Harris's Hawk (Parabuteo unicinctus)

2020 ◽  
Author(s):  
James F. Dwyer ◽  
James C. Bednarz
Keyword(s):  

2011 ◽  
Author(s):  
Desiree I. Sharpe ◽  
Erin N. Colbert-White ◽  
E. Monteen McCord


2011 ◽  
Author(s):  
James F. Dwyer ◽  
James C. Bednarz
Keyword(s):  


2009 ◽  
Vol 43 (2) ◽  
pp. 152-154 ◽  
Author(s):  
James F. Dwyer ◽  
R. William Mannan


1989 ◽  
Vol 142 (1) ◽  
pp. 17-29 ◽  
Author(s):  
C. J. PENNYCUICK ◽  
M. R. FULLER ◽  
LYNNE McALLISTER

Two Harris' hawks were trained to fly along horizontal and climbing flight paths, while carrying loads of various masses, to provide data for estimating available muscle power during short flights. The body mass of both hawks was about 920 g, and they were able to carry loads up to 630 g in horizontal flight. The rate of climb decreased with increasing all-up mass, as also did the climbing power (product of weight and rate of climb). Various assumptions about the aerodynamic power in low-speed climbs led to estimates of the maximum power output of the flight muscles ranging from 41 to 46 W. This, in turn, would imply a stress during shortening of around 210 kPa. The effects of a radio package on a bird that is raising young should be considered in relation to the food load that the forager can normally carry, rather than in relation to its body mass.



1990 ◽  
Vol 149 (1) ◽  
pp. 449-468 ◽  
Author(s):  
VANCE A. Tucker

1. The mean, minimum drag coefficients (CD,B) of a frozen, wingless peregrine falcon body and a smooth-surfaced model of the body were 0.24 and 0.14, respectively, at air speeds between 10.0 and 14.5 ms−1. These values were measured with a drag balance in a wind tunnel, and use the maximum crosssectional area of the body as a reference area. The difference between the values indicates the effect of the feathers on body drag. Both values for CD,B a r e lower than those predicted from most other studies of avian body drag, which yield estimates of CD,B up to 0.41. 2. Several factors must be controlled to measure minimum drag on a frozen body. These include the condition of the feathers, the angle of the head and tail relative to the direction of air flow, and the interference drag generated by the drag balance and the strut on which the body is mounted. 3. This study describes techniques for measuring the interference drag generated by (a) the drag balance and mounting strut together and (b) the mounting strut alone. Corrections for interference drag may reduce the apparent body drag by more than 20%. 4. A gliding Harris' hawk (Parabuteo unicinctus), which has a body similar to that of the falcon in size and proportions, has an estimated body drag coefficient of 0.18. This value can be used to compute the profile drag coefficients of Harris' hawk wings when combined with data for this species in the adjoining paper (Tucker and Heine, 1990).



2019 ◽  
Vol 28 (2) ◽  
pp. 330-332 ◽  
Author(s):  
Renata Fagundes Moreira ◽  
Laura de Campos Farezin ◽  
Ugo Araújo Souza ◽  
Bruna Zafalon da Silva ◽  
Derek Blaese Amorim ◽  
...  

Abstract The hippoboscids are cosmopolitan permanent obligate hematophagous ectoparasites of birds, domestic and wild mammals and, occasionally, humans. Some species may act as vectors or hosts of etiological pathogenic agents. The aims of this study were to report on the first cases of Hippoboscidae in Crax blumenbachii and Parabuteo unicinctus; to provide new reports from Brazil on Tyto furcata and Asio stygius parasitized by Icosta americana; to report on individuals of Bubo virginianus, Falco sparverius and Accipiter striatus parasitized by genera Ornithoctona; and to provide new reports on parasitism of O. erythrocephala in the state of Rio Grande do Sul. The birds of prey and C. blumenbachii were attended at a rehabilitation center in Porto Alegre and at a veterinary hospital in Cruz Alta. These new records demonstrate the huge gap that exists regarding studies on avian ectoparasites and highlight potential vectors of hemoparasites for the bird species studied.



2006 ◽  
Vol 20 (2) ◽  
pp. 105-112 ◽  
Author(s):  
Petra Zsivanovits ◽  
Deborah J. Monks ◽  
Neil A. Forbes ◽  
Krisztina Ursu ◽  
Rüdiger Raue ◽  
...  


The Auk ◽  
1991 ◽  
Vol 108 (3) ◽  
pp. 638-648 ◽  
Author(s):  
Carol Masters Vleck ◽  
Arthur R. Goldsmith


1990 ◽  
Vol 149 (1) ◽  
pp. 469-489 ◽  
Author(s):  
VANCE A. TUCKER ◽  
CARLTON HEINE

1. A Harris' hawk with a mass of 0.702 kg and a maximum wing span of 1.02 m glided freely in a wind tunnel at air speeds between 6.1 and 16.2ms−1. The glide angle varied from 8.5% at the slowest speed to a minimum of 5% at speeds between 8.0 and 14.7 ms−1. The maximum ratio of lift to drag was 10.9 and the minimum sinking speed was 0.81ms−1 2. Wing span decreased when either air speed or glide angle increased. Wing area was a parabolic function of wing span 3. Lift and profile drag coefficients of the wings fell in a polar area similar to that for a laggar falcon (Falco jugger) and a black vulture (Coragyps atratus). A single polar curve relating lift coefficients to minimum profile drag coefficients can predict the maximum gliding performance of all three birds when used with a mathematical model for gliding flight 4. The parasite drag values that have been used with the model are probably too high. Thus, the profile drag coefficients determined from the polar curve mentioned above are too low, and the predicted wing spans for gliding at maximum performance are too large. The predicted curve for maximum gliding performance is relatively unaffected 5. The maximum lift coefficient for the Harris' hawk in the wind tunnel was 1.6. This value is probably less than the maximum attainable, since the hawk's wings never appeared to stall. The best estimate of the minimum profile drag coefficient is 0.026 at a lift coefficient of 0.60.



Sign in / Sign up

Export Citation Format

Share Document