Knowledge for a sustainable world

BSc (Special), ARCS, PhD, FRES, C.Biol.

Dr Don Reynolds is an ecological entomologist specializing in insect migration and movement. He has particular experience (over 46 years) in the use of radar and aerial sampling techniques to study the migration of insect pests and beneficials in both developing countries and in the UK.  Don Reynolds has worked at the Natural Resources Institute throughout his career.  From 1973 to 1996, he worked with Prof. Joe Riley and Alan Smith, carrying out studies which significantly advanced our understanding of the migration of economically-important agricultural pests in Africa and Asia.  The pest species included:  Sahelian grasshoppers in West Africa, African armyworm in East Africa, Old World bollworm in India; and brown planthopper in the Philippines and China. The various projects involved collaborations with, among others, the UNDP, Kenya Agriculture Research Organisation (KARI), the Desert Locust Control Organisation for Eastern Africa (DLCOEA),  International Rice Research Institute (IRRI), International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), and Nanjing Agricultural University in China.

Since 1996, Dr Reynolds’ work has had a more UK and European focus. The main collaboration has been with Dr Jason Chapman (formerly at Rothamsted Research, now at the University of Exeter) on the long-term (10-year) automatic monitoring of high-altitude insect migration over the UK by means of a special-purpose vertical-looking radar (VLR) system and by aerial netting.  These studies have elucidated the migration strategies of pests such as the diamondback and silver-Y moths, and natural enemies such as green lacewings, hoverflies, and carabid beetles.  Don Reynolds has participated in some ground-breaking research on the orientation mechanisms that high-flying migrant insects use to maintain their seasonal migration directions, and on the benefits underlying the seasonal migrations to the UK.

Don Reynolds' other main research topic has been the use of harmonic scanning radar technology for research into bee and lepidoperan low-altitude navigation mechanisms and foraging strategies. 

Don Reynolds also has an interest in other aspects of aeroecology (e.g. remote sensing of birds and bats), and he was UK representative in the European Network for the Radar surveillance of Animal Movement (ENRAM) – a research network whose activities were funded by the EU COST Programme.

Since 1996 Dr Reynolds has participated in collaborations with, among others, University of Illinois, Free University of Berlin, the University of Oldenburg (Germany), Institute of Animal Health (Pirbright), the Met Office and, latterly, the Departments of Biology or Zoology at the Universities of Lund (Sweden), York, Oxford, and Exeter.  Recent new collaborations have been with the University of Oklahoma, the University of Notre Dame (Indiana) and with the Laboratory of Malaria and Vector Research at the U.S. National Institute of Allergy and Infectious Diseases.

Don Reynolds has about 97 refereed journal papers (including ones in Nature, Science, PNAS and Current Biology), as well other book chapters and articles totalling about 118 scientific publications on insect movement.  He has co-authored the definitive monograph on the discipline of ‘Radar Entomology’ (Drake, V.A. & Reynolds, D.R. (2012) Radar Entomology: Observing Insect Flight and Migration).

Many insect species engage in long-range migrations, and the movements of vast numbers of individuals has implications for pest management, conservation, and environmental change. However, most of these migrations take place high in air, and often at night, and so observation and data collection are intrinsically problematic.  This apparently intractable problem can be addressed by a combination of remote-sensing systems, particularly entomological radar, and aerial sampling, and Dr Reynolds has been fortunate enough to devote virtually the much of his scientific career to this area of research.  As with any new sensing system, the application of radar to insect migration and movement revealed a series of hitherto-unseen (and rather marvellous phenomena), leading to numerous behavioural, ecological or biometeorological insights, and improvements in our understanding of the migration ecology of a range of agricultural pests.  More recent academic studies of the silver-Y moth  and hoverflies in the UK, using vertical-looking radar, have revealed surprisingly sophisticated flight behaviours in these migrants;  the findings have led to fundamental changes in our understanding of insect migration.

