Revisiting my trip to New Mexico over Thanksgiving break...
While the Sandhill Cranes get a lot of the spotlight at Bosque del Apache, the geese also provide spectacular sights and photo opps at the refuge. In a welcome turn from the hordes of sky carp we get around the Front Range of Colorado, white-cheeked geese (Canada & Cackling) are kind of scarce there. But so-called "white" geese (Snow and Ross's in the genus Chen) are present in force and typically show well. For some reason, the Farm Loop on the refuge didn't have corn planted this year so the goose situation had changed. It was tough to get the massive "blast off" shots that happened over there when a coyote or eagle spooked 4 or 5-digit goose flocks, but there were still plenty of chances to study and photograph almost all of the Chen flavors (still haven't seen the elusive dark-morph Ross's Goose...)
Snow Geese are in the majority, but not all are snowy white. So-called "Blue" Geese, the dark morph, are smattered throughout the flocks of white birds for variety. Some Blue Geese are "bluer" than others, and juveniles can look nearly all black. While larger than Ross's Geese, there are lesser Snow Geese that approach the diminutive Ross's in size. A distinctive mark to ID Snow Geese is the wide "grin patch" of combed black where the upper and lower halves of the bill meet (above and below the tomia, or inner cutting edges of the bill.) The bill also is longer than a Ross's and the junction of the bill and facial feathers curves outwards towards the bill tip. In flight you'll notice that Snow Geese have longer-looking necks than Ross's Geese.
In contrast, Ross's Geese are the smallest in the bunch (but judging size on a lone bird can be a dangerous task, and about any white goose looks small amongst large races of Canada Geese.) More importantly, they show little if any grin patch and have stubbier bills and necks. The junction of the bill and facial feathers is nearly straight up-and-down. Their heads look more rounded, and between that and the shorter bill I'll anthropomorphise and call them "cuter." Not as cute are the bluish warty bumps (caruncles) that mature male birds develop at the base of their bill.
Sometimes problematic birds show up that don't quite fit either end very nicely. These hybrid Ross's x Snow Geese blend traits of each and typically have small grin patches. I suspect the bird below is a hybrid because its bill looks a bit longish and it has a little more grin patch then I'd like for a slam-dunker Ross's. Here's a link to what I think is another hybrid Ross's x Snow Goose example.
Test time! Spot the Ross's and/or Snow geese flying by in the lovely sunrise light:
And here's a lovely mix of Ross's and Snows on the water: