Upwash exploitation and downwash avoidance by flap phasing in ibis formation flight

@article{Portugal2014UpwashEA,
  title={Upwash exploitation and downwash avoidance by flap phasing in ibis formation flight},
  author={Steven J. Portugal and Tatjana Y. Hubel and Johannes Fritz and S. Heese and Daniela Trobe and Bernhard Voelkl and Stephen Hailes and Alan M. Wilson and James R. Usherwood},
  journal={Nature},
  year={2014},
  volume={505},
  pages={399-402}
}
Many species travel in highly organized groups. The most quoted function of these configurations is to reduce energy expenditure and enhance locomotor performance of individuals in the assemblage. The distinctive V formation of bird flocks has long intrigued researchers and continues to attract both scientific and popular attention. The well-held belief is that such aggregations give an energetic benefit for those birds that are flying behind and to one side of another bird through using the… 

Energy Management of Echelon Flying Northern Bald Ibises with Different Wingspans and Variable Wingtip Spacing

In this paper, the flocking flight of Northern Bald Ibises ( Geronticus eremita ) and their induced drag during the flock are investigated. Northern Bald Ibises are long-range migratory birds. These

Flow interactions between uncoordinated flapping swimmers give rise to group cohesion

TLDR
Results show how flapping kinematics can be used to control locomotion within wakes, and that flow interactions provide a mechanism which promotes group cohesion.

Flocking of V-shaped and Echelon Northern Bald Ibises with Different Wingspans: Repositioning and Energy Saving

TLDR
V-shaped and echelon formations help migratory birds to consume less energy for migration and also small birds have the chance to take the lead during the flock, it is found.

The roller coaster flight strategy of bar-headed geese conserves energy during Himalayan migrations

TLDR
A “roller coaster” strategy, of tracking the underlying terrain and discarding large altitude gains only to recoup them later in the flight with occasional benefits from orographic lift, is shown to be energetically advantageous for flights over the Himalayas.

Bird flight: Fly with a little flap from your friends

TLDR
In-air measurements of northern bald ibises flying in a V formation show that the birds conform to predictions for saving energy by regulating their relative body position and synchronizing their flapping motion, and the data reveal a sophisticated and dynamic process of in-flight control.

Ecology of tern flight in relation to wind, topography and aerodynamic theory

TLDR
This study reports on flight track measurements in five geometrically similar tern species ranging one magnitude in body mass, from both migration and the breeding season at the island of Öland in the Baltic Sea, showing that the selection of airspeed is a behavioural trait that depended on a complex blend of internal and external factors.

Field Flight Dynamics of Hummingbirds during Territory Encroachment and Defense

TLDR
Although birds departing from the feeder while chased did so faster than freely-departing birds, these speed gains were accomplished by modulating kinetic and potential energy gains rather than increasing overall power output, essentially trading altitude for speed during their evasive maneuver.

Soaring and intermittent flap-gliding during migratory flights of Northern Bald Ibis

Migratory journeys represent an energetic challenge for many long-distance migrants. The choice of flight times, migration route, altitude, travelling speed, wingbeat patterns, soaring as well as

Compound-V formations in shorebird flocks

TLDR
An interaction rule is identified that holds across single and mixed-species flocks of four migratory shorebird species spanning a seven-fold range of body masses and is proposed to be an intermediary between the cluster flock of starlings and the simple-V formations of geese and other large migratory birds.

Birds invest wingbeats to keep a steady head and reap the ultimate benefits of flying together

TLDR
It is shown that, for pigeons flying in pairs, two heads are better than one but keeping a steady head necessitates energetically costly kinematics, which will offset any additional energetic costs as long as the metabolic power requirements are not increased above 9%.
...

References

SHOWING 1-10 OF 44 REFERENCES

ENERGY SAVINGS IN FORMATION FLIGHT OF PINK-FOOTED GEESE

  • CuttsSpeakman
  • Environmental Science
    The Journal of experimental biology
  • 1994
TLDR
There was a significant correlation between depth and wing-tip spacing, supporting an alternative communication hypothesis, whereby the birds position themselves to obtain maximum information on their neighbour's position.

Phasing of dragonfly wings can improve aerodynamic efficiency by removing swirl

TLDR
A mechanical model dragonfly is demonstrated with a mechanical model wings that, despite presenting no advantage in terms of lift, flying with two pairs of wings can be highly effective at improving aerodynamic efficiency.

Precision and Dynamics of Positioning by Canada Geese Flying in Formation

TLDR
Recon reconstructing perspective-distorted film images of geese flying in V formations to allow measurements of wing tip spacing (WTS), depth (the distance along the flight path between birds), and some position adjustments appeared to reflect the distribution of savings predicted from vortex theory.

Flying in a flock comes at a cost in pigeons

TLDR
Here data is used from innovative back-mounted Global Positioning System and 6-degrees-of-freedom inertial sensors to show that pigeons do not gain an aerodynamic advantage from flying in a flock, and the increased flap frequency suggests a considerable energetic cost to flight in a tight cluster flock.

Wake structure and wing kinematics: the flight of the lesser dog-faced fruit bat, Cynopterus brachyotis

TLDR
The degree of consistency within trials and looked at individual variation in flight parameters, and found distinct differences between individuals as well as within individuals.

Kin selection and reciprocity in flight formation

TLDR
Combining theories of animal flight and sociality, it is suggested that some of the variation in flight formations has its base in kin selection and reciprocation.

Changes in kinematics and aerodynamics over a range of speeds in Tadarida brasiliensis, the Brazilian free-tailed bat

TLDR
The comparison of the aerodynamics of T. brasiliensis with those of other, frugivorous bats and with common swifts, Apus apus, a bird with wing morphology, kinematics and flight ecology similar to that of these bats reveals that the cyclical pattern of aerodynamic forces associated with a wingbeat shows more similarities between T. Brasiliensis and A. apus.

A Computational Investigation of Bio-Inspired Formation Flight and Ground Eect

TLDR
This paper presents a preliminary computational study of energy saving strategies in flapping flight and predicts optimal savings are predicted to occur when the unsteady wake vorticity is exploited by ensuring that the two flappers’ wakes are in spatial phase with wingtips slightly overlapping.