scholarly journals Predicting Wingbeat Frequency and Wavelength of Birds

1990 ◽  
Vol 150 (1) ◽  
pp. 171-185 ◽  
Author(s):  
C. J. PENNYCUICK
Keyword(s):  
Multiple Regression ◽  
Dimensional Analysis ◽  
Bird Species ◽  
Field Observations ◽  
Wingbeat Frequency ◽  
Wing Area ◽  
Wing Span ◽  
Air Density ◽  
Flight Muscles ◽  
Advance Ratio

Wingbeat frequencies were observed in the field for 32 morphologically diverse bird species, representing 18 families, and ranging in mass from 20 g to nearly 5 kg. A combination of multiple regression and dimensional analysis was used to show that wingbeat frequency (f) may be estimated by: f = 1.08(m1/3g1/2b−1S−1/4p−1/3 where m is the bird's body mass, g is the acceleration due to gravity, b is the wing span, S is the wing area and p is the air density. The predicted wingbeat frequency can be used to estimate the power available from a bird's flight muscles, and an estimate of the power required to fly can be obtained for comparison from the computer programs of Pennycuick (1989a). Field observations of airspeed are given for 30 of the 32 species. These are combined with the observations of wingbeat frequency to estimate wingbeat wavelength, and the ratio of wavelength to wing span, which is closely related to the ‘advance ratio’ as used by Ellington (1984).

scholarly journals Elevational niche-shift migration: Why the degree of elevational change matters for the ecology, evolution, and physiology of migratory birds

The Auk ◽  
2021 ◽  
Author(s):  
Jessie L Williamson ◽  
Christopher C Witt
Keyword(s):  
Partial Pressure ◽  
Bird Species ◽  
Seasonal Migration ◽  
Critical Examination ◽  
Niche Shift ◽  
Migratory Connectivity ◽  
Migratory Species ◽  
Arterial Blood ◽  
Air Density ◽  
Elevational Migration

Abstract Elevational migration can be defined as roundtrip seasonal movement that involves upward and downward shifts in elevation. These shifts incur physiological challenges that are proportional to the degree of elevational change. Larger shifts in elevation correspond to larger shifts in partial pressure of oxygen, air density, temperature, and ultraviolet (UV) exposure. Although most avian examples of elevational migration involve subtle shifts that would have minimal impacts on physiology, shifts of any magnitude have previously been considered under the broad umbrella of “elevational migration”. Here, we consider extreme seasonal elevational movements (≥2,000 m), sufficient to shift the elevational dimension of the eco-climatic niche. Migratory bird populations typically maintain inter-seasonal stability in the temperature, precipitation, and elevational aspects of their climatic niches, a tendency that likely reflects genetic physiological specialization on environmental conditions such as atmospheric pressure. A shift of ≥2,000 m involves a ≥20% change in air density and oxygen partial pressure, sufficient to incur functionally impactful declines in arterial blood-oxygen saturation and require compensatory shifts in respiratory physiology. We refer to this phenomenon as elevational niche-shift migration (ENSM). In this review, we analyzed >4 million occurrence records to identify 105 populations, representing 92 bird species, that undergo complete or partial ENSM. We identified key ecological and evolutionary questions regarding the causes and consequences of ENSM. Our synthesis reveals that ENSM has evolved independently in at least 29 avian families spanning 10 orders. Nonetheless, ENSM is rare relative to other forms of seasonal migration, consistent with the general tendency of seasonal niche conservatism by migratory species and evolutionarily conserved elevational range limits. For many migratory species and populations, within-species patterns of migratory connectivity are not sufficiently understood to determine ENSM status. ENSM is distinguished by its scale within the broader phenomenon of elevational migration. Critical examination of ENSM illustrates fundamental constraints on the ecology and evolution of migration systems, topographical influences on geographic patterns of migratory connectivity, and the remarkable metabolic flexibility of certain bird species that allows them to occupy disparate elevations across different seasons.

scholarly journals Flightin maintains myofilament lattice organization required for optimal flight power and courtship song quality in Drosophila

2017 ◽  
Vol 284 (1854) ◽  
pp. 20170431 ◽  
Author(s):  
Samya Chakravorty ◽  
Bertrand C. W. Tanner ◽  
Veronica Lee Foelber ◽  
Hien Vu ◽  
Matthew Rosenthal ◽  
...  
Keyword(s):  
Power Output ◽  
Lattice Structure ◽  
Courtship Song ◽  
Fine Tuning ◽  
Male Reproductive Success ◽  
Supporting Evidence ◽  
Force Transmission ◽  
Wingbeat Frequency ◽  
Terminal Domain ◽  
Flight Muscles

