Rethinking classic starling displacement experiments : evidence for innate or for learned migratory directions?

Funding for the present work came from the Spinoza Premium 2014 awarded to TP by the Netherlands Organization for Scientific Research (NWO), with supplementary funding from an anonymous donor, the Gieskes-Strijbis Fonds and the Ubbo Emmius Fonds of the University of Groningen. TO was supported by Rubicon a grant from NWO (ref. 019.172EN.011)In an attempt to encourage the discourse on sources of individual variation in seasonal migration patterns and the microevolution of bird migration, we here critically examine the published interpretations of a now classic displacement study with starlings Sturnus vulgaris. Based on the ring recoveries after experimental displacement towards the south and southeast of Dutch capture sites of over 18 000 hatch‐year and older starlings, in a series of analyses published in Ardea from 1958 to 1983, A. C. Perdeck established that displaced starlings showed appropriately changed orientations only when they were experienced. During both southward and northward migration, released adults navigated to an apparently previously learned goal (i.e. the wintering or the breeding area) by showing appropriately changed orientations. Juveniles showed appropriate directions when returning to the breeding grounds. In contrast, during their first southward migration displaced juveniles carried on in the direction (and possibly the distance) expected for their release at the Dutch capture site. From the mid‐1970s this work has become cited as evidence for starlings demonstrating ‘innate’ migratory directions. If the definition of innateness is ‘not learned by the individual itself’, then there is a range of non‐innate influences on development that are not ruled out by Perdeck's experimental outcomes. For example, young starlings might have carried on in the direction that they learned to migrate before being caught, e.g. by observing the migratory directions of experienced conspecifics. We argue that, despite over 60 citations to Perdeck as demonstrating innate migratory directions, the jury is out.Publisher PDFPeer reviewe

Über die Erforschung der einheimischen Säugetier-Fauna

Von H. Freiherr Geyr von Schweppenbur

Ins Land der Tuareg

Volume: 65Start Page: 241End Page: 31

Zur Ornis von Ost- und Westpreufsen

Volume: 61Start Page: 143End Page: 16

Computation of Helicopter Fuselage Aerodynamics Using Navier-Stokes CFD Methods

This paper describes the research activities conducted by the European Research consortium HELIFUSE during the first of this Brite-EuRaM project. The work consisted of Navier-Stokes computations on pre-selected test cases taken out of an extensive wind tunnel test programme at the ONERA F1 wind tunnel. The calculations were performed by three national research institutes (CIRA, DLR, ONERA), three helicopter manufacturers (Agusta, Eurocopter, GKN-Westland), one software company (Simulog) and two universities (DTU, IAG). The aim of the work was to simulate the complex flowfield around the fuselage of the wind tunnel tests. Blind test calculations and wind tunnel data were in very good agreement for the surface pressure distribution, but showed some discrepancies in the drag prediction accuracy. In order to understand the reasons for this scatter, two additional computational tests were performed: 1.) computation of a fuselage test case with one Navier-Stokes code on all the different structured grids; 2.) computations by all the structured Navier-Stokes codes on one common grid. These results have reduced the large scatter in the drag data from CFD analysis, although some discrepancies still exists