I was at the Portneuf Wellness Complex (Chubbuck) Saturday morning and saw
a distant flock of large birds. I immediately thought Canada goose, but
when I got my binoculars on them I knew right away that the flock formation
was all wrong for this species. The birds were not in any version of a V,
more like a broad U with multiple tendrils of varying lengths. They then
started molding into 2 large condensed flocks and started to behave like a
starling murmuration – the boiling, rolling movement of many birds acting
as one when a predator is nearby.

I immediately began to worry that I would get a good enough look at the
birds to identify them. They were far too large to be starlings. They
were fortunately were drifting my way. It appeared to be about 700-1000
birds, sometimes splitting into 2 large flocks and a third small one.
Sometimes all gathering in one flock.

I was very fortunate that the birds came in directly over my head and I was
able to ID them as Franklin’s gulls. I am pretty new to the west. Is this
unusual for this species? They continued this behavior until they drifted
out of sight to the west. I looked around for something like a peregrine
to cause this behavior, but the closest thing I saw to a predator near them
was an osprey.

I was able to get pictures and will get a more accurate count for my eBird
checklist.

Pretty neat!

Steven F. Kahl
Deputy Project Leader
Southeast Idaho National Wildlife Refuge Complex
4425 Burley Dr., Ste. A
Chubbuck, ID 83202
P (208) 237-6615 ext 112
F (208) 237-8213