<< Previous Next >>

Tawny Owl


Tawny Owl
Photo Information
Copyright: Peter van Zoest (PeterZ) Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 2411 W: 94 N: 5569] (17712)
Genre: Animals
Medium: Color
Date Taken: 2009-05-21
Categories: Birds
Camera: Nikon D300, AF Nikkor 70-300mm f4-5.6 G, Digital RAW
Exposure: f/8, 1/250 seconds
Details: (Fill) Flash: Yes
More Photo Info: [view]
Photo Version: Original Version
Date Submitted: 2009-05-25 8:07
Viewed: 884
Points: 60
[Note Guidelines] Photographer's Note
This photo is taken in a bird park. These Tawny Owls got a lot of space there to fly around. This is the brown-morph.
There are 4.500 – 5.500 breeding pairs of them in the Netherlands.

The Tawny Owl (Strix aluco) is a stocky, medium-sized owl which is common in woodlands across much of Eurasia. Its underparts are pale with dark streaks, and the upperparts are either brown or grey, with several of the eleven recognised subspecies having both variants. The nest is typically in a tree hole, and eggs and young are fiercely defended against potential predators. This owl is non-migratory and highly territorial, and many young birds starve if they cannot find a vacant territory once parental care ceases.

This nocturnal bird of prey hunts mainly rodents, usually by dropping from a perch to seize its victim, which is swallowed whole, although in more urban areas its diet includes a higher proportion of birds. Its night hunting is aided by vision and hearing adaptations and silent flight. The Tawny is capable of catching smaller owls, but may itself be killed by the Eagle Owl or Northern Goshawk, and foxes are an important cause of mortality in newly fledged young.

Although this owl is often claimed to have exceptional night vision, its retina is no more sensitive than a human's, but its asymmetrically placed ears give the Tawny Owl excellent directional hearing. Its night-time habits and eerie, easily imitated call have lead to an association in myth with bad luck and death.

Description
The Tawny Owl is a robust bird, 37–43 cm (14.5–17 in) in length with an 81–96 cm (32–38 in) wingspan. Its large rounded head lacks ear tufts, and the facial disc surrounding the dark brown eyes is usually rather plain. The nominate race has two morphs which differ in their plumage colour, one form having rufous brown upperparts and the other greyish brown, although intermediates also occur. The underparts of both morphs are whitish and streaked with brown. This species is sexually dimorphic; the female is much larger than the male, 5% longer and more than 25% heavier.

The Tawny Owl flies with long glides on rounded wings, less undulating and with fewer wingbeats than other Eurasian owls, and typically at a greater height. As with most owls, its flight is silent due to its feathers' soft, furry upper surfaces and a fringe on the leading edge of the outer primaries. Its size, dumpy shape and broad wings distinguish it from other owls found within its range; Great Grey, Eagle and Ural Owls are similar in shape, but much larger.
An owl's eyes are placed at the front of the head and have a field overlap of 50–70%, giving it better binocular vision than diurnal birds of prey (overlap 30–50%). The Tawny Owl's retina has about 56,000 light-sensitive rod cells per square millimetre (36 million per square inch); although earlier claims that it could see in the infrared part of the spectrum have been dismissed, it is still often said to have eyesight 10 to 100 times better than humans in low-light conditions. However, the experimental basis for this claim is probably inaccurate by at least a factor of 10. The owl's actual visual acuity is only slightly greater than that of man, and any increased sensitivity is due to optical factors rather than to greater retinal sensitivity; both humans and owl have reached the limit of resolution for the retinas of terrestrial vertebrates.
Adaptations to night vision include the large size of the eye, its tubular shape, large numbers of closely packed retinal rods, and an absence of cone cells, since colour vision is unnecessary at night. There are few coloured oil drops, which would reduce the light intensity. Unlike diurnal birds of prey, owls normally have only one fovea, and that is poorly developed except in diurnal hunters like the Short-eared Owl.

Hearing is important for a nocturnal bird of prey, and as with other owls, the Tawny's two ear openings differ in structure and are asymmetrically placed to improve directional hearing. A passage through the skull links the eardrums, and small differences in the time of arrival of a sound at each ear enables its source to be pinpointed. The left ear opening is higher on the head than the larger right ear and tilts downward, improving sensitivity to sounds from below. Both ear openings are hidden under the facial disk feathers, which are structurally specialized to be transparent to sound, and are supported by a movable fold of skin (the pre-aural flap).
The internal structure of the ear, which has large numbers of auditory neurons, gives an improved ability to detect low frequency sounds at a distance, which could include rustling made by prey moving in vegetation. The Tawny Owl's hearing is ten times better than a human's, and it can hunt using this sense alone in the dark of a woodland on an overcast night, but the patter of raindrops makes it difficult to detect faint sounds, and prolonged wet weather can lead to starvation if the owl cannot hunt effectively.
The commonly heard contact call is a shrill, kew-wick but the male has a quavering advertising song hoo ... ho, ho, hoo-hoo-hoo-hoo. The call is easily imitated by blowing into cupped hands through slightly parted thumbs, and a study in Cambridgeshire found that this mimicry produced a response from the owl within 30 minutes in 94% of trials. A male’s response to a broadcast song appears to be indicative of his health and vigour; owls with higher blood parasite loads use fewer high frequencies and a more limited range of frequencies in their responses to an apparent intruder.

Geographical variation
Although both colour morphs occur in much of the European range, brown birds predominate in the more humid climate of western Europe, with the grey phase becoming more common further east; in the northernmost regions, all the owls are a cold-grey colour. Siberian and Central Asian subspecies have grey and white plumage, the North African race is dark grey-brown, and South and East Asian birds have barred, not striped, underparts, and fine lines around the facial disc. The Siberian and Scandinavian subspecies are 12% larger, 40% heavier, and have 13% longer wings than western European birds, in accordance with Bergmann's rule which predicts that northern forms will typically be bigger than their southern counterparts.

The plumage colour is genetically controlled, and studies in Finland and Italy indicate that grey morph Tawny Owls have more reproductive success, better immune resistance, and fewer parasites than brown birds. Although this might suggest that eventually the brown morph could disappear, the owls show no colour preference when choosing a mate, so the adverse selection pressure is reduced. There are also environmental factors involved. The Italian study showed that brown-morph birds were found in denser woodland, and in Finland, Gloger's rule would suggest that paler birds would in any case predominate in the colder climate.
Raptorman, zetu, Alex99, techranger, siggi, boreocypriensis, cicindela, nglen, rousettus, jaycee, CeltickRanger, nasokoun, Juyona, efsus, MMM, cirano, Noisette, goldyrs, maurydv, tuslaw, goutham_ramesh, anel, SelenE has marked this note useful
Only registered TrekNature members may rate photo notes.
Add Critique [Critiquing Guidelines] 
Only registered TrekNature members may write critiques.
Discussions
ThreadThread Starter Messages Updated
To goutham_ramesh: AvifaunaPeterZ 1 05-28 09:12
To pvs: OranjebruinPeterZ 1 05-25 08:29
You must be logged in to start a discussion.

Critiques [Translate]

Hello Peter ,
Excellent species , very sharp and detailed photo .
TFS and good luck .

  • Great 
  • pvs Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 1168 W: 261 N: 3035] (13835)
  • [2009-05-25 8:17]
  • [+]

Ha Peter,

Een fraaie opname van de bosuil,met goed gebruik van invulflits,op mijn scherm komen de kleuren van de uil (denk ik) iets te oranjebruin over,maar wie weet zijn de kleuren van deze uil ook wel zo,daar ik ze ook niet alledaags tegenkom,

Groetjes
Paul

  • Great 
  • zetu Gold Star Critiquer/Silver Workshop Editor/Gold Note Writer [C: 657 W: 15 N: 1636] (6365)
  • [2009-05-25 8:20]

Hello Peter
Great capture with excellent details and vivid colors.
Regards
Razvan

  • Great 
  • Alex99 Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 3596 W: 143 N: 5696] (18621)
  • [2009-05-25 8:36]

Hi Peter.
What a cute owl you have shared with nicely composed shot. Its pose and glance as well as colouration are simply amazing. I like very impressive branches and leaves (and sharp and blurred). BG is very delicate. Lens work is very good. Kind wishes and TFS.
Alexei.

Hi Peter...
A well composed and detailed capture of a beautiful owl. I wonder if he is a wise old owl? Our world could use some wisdom... :) TFS.

Larry

  • Great 
  • siggi Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 1385 W: 56 N: 4777] (16434)
  • [2009-05-25 10:13]

Hello Peter,
A lovely portrait of this littleTawny Owl .Very good details in the plumage.Good DOF and POV.Nicely lit with well saturated colours.TFS
Best regards Siggi

hallo Peter
hier gaat je hart sneller van kloppen als je hem in de boom ziet zitten
super compositie en supper kleuren
great shot
groetjes lou

Ciao Peter, superb portrait of wonderful owl with fine details and excwllent sharpness, very well done, ciao Silvio

Ha Peter,

Prachtig shot van deze uil
Scherpte, compositie, POV en DOF zijn Perfect
Over de kleur denk ik dat Paul gelijk heeft of misschien iets te veel contrast?

TFS Thijs

  • Great 
  • Argus Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 3831 W: 190 N: 11410] (35161)
  • [2009-05-25 11:38]

Hello Peter,
A fine capture of a red-brown variant of the Tawney Owlsittng in what looks like fine natural environment despite it being a captive bird. The POV and technical standard are excellent in this fine full-frame composition.
One day I hope to take a shot of this species, but one has to be lucky in the wild!
Thanks and have a good week,
Ivan

Hi Peter,
What a beautiful capture of a Tawny owl from frontal POV with neat details and excellent composition.
TFS and greetings from Kizkalesi (Mersin province)

Bayram

Hello Peter!
This Strix aluco looks like watich you! :> Nice eye-contact and good colourations of picture. Anyway, this time I think that picture was cropped a little too much (or maybe a little too much sharpened?) :)
Greetings from Poland,
Radomir

  • Great 
  • nglen Gold Star Critiquer/Silver Workshop Editor/Gold Note Writer [C: 2924 W: 34 N: 8671] (32310)
  • [2009-05-25 13:10]

Hi Peter. I must say thanks for the interesting notes. This picture of the Owl looks like an oil painting . With its rich colours and fine detail in the feathers. It has its eyes on you . You were able to take this from a good POV. Well done TFS.
Nick..

hello Peter!
this a really good spotted owl plumage well captured in classic pose..

best sERGIO

Hello Peter
Tawny Owl's great capture with sharp focus and great eyes contact. POV, colors and lighting also great. good informative notes. thanks for sharing, have a good night
Ahmet

  • Great 
  • jaycee Gold Star Critiquer/Silver Workshop Editor/Gold Note Writer [C: 2493 W: 11 N: 6885] (21912)
  • [2009-05-25 16:44]

Hi Peter,

This Tawny Owl is marvelous! You must have been close to him - I have never been able to get close to an Owl! A wonderful pose as he locks eyes with you. Excellent natural colors and fine details of his face, eyes, beak and feathers. I would be THRILLED to get a shot like this.

Jane

hello Peter

a superb photo of the Tawny Owl with the fine frontal POV,
the wonderful eye-contact with you, superb focus with
great sharpness and details, i love the tight framing
(j'aime le cadrage sérré), TFS

Asbed

hello Peter
attractive photographic bird, beautiful presentation through a tight composition,full rich colours and sharp,very fine photo
TFS
Nasos

  • Great 
  • Juyona Gold Star Critiquer/Silver Workshop Editor/Gold Note Writer [C: 2269 W: 10 N: 2650] (15641)
  • [2009-05-25 23:49]

Hola Peter,
buena captura,
precioso plumaje y fino foco...
magnífico encuadre,
saludos

  • Great 
  • efsus Gold Star Critiquer/Silver Workshop Editor/Gold Note Writer [C: 436 W: 10 N: 738] (3210)
  • [2009-05-26 3:09]

Merhaba Peter!
Bu muhteşem türün enfes bir karesini sunmuşsun. Tebrikler.
Selamlar.

Hüseyin

Hi Peter,
A very well taken portrait of this Tawny.
Nice contrast and saturation with good detail.
TFS & Cheers,
Steve

  • Great 
  • MMM Gold Star Critiquer/Gold Note Writer [C: 924 W: 0 N: 1995] (8957)
  • [2009-05-26 10:14]

Hi Peter
Beautiful composition.Everything is fine with me.Great POV and nice pose,sharp image with great colors,I also like that catch light in the eye and the eye's contaact with you.
TFS Michel

  • Great 
  • cirano Gold Star Critiquer/Gold Note Writer [C: 656 W: 0 N: 228] (4954)
  • [2009-05-26 11:01]

Slav Peter,
What a lovely owl.Excellent capture and good details and sharpness.
Thanks for sharing.
Regards.
Dûrzan

Hello Peter
very beautiful and very sharp shot of this Tawny Owl, i lik the details on his face and his plumage, beautiful colors, nice pose and imressive look
Have a good night
Jacqueline

What an amazing shot of this Owl, Peter, especially posing for you, I feel!
Very well captured, my friend!
Greetings from India!
Goldy

Hello Peter,
what a wonderful capture of Tawny Owl taken from an excellent POV with very good sharpness and bright colours, fantastic visual impression.
TFS
Best regards
Maurizio

  • Great 
  • tuslaw Gold Star Critiquer/Silver Workshop Editor/Gold Note Writer [C: 511 W: 20 N: 1393] (4863)
  • [2009-05-27 19:23]

Beautiful image Peter,
A gorgeous bird shown in a a nice natural pose with great colors and excellent detail. Love the intense gaze and the catch light in it's eyes. Very informative notes!! TFS.
I've checked my guide book and apparently we don't have this species here in the US.
Ron

Did you shoot this Avifauna ( I think its near Alpen de rijn!). This bird park was one of my favorite place in your beautiful country. The picture of the owl is good, but the BG has some disturbances which i know cannot be avoided in this park :-)
I love the catch light here

  • Great 
  • anel Gold Star Critiquer/Gold Note Writer [C: 1731 W: 0 N: 3942] (15822)
  • [2009-05-29 1:52]

hello Peter,
A pleasant diagonal presentation for this beautiful Tawny Owl. I like the natural colors of this shot. The expression of the bird is interesting too, gives the impression of some kind of philosophical quietness. Pleasant picture.
Thanks . Have a nice day
Anne

  • Great 
  • SelenE Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 2405 W: 63 N: 4227] (13822)
  • [2009-05-30 15:40]

Hi Peter,
How cute :o) I love that expression you captured. Nice POV, good eye contact and composition.
TFS
Have a nice weekend,
Selen

Calibration Check
















0123456789ABCDEF