Tuesday, May 12, 2020

Shibden Valley

Four days ago I saw a Lesser Whitethroat next to Kell Lane - about 100m north of where I saw one in 2017. It was in a large hawthorn west of the road, about 50m above where Staups Lane joins Kell Lane.
My experience makes me think that descriptions of this species in guide books leave something to be desired, and I'd be interested to know what other bloggers think.
Vinicombe et al (The Helm guide to bird ID) say that the head is grey, often with darker lores and ear coverts, the upperparts are grey-brown, and the underparts appear clean silky-white. Svensson et al (Collins bird guide) say the bird is always grey-brown above with greyer crown and tail, and darker grey ear coverts - darker than crown; and their pictures show buff underparts. Neither mentions any difference between the sexes.
My bird was small and very active, making it difficult to see all its features (I didn't see the legs, for example). It stayed in the bush, and after maybe a minute flew off - when the white sides to the short tail were clearly seen.
The sun was shining, and to me the cap and ear coverts both looked light to mid-brown - with no difference in colour. The upperparts were mid-brown, and the underparts a clean light buff (not "silky-white"). I didn't see a whiter throat, but cannot exclude this. And I didn't see any grey in the upperparts.
There are several races of Lesser Whitethroat worldwide, but I have to assume that in Calderdale in spring I'm looking at the W European race.
In the past I have seen Lesser Whitethroats that fit the above textbook descriptions, and in which the white throat stands out. What I wonder is whether these are males, and whether females differ from males in having brown caps and ear coverts, (similar to the sex difference in Common Whitethroat).
This would make the bird I saw three days ago a female. I haven't seen it again as yet, (and I haven't seen a grey-capped bird either!).
The latest two issues of Birdwatch have included three photos of Ferruginous Duck, but I don't recall any recent ones of Lesser Whitethroat. It's not hard to see why, given the way the bird refuses to stay still in the open in the way its Common cousin (and Ferruginous Duck) often does. If photographers could get more spring photos of UK Lessers (before there are any juveniles to muddy the picture), maybe a sex difference will become apparent?


darrell j prest said...

According to bwp 1st winter males have a duller more brown cap

Peter Smith said...

Thanks Darrell. But wouldn't it have had its spring body moult by now? Where's MC when we need him?

Jeff Cox said...

Hi Peter. I have several photos of Lesser Whitethroat from April 2015, 2018 and 2019 taken over here on the East Coast of Yorkshire where I live now. Never saw one when I liven in Calderdale. Let me know if you want any :)

Peter Smith said...

Thanks Jeff. I've looked at one on your Hornsea blog. I just wonder whether most of the ones that people photograph in spring are males, because the females are skulking or incubating? At this time of year I see several male Common Whitethroats, but rarely a female. I hope you're having a good spring.

Mick C said...

Hi Pete
Hope you're keeping well! Quite a coincidence. I've been looking at lesser throats close to home (hard to get clear view though) which, prior to lockdown, I didn't. And, some years back looked into moult etc cos had an eastern type at spurn and, more recently, intrigued by folk blithely (no pun etc) identifying ssp in field in autumn at spurn inc birds I've seen. AND, this ID being proved right by dna!
Re your Qs. I find detailed info confusing tbh. But, in summary, re nominate
Plumage same in both sexes
Contra your refs, I know latest Svensson says unders pinky BUFF. I've judged unders to look vaguely greyish buff sometimes. My reading is ...
Ageing in field at any season, and perhaps especially in spring, usually impossible. Because this relies on seeing some retained juv tail, tertial or covert (?) feathers.
However, I did read (I think) that head pattern can vary with less obvious mask on some. Again, I've found mask can be subtle. Retained juv pattern in spring????
Uppers grey brown.or earth brown. So not always predominantly grey?? Certainly, I see upperparts as 'brown' sometimes, albeit dull but sometimes more grey looking.
I note DJP ref to BWP 1w. Ads and juvs moult body in autumn. I find info re pre nuptial moult a bit confusing. Both ages have partial but all I've read refers to some tail and wing moult ie not head/ body in nominate at this time. So, a lot of waffle from me to say plumage same in sexes, ageing very difficult in field.

Have you looked at 'paler' end Blythe!!
You didn't see leg colour. Any chance it was a different 1s sylvia?

Keep safe

Mick C said...

Actually, given his experience at spurn, your very own Dan Branch might be able to assist!

Peter Smith said...

Thanks very much Mick for such detailed thoughts. (I'm sorry I don't understand the Blythe reference). The sun was bright when I saw the bird, and this could have made the bird look lighter brown than it would have done in neutral light. From what you say it looks as if DJP hit the nail on the head with his reference to some 1st winter males having a browner cap, since I was wrong to think this must have moulted by now.
I can't think of another Sylvia with clear white tail sides that would look like this bird.
Best wishes, Pete

Mick C said...

Lesser whitethroat sup sp blyth ... paler