Which is bigger Kestrel or Sparrowhawk?

[Cowgirl]

Hi there,

Hope you experts can settle an old argument between me & hubbie (there may also be money riding on it!) aka thread title.

I have been looking at three sites RSPB, Birds of Britain (BOB) & British Garden Birds (BGB) to try & sort this out.

1. RSPB doesn't give dimensions! Doh!
2. BOB gives a kestral as 13 -15 inch & BGB as 10 - 14
3. Both give a sprawk as 12 - 16

What is the official size of a kestral then?

I know there are variations, but I'm only interested in official.

He's wrong anyway cos he says kestral is smallest Bird of Prey & I'm pretty sure it's a merlin!

What I'm not sure about is if a kestral is bigger than a sparrowhawk.

[nigel_b]

From British Birds of Prey, Leslie Brown (1989) p283

Female Sparrowhawk body weight 940g
Male Sparrowhawk body weight 140g
Female Kestrel body weight 220g
Male Kestrel body weight 180g


From Collins Bird Guide 1st ed.

Fem Sp length 35-41cm, wingspan 67-80cm
Male Sp length 29-34cm, wingspan 58-65cm
Both Kes length 31-37cm, wingspan 68-78cm

so in order of size biggest first its probably

1) Female sparrowhawk
2) Female Kestrel
3) Male Kestrel
4) Male Sparrowhawk

[Tracey.A]

In the RSPB handbook of British birds, the sizes for the following birds are:-

Sparrowhawk 28-38 cm.
Kestrel 32-35 cm.
Merlin 25-30 cm.

Tracey

[darrenm]

Male Sparrowhawk are roughly the same size has a Kestrel in both body and wing span but Female Sparrowhawks are generally larger than both.

The Collins Bird Guide by Mullarney, Svensson, Zetterstrom and Grant gives these dimensions;

(Common) Kestrel L 31-37cm and WS 68-78cm.

(Eurasian) Sparrowhawk (male) L 29-34 cm and WS 58-65cm, (female) L 35-41cm and WS 67-80 cm

The Merlin is the smallest resident Bird of prey in the UK. L 26-33cm and WS 55-69cm.

Hope this info is of some help

[Cowgirl]

Woo Hoo! Thank you.

I wasn't sure that a male sprawk was the smaller of the two (but argued for it anyway, hey, I'm female that's what we do!) Your replies have given me enough evidence tho'

Thank you for your prompt replies

Now off to gloat.....

[thebeard]

Female Sparrowhawk body weight 940g
Male Sparrowhawk body weight 140g

is that right, seems a massive difference!!!

[nigel_b]

Originally Posted by thebeard

is that right, seems a massive difference!!!

Its what the book says, I'll check it further and get back to you.

Edit: There's a couple of websites giving 340g as female weight. Has to seem more reasonable? Maybe there is a typo in the original BBoP book?

Dont forget when a dimension such a length doubles, area goes up by a factor of 4 and volume (and hence weight) by a factor of 8.

[nigel_b]

I cant edit the original post but it seems there is a misprint in British Birds of Prey. The female sparrowhawk weight should probably be about 320g not 940g. I've corrected it below:

Originally Posted by nigel_b

From British Birds of Prey, Leslie Brown (1989) p283

Female Sparrowhawk body weight 320g
Male Sparrowhawk body weight 140g
Female Kestrel body weight 220g
Male Kestrel body weight 180g


From Collins Bird Guide 1st ed.

Fem Sp length 35-41cm, wingspan 67-80cm
Male Sp length 29-34cm, wingspan 58-65cm
Both Kes length 31-37cm, wingspan 68-78cm

so in order of size biggest first its probably

1) Female sparrowhawk
2) Female Kestrel
3) Male Kestrel
4) Male Sparrowhawk

[Elizabeth B]

Re: Which is bigger Kestral or Sparrowhawk?

--------------------------------------------------------------------------------
The BTO's BirdFacts site is an excellent source of information::BTO - Birds of Britain

ie

Kestrel
Length: 34 cm Wingspan: 76 cm Weight: M: 190 g F: 220 g
BTO BirdFacts - Kestrel

Sparrowhawk
Length: 33 cm Wingspan: 62 cm Weight: M: 150 g F: 260 g
BTO BirdFacts - Sparrowhawk

Merlin
Length: 28 cm Wingspan: 56 cm Weight: M: 180 g F: 230 g
BTO BirdFacts - Merlin

[Picidae]

Without quoting from books or online references to size (as these quite often vary and are only mean measurements) but from experience in the field: Kestrel is on the whole larger than Sparrowhawks but there can be overlap with individual female Sparrowhawks but not always (remembering there is always slight intraspecific variation with any bird species). Size is not always consurmate with weight especially comparing birds such as falcons and accipiters, since body weight is linked to feeding/hunting ecology and particular prey availability in particular hunting areas Wiley InterScience :: Session Cookies ).