• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Curlew sp. at Minsmere (3 Viewers)

me1000 said:
O.K. so my question to you all cannot be answered.
So why can`t Curlews be hybrids ???????????????????????????
me

Sorry me, I am not online outside office hours (yet) or I would have answered your question earlier (or at least tried). I am not sure it is a simple case of "can't" so much as "don't" and there are no records (that I am aware of) of Eurasian curlew and whimbrels hybridising and they have enough opportunity to form pairs. Do not let wildfowl fool you, hybridisation is not that common in birds but there is a lot to the issue. At basic level, courtship strategies are different for each species with there being all kinds of specific cues such as voice - length of song/call, pitch and loudness: plumage - "the eye of the beholder": power - smaller birds would back down in a contest with another male. We might ask "what could possibly break down those barriers?" In wildlfowl, it is thought to be birds of captive origin not knowing what they are supposed to be and in some cases, the drake being more robust than his 'rival' drake. This is not an invariable situation but it possibly illustrates the point quite well.

OK, we have broken down the courtship barrier, what comes next? Well, the old classification of a species not being able to interbreed still stands at this stage. Despite the exceptions (and there are a slowly growing number), most species cannot interbreed even within genera. Or let me modify that, they can copulate but not produce eggs or fertillised eggs. As an example, there is no barrier to foxes and domestic dogs attempting to breed (I believe it has happened) but no fertilisation takes place.

The next stage is if fertile eggs are produced - many eggs will not hatch but even if they do, there is a fair chance the young will not be fertile. Coming back to wildfowl, it seems evolution has been a little more complex (and recent?) in this group (or in a few genera) and that explains why there is an exception. It is debatable whether a similar situation would exist in Numenius because species must have been isolated to become distinct at some point. What may have happened is that a few species (of Numenius) subsequently expanded again to overlap with others and there is enough definition between the species to make breeding unlikely (at best).

The question then comes down to isolated birds in a declining (or nearly extinct) population. Much of the time, the birds will form associations with other birds and even gender pairs but there are many more non-breeding examples than there are breeding examples. Therefore, the evidence does not fit with a rare bird hybridising through lack of mates, as it does not seem to be one of the conditions that leads to hybridisation - perhaps I should add, in natural systems.

In conclusion, the Numenius genus does not seem to produce hybrids although I am sure someone will point to possibles but statistically, the evidence does not favour this idea. However, what this does not say is that there is still a possibility of 'genetic' birds of any Numenius species that closely approximate birds of another species and this is possibly the main area to eliminate. The Minsmere (and by argument, the Druiridge bird) could be genetic variants of something else and even though I am not completely convinced by this idea, the conservation status of the SBC makes it imperative that we find out.

Hmm, not a bad post to say I promised myself I would avoid the rest of this debate. ;) Seriously though, please don't dive in and and beat me up over this post, it is meant for discussion and NOT to prove a case - OK?
 
Last night I had a long discussion about the bird with some friends who have also seen it. Opinion was divided with most thinking it probably is one. I'm still not convinced and in fact I'm wondering if I saw the right bird. I was there on Saturday and got to the levels just in time (c9.20) to see the curlew sp. fly off. I then saw the curlew sp. in the stubble field (along with several hundred other birders) around midday. Despite it being small, grey and short-billed I can't help thinking it was like a small curlew (i.e. didn't have particularly different jizz). I did note it stand very upright on occassion but the general feeding behaviour, in my opinion, was not that different from the two Curlews. Friends swear blind it was totally different in terms of jizz, build etc. but I'm not convinced. Did I see (and photograph) the wrong bird?
 
I'm sure the vast majority of people have been looking at the right bird. It didn't have the right posture, structure, behaviour or bill shape as i mentioned and that was more than enough to make me wonder about its provenance....we still don't know what it is exactly but it would appear to be an adult (something my mate was putting to many folks on Sat and getting cold shouldered.....eight tail bars!) and therefore as LGRE posted it can't be what we previously thought of as adult-type SBC.

It could turn out to be a hybrid, previously unknown race, even sushkini race perhaps which are known to be phenotypically very close to perceived appearance of SBC. With regard to hybridisation, it may have been occuring more than we think ;)
 
Tim Allwood said:
I'm sure the vast majority of people have been looking at the right bird. It didn't have the right posture, structure, behaviour or bill shape as i mentioned and that was more than enough to make me wonder about its provenance....we still don't know what it is exactly but it would appear to be an adult (something my mate was putting to many folks on Sat and getting cold shouldered.....eight tail bars!) and therefore as LGRE posted it can't be what we previously thought of as adult-type SBC.

It could turn out to be a hybrid, previously unknown race, even sushkini race perhaps which are known to be phenotypically very close to perceived appearance of SBC. With regard to hybridisation, it may have been occuring more than we think ;)

I didn't see the tail pattern in the field. People I've spoken to have said it looked good for S-B Curlew whereas the recent photos clearly show 8 tail bars. Is it this feature that ages the bird as an adult?
 
Sorry Marek, can't answer that one. I've only said all along that I doubted this bird's (and it's NE predecessor's) credentials as a Slender-billed Curlew.
Wanting to be able to nicely pigeon-hole everything isn't something I do.
Accept it, we know what it isn't not what it is.
 
marek_walford said:
I'd like to tell you it's a SBC but...

So, what is it then?

I guess the first answer to that, based on other preceding messages, is.....is it the same bird??
There are obviously a lot more (and clearer) pictures coming out at the moment so surely some-one can advise whether this is still "the bird" or the small pale EC mentioned in #211.

If some-one could clear that at least I'd know which one I'd seen!!!!
 
Allen said:
I guess the first answer to that, based on other preceding messages, is.....is it the same bird??
I'm not sure it's conclusively established that there ever was a second "small curlew" - only that some people were looking at the wrong bird at some point. I'm convinced all the photos on Surfbirds and in the other links posted here are of the same individual.

As I said before, despite a good numer of pro-SBC features I'm far from convinced. Going on what I've read, the points I want answers to are:

Why does the bird show:

1) such a thick bill without the fine tip said to be characteristic of SBC?
2) No markedly dark mantle compared to Eurasian Curlew?
3) such a clear eye-ring?
4) Tertials quite unlike those described for the Druridge bird, but very similar to adult Eurasian (even if the "ladder" effect on the outer webs is more striking)?
5) other feather patterns (mantle, scapulars, wing coverts) that don't seem to differ from Eurasian Curlew (though need to do more checking to be sure this is actually the case)
6) such dark tail bars
7) so many tail bars
8) insufficiently distinct breast streaking
9) such a dark ground colour to the breast

I'm not claiming any expertise here and not all these points may be valid for 1st-winter SBC. If any are wrong-headed I hope someone will correct me and cite the evidence. They are just the things that seemed anomalous to me when I was looking at it.
 
Last edited:
there's only ever been one bird. although some people may have decided to look at a curlew....

can't really answer most of those those questions Jason until we finally work out what it is , but notably, those of us that were sceptical from the start (chris, me, Jane, ground roller etc) haven't at any point been able to say what it actually is or even might be! at any point. The possibilities have been posted a few times but despite lots of discussion and reading i'm no nearer coming up with a suggestion!
 
Found a comment from Italy:-

"Subject: Re: Minsmere Curlew

Hi Szaby,

could you please send this message to EuroTwitch in case they do not get it.

I think the Numenius sp. in question it´s a very small juv. arquata, not a tenuirostris!

The legs are grey not balck as should be, the thigh (the feathering) its short, not long as in SBC leaving exposed long tibia, the face pattern could be ok for the least marked SBC but not quite good, the tail barring its wrong, also tertial pattern, the underwing visible in one picture I´ve seen its yes very white and clean but when you look at the outer primaries these do not appear to be uniformly grey as in SBC but barred or anyway not contrastingly darkish. Also other minor characters are wrong.

I think with curlews we have yet much to learn and study, especially when talking about the quite small and very pale white underwinged Greater Curlew of the so called suskinii-type (whetever a race valid or not but anyway odd arquata that exist and are around). I´ve studied that birds in museums (ex. in Almaty) and in the field.

Cheers,

Andrea Corso
Italy"

Andy.
 
Steve said:
Reader it's post #243 on your script.

Thanks Steve. I had missed that one.

It would be great if the results of this could substantiate the claims that this is a SBC.

To my mind I can't accept that it is based on all that I have seen so far.
 
Andrew Rowlands said:
Found a comment from Italy:-

"Subject: Re: Minsmere Curlew

the thigh (the feathering) its short, not long as in SBC leaving exposed long tibia

Andy.

This is something that I noted on my field notes on the bird I saw in Greece. I mentioned it quite early on in this thread then promptly forgot about it. Along with the bill (which I can never accept is an SBC) those thigh feathers do seem to stop far short of what I had witnessed on a bird that I class as a good SBC.
 
Why are people having an issue with the number of bars in the tail?

Here is a quote from BWPI on Juv SBC - Tail with narrower, more regular, and more numerous dark bars than adult; outer web of t6 with 6–9 bars, inner 4–9 (outer with 3–6, inner 1–2 in most adults). - So if this is a first year bird the tail too barred theory has been ruled out!!
 
Has anyone else noticed how much clearer the eye ring is looking in recent photos, as well as there appears to be more spotting?

Also in the latest pictures the head structure looks very good for SBC, it is far more sloping than the accompanying round headed EC.
 
curlew sp.

Ashley beolens said:
Has anyone else noticed how much clearer the eye ring is looking in recent photos, as well as there appears to be more spotting?

Also in the latest pictures the head structure looks very good for SBC, it is far more sloping than the accompanying round headed EC.

When I saw the bird yesterday morning, it struck me that the markings on its left flank seemed neater and less broken up than in the initial pictures. But no reason to doubt that it is the same bird. It may even depend on weather it is being watched and photographed in wet or dry conditions.

On a separate point, I have yet to get my hands on an old copy of BB. What are the main points of difference betwen this bird and the Druridge bay bird (leaving aside for a moment what species each might be).

Lastly, is it about time this bird had a name? I suggest Glenda.
 
Warning! This thread is more than 19 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Users who are viewing this thread

Back
Top