ID: Vegetarian or Large Tree Finch? Isabela, Galapagos (2 Viewers)

[rosmo01]

Finch located high above Darwin's Lake on the west coast of Isabela.

 

[screaming piha]

I think this is a Medium Ground Finch.

A few examples here: http://www.flickr.com/photos/jjbirder/sets/72157614217328919/

 

[rosmo01]

Thanks for your input.

Seems to be difficult to ID - you're the reply one so far....

 

[screaming piha]

Perhaps a little more explanation might be useful as no one else has joined in.

This Large Tree Finch shows the typical conical bill with a convex upper and lower mandible. http://www.flickr.com/photos/jjbirder/3288098247

I have no pics of Vegetarian Finch, but it has a bill shape like that of Large Tree Finch.

Large Ground Finch has a huge bill that extends to the crown (sorry, can't recall the technical term, maybe shield?). http://www.flickr.com/photos/jjbirder/3288957874

Medium Ground Finch has a smaller bill that in many individuals extends to the crown a little as with your bird. http://www.flickr.com/photos/jjbirder/3293099751

The lower mandible of Medium Ground is straight or stepped like your bird and this http://www.flickr.com/photos/jjbirder/3288879214 and this (from the same island as yours) http://www.flickr.com/photos/jjbirder/3285556021

Medium Ground Finch is nightmare to unravel. Bill ranges from large to small and bill shape seems to vary depending on the pose. And there are large and small morphs (possibly two species). And hybrids with Large GF and with Small GF. And birds on different islands seem different.

It took months of checking and considerable help for me to get confident of the ID for my pics of finches. Many of my suspect Vegetarian and Medium and Large Tree Finch pics turned out to be Medium Ground Finch. A frustrating but fun process!

 

[Brian J Small]

Below is a photo of specimens from the NHM, Tring, showing the relative bill sizes of, Small, Medium and Large Ground Finches.

Make your own choice...BTW I think Medium too.

Brian S

 

[screaming piha]

Thanks for posting that really useful pic Brian.

Do you have a similar pic for the Tree Finches? Would like to see if you have.

I forgot earlier, but I have pics of the finch photo display at the Darwin Centre

http://www.flickr.com/photos/jjbirder/3311932249
http://www.flickr.com/photos/jjbirder/3311931449

 

[Brian J Small]

I don't have direct side-by-side comparisons, but I have these, which show the variation in bill shape/size in subspecies for Large Tree Finch, Medium compared with habeli Large, and the two subspp. of Small Tree Finch - salvini bill being quite similar in shape to Medium, but smaller.

Brian S

 

[screaming piha]

Thanks Brian. Interesting. Glad to see someone remembered to label those specimens properly, unlike one collector I could name!

 

[rosmo01]

Many thanks for your details!

 

[Brian J Small]

Thanks Brian. Interesting. Glad to see someone remembered to label those specimens properly, unlike one collector I could name!

You're talking of the great CD himself?

http://www.sulloway.org/Finches.pdf

Brian S

 

[screaming piha]

That's the fella. I wonder whatever happened to him?