Richardson's Canada Goose or not? (1 Viewer)

Binocularface · Dec 30, 2003

Hi

I visited Caerlaverock WWT reserve in Dumfries and Galloway today to have a look at the small race Canada Geese that have been present over the past week or so.

One of the birds seem to be ok for Richardson's Canada Goose, the other bird is very similar in size, general structure and over all colouration but it seems to have a much squarer head shape. Is this within the variation for Richardson's or is it something different?

I have attached some images of both birds below. For more images of these birds click the following link:

http://www.solwaybirder.org.uk/RCG.html

Hope someone can help!

Regards
Tristan

Stephen Dunstan · Dec 30, 2003

Tristan,

I don't think it points towards any other race, so you probably have two choices:

- individual variation
- hybrid / intergrade

They don't look to be associating with other geese from your pictures - were they? If not they are presumably escapes?

Regards,

Stephen.

Binocularface · Dec 30, 2003

Stephen Dunstan said:
Tristan,

I don't think it points towards any other race, so you probably have two choices:

- individual variation
- hybrid / intergrade

They don't look to be associating with other geese from your pictures - were they? If not they are presumably escapes?

Regards,

Stephen.

Hi Stephen

Individual variation I find fair enough, but for hybrid/intergrade it would surely show some characteristics of another form?

As with ducks and geese, it's a bit of a lottery!
According to the reserve warden I spoke to today, two small race Canada Geese were seen coming in with Greenland Whitefronted Geese at Loch Ken RSPB on 20th October. These birds match the description of the birds that are now at Caerlaverock (since 17th December). Bearing in mind that these two birds are so distinctly different I think it is probably likely that the Caerlaverock birds are the same ones as seen at Loch Ken!

Regards
Tristan

Lee Evans · Dec 30, 2003

Geese Id

Hi Tristan

These two Canada Geese first appeared with Greenland White-fronted Geese at Loch Ken (Dumfries & Galloway) before later joining the Canada Geese flock thereabouts. The Canada flock then relocated to Caerlaverock where they still remain. In my opinion, these two birds are both hutchinsii (Richardson's Canada Goose) and the variation between them is fairly typical of this form. I also consider them to be genuine vagrants, quite possibly individuals that overshot their normal wintering grounds with the Greenland White-fronted Geese on Islay (Argyll).

Canada Goose racial identification is fraught with problems because of the increasing amount of intergradation that is now taking place between the populations in North America. Many of the Canada Goose forms have undergone massive population increases and have started to infringe on each other's historical geographic distributions. As a result, much intergradation is taking place so pigeonholing individuals (particularly vagrants in Europe) with specific racial identities can be somewhat foolhardy.

Very best wishes

Lee G R Evans

(PS By the way, any chance you can Email me your superb images)

MarkHows · Jan 6, 2004

I saw these birds at the weekend, they are easy to locate for those wishing to. They were feeding with the Whooper swans at the time in a field.

Mark

Steve G · Jan 6, 2004

Hi, I've also got some images of these same birds that I'll post tonight on return from work. As Lee states above it seems that these 2 birds first came into the region attached to the wintering Loch Ken Greenland Whitefronts but then more recently attached to the feral Canadas that commute between Loch Ken & the feeding pond (

) at Caerlaverock where they can be seen with their sleeves rolled up competing in the feeding free for all. Though lacking experience in these matters I had thought them to be hutchinsii. One in particular has a prominent neck collar apart from the difference in size & build proportions (to feral Canadas).

Stephen Dunstan · Jan 6, 2004

What people choose to deem 'apparently wild' in terms of unringed small (and not so small) Canadas / Red-breasted Geese / Snow Geese is clearly personal preference. Personally I don't have much faith in birds which desert carrier species flocks, how do we know when they joined up in the first place?

Regards,

Stephen.

Edward woodwood · Jan 6, 2004

Quite right Stephan, you can lay percentages on it etc but you'll never know unless they've been ringed at some point.

Plus, as has been mentioned, the variability of these forms in the wild and in captivity and the fact that some features still seem to be poorly understood (or perhaps they're not consistent features at all like neck rings etc) all adds up to it being very difficult to be certain about anything....plus there are other reasons why Canada Goose can be 'small' as alluded to by Spud (logos) in a couple of posts a few weeks back.

Steve G · Jan 6, 2004

Stephen Dunstan said:
What people choose to deem 'apparently wild' in terms of unringed small (and not so small) Canadas / Red-breasted Geese / Snow Geese is clearly personal preference. Personally I don't have much faith in birds which desert carrier species flocks, how do we know when they joined up in the first place?

Regards,

Stephen.

I can't argue with this logic. Apparently the birds appeared with Greenland Whitefronts but seem not to have been in evidence prior to this. Moving allegiance from Whitefronts to feral Canadas when the opportunity arose does not mitigate against them being wild birds; but lacking hard knowledge in these matters I am unable to contribute to the debate of wild small race vs runty Canadas. One thing was certain, in comparison to the feral "lumberjack" Canucks these particular birds were positively dainty. Now that they are "on welfare" at the Caerlaverock grain handouts they should be fairly easy to net for biometrics, ringing ( & astrological star charts),etc. Perhaps we could club together for a radio-tracking device to be fitted in the hope that it will help shed light on proceedings ( aye, right!!

