Frigate birds track atmospheric conditions over months-long transoceanic flights

Understanding how animals respond to atmospheric conditions across space is critical for understanding the evolution of flight strategies and long-distance migrations. We studied the three-dimensional movements and energetics of great frigate birds (Fregata minor) and showed that they can stay aloft for months during transoceanic flights. To do this, birds track the edge of the doldrums to take advantage of favorable winds and strong convection. Locally, they use a roller-coaster flight, relying on thermals and wind to soar within a 50- to 600-meter altitude band under cumulus clouds and then glide over kilometers at low energy costs. To deal with the local scarcity of clouds and gain longer gliding distances, birds regularly soar inside cumulus clouds to use their strong updraft, and they can reach altitudes of 4000 meters, where freezing conditions occur.

[1]  MARINE METEOROLOGY. SOME RESULTS OF A TRADE CUMULUS CLOUD INVESTIGATION , 1953 .

[2]  P. S. Enger.  Heat regulation and metabolism in some tropical mammals and birds. , 1957, Acta physiologica Scandinavica.

[3]  C. H. Blake,et al.  Locomotor Mechanisms of Birds , 1962 .

[4]  C. Pennycuick.  Thermal Soaring Compared in Three Dissimilar Tropical Bird Species, Fregata Magnificens, Pelecanus Occidentals and Coragyps Atratus , 1983 .

[5]  M. Handzic.  5 , 1824, The Banality of Heidegger.

[6]  Jeremy M. V. Rayner,et al.  The Mechanics of Flight and Bird Migration Performance , 1990 .

[7]  Thomas Alerstam,et al.  Optimal Bird Migration: The Relative Importance of Time, Energy, and Safety , 1990 .

[8]  Gareth Jones,et al.  Bird Flight Performance. A Practical Calculation Manual, C.J. Pennycuick. Oxford University Press, Oxford (1989), x, +153. Price £25 , 1990 .

[9]  G. Spindler,et al.  An Integrative View , 1992 .

[10]  Charles M. Bishop.  Heart mass and the maximum cardiac output of birds and mammals: implications for estimating the maximum aerobic power input of flying animals. , 1997 .

[11]  Kwo-Sen Kuo,et al.  Clustering, randomness, and regularity in cloud fields: 5. The nature of regular cumulus cloud fields , 1998 .

[12]  R J Full,et al.  How animals move: an integrative view. , 2000, Science.

[13]  Charles M. Bishop,et al.  Heart rate and the rate of oxygen consumption of flying and walking barnacle geese (Branta leucopsis) and bar-headed geese (Anser indicus). , 2002, The Journal of experimental biology.

[14]  O. Hoegh‐Guldberg,et al.  Ecological responses to recent climate change , 2002, Nature.

[15]  H. Weimerskirch,et al.  Flight performance: Frigatebirds ride high on thermals , 2003, Nature.

[16]  Michel Potier,et al.  Foraging strategy of a top predator in tropical waters: great frigatebirds in the Mozambique Channel , 2004 .

[17]  Joseph B. Williams,et al.  Courtship display by great frigatebirds, Fregata minor: an energetically costly handicap signal? , 2005, Behavioral Ecology and Sociobiology.

[18]  Niels C. Rattenborg,et al.  Do birds sleep in flight? , 2006, Naturwissenschaften.

[19]  David C. Douglas,et al.  Extreme endurance flights by landbirds crossing the Pacific Ocean: ecological corridor rather than barrier? , 2008, Proceedings of the Royal Society B: Biological Sciences.

[20]  Thijs Heus,et al.  A refined view of vertical mass transport by cumulus convection , 2008 .

[21]  John A. Lesku,et al.  Adaptive Sleep Loss in Polygynous Pectoral Sandpipers , 2012, Science.

[22]  H. Weimerskirch,et al.  Changes in Wind Pattern Alter Albatross Distribution and Life-History Traits , 2012, Science.

[23]  R. J. Spivey,et al.  Integration of exercise response and allometric scaling in endotherms. , 2013, Journal of theoretical biology.

[24]  Felix Liechti,et al.  First evidence of a 200-day non-stop flight in a bird , 2013, Nature Communications.

[25]  R. J. Spivey,et al.  Interpretation of body-mounted accelerometry in flying animals and estimation of biomechanical power , 2013, Journal of The Royal Society Interface.

[26]  Analysing the intermittent flapping flight of a Manx Shearwater, Puffinus puffinus, and its sporadic use of a wave-meandering wing-sailing flight strategy , 2014 .

[27]  Monitoring and Prediction of Tropical Cyclones in the Indian Ocean and Climate Change , 2014 .

[28]  An implantable instrument for studying the long-term flight biology of migratory birds. , 2014, The Review of scientific instruments.

[29]  B Kranstauber,et al.  Global aerial flyways allow efficient travelling. , 2015, Ecology letters.

[30]  M. Wikelski,et al.  The roller coaster flight strategy of bar-headed geese conserves energy during Himalayan migrations , 2015, Science.