Dr Reynolds has also participated in research using scanning harmonic radar, which allows tagged insects to be tracked over distances of several hundred metres. This technology was originally developed by the Natural Resources Institute, and its use has led to significant advances in bee neuroethology (the interface between behaviour under natural conditions and neurological mechanisms), the ecology of pollinators,  odour-mediated anemotactic  flights in moths, and optimal searching strategies.

Among other remote sensing methods, Dr Reynolds has recently collaborated use of a collocated Ka-band ‘cloud’ radar and Doppler Lidar in Oklahoma make detailed studies of the vertical motion of small insects (relative to the vertical motion of the air in which they are flying) in the convective and nocturnal boundary layers.

Quantifying long-range migration in Lepidoptera: integrating population dynamics and flight behaviour.

BBSRC research grant BB/D01932X/1 awarded to Rothamsted Research (Ian Woiwod and Jason Chapman). Project period: 2006–2009.

Don Reynolds was associated with this project which used the two Rothamsted vertical-looking radars to characterise the migration of selected long-range migrant Lepidoptera (particularly Autographa gamma – the silver-Y moth). Lepidoptera like A. gamma have evolved continental-scale migrations to northern temperate latitudes in order to exploit temporary breeding habitats in which they are unable to over-winter. Given that such movements will become more frequent under climate warming, it was desirable to obtain a better understanding of the mechanisms that underpin these migrations, as this is certain to be needed for integrated pest management strategies in the future. Very little was known about how the species influenced their displacement directions by means of their flight timing and their flight altitude and orientation.

A complex suit of behaviours influencing flight trajectories of A. gamma were discovered, including: (a) selection of seasonally-favourable tailwinds; (b) migratory flight at the altitudes of the fastest winds; (c) adoption of flight headings that partially counteracted crosswind drift; and (d) the seasonal reversal of preferred directions between spring and autumn. Monitoring the migration flux of moths into the UK in spring in comparison with the outgoing migration flux in autumn revealed that summer breeding produced a fourfold increase in abundance. This demonstrated unequivocally the reproductive benefits of this type of migration system.

European Network for the Radar surveillance of Animal Movement (ENRAM), COST (European Cooperation in Science and Technology), ESSEM COST Action ES1305

This newly-starting (October 2013) Europe-wide programme will "foster an essential international and multi-disciplinary approach by establishing a European network of radar biologists, meteorologists and engineers, which will coordinate existing monitoring efforts and prediction of animal movement patterns, extend these to a continental scale, and improve weather radar products for meteorological applications."

The rationale is that the migration of birds, bats and insects is of scientific and practical importance, and wide public appeal. The aerial movement of billions of organisms through Europe 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. In our changing world it is vitally important that the timing, intensity and spatial distribution of these movements are monitored and the factors that drive these patterns understood.

  • Gao, B., Wotton, K.R., Hawkes, W.L.S., Menz, M.H.M., Reynolds, D.R., Zhai, B.-P., Hu, G. & Chapman, J.W. (2020) Adaptive strategies of high-flying migratory hoverflies in response to wind currents. Proceedings of the Royal Society B: Biological Sciences, 287, 20200406, http://dx.doi.org/10.1098/rspb.2020.0406

  • Wainwright, C.E., Reynolds, D.R. & Reynolds, A.M. (2020) Linking small-scale flight manoeuvers and density profiles to the vertical movement of insects in the nocturnal stable boundary layer. Scientific Reports, 10, article 1019, 11pp.

  • Menz M.H.M., Reynolds, D.R., Gao, B., Hu, G., Chapman J.W., Wotton, K.R. (2019) Mechanisms and consequences of partial migration in insects. Frontiers in Ecology and Evolution, 7, article 403, 9 pp.

