Last weekend at Cascade Reservoir in central Idaho I photographed three female Goldeneye. Initially I thought I had captured two Common Goldeneye, with a Barrow’s Goldeneye in between.

After reviewing the photos, my initial identification became muddled. I wondered if the middle bird was indeed a Barrow’s. For one thing, it simply didn’t fit the bill shape, but it was obviously different from the other birds.

Of course some review provided me with a helpful article on David Sibley’s blog. He details the dilemma of differentiating female Goldeneye.

When I first saw the middle bird, I noticed the difference in head shape, which set me towards Barrow’s in the field. After reviewing the photos, the head shape is one aspect that made me question my initial ID. I expect the head shape to be more dramatic on a Barrow’s Goldeneye, with a steeper forehead. Still, as Sibley cautions, using head shape can be problematic, as it changes with the mood and activity of the bird.

The bill shape for the middle bird is different from the other two, but the difference is subtle. I started questioning my identification because although the bill seems smaller and shorter, it isn’t quite the right shape for Barrow’s. The bill of the middle bird is still rather geometric, or straight edged, as I’d expect in a Common Goldeneye.

I’ll admit, the difference in bill color of the middle bird is what my in the field identification was mainly based upon. This is where the learning comes in to play. I consulted my friend and new found birding mentor, Jay Carlisle, just after I had looked over some of the photos on our drive away from the shoreline. He couldn’t focus on the photos in the car (so he said, but perhaps he was being polite). He simply said that although he could only bear a quick glance, the bill color for Common Goldeneye can appear lighter. Sibley describes the occurance of light billed female Common Goldeneye as very rare. He does, however, talk about the bill color of juveniles as being an olive yellow color. This color description seems to fit the middle bird.

Of course there are many other factors that contribute to a positive ID either way. Regrettably, I did not study the birds as much as I should have in the field. Regardless, I believe I have a confident ID on the middle bird. I believe it is a juvenile Common Goldeneye. Although the shape differs from the other birds, and the bill color is not black, as you might expect for a female common goldeneye, there is nothing else that suggests that this bird is a Barrow’s. So, separated from the two adult Common Goldeneye based on bill color, smaller head size, muted eye color, the bird must be a juvenile Common Goldeneye.

I can’t quite claim that I have the issue down to a science, although it has been a worthy learning exercise. I encourage and welcome any discussion on the topic. It would be fun to hear what others think.