A Bit of an Unusual Sight: Greater White-fronted Geese East of the Sierra Nevada

We were in the eastern Sierra Nevada and Owens Valley last weekend for a geology field study course, but of course I was on the lookout for interesting birds. We stopped at the Mono Lake County Park and I saw a flock of geese that got my curiosity up. They were clearly Greater White-fronted Geese (Anser albifrons), which is a species I normally expect to see back home in the Great Valley. I checked out the eBird Range map for the species, and saw that they are indeed a little unusual. There are sightings almost every year, but usually of just one or two at a time. Local birders have noted the unusual size of the group, more than two dozen.

I don't know if this flock is off course, or if they are just passing through on their way farther south. The great majority of this species winter in the refuges of the Great Valley, including the San Joaquin River NWR a few miles west of my fair city of Modesto. In any case, their presence is a sure sign that fall has arrived. They've spent the summer in the Arctic, but it's getting colder out there now.