  • Huestis, D.L., Dao, A., Diallo, M., Sanogo, Z.L., Samake, D., Yaro, A.S., Ousman, Y., Linton, Y.-M., Krishna, A., Veru, L., Krajacich, B.J., Faiman, R., Florio, J., Chapman, J.W., Reynolds, D.R., Weetman, D., Mitchell, R., Donnelly, M.J., Talamas, E., Chamorro, L., Strobach, E. & Lehmann, T. (2019) Windborne long-distance migration of malaria mosquitoes in the Sahel. Nature, 574, 404–408. https://doi.org/10.1038/s41586-019-1622-4

  • Wotton, K.R., Gao, B., Menz, M.H.M., Morris, R.K.A., Ball, S.G., Lim, K.S., Reynolds, D.R., Hu, G. & Chapman, J.W. (2019) Mass seasonal migrations of hoverflies provide extensive pollination and crop protection services. Current Biology, 29(13), 2167–2173. https://doi.org/10.1016/j.cub.2019.05.036

  • Jones, C.M., Parry, H., Tay, W.T., Reynolds, D.R. & Chapman, J.W. (2019) Movement ecology of pest Helicoverpa: implications for ongoing spread. Annual Review of Entomology, 64, 277-295. https://doi.org/10.1146/annurev-ento-011118-111959

  • Hüppop, O., Ciach, M., Diehl, R., Reynolds, D.R., Stepanian, P.M. & Menz, M.H.M. (2019) Perspectives and challenges for the use of radar in biological conservation. Ecography, 42 (5), 912-930. https://doi.org/10.1111/ecog.04063 

  • Bauer, S., Shamoun‐Baranes, J., Nilsson, C., Farnsworth, A., Kelly, J., Reynolds, D.R., Dokter, A.M., Krauel, J., Petterson, L.B., Horton, K.G. & Chapman, J.W. (2019) The grand challenges of migration ecology that radar aeroecology can help answer. Ecography, 42(5), 861-875. https://doi.org/10.1111/ecog.04083

  • Mirkovic, D., Stepanian, P.M., Wainwright, C.E., Reynolds, D.R. & Menz, M.H.M. (2019) Characterizing animal anatomy and internal composition for electromagnetic modelling in radar entomology. Remote Sensing in Ecology and Conservation, 5(2), 169-179.  https://doi.org/10.1002/rse2.94

  • Hu, G., Lu, M.-H., Reynolds, D.R., Wang, H.-K., Chen, X., Liu, W.-C., Zhu, F., Wu, X.-W., Xia, F., Xie, M.-C., Cheng, X.-N., Lim, K.-S., Zhai, B.-P. & Chapman, J.W. (2018) Long-term seasonal forecasting of a major migrant insect pest: the brown planthopper in the Lower Yangtze River Valley. Journal of Pest Science, 92, 417-428. https://doi.org/10.1007/s10340-018-1022-9

  • Reynolds, D.R. & Chapman, J.W. (2018) Long-range migration and orientation behaviour. Insect Behavior: From Mechanisms to Ecological and Evolutionary Consequences (ed. by A. Córdoba-Aguilar, D. González-Tokman & I. González-Santoyo), pp. 98-115. Oxford University Press, Oxford, UK. ISBN: 9780198797500 https://doi.org/10.1093/oso/9780198797500.003.0007 

  • Reynolds, D.R., Chapman, J.W. & Drake, V.A. (2017) Riders on the wind: the aeroecology of insect migrants. Aeroecology (ed. by P.B. Chilson, W.F. Frick, J.F. Kelly & F. Liechti), pp. 145-177. Springer International Publishing AG, Cham, Switzerland.   ISBN: 978-3-319-68574-8.  https://doi.org/10.1007/978-3-319-68576-2_7 

  • Reynolds, D.R., Chapman, J.W. & Stewart, A.J.A. (2017) Windborne migration of Auchenorrhyncha (Hemiptera) over Britain. European Journal of Entomology, 114, 554-564. https://doi.org/10.14411/eje.2017.070

