Volume 50, No. 2

Search by author or title:

Common Mergansers Mergus merganser use wings to pursue a fish underwater


1Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada (
2Nature Alaska, Juneau, Alaska, USA


LAPSANSKY, A.B. & ARMSTRONG, R.H. 2022. Common Mergansers Mergus merganser use wings to pursue a fish underwater. Marine Ornithology 50: 111 - 114

Received 11 January 2022, accepted 15 March 2022

Date Published: 2022/10/15
Date Online: 2022/07/22
Key words: diving, foot-propelled, Mergus merganser, wing-propelled, swimming


Common Mergansers Mergus merganser dive into lakes, rivers, and coastal waters to feed on fish and other aquatic prey. This species and others in the genus Mergus are traditionally classified as foot-propelled divers. When submerged, mergansers are expected to swim by kicking their feet, holding their wings close to their bodies. Here, we report, with video evidence, an event in which four mergansers used their wings underwater to chase down and capture a large fish. Documentation of wing use by this classically defined “foot-propelled diver” illustrates the gaps in our understanding of avian diving physiology, hydrodynamics, and behavior.


ASHMOLE, N.P. 1971. Sea Bird Ecology and the Marine Environment. In: FARNER, D.S. & KING, J.R. (Eds.) Avian Biology. New York, USA: Academic Press.

CHIN, D.D. & LENTINK, D. 2019. Birds repurpose the role of drag and lift to take off and land. Nature Communications 10: 5354. doi:10.1038/s41467-019-13347-3

CLIFTON, G.T. & BIEWENER, A.A. 2018. Foot-propelled swimming kinematics and turning strategies in Common Loons. The Journal of Experimental Biology 221: jeb168831. doi:10.1242/jeb.168831

FISH, F.E. 1996. Transitions from drag-based to lift-based propulsion in mammalian swimming. American Zoologist 36: 628-641. doi:10.1093/icb/36.6.628

FORBUSH, E.H. 1922. Some Under-water Activities of Certain Waterfowl. Department of Agriculture Departmental Bulletin No. 8. Boston, USA: Division of Information, Commonwealth of Massachusetts.

GODOY-DIANA, R. & THIRIA, B. 2018. On the diverse roles of fluid dynamic drag in animal swimming and flying. Journal of The Royal Society Interface 15: 20170715. doi:10.1098/rsif.2017.0715

HEATH, J.P. & GILCHRIST, H.G. 2010. When foraging becomes unprofitable: energetics of diving in tidal currents by Common Eiders wintering in the Arctic. Marine Ecology Progress Series 403: 279-290. doi:10.3354/meps08482

HEATH, J.P., GILCHRIST, H.G. & YDENBERG, R.C. 2006. Regulation of stroke pattern and swim speed across a range of current velocities: diving by Common Eiders wintering in polynyas in the Canadian Arctic. Journal of Experimental Biology 209: 3974-3983. doi:10.1242/jeb.02482

HEDRICK, T.L. 2008. Software techniques for two- and three-dimensional kinematic measurements of biological and biomimetic systems. Bioinspiration & Biomimetics 3: 034001. doi:10.1088/1748-3182/3/3/034001

HUI, C.A. 1985. Maneuverability of the Humboldt Penguin (Spheniscus humboldti) during swimming. Canadian Journal of Zoology 63: 2165-2167. doi:10.1139/z85-318

JACKSON, P.S., LOCKE, N. & BROWN, P. 1992. The Hydrodynamics of Paddle Propulsion. 11th Australasian Fluid Mechanics Conference. Hobart, Australia: University of Tasmania.