).

Binocularface · Jan 6, 2004

Stephen Dunstan said:
What people choose to deem 'apparently wild' in terms of unringed small (and not so small) Canadas / Red-breasted Geese / Snow Geese is clearly personal preference. Personally I don't have much faith in birds which desert carrier species flocks, how do we know when they joined up in the first place?

Surely the best we can do is make an educated guess (as we do with many vagrants in the UK). As far as I am aware the two Richardson's Canada Geese came in with an 'arrival' of Greenland Whitefronts at Loch Ken. Correct me if I am wrong but I think there is a small population of Richardson's Canada Geese in Greenland?

The fact that they have 'hooked up' with a feral population of Atlantic Canada Geese is not a major problem as I would imagine they would have a more comfortable association with this species than they would with Greenland Whitefronts.

Whatever the true origins of these birds are, one thing is for sure; They have been an education!

Andrew Whitehouse · Jan 6, 2004

In Islay it's usually larger forms that associate with Greenland Whitefronts (the ones some reckon are parvipes for instance) whereas smaller birds ('Richardson's') tend to be with Barnacles. I think that it's the larger birds that breed in west Greenland, which explains why they get in with the GWFs that also breed there (and where the Canadas are reputedly outcompeting GWFs for nest sites). I think the smaller forms generally breed much further west, across in Arctic Canada so lord knows how they end up in this country. They're all just Canada Geese though so don't get too excited about them!

Edward woodwood · Jan 6, 2004

yes, you can make an 'educated guess but you'll not know for sure unless they've been rung

and as I also mentioned the ID of these things is far from certain as also mentioned in Lee's post

Stephen Dunstan · Jan 6, 2004

Tristan,

I agree completely, my educated guess is that birds which readily switch to a feral Canada Goose flock from a Greenland Whitefront flock are on the balance of probability not wild. I have my reasons for thinking that, you have you reasons for thinking otherwise.

In the Pinkfoot flock here on the Fylde in recent years we have had minima Canada (not a strong candidate for vagrancy), a Lesser Whitefront (Pinkfoot wrong carrier) and a couple of Bar-headed Geese (no further questions your honour). I would still like to think the Snow Geese, 'Lesser' Canada types and so on are wild, but if they start to hang out with the local feral crew I forget them.

Each to their own on this, as I said.

Regards,

Stephen.

Steve G · Jan 6, 2004

Fifebirder said:
.......... They're all just Canada Geese though so don't get too excited about them!

Well ok but these birds really did stand out. On looking at them closely its difficult not to find them attractive in comparison to the lumbering Canadas. But aesthetics apart they really are built differently with differing body proportions, bill structure & subtly different plumage.

Edward woodwood · Jan 6, 2004

the bird with the more B.c.canadensis head shape is very similar to one at Buckenham at the moment - originally thought to be hutchinsii but now regarded as minima (the commonly kept form). Along with similar rounded head shape, it also has a good neck collar, and appears to have a similar colour breast to this bird. I had thought hutchinsii were thought to have paler/palest breasts of the smaller forms?

Stephen Dunstan · Jan 6, 2004

In terms of Steve's point about ringing I don't see why the WWT couldn't Darvic or colour ring them. They obviously think they are sufficiently interesting and of open enough origin to put the news out, so why not ring them if they are coming to handouts.

Stephen.

Steve G · Jan 6, 2004

These birds were fairly pale-breasted though it was a dull day & the images don't show this well. Is the paleness of the breast not a relative feature used when comparing this with the darker breasted minima form to which it is closest in size? Certainly the compact Barnacle goose body-build of short thick neck & dumpy body seems to fit the hutchinsii type. Perhaps some of our North American members could comment on these birds.
With respect to provenance, well who knows; though they were first identified in association with a plausible carrier species ( Greenland White-fronts at Loch Ken).

Edward woodwood · Jan 7, 2004

just what are the standard refs for ID of these forms?
winter dowitchers I can just about do but I find people are id-ing these and I'm left feeling frankly bemused
I've researched a lot and just found lots of contradictions

I'd like to know why these things are what people are saying they are from original references if possible so I can dig deeper.....

pix on some goose id sites are mis identified according to other sites

Stephen Dunstan · Jan 7, 2004

Tim,

The Sibley guide covers it. There are two articles by Chris Batty and Tim Lowe in Birding World dealing with why they think almost all birds around the time they were written fit into one of the subspecies.

Stephen.

Steve G · Jan 7, 2004

Stephen Dunstan said:
Tim,

The Sibley guide covers it. There are two articles by Chris Batty and Tim Lowe in Birding World dealing with why they think almost all birds around the time they were written fit into one of the subspecies.

Stephen.

Hi Stephen,
Do you know which issue of Birding World it was in -I'll try to borrow a copy from a friend as I obviously need to brush up on this (badly

).
Cheers,
Steve

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