The indirect flight muscles (IFMs) of Drosophila and other insects with asynchronous flight muscles are characterized by a crystalline myofilament lattice structure. The high-order lattice regularity is considered an adaptation for enhanced power output, but supporting evidence for this claim is lacking. We show that IFMs from transgenic flies expressing flightin with a deletion of its poorly conserved N-terminal domain ( fln ΔN62 ) have reduced inter-thick filament spacing and a less regular lattice. This resulted in a decrease in flight ability by 33% and in skinned fibre oscillatory power output by 57%, but had no effect on wingbeat frequency or frequency of maximum power output, suggesting that the underlying actomyosin kinetics is not affected and that the flight impairment arises from deficits in force transmission. Moreover, we show that fln ΔN62 males produced an abnormal courtship song characterized by a higher sine song frequency and a pulse song with longer pulses and longer inter-pulse intervals (IPIs), the latter implicated in male reproductive success. When presented with a choice, wild-type females chose control males over mutant males in 92% of the competition events. These results demonstrate that flightin N-terminal domain is required for optimal myofilament lattice regularity and IFM activity, enabling powered flight and courtship song production. As the courtship song is subject to female choice, we propose that the low amino acid sequence conservation of the N-terminal domain reflects its role in fine-tuning species-specific courtship songs.

Scaling bat wingbeat frequency and amplitude

2002 ◽  
Vol 205 (17) ◽  
pp. 2615-2626 ◽  
Author(s):  
R. D. Bullen ◽  
N. L. McKenzie
Keyword(s):  
Lower Half ◽  
Flight Speed ◽  
Simple Relationship ◽  
Wingbeat Frequency ◽  
Wing Area ◽  
High Speeds ◽  
Second Mode ◽  
Speed Range

SUMMARYWingbeat frequency (fw) and amplitude(θw) were measured for 23 species of Australian bat,representing two sub-orders and six families. Maximum values were between 4 and 13 Hz for fw, and between 90 and 150° forθ w, depending on the species. Wingbeat frequency for each species was found to vary only slightly with flight speed over the lower half of the speed range. At high speeds, frequency is almost independent of velocity. Wingbeat frequency (Hz) depends on bat mass (m, kg) and flight speed (V, ms-1) according to the equation: fw=5.54-3.068log10m-2.857log10V. This simple relationship applies to both sub-orders and to all six families of bats studied. For 21 of the 23 species, the empirical values were within 1 Hz of the model values. One species, a small molossid, also had a second mode of flight in which fw was up to 3 Hz lower for all flight speeds.The following relationship predicts wingbeat amplitude to within±15° from flight speed and wing area (SREF,m2) at all flight speeds:θ w=56.92+5.18V+16.06log10SREF. This equation is based on data up to and including speeds that require maximum wingbeat amplitude to be sustained. For most species, the maximum wingbeat amplitude was 140°.

Aerodynamics of Gliding Flight of a Black Vulture Coragyps Atratus

1970 ◽  
Vol 53 (2) ◽  
pp. 363-374 ◽  
Author(s):  
G. CHRISTIAN PARROTT
Keyword(s):  
Wind Tunnel ◽  
Wing Area ◽  
Drag Coefficients ◽  
Wing Span ◽  
Drag Forces ◽  
Gliding Flight ◽  
Black Vulture ◽  
Air Speed

1. A black vulture (mass = 1.79 kg) gliding freely in a wind tunnel adjusted its wing span and wing area as its air speed and glide angle changed from 9.9 to 16.8 m/s and from 4.8° to 7.9°, respectively. 2. The minimum sinking speed was 1.09 m/s at an air speed of 11.3 m/s. 3. The maximum ratio of lift to drag forces was 11.6 at an air speed of 13.9 m/s. 4. Parasite drag coefficients for the vulture are similar to those for conventional airfoils and do not support the contention that black vultures have unusually low values of parasite drag.

Soaring and Gliding Flight of the Black Vulture

1958 ◽  
Vol 35 (2) ◽  
pp. 280-285
Author(s):  
B. G. NEWMAN
Keyword(s):  
Flow Separation ◽  
Angle Of Attack ◽  
High Angle ◽  
High Angle Of Attack ◽  
Wing Area ◽  
Wing Span ◽  
Gliding Flight ◽  
Black Vulture ◽  
Wing Geometry

1. The soaring and gliding performance of the black vulture has been analysed and the following conclusions are drawn. 2. The wing span of the bird is altered in flight so that it may perform two tasks efficiently. First, that it may soar in rising currents of air for which a low sinking speed and thus a large wing span are required. Secondly, that it may penetrate into wind without undue loss of height for which a reduced wing area is desirable. Adjustment of the wing geometry towards the optimum soaring configuration is achieved by bending forward and opening the primary tip feathers. 3. Since the airflow readily separates from the flat primary feathers at high angle of attack, these feathers, which are emarginated, are parted to form slots. The alula also presumably assists in delaying the flow separation over the primaries. 4. It is unlikely that the opening of the primaries reduces the vortex drag.