  • Wainwright, C.E., Stepanian, P.M., Reynolds, D.R. & Reynolds, A.M. (2017) The movement of small insects in the convective boundary layer: linking patterns to processes. Scientific Reports, 7, article 5438. https://doi.org/10.1038/s***************-0  

  • Bauer, S., Chapman, J.W., Reynolds, D.R., Alves, J.A., Dokter, A.M., Menz, M.M.H., Sapir, N., Ciach, M., Pettersson, L.B., Kelly, J.F., Lejijnse, H. & Shamoun-Baranes, J. (2017) From agricultural benefits to aviation safety: Realizing the potential of continent-wide radar networks. BioScience, 67 (10), 912-918.  https://doi.org/10.1093/biosci/bix074

  • Drake, V.A., Chapman, J.W., Lim, K.S., Reynolds, D.R., Riley, J.R. & Smith, A.D. (2017) Ventral-aspect radar cross sections and polarization patterns of insects at X band and their relation to size and form. International Journal of Remote Sensing, 38 (18), 5022-5044. https://doi.org/10.1080/01431161.2017.1320453

  • Hu, G., Lim, K.S., Horvitz, N., Clark, S.J., Reynolds, D.R., Sapir, N. & Chapman, J.W. (2016) Mass seasonal bioflows of high-flying insect migrants. Science, 354 (6319) 1584-1587. https://doi.org/10.1126/science.aah4379 

  • Reynolds, A.M., Reynolds, D.R., Sane, S.P., Hu, G. & Chapman, J.W. (2016) Orientation in high-flying migrant insects in relation to flows: mechanisms and strategies. Philosophical Transactions of the Royal Society B, 371, 20150392. https://doi.org/10.1098/rstb.2015.0392 

  • Hu, G., Lim, K.S., Reynolds, D.R., Reynolds A.M. & Chapman, J.W. (2016) Wind-related orientation patterns in diurnal, crepuscular and nocturnal high-altitude insect migrants. Frontiers in Behavioral Neuroscience, 10, article 32 (8 pp). https://doi.org/10.3389/fnbeh.2016.00032

  • Chapman, J.W., Nilsson, C., Lim, K.S., Bäckman, J., Reynolds, D.R. & Alerstam, T. (2016) Adaptive strategies in nocturnally migrating insects and songbirds:  contrasting responses to wind. Journal of Animal Ecology, 85, 115-124. https://doi.org/10.1111/1365-2656.12420

  • Chapman, J.W., Nilsson, C., Lim, K.S., Bäckman, J., Reynolds, D.R., Alerstam, T. & Reynolds, A.M.  (2015) Detection of flow direction in high-flying insect and songbird migrants. Current Biology, 25 (17), R733–R752. https://doi.org/10.1016/j.cub.2015.07.074

  • Reynolds, A.M., Jones, H.B.C., Hill, J.K., Pearson, A.J., Wilson, K., Wolf, S., Lim, K.S., Reynolds, D.R. & Chapman, J.W. (2015) Evidence for a pervasive ‘idling-mode’ activity template in flying and pedestrian insects. Royal Society Open Science, 2, 150085. https://doi.org/10.1098/rsos.150085 

  • Chapman, J.W., Reynolds, D.R. & Wilson, K. (2015) Long-range seasonal migration in insects: mechanisms, evolutionary drivers and ecological consequences. Ecology Letters, 18, 287-302. https://doi.org/10.1111/ele.12407

  • Reynolds, D.R., Reynolds, A.M. & Chapman, J.W. (2014) Non-volant modes of migration in terrestrial arthropods. Animal Migration, 2, 8-28. https://doi.org/10.2478/ami-2014-0002

