Optimization of dynamic soaring in a flap-gliding seabird affects its large-scale distribution at sea

Dynamic soaring harvests energy from a spatiotemporal wind gradient, allowing albatrosses to glide over vast distances. However, its use is challenging to demonstrate empirically and has yet to be confirmed in other seabirds. Here, we investigate how flap-gliding Manx shearwaters optimize their flight for dynamic soaring. We do so by deriving a new metric, the horizontal wind effectiveness, that quantifies how effectively flight harvests energy from a shear layer. We evaluate this metric empirically for fine-scale trajectories reconstructed from bird-borne video data using a simplified flight dynamics model. We find that the birds’ undulations are phased with their horizontal turning to optimize energy harvesting. We also assess the opportunity for energy harvesting in long-range, GPS-logged foraging trajectories and find that Manx shearwaters optimize their flight to increase the opportunity for dynamic soaring during favorable wind conditions. Our results show how small-scale dynamic soaring affects large-scale Manx shearwater distribution at sea.publishedVersio

Optimization of dynamic soaring in a flap-gliding seabird affects its large-scale distribution at sea

Funding: This work was supported by the University of Oxford Christopher Welch Scholarship (to J.A.K.); ASAB Undergraduate Project Scholarship (to J.A.K.); UKRI BBSRC scholarship grant number BB/M011224/1 (to J.W. and N.G.); The Queen’s College, University of Oxford (to A.L.F.); Junior Research Fellowship at St. John’s College, University of Oxford (to O.P.); Merton College, University of Oxford (to T.G.); Mary Griffiths Award (to T.G.); BBSRC David Phillips Fellowship grant numbers BB/G023913/1 and BB/ G023913/2 (to C.R.); and Jesus College, University of Oxford (to G.K.T.). This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 682501) (to G.K.T.)Dynamic soaring harvests energy from a spatiotemporal wind gradient, allowing albatrosses to glide over vast distances. However, its use is challenging to demonstrate empirically and has yet to be confirmed in other seabirds. Here, we investigate how flap-gliding Manx shearwaters optimize their flight for dynamic soaring. We do so by deriving a new metric, the horizontal wind effectiveness, that quantifies how effectively flight harvests energy from a shear layer. We evaluate this metric empirically for fine-scale trajectories reconstructed from bird-borne video data using a simplified flight dynamics model. We find that the birds' undulations are phased with their horizontal turning to optimize energy harvesting. We also assess the opportunity for energy harvesting in long-range, GPS-logged foraging trajectories and find that Manx shearwaters optimize their flight to increase the opportunity for dynamic soaring during favorable wind conditions. Our results show how small-scale dynamic soaring affects large-scale Manx shearwater distribution at sea.Publisher PDFPeer reviewe

Behavioural adaptations to breeding in a long-lived pelagic seabird

The traits of organisms evolve by natural selection to maximise fitness; however, we do not observe Darwinian Demons. This is because all organisms face various types of constraint, which ultimately limit fitness. Reproduction is inextricably linked with fitness, and constraints on reproduction have extensive implications for evolution and adaptation. Two broad types of constraints on breeding are treated here. Firstly, breeding may be constrained by life-history trade-offs, perhaps most fundamentally in that current reproductive effort is constrained by its costs to future reproduction. Secondly, breeding may be constrained by the physical and ecological conditions and finite resources that are accessible from the breeding site, to which organisms may be tied to varying extents. The life-history and behaviour of animals are profoundly affected by these constraints, and they are especially influential in long-lived species. This thesis examines behavioural adaptations to each of these types of constraint in a long-lived pelagic seabird: the Manx Shearwater, Puffinus puffinus. Firstly, I investigate how patterns of behaviour vary between sexes and populations in preparation for breeding and how this variation is related to the ecological and physiological constraints faced by the groups during breeding. Secondly, I test the responsiveness of parents to changes in offspring hunger during food provisioning and discuss the influence of constraint by costs to future reproduction. I tackle these questions using well-established biologging methods to remotely monitor behaviour in a natural and experimental setting.</p

Behavioural adaptations to breeding in a long-lived pelagic seabird

The traits of organisms evolve by natural selection to maximise fitness; however, we do not observe Darwinian Demons. This is because all organisms face various types of constraint, which ultimately limit fitness. Reproduction is inextricably linked with fitness, and constraints on reproduction have extensive implications for evolution and adaptation. Two broad types of constraints on breeding are treated here. Firstly, breeding may be constrained by life-history trade-offs, perhaps most fundamentally in that current reproductive effort is constrained by its costs to future reproduction. Secondly, breeding may be constrained by the physical and ecological conditions and finite resources that are accessible from the breeding site, to which organisms may be tied to varying extents. The life-history and behaviour of animals are profoundly affected by these constraints, and they are especially influential in long-lived species. This thesis examines behavioural adaptations to each of these types of constraint in a long-lived pelagic seabird: the Manx Shearwater, Puffinus puffinus. Firstly, I investigate how patterns of behaviour vary between sexes and populations in preparation for breeding and how this variation is related to the ecological and physiological constraints faced by the groups during breeding. Secondly, I test the responsiveness of parents to changes in offspring hunger during food provisioning and discuss the influence of constraint by costs to future reproduction. I tackle these questions using well-established biologging methods to remotely monitor behaviour in a natural and experimental setting.</p

Supplementary Data accompanying: "Optimization of dynamic soaring in a flap-gliding seabird impacts its large-scale distribution at sea"

This archive contains the data associated with the paper “Optimization of dynamic soaring in a flap-gliding seabird impacts its large-scale distribution at sea”. It contains: (i) a zipped folder (OnboardVideos.zip) containing the raw video data of n=9 flight trajectories flown by 6 individual Manx Shearwaters on 6 different days; (ii) the horizon end point coordinates output by the semi-automatic horizon detection algorithm, and the parameters needed to process these coordinates (dataAndProcessingParameters.mat) to generate the data set on which the analyses presented in the Results section can be conducted in Matlab; (iii) the processed video data needed to conduct the analyses presented in the Results section (processedVideoData.csv); and (iv) the processed GPS and wind data from n=349 two-leg trajectories, and n=38 one-leg trajectories, needed to conduct the analyses presented in the Results section (trackSummaries2016To2019.csv); (v) a zipped folder (GPSTracks.zip) containing the corresponding GPS tracks and associated wind data as individual CSV files; (vi) a README file giving further details on content