Diet and Breeding Seasonality among a Population of Sharp-Tailed Munias, Lonchura striata, in Malaysia

The Auk ◽  
1980 ◽  
Vol 97 (1) ◽  
pp. 160-166
Author(s):  
Michael L. Avery
Keyword(s):  
Food Habits ◽  
Bird Species ◽  
Reproductive Activity ◽  
Peninsular Malaysia ◽  
Rice Cultivation ◽  
Filamentous Alga ◽  
Field Observations ◽  
Insect Abundance ◽  
Breeding Seasonality ◽  
Natural Cycles

Abstract From April 1975 through March 1977, the food habits and breeding seasonality of a population of Sharp-tailed Munias (Lonchura striata) were studied in northwestern peninsular Malaysia. The abundance of munias on the study area varied in accordance with the 6-month rice-growing cycle there. The population peaked in March and September when juvenile birds were most numerous and when rice was most plentiful. Field observations and stomach analyses showed that the munias ate rice and the green filamentous alga, Spirogyra, almost exclusively. The primary periods of algae eating occurred in January and June-August, coinciding with the munias' two peak periods of reproductive activity, as determined by gonadal examination. Apparently munias on the study area ate Spirogyra as a source of protein to enable them to become physiologically ready for breeding, much as othe tropical bird species eat insects. Thus, unlike other species, Sharp-tailed Munias' breeding seasonality is determined by manmade cycles of rice cultivation rather than by natural cycles of rain and insect abundance.

FORMULATION OF MATHEMATICAL MODEL FOR MAINTENANCE COST OF A STONE CRUSHING PLANT BASED ON DIMENSIONAL ANALYSIS AND MULTIPLE REGRESSION

2013 ◽  
pp. 1-6
Author(s):  
PROF. ANJALI J. JOSHI ◽  
DR. JAYANT P. MODAK
Keyword(s):  
Mathematical Model ◽  
Multiple Regression ◽  
Dimensional Analysis ◽  
Least Square Method ◽  
Least Square ◽  
Maintenance Cost ◽  
Design Data ◽  
Static And Dynamic Analysis ◽  
Dimensionless Equation ◽  
Crushing Plant

This paper presents the approach for the mathematical modeling of maintenance cost for the set up of new Stone Crushing Plant based on the dimensional analysis and multiple regression. Presented maintenance cost mathematical model is derived based on the generated design data. Design data is generated from actual design of all stone crushing plants followed by static and dynamic analysis. Estimation of design data is carried out based on the assumed plant layout. Dimensional analysis is used to make the independent and dependent variables dimensionless and to get dimensionless equation. Later, multiple regression analysis is applied to this dimensionless equation to obtain the index values based on the least square method. The mathematical model of maintenance cost is formulated using these obtained index values. Finally, the formulated model is evaluated on the basis of correlation and root mean square error between the computed values by model and the estimated values.

scholarly journals Rediscovery and subsequent observations of Kaempfer's Tody-tyrant Hemitriccus kaempferi in Santa Catarina, Brazil, with notes on conservation, life history and plumage

2000 ◽  
Vol 10 (4) ◽  
pp. 371-379 ◽  
Author(s):  
Juan Mazar Barnett ◽  
Guy M. Kirwan ◽  
Mark Pearman ◽  
Luciano Nicolás Naka ◽  
Joe A. Tobias
Keyword(s):  
Life History ◽  
Natural History ◽  
Atlantic Forest ◽  
Threatened Species ◽  
Bird Species ◽  
Type Locality ◽  
Field Observations ◽  
Southern Brazil ◽  
Santa Catarina ◽  
Made In

Previously known from two specimens, Kaempfer's Tody-tyrant Hemitriccus kaempferi is a globally threatened species endemic to the southern Brazil Atlantic Forest. The first field observations of this little-known taxon were made in the 1990s and our data therefore provide the first published information on its natural history, including breeding biology, behaviour and vocalizations, as well as a new locality. As very little information has appeared in the literature concerning the identification of this species, we present notes on its plumage and habits. Remarks concerning the species's conservation prospects and the importance of the remaining forest in the vicinity of the type-locality for other threatened bird species are made.

scholarly journals Metabolic ‘engines’ of flight drive genome size reduction in birds

2014 ◽  
Vol 281 (1779) ◽  
pp. 20132780 ◽  
Author(s):  
Natalie A. Wright ◽  
T. Ryan Gregory ◽  
Christopher C. Witt
Keyword(s):  
Genome Size ◽  
Body Mass ◽  
Flight Muscle ◽  
Bird Species ◽  
Size Reduction ◽  
Muscle Size ◽  
Physical Size ◽  
Metabolic Intensity ◽  
Flight Muscles ◽  
Mechanistic Basis

The tendency for flying organisms to possess small genomes has been interpreted as evidence of natural selection acting on the physical size of the genome. Nonetheless, the flight–genome link and its mechanistic basis have yet to be well established by comparative studies within a volant clade. Is there a particular functional aspect of flight such as brisk metabolism, lift production or maneuverability that impinges on the physical genome? We measured genome sizes, wing dimensions and heart, flight muscle and body masses from a phylogenetically diverse set of bird species. In phylogenetically controlled analyses, we found that genome size was negatively correlated with relative flight muscle size and heart index (i.e. ratio of heart to body mass), but positively correlated with body mass and wing loading. The proportional masses of the flight muscles and heart were the most important parameters explaining variation in genome size in multivariate models. Hence, the metabolic intensity of powered flight appears to have driven genome size reduction in birds.

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