  • Stefanescu, C., Páramo, F., Åkesson, S., Alarcón, M., Ávila, A., Brereton, T., Carnicer, J., Cassar, L.F., Fox, R., Heliölä, J., Hill, J.K., Hirneisen, N., Kjellén, N., Kühn, E., Kuussaari, M., Leskinen, M., Liechti, F., Musche, M., Regan, E.C., Reynolds, D.R., Roy, D.B., Ryrholm, N., Schmaljohann, H., Settele, J., Thomas, C.D., van Swaay, C. & Chapman, J.W. (2013) Multi-generational long-distance migration of insects: studying the painted lady butterfly in the Western Palaearctic. Ecography, 36, 474-486.  https://doi.org/10.1111/j.1600-0587.2012.07738.x

  • Drake, V.A. & Reynolds, D.R. (2012) Radar entomology: observing insect flight and migration. CABI, Wallingford, UK, 496 pp. ISBN: 9781845935566

  • Chapman, J.W., Bell, J.R., Burgin, L.E., Reynolds, D.R., Pettersson, L.B., Hill, J.K., Bonsall, M.B. & Thomas, J.A. (2012) Seasonal migration to high latitudes results in major reproductive benefits in an insect. Proceedings of the National Academy of Sciences, USA, 109 (37), 14924-14929. https://doi.org/10.1073/pnas.1207255109

  • Chapman, J.W., Klaassen, R.H.G., Drake, V.A., Fossette, S., Hays, G.C., Metcalfe, J.D., Reynolds, A.M., Reynolds, D.R. and Alerstam, T. (2011) Animal orientation strategies for movement in flows. Current Biology, 21, R861-R870. https://doi.org/10.1016/j.cub.2011.08.014

  • Alerstam, T., Chapman, J.W., Bäckman, J., Smith, A.D., Karlsson, H., Nilsson, C., Reynolds, D.R., Klaassen, R.H.G. & Hill, J.K. (2011) Convergent patterns of long-distance nocturnal migration in noctuid moths and passerine birds. Proceedings of the Royal Society B: Biological Sciences, 278, 3074–3080. https://doi.org/10.1098/rspb.2011.0058

  • Chapman, J.W, Drake, V.A. & Reynolds, D.R. (2011) Recent insights from radar studies of insect flight. Annual Review of Entomology, 56, 337-356. https://doi.org/10.1146/annurev-ento-120709-144820

  • Chapman, J.W., Nesbit, R.L., Burgin, L.E., Reynolds, D.R., Smith, A.D., Middleton, D. R. & Hill, J.K. (2010) Flight orientation behaviors promote optimal migration trajectories in high-flying insects. Science, 327, 682-685. https://doi.org/10.1126/science.1182990

  • Reynolds, A.M., Reynolds, D.R., Smith, A.D. & Chapman, J.W. (2010) A single wind-mediated mechanism explains high-altitude ‘non-goal oriented’ headings and layering of nocturnally migrating insects.  Proceedings of the Royal Society B: Biological Sciences, 277, 765-772. https://doi.org/10.1098/rspb.2009.1221

  • Niitepõld, K., Smith, A.D., Osborne, J.L., Reynolds, D.R., Carreck, N.L., Martin, A.P., Marden, J.H., Ovaskainen, O. & Hanski, I. (2009) Flight metabolic rate and Pgi genotype influence butterfly dispersal rate in the field. Ecology, 90 (8), 2223–2232. https://doi.org/10.1890/08-1498.1

  • Reynolds, A.M., Sword, G.A., Simpson, S. J. & Reynolds, D.R. (2009) Predator percolation, insect outbreaks and phase polyphenism. Current Biology, 19, 20-24. https://doi.org/10.1016/j.cub.2008.10.070

  • Reynolds, A.M. & Reynolds, D.R. (2009) Aphid aerial density profiles are consistent with turbulent advection amplifying flight behaviours: abandoning the epithet ‘passive’. Proceedings of the Royal Society B, 276, 137-143. https://doi.org/10.1098/rspb.2008.0880

