Marsh Harriers - Age Sex help please. Cambs UK (1 Viewer)

J

JCLynn

Well-known member

• Oct 9, 2009

• #1

Hi all.
I would realy appreciate any help from other BFers, to age and sex these two Marsh Harriers. This will help me greatly with regard to the accuracy of my 'local records'. Both birds photographed today 09/10/2009. I believe, at least, that one is M and one is F, but I could be wrong on both counts. The female ( well proposed female ) also appears to be banded on the right leg.
Here is what I think, 1st pic - 2nd or 3rd cy female, 2nd pic - 1cy male, and I appreciate that I may well be miles out.
Many thanks in advance.
Joe

 

ta brandreth

Well-known member

• Oct 9, 2009

• #2

I'll take a punt on 2nd year female?

 

Adin 92

Well-known member

• Oct 9, 2009

• #3

both females

 

O

Original PaulE

Well-known member

• Oct 9, 2009

• #4

it may be my monitor but i would say pic 1 juv orangey head pic2 adult female creamy head but i could be wrong
cheers

 

J

JCLynn

Well-known member

• Oct 9, 2009

• #5

Thanks for that everyone. I struggle to age these birds.
Yes Paul, pic 1 is more bright and 'orangey' on the head.
So? The birds with the more brighter yellow/orange heads are the sub-adults? And the creamy to off white heads are adult female?
There are half a dozen assorted Marsh Harriers that hunt on my 'patch' I recognise most of them. Not saying I know what age/sex they are but I know them as individuals. The second photo was a 'new bird' that I hadn't seen before.

 

Biancone

to err is human

• Oct 9, 2009

• #6

Well, I'd suggest the second bird is a juvenile (fairly even dark 'sooty' brown dorsally, but distinct pale line formed by margins of greater coverts) and birds this age can't be sexed in field. The first is tricky, I can't see any hint of the pale breast band typical of adult females, and we can't see the tail colour clearly (paler, slightly rust brown in adult females), and it's hard to be certain of the actual crown colour. Just on the photo I wouldn't disagree if someone suggested this was another juvenile!

 

Biancone

to err is human

• Oct 9, 2009

• #7

Apologies, just crossed with last post from cheersm8. Yes, the books tell you head richer, sometimes golden, yellow crown is typical for juveniles in first plumage and this fades to appear progressively less rich/more pale through the first winter and into the second plumage. One problem is that ambient light and the background all play a large part in how we perceive the colour. although it helps if you can regularly see the birds as you seem able to!

 

J

JCLynn

Well-known member

• Oct 9, 2009

• #8

Biancone said:

Apologies, just crossed with last post from cheersm8. Yes, the books tell you head richer, sometimes golden, yellow crown is typical for juveniles in first plumage and this fades to appear progressively less rich/more pale through the first winter and into the second plumage. One problem is that ambient light and the background all play a large part in how we perceive the colour. although it helps if you can regularly see the birds as you seem able to!

Click to expand...

I'm not well up on all of the intricate Harrier behaviour, but it was nice to see the Juvenile today. Although the resident pair did breed succesfully this year, the two young seemed to have left the area in mid september, leaving only the resident pair and interlopers from the surrounding area. We've had two of the very dark, juvenile types back again the past week. Whether they are the original youngsters I have no idea. As the one that I think is a juvenile, has a 'band' I would say that he/she is not one of the residents offspring as they were not ringed.