Greater vs Lesser Scaup - Minnesota, USA (1 Viewer)

bost85

Well-known member

• Sep 19, 2012

• #1

I took these back in April of this year in Minnesota, USA. I wonder if the first one could be a lesser scaup? The white band on its wing seems short enough to be consistent with that. #2-4 are the same duck and the forward peak of their head seems consistent with greater scaup? Thanks!

 

Attachments

• 
  IMG_3444.JPG

  101.2 KB · Views: 106
• 
  IMG_4480.jpg

  125.4 KB · Views: 128
• 
  IMG_4488.JPG

  137.7 KB · Views: 144
• 
  IMG_4489.jpg

  116.7 KB · Views: 126

chris butterworth

aka The Person Named Above

• Sep 19, 2012

• #2

Apart from the head shape and the wingbar the vermiculations on the back aren't coarse enough for Lesser and the tip of the bill is showing far to much black. Greater Scaup.

Chris

 

Jan-Paul Charteris

Sussex birder and budding moth enthusiast

• Sep 19, 2012

• #3

Lesser for me

 

Microtus

Maryland USA (he/him)

• Sep 19, 2012

• #4

Lesser for me too.

 

chris butterworth

aka The Person Named Above

• Sep 19, 2012

• #5

Just borrowed a laptop ( looking on phone before ). The vermiculations are very coarse at the rear of the back + only the nail on the bill is black. Lesser.

Chris

 

Jan-Paul Charteris

Sussex birder and budding moth enthusiast

• Sep 19, 2012

• #6

Just out of interest, what age do female Lesser Scaups gain a pale iris? I've seen photos of female types with a pale iris, but birds like that one look adult, and I've seen photos of known adults with a darkish iris? In Greater Scaup the imms only seem to have a dark iris to somewhere around mid-2cy I think going on experience and observations

 

Microtus

Maryland USA (he/him)

• Sep 19, 2012

• #7

Pyle's Identification Guide to North American Birds, Part II says, for both species of scaup:
Juv female (Jun-Oct) have olive or brownish irides
Juv-HY/SY female (Oct-Sep) "iris brown, becoming olive brown by Jan-May"
AHY/ASY female (Oct-Sep) "iris yellowish brown (SY/TYs?) to moderately bright yellow"

It looks like it the eyes might not become fully yellow until the third calendar year.
(HY-hatching year; SY-second year; A-after; TYs-third years)

 

Jan-Paul Charteris

Sussex birder and budding moth enthusiast

• Sep 19, 2012

• #8

Microtus said:

Pyle's Identification Guide to North American Birds, Part II says, for both species of scaup:
Juv female (Jun-Oct) have olive or brownish irides
Juv-HY/SY female (Oct-Sep) "iris brown, becoming olive brown by Jan-May"
AHY/ASY female (Oct-Sep) "iris yellowish brown (SY/TYs?) to moderately bright yellow"

It looks like it the eyes might not become fully yellow until the third calendar year.
(HY-hatching year; SY-second year; A-after; TYs-third years)

Click to expand...

Cheers for that :t: I had wondered before as it seemed Greater Scaup advanced in iris colour more quickly than Lesser, but perhaps I don't see quite enough Greaters even to be fully aware of variation in late 2cy. Certainly I've see young males in November of their 2cy with bright yellow iris though

 

Microtus

Maryland USA (he/him)

• Sep 19, 2012

• #9

Cheers for that

Click to expand...

. Sure thing.

It's possible that your Greaters are different to our Greaters as far as aging/eye color go.

 

bost85

Well-known member

• Sep 19, 2012

• #10

Thanks for the ID and thanks for the explanation behind the ID! Good to know!