  • Reynolds, A.M., Reynolds, D.R. & Riley, J.R. (2009) Does a ‘turbophoretic’ effect account for layer concentrations of insects migrating in the stable night-time atmosphere? Journal of the Royal Society - Interface, 6, 87-95. https://doi.org/10.1098/rsif.2008.0173

  • Ovaskainen, O., Smith, A.D., Osborne, J.L., Reynolds, D.R., Carreck, N.L., Martin, A.P., Niitepõld, K. & Hanski, I. (2008) Tracking butterfly movements with harmonic radar reveals an effect of population age on movement frequency. Proceedings of National Academy of Sciences, USA, 105 (49), 19090-19095. https://doi.org/10.1073/pnas.0802066105

  • Chapman, J.W., Reynolds, D.R., Hill, J.K, Sivell, D., Smith, A.D. & Woiwod, I.P. (2008) A seasonal switch in compass orientation in a high-flying migrant moth. Current Biology, 18, R908–R909. https://doi.org/10.1016/j.cub.2008.08.014

  • Chapman, J.W., Reynolds, D.R., Mouritsen, H., Hill, J.K, Riley, J.R., Sivell, D., Smith, A.D. & Woiwod, I.P. (2008) Wind selection and drift compensation optimize migratory pathways in a high-flying moth. Current Biology, 18, 514–518. https://doi.org/10.1016/j.cub.2008.02.080

  • Reynolds, A.M., Smith, A.D., Menzel, R, Greggers, U., Reynolds, D.R. & Riley, J.R. (2007) Displaced honey bees perform optimal scale-free search flights. Ecology 88, 1955–1961. https://doi.org/10.1890/06-1916.1

  • Riley, J.R., Greggers, U., Smith, A.D., Reynolds, D.R. & Menzel, R. (2005) The flight paths of honeybees recruited by the waggle dance. Nature, 435, 205-207.  https://doi.org/10.1038/nature03526

  • Riley, J.R., Greggers, U., Smith, A.D., Stach, S., Reynolds, D.R., Stollhoff, N., Brandt, R., Schaupp, F. & Menzel, R. (2003) The automatic pilot of honeybees. Proceedings of the Royal Society of London, B, 270, 2421-2424. https://doi.org/10.1098/rspb.2003.2542

  • Capaldi, E.A., Smith, A.D., Osborne, J.L., Fahrbach, S.E., Farris, S.M., Reynolds, D.R., Edwards, A.S., Martin, A., Robinson, G.E., Poppy, G.M. & Riley, J.R. (2000). Ontogeny of orientation flight in the honeybee revealed by harmonic radar. Nature, 403, 537-540. https://doi.org/10.1038/35000564 

  • Riley, J.R., Reynolds, D.R., Smith, A.D., Edwards, A.S., Osborne, J.L., Williams, I.H. & McCartney, H.A. (1999) Compensation for wind drift by bumble-bees. Nature, 400, 126. https://doi.org/10.1038/22029

  • Riley, J.R., Smith, A.D., Reynolds, D.R., Edwards, A.S., Osborne, J.L., Williams, I.H., Carreck, N.L. & Poppy, G.M. (1996) Tracking bees with harmonic radar. Nature, 379, 29-30. https://doi.org/10.1038/379029b0 

  • Riley, J.R. & Reynolds, D.R. (1990) Nocturnal grasshopper migration in West Africa:  transport and concentration by the wind, and the implications for air-to-air control.  Philosophical Transactions of the Royal Society of London, B, 328, 655-672. https://doi.org/10.1098/rstb.1990.0134

My main tasks are research and other forms of scholarly activity, particularly ones likely to  contribute to the next Research Excellence Framework (REF)

  • Emeritus Scientist position at Rothamsted Research

  • Formerly Member of the Management Committee of the “European Network for the Radar surveillance of Animal Movement (ENRAM)”.

  • Life-time Achievement Award for contributions to ‘Radar Entomology’ (presented at 2nd International Radar Aeroecology Conference, Zhenzhou, China, September 2019
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