mantled albatrosses, there is divergence of preferences in sooty albatrosses depending on whether they are in sympatry with their congener or in allopatry.
Main Conclusions
This study represents the most comprehensive work on this genus to date and highlights how habitat preferences and behavioural plasticity may influence species distributions under different competitive conditions
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Divergent foraging habitat preferences between summer-breeding and winter-breeding Procellaria petrels
Funder: British Antarctic Survey; Id: http://dx.doi.org/10.13039/501100007849Funder: Foreign and Commonwealth Office; Id: http://dx.doi.org/10.13039/501100000617Funder: Gates Cambridge Trust; Id: http://dx.doi.org/10.13039/501100005370Funder: Government of South Georgia and the South Sandwich IslandsFunder: South African National Antarctic ProgramForaging niche specialization is thought to occur when different members of speciose communities divide resources in either time or space. Here we compared habitat preferences of the congeneric Grey Petrel Procellaria cinerea and Whiteâchinned Petrel Procellaria aequinoctialis, tracked in the same calendar year using GPS loggers from Gough Island and Bird Island (South Georgia), respectively. We identified periods of active foraging and determined habitat characteristics using remoteâsensing data. Although these highly pelagic species could potentially overlap at sea across large areas, they showed markedly different foraging preferences during their incubation periods, which are temporally offset because Grey Petrels breed during the austral winter. Grey Petrels foraged mostly in pelagic coldâwater areas to the northâwest of South Georgia, whereas Whiteâchinned Petrels foraged almost exclusively in the warm, shallow waters of the Patagonian Shelf. Within each species, foraging habitat characteristics were highly consistent. Our results demonstrate the diversity of habitat preferences within genera, and provide further evidence that colonyâspecific information on habitat preference is crucial to identify important feeding areas for pelagic predators
Climate shaped how Neolithic farmers and European hunter-gatherers interacted after a major slowdown from 6,100 BCE to 4,500 BCE.
The Neolithic transition in Europe was driven by the rapid dispersal of Near Eastern farmers who, over a period of 3,500âyears, brought food production to the furthest corners of the continent. However, this wave of expansion was far from homogeneous, and climatic factors may have driven a marked slowdown observed at higher latitudes. Here, we test this hypothesis by assembling a large database of archaeological dates of first arrival of farming to quantify the expansion dynamics. We identify four axes of expansion and observe a slowdown along three axes when crossing the same climatic threshold. This threshold reflects the quality of the growing season, suggesting that Near Eastern crops might have struggled under more challenging climatic conditions. This same threshold also predicts the mixing of farmers and hunter-gatherers as estimated from ancient DNA, suggesting that unreliable yields in these regions might have favoured the contact between the two groups
Patterns of Opioid and Benzodiazepine Use in Opioid-NaĂŻve Patients with Newly Diagnosed Low Back and Lower Extremity Pain
BACKGROUND: The morbidity and mortality associated with opioid and benzodiazepine co-prescription is a pressing national concern. Little is known about patterns of opioid and benzodiazepine use in patients with acute low back pain or lower extremity pain
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Habitat preferences of <i>Phoebetria</i> albatrosses in sympatry and allopatry
Publication status: PublishedFunder: Natural Environment Research Council; doi: http://dx.doi.org/10.13039/501100000270Funder: Gates Cambridge Trust; doi: http://dx.doi.org/10.13039/501100005370Funder: Prince Albert II of Monaco Foundation; doi: http://dx.doi.org/10.13039/501100011592Funder: Institut Polaire Français Paul Emile Victor; doi: http://dx.doi.org/10.13039/501100004796AbstractAimCompetition is often proposed to drive niche segregation along multiple axes in speciose communities. Understanding spatial partitioning of foraging areas is particularly important in species that are constrained to a central place. We present a natural experiment examining variation in habitat preferences of congeneric Southern Ocean predators in sympatry and allopatry. Our aim was to ascertain consistency of habitat preferences within species, and to test whether preferences changed in the presence of the congener.LocationSouthern Hemisphere.TaxonMultiple colonies of both species within the genus Phoebetria (sooty albatrosses).MethodsThe two Phoebetria albatrosses breed on islands located from ~37â55°S â sooty albatrosses (P. fusca) in the north and lightâmantled albatrosses (P. palpebrata) in the south â with sympatric overlap at locations ~46â49°S. We analysed GPS and PTT tracks from 87 individuals and multiple remotely sensed environmental variables using GAMs, to determine and compare the key factors influencing habitat preference for each species at each breeding colony.ResultsWhile foraging habitat preferences are consistent in lightâmantled albatrosses, there is divergence of preferences in sooty albatrosses depending on whether they are in sympatry with their congener or in allopatry.Main ConclusionsThis study represents the most comprehensive work on this genus to date and highlights how habitat preferences and behavioural plasticity may influence species distributions under different competitive conditions.</jats:sec
Age and frailty are independently associated with increased COVID-19 mortality and increased care needs in survivors: results of an international multi-centre study
Introduction: Increased mortality has been demonstrated in older adults with coronavirus disease 2019 (COVID-19), but the effect of frailty has been unclear.
Methods: This multi-centre cohort study involved patients aged 18 years and older hospitalised with COVID-19, using routinely collected data. We used Cox regression analysis to assess the impact of age, frailty and delirium on the risk of inpatient mortality, adjusting for sex, illness severity, inflammation and co-morbidities. We used ordinal logistic regression analysis to assess the impact of age, Clinical Frailty Scale (CFS) and delirium on risk of increased care requirements on discharge, adjusting for the same variables.
Results: Data from 5,711 patients from 55 hospitals in 12 countries were included (median age 74, interquartile range [IQR] 54â83; 55.2% male). The risk of death increased independently with increasing age (>80 versus 18â49: hazard ratio [HR] 3.57, confidence interval [CI] 2.54â5.02), frailty (CFS 8 versus 1â3: HR 3.03, CI 2.29â4.00) inflammation, renal disease, cardiovascular disease and cancer, but not delirium. Age, frailty (CFS 7 versus 1â3: odds ratio 7.00, CI 5.27â9.32), delirium, dementia and mental health diagnoses were all associated with increased risk of higher care needs on discharge. The likelihood of adverse outcomes increased across all grades of CFS from 4 to 9.
Conclusion: Age and frailty are independently associated with adverse outcomes in COVID-19. Risk of increased care needs was also increased in survivors of COVID-19 with frailty or older age.</p