Multiple leading edge vortices of unexpected strength in freely flying hawkmoth

Composite image of a representative vector field, color coded by vorticity, showing the complex leading edge vortex above the wing on top of a photo of a Hummingbird hawkmoth (Macroglossum stellatarum).

The first study of the flow above the wings of a freely flying insect, showing the structure of the lift boosting leading edge vortex, is published today by the Animal Flight Lab in Scientific Reports. The leading edge vortex is generally seen as a stable vortex, attached to the top surface of the wing, but this new study finds it to have a complex structure. At the inner wing the vortex has a single core, but mid wing and outwards the vortex is highly variable with multiple simultaneous cores. The highly variable flow may affect the aerodynamic control of the moth. In addition to the high complexity, the circulation of the vortex on the outer part of the wing is higher than the circulation measured in the wake behind the animal. This implies that the vortex accounts for the entire lift production at the outer wing and is in fact stronger than is necessary to generate the required lift force, which suggests a high aerodynamic cost of flight in the moths. These new findings will serve as a baseline comparison for past and future studies of the aerodynamics of insect flight based on tethered animals and mechanical flappers.

/Christoffer Johansson Westheim

Joint forces to monitor animal movement through the aerosphere

Researchers from across Europe and a wide range of expertise – including ecology, biogeography, ornithology, entomology, meteorology, mathematics and engineering – now join forces in the field of aeroecology to foster continental-scale remote sensing of animal migration for the first time.

The research network is named ENRAM (“the European Network for the Radar surveillance of Animal Movement’) and currently involves scientists from 15 countries. Sweden and CAnMove are represented in the Management Committee by Professor Susanne Åkesson and Associate Professor Lars Pettersson with Drs Johan Bäckman and Markus Franzén as deputies. The collaboration will run for four years and is funded by COST (European Cooperation in Science and Technology), one of the longest-running European frameworks supporting cooperation among scientists and researchers across Europe.

The background to the project is that the aerial movement of billions of organisms through Europe each spring and autumn brings enormous benefits in terms of ecosystem services, but also poses great risks through air-traffic collisions, invasions of crop pests and spread of disease. Mass movements through the aerosphere are detected by weather radar measurements and have a severe impact on the accuracy of weather radar products. Therefore meteorologists and hydrologists need to be able to recognise and filter these biological echoes. At the same time, weather radar data have the potential of providing detailed information on the intensity, timing, altitude and spatial scale of mass movements of a broad range of taxa that move through the aerosphere.

The ideal platform to carry out standardized continent-wide monitoring of aerial movements is the existing Europe-wide network of weather radars, which in principal is already sensing these biological targets. The principal goal of the ENRAM network is to establish international and interdisciplinary collaboration needed to achieve coordinated monitoring of animal movements through the aerosphere over the European continent.

//Lars Pettersson

News from NanoLab

Yesterday the new method paper by Ekvall et al. covering the nano-labelling and tracking of small aquatic organisms is published online in PLOS ONE. The paper is entitled “Three-dimensional tracking of small aquatic organisms using fluorescent nanoparticles” and covers the labelling using poly-L-lysine coated nanoparticles (quantum dots) as well as the video- and tracking system.  In the paper we combine biology, chemistry and physics and, by doing this, present a method that allows three-dimensional (3D) tracking of individual mm-sized aquatic organisms. The method is based on in-vivo labelling of the organisms with fluorescent nanoparticles, so-called quantum dots, and tracking of the organisms in 3D via the quantum-dot fluorescence using a synchronized multiple camera system. It allows for the efficient and simultaneous study of the behaviour of one as well as multiple individuals in large volumes of observation, thus enabling the study of behavioural interactions at the community scale. The method is non-perturbing – we demonstrate that the labelling is not affecting the behavioural response of the organisms – and is applicable over a wide range of taxa, including cladocerans as well as insects, suggesting that our methodological concept opens up for new research fields on individual behaviour of small animals. Hence, this offers opportunities to focus on important biological, ecological and behavioural questions never before possible to address. For the full version of the exciting paper - visit this link:

If you have not yet seen the NanoLAB descriptive YouTube video I recommend you to visit this link and have a look at how the labelling and system works!

/The NanoLab Team – Mikael, Giuseppe, Johan B and Lars-Anders

Ecology of Animal Migration course 2013

 On Friday 35 students studying in 13 different countries (and more nationalities!) completed the two-week CAnMove organised 'Ecology of Animal Migration Course'.
The course began with students giving short presentations of their own work. It was fantastic to see the diversity of topics covered, and the great enthusiasm for studies of animal migration!
Students then attended lectures and classes on many different topics including genetics of migration, conservation, locomotion, and many more. We were very happy to welcome back to Lund guest lecturers; Jason Chapman,  Colin Pennycuick, John McNamara, Thord Fransson, Raymond Klaassen, Miriam Liedvogel, Tim Guilford, Theunis Piersma, and Brendan Godley. Plus three new faces, Navinder Singh, Wolfgang Goymann, and Sonia Altizer, with Sonia making the first 'virtual' appearance, giving her lecture very effectively by video link.

It wasn't all in the lecture theatre though, with students enjoying excursions to Falsterbo bird observatory, and the University field station at Stensoffa. Plus Colin Pennycuick gave his very popular flight lab.
Thursday saw the course dinner, where we enjoyed a buffet at Finn Inn, followed by most of us walking down to 'Café Ariman', adopted as the course bar!
Thanks to the course organisers and others assisting with the course (including coffee making!); Rachel Muheim, Anders Hedenström, Christina Rengefors, Nataliia Kulatska, Helena Osvath, Cecilia Nilsson, Kozue Shiomi, Yannis Vardanis, Mihaela Ilieva, and Marco Klein Heerenbrink.

//Tom Evans

VR grants

Today the Swedish Research Council announces the grants from 2013:s call. Congratulations to Staffan Bensch, Dennis Hasselqvist, Per Henningsson, Christoffer Johansson, Jan-Åke Nilsson and Susanne Åkesson who all got new funding! To VRs web site.