JOHANSSON, L.C. & NORBERG, R.Å. 2003. Delta-wing function of webbed feet gives hydrodynamic lift for swimming propulsion in birds. Nature 424: 65-68. doi:10.1038/nature01695

JOHANSSON, L.C. & NORBERG, U.M.L. 2000. Asymmetric toes aid underwater swimming. Nature 407: 582-583. doi:10.1038/35036689

JOHANSSON, L.C. & NORBERG, U.M.L. 2001. Lift-based paddling in diving grebe. Journal of Experimental Biology 204: 1687-1696. doi:10.1242/jeb.204.10.1687

KIKUCHI, D.M., WATANUKI, Y., SATO, N., HOSHINA, K., TAKAHASHI, A. & WATANABE, Y.Y. 2015. Strouhal number for flying and swimming in Rhinoceros Auklets Cerorhinca monocerata. Journal of Avian Biology 46: 406-411. doi:10.1111/jav.00642

LAPSANSKY, A.B., ZATZ, D. & TOBALSKE, B.W. 2020. Alcids ‘fly' at efficient Strouhal numbers in both air and water but vary stroke velocity and angle. eLife 9: e55774. doi:10.7554/eLife.55774

LOVVORN, J.R. 1991. Mechanics of Underwater Swimming in Foot-Propelled Diving Birds. Acta XX Congressus Internationalis Ornithologici III: 1868-1874.

LOVVORN, J.R. & BROOKS, M.L. 2021. Feeding on epibenthic zooplankton by Long-tailed Ducks: patch structure, profitability, and food web implications. Ecosphere 12: e03780. doi:10.1002/ecs2.3780

PEARCE, J., MALLORY, M.L. & METZ, K. 2020. Common Merganser (Mergus merganser), version 1.0. In: BILLERMAN, S.M. (Ed.) Birds of the World. Ithaca, USA: Cornell Lab of Ornithology. doi:10.2173/bow.commer.01

RIBAK, G., WEIHS, D. & ARAD, Z. 2004. How do cormorants counter buoyancy during submerged swimming? Journal of Experimental Biology 207: 2101-2114. doi:10.1242/jeb.00997

RICHMAN, S.E. & LOVVORN, J.R. 2008. Costs of diving by wing and foot propulsion in a sea duck, the White-winged Scoter. Journal of Comparative Physiology B 178: 321-332. doi:10.1007/s00360-007-0225-9

ROPERT-COUDERT, Y., GRÉMILLET, D. & KATO, A. 2006. Swim speeds of free-ranging Great Cormorants. Marine Biology 149: 415-422. doi:10.1007/s00227-005-0242-8

SPRING, L. 1971. A comparison of functional and morphological adaptations in the Common Murre (Uria aalge) and Thick-Billed Murre (Uria lomvia). The Condor 73: 1-27. doi:10.2307/1366120

STORER, R.W. 1960. Evolution in the diving birds. In: BERGMAN, G., DONNER, K.O. & HAARTMAN, L.V. (Eds.) Proceedings of the XII International Ornithological Congress. Helsinki, Finland: Tilgmannin Kirjapaino

SWENNEN, C. & DUIVEN, P. 1991. Diving speed and food-size selection in Common Guillemots, Uria aalgae. Netherlands Journal of Sea Research 27: 191-196. doi:10.1016/0077-7579(91)90012-P

TOWNSEND, C.W. 1924. Diving of grebes and loons. The Auk 41: 29-41. doi:10.2307/4074084

VOGEL, S. 1994. Life in Moving Fluids: The Physical Biology of Flow, 2nd Edition. Princeton, USA: Princeton University Press.

WALKER, J.A. & WESTNEAT, M.W. 2000. Mechanical performance of aquatic rowing and flying. Proceedings of the Royal Society B 267: 1875-1881. doi:10.1098/rspb.2000.1224

WATANUKI, Y., WANLESS, S., HARRIS, M. ET AL. 2006. Swim speeds and stroke patterns in wing-propelled divers: a comparison among alcids and a penguin. Journal of Experimental Biology 209: 1217-1230. doi:10.1242/jeb.02128

WILSON, R.P., WILSON, M.-P. & NOLDEKE, E.C. 1992. Pre-dive leaps in diving birds: Why do kickers sometime jump? Marine Ornithology 20: 7-16.

Search by author or title:

Browse previous volumes: