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Old Thursday 17th August 2017, 08:09   #1
ChrisKten
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Sparrowhawk Eye size and Nape patterns.

said that I'd look through my Sparrowhawk pics for any evidence of differing Nape patterns on males and female, especially juves. Also to see if there's a relationship between eye/head size and gender.

I've over 10,000 pics of Sparrowhawks, and the vast majority are of behaviour, as that's what I'm most interested in. Finding pics that show what I'm looking for won't be easy, and I don't have the time ATM. But, I thought that I'd upload 20+ pics that are of birds that I'm positive(ish) of the gender, and see if any here that are interested can see any of the aforementioned relationships. I must admit that my eyes aren't really good enough to see these differences unless there's a stark contrast, so I can see no difference in eye size. I can see differences in nape patterns, but I'll need to sort out more pics to illustrate this.

Anyway, here's a few pics to be getting on with; I only expect 2 or 3 in this forum to have any interest in this, and they need to see the thread and have the time first

Not that it matters in this case, but all pics through double glazing

Only the first pic in this group is a female
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Old Thursday 17th August 2017, 08:12   #2
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Another 5:
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Old Thursday 17th August 2017, 08:13   #3
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More...
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Old Thursday 17th August 2017, 08:17   #4
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Last lot for now
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Old Thursday 17th August 2017, 08:52   #5
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Thanks for starting this Chris.

We need a 'Jane' to dissect the pictures because my eyes are a bit like yours and she is great at this sort of thing. The point made in the other thread was that the eye size doesn't change between sexes but with males being a 1/3 smaller proportionately their eyes will be larger compared to their head size eg 1cm vs 10cm 1in10 compared to 1cm vs 7cm 1in7 (obviously not the correct measurements) - or put simply the males eyes will appear larger.

Lets see where this takes us anyway and lets hope that we can get a good selection of birds for comparison.

Should add I don't have any close ups of SH to help...
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Old Friday 18th August 2017, 06:41   #6
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This seemed like a good idea at the time, but with only the two of us interested, and neither having great eyesight, perhaps not such a good idea after all.

I'll check back on the thread at the weekend or next week maybe... I won't sort out any more pics though.
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Old Sunday 20th August 2017, 17:49   #7
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Originally Posted by ChrisKten View Post
This seemed like a good idea at the time, but with only the two of us interested, .......
Chris, There's at least three interested! But I'm like everyone (?) else: I'm waiting for someone else to do the legwork and tell us the answer. I was tempted to make a start but then I thought what could be involved - e.g. download images and put male/female side by side in a 'compare' tool, scale one or the other up or down, then compare across directly. I tried the 'quick & dirty' way, just eye-balling (not supposed to be a joke...) images one after the other, and very soon got too confused. Mind you that happens quite easily.

Just to confuse things further, I've a pet notion that the eye in Sparrowhawk and Goshawk is a similar size, but the head is larger in Goshawk, making the eye look relatively smaller. Might be nonsense, probably is, but all my Goshawk images are of birds a million miles away so I'll never be testing it.

Whatever, it's always a great pleasure to look at your Sparrowhawk images!

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Old Wednesday 23rd August 2017, 08:05   #8
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I think we're going to have a long wait for any responses, Brian

(I will have a proper look through my images when I feel up to it - I've an appointment with the Opticians in a few weeks, maybe new glasses will help )
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Old Thursday 31st August 2017, 16:21   #9
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I've heard the same thing (re eye size) said about peregrines but you'd really need to examine birds of both sexes in the hand to confirm it. By the way - those are beautiful shots, ChrisKten.
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Old Tuesday 12th September 2017, 10:13   #10
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Looks dangerous yet beautiful! Nice find
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Old Monday 18th September 2017, 15:03   #11
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Hello Chris... I know this is going off topic but do you mind if I ask you a pigeon question??
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Old Monday 18th September 2017, 19:29   #12
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Hello Chris... I know this is going off topic but do you mind if I ask you a pigeon question??
Of course I don't mind... ask away (Although I can't promise to know the answer )
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Old Tuesday 19th September 2017, 15:18   #13
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As you know all domestic pigeons originate from the Rock Dove.. The most common colour seen in Racing/Feral pigeons is known as Blue-bar, just like the wild Rock Dove, or blue-checker, not like the wild Rock Dove..
The question is do you get wild Rock Dove with a blue-checker pattern??
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Old Tuesday 19th September 2017, 16:09   #14
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TBH, I don't know. I've never seen a Wild Rock Dove - I'm not even sure that I'd recognise one if I did. In fact, I'm not even sure there are any truly wild Rock Doves... don't they have domestic ancestry by now? I mean Feral Pigeons are everywhere, and they will breed with anything that keeps still for long enough and moves it's tail out of the way (Seriously, I've seen Pigeons try to mate with Collared Doves, and they also try to mate with sick Pigeons, even if the sick bird is another male)
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Old Tuesday 19th September 2017, 20:13   #15
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TBH, I don't know. I've never seen a Wild Rock Dove - I'm not even sure that I'd recognise one if I did. In fact, I'm not even sure there are any truly wild Rock Doves... don't they have domestic ancestry by now? I mean Feral Pigeons are everywhere, and they will breed with anything that keeps still for long enough and moves it's tail out of the way (Seriously, I've seen Pigeons try to mate with Collared Doves, and they also try to mate with sick Pigeons, even if the sick bird is another male)
I've never seen a wild one either... I assume like all ancestors of domestic breeds they're a little smaller.. The Feral/racing/carrier (not the breed) are all domesticated Rock Doves somewhat removed from their wild ancestor...
You often see Feral pigeons described a Rock Doves, even the checkered variety which has led me to ask the question... It's a little like calling a dog a wolf.. Technically correct but not correct...
Thank you Chris for your reply... I'll continue to watch out for the answer to my question....
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Old Tuesday 19th September 2017, 23:20   #16
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Back onto topic... Have you asked these questions on a falconry forum? Although there are far less Sparrowhawks trained today than 50 years ago.. When you train a bird of prey you observe them from every possible angle at close quarters over many years and when you've trained numerous birds you can develop an eye for subtle differences not always noticeable in photographs..
I also note your interested in behaviour.. Have you ever came across Sparrowhawks cooperating while hunting?
Have you ever come across wild birds of prey interacting with man?
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Old Wednesday 20th September 2017, 07:30   #17
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Back onto topic... Have you asked these questions on a falconry forum? Although there are far less Sparrowhawks trained today than 50 years ago.. When you train a bird of prey you observe them from every possible angle at close quarters over many years and when you've trained numerous birds you can develop an eye for subtle differences not always noticeable in photographs..
I also note your interested in behaviour.. Have you ever came across Sparrowhawks cooperating while hunting?
Have you ever come across wild birds of prey interacting with man?
Actually, I keep meaning to ask in a falconry forum, but I get distracted easily by events in the garden... maybe I'll join and ask opinions later; I'll post any relevant info that I get.

There's a thread here about Sparrowhawk hunting co-operation - only anecdotal, and only very rarely seen (or misinterpreted). Have a read of the link I posted there, although not strictly relevant to your question, you might find it interesting. Actually I'll post it again here: http://www.internationalornithology..../S24/S24.3.htm.

As for wild Raptors interacting with Man... only in the same way as a Robin might follow around a farmer ploughing a field. Sparrowhawks often use me as a distraction - when I'm in the garden clearing up and/or hand-feeding a few Pigeons, the smaller birds and the Pigeons that aren't used to me yet, concentrate on me. Rather than scan for predators, they watch me in case I'm a predator. The smaller birds treat me a bit like I'm a Crow eating a nut... they'll pick up any bits the Crow might drop, but be wary of being grabbed by the Crow.

So while the other birds are watching me, a Sparrowhawk will swoop into my trees and attempt to get a meal... I even had one try to take a Pigeon from my arm once. Fred, OTOH, (a male Sparrowhawk that visited for over 6 years) would stay in my trees while I was in the garden, and totally ignore me. Although he was a bit different, he preferred Mice to Birds. I've also often seen Sparrowhawks use noise/disturbance caused by people as a distraction, but they use wind blowing branches and changes in light/weather too.

There are also totally unnatural interactions with Man; feeding dead Mice to attract Sparrowhawks for photography springs to mind - as does feeding Red Kites. The later appeared to help the species, the former makes an intelligent hunter mentally and physically lazy... IMHO, which I can't see being good in the long term.
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Old Wednesday 20th September 2017, 21:48   #18
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Hi Chriksten
Sorry this is not directly to do with eyesize but as you have seen many more sparrowhawks than me you might be willing to have a look at a couple of pics I took on exmoor recently, and identify the predator. The prey is a kestrel and some say the predator is a female sparrowhawk and others say it is a male Goshawk.
The pics are not great but I'm intrigued as to the white markings around the head. I saw the kestrel hunting 15mins before the pics were taken, so I assume it was probably taken on the ground. Unfortunately my camera was in butterfly mode so I was totally unprepared and suprised when the hawk with prey took off from rushes not 20ft from me! It flew about 100mtrs across a bog and stream and went back down into the rushes.
I assumed it was a male sparrowhawk with prey. Only when I later processed the pics did I realise it had a kestrel which I felt was perhaps too big for a male to fly with. Kestrels are noted as occasional sparrowhawk prey items.
I would be very interested if you have an opinion on the hawks identity. Oh Dear I cant work out how to attach the pics
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Old Thursday 21st September 2017, 06:13   #19
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Hi Bob,

Just from the size and lack of any white lining to the tail bars, I'd say it's a Sparrowhawk. From size and prey choice, I'd say a female, and from what I can see of the breast barring, an adult. My eyes aren't good enough to be any more definite from the pics.
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Old Thursday 21st September 2017, 07:00   #20
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That's quite an amazing shot! Agree with Chris on adult female Sparrowhawk for the reasons given, I would add angular outer tail feather.
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Old Thursday 21st September 2017, 17:35   #21
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Many thanks Chris and Tom for I.D.ing the sparrowhawk with kestrel.
I'm attaching a couple of pics of a male sparrowhawk which i took some years ago.
I t stole one of my sparrows and flew across the field. I tracked it down and found it in the middle of a hedge looking very guilty!
Thought the shots might be good for your measuring task. Sorry I have not time to get involved with the project.
Thanks again , Bob
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Old Thursday 21st September 2017, 17:54   #22
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A couple of nice head shots, Bob. You did well to find it - I know all the spots they favour in my trees, but I often can't find them until they move... and my garden is only 20ft*20ft, so it's not as if they're far away.

Oh, and it may have" looked guilty", but I guarantee it never felt guilty

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