In the treetops high above Gardner Park an uncommon visitor is flying about. Its short curved bill is built for feeding on seeds and fruit. Below, near the banks of Bozeman Creek, the bright red hulls of berries litter the snow. It’s these morsels of food, mountain ash berries, for which the pine grosbeak has come.
The pine grosbeak, a robin-sized finch, summers in the boreal forest of northern Canada, except for a small band extending south along the Rocky Mountains where the birds remain year-round. The male has a bright red head, gray breast and gray flanks. Around Bozeman, the pine grosbeak breeds near Hyalite Lake and Emerald Lake in Hyalite Canyon during the summer months. The birds move down into the foothills when the snow flies.
For whatever reason, a flock of pine grosbeaks has moved out into the valley this winter and the birds have been regularly spotted around Gardner Park. It’s a thrill for winter birders like Robin Wolcott, a member of the Sacajawea Audubon Society and an editor for eBird, an online database for submitting bird sightings.
“The pine grosbeak are feeding on those mountain ash berries, but why they are down here this year I have no idea,” Wolcott said Monