observation on sparrow hawk speed

[rawoak]

While driving along a single track country road this morning a sparrow hawk flew past us going in the same direction as were we. Now I was not going fast as the road is notorious for traffic bumps when the bird flew past and I checked my speed thinking I must be going slower than I thought, no we were doing 28 or so and the bird was increasing the gap now about 30 feet. so I speeded up and to keep the gap I needed to travel at 35 mph. I wondered if any one had had the same experience and if such speed were unusual for sparrow hawks.

[Acipiter]

Never had such a experience as one flying along side Rawoak, but I have had them fly across me when driving more then once. I do agree it does look pretty Quick, but it is allusion. They are not as quick as you may think, 25 to 30 miles a hour is about right. Of course I have no way to verify that, Just passing on what I have read.

[AndyC]

I've followed them down country lanes when driving at least a dozen times, sometimes only for a few yards but on two or three occasions for upwards of
200yards. These longer flights have been at around 30 - 35mph (according to the speedo which probably reads a bit high). I have twice been lucky enough to have hen harriers fly down the road in front of me following roadside ditches (in Sutherland) and was surprised to find them doing a good 40mph!


Andy

[FUDGEY]

I actually disagree with the books. Having spent a lot of time witnessing attacks lately I would say over 40mph at least. I agree it might be a little deceiving. I say 40mph as it looks like 70mph when you witness it.

[rawoak]

Certanily I would agree the speedo is a little fast and our car is 10 years old but it's interesting how often this seems to happen. I am sure the bird we saw was not hunting at the time it passed us (isnt that embarassing to be overtaken by a bird ,) Could it have been hoping to catch something unawears. I guess we will never know. I guess I will now be looking out for another. Do they play I have watched Peregrine's play high in the air over cliffs so it's a thought, was it racing me
Rawoak

[Acipiter]

I will have to have a word with Professor Ian Newton and tell him he is wrong Alan, quote from his book. To catch its prey, a sparrowhawk has the benefit of a keen eye, great stealth and manoeuvrability, but it is not especially fast in level flight. The usual speed is 30 40 km per hour (20 to25mph) reaching 50 km per hour (30 mph) in a short burst. The hawk is thus some what faster then most songbirds, which fly at less then 35km (22mph). but slower then swallows, waders and larger prey, such as pigeons. As you know I never just take the word Of what it says in books, and always try to prove for my self what is written. Could he have got it wrong? I will leave that up to you to decide.

[FUDGEY]

I shouldnt really go against his findings, but Im only going with my what my eye sees and my head thinks. It is more likely that I am wrong than right I agree. I just seen a clip on the One Show saying Swifts can go at 60mph. I dont think a Spar could go as fast as this, but Im still saying 50mph. At my hide there is a 45 degree slope that the Hawk comes down. So in reality its closer to a stoop and not level flight. Does Ian Newtown say this is a level flight speed? I wonder how accurate we could work it out if I used a stopwatch and measured the distance travelled? I could time her over 20 yards I reckon and measure the distance pretty accurately.

[Acipiter]

Hi Alan, Yes he does say 30 mph is level flight speed, I have had then flash past me when I have been in the wood. And I have to admit It does look very Quick indeed, much faster then 25 to 30 mph. And I was some what surprised It was so low. On the question of trying to time one, I am not sure how it could be done spot on. Do they set up two cameras a certain distance apart, and time how long it takes to fire the shutters between the two cameras. Maybe someone could tell you the best and easiest way to go about it. Using a stop watch, I am not sure how you could be in the right place at the right time. But if you manage it some way let us know, I for one would be most interested in your findings.

[King Edward]

Originally Posted by FUDGEY

I could time her over 20 yards I reckon and measure the distance pretty accurately.

I think you'd struggle to do the timing accurately enough by hand over such a short distance. At 30 mph, 20 yards would only take 1.4 seconds. And at 40 mph, only 1.0 seconds. Even a short lag in pressing the stopwatch button could introduce substantial error into the calculation.

If you have a camera with a high speed burst mode (known time between frames), you might perhaps be able to calculate the distance between two or three successive frames. You'd need a good vantage point, though, to minimise parallax errors to make sure you could locate her position exactly in each frame.

I think Newton is referring to level flight speed, not stooping. I have been passed/overtaken a few times by Sparrowhawk flying low up lanes/hedgerows, and while it gives an impression of speed I think that's largely due to surprise and the bird's proximity to the ground/hedge etc., rather than to actual high speed.

[rawoak]

In my case I did look at the speedo and the registered speed on the instrment was 35 mph allowing for a small error at that speed (at slow speeds the error would be small,) I still think the bird in question was traveling at at least 30 and more like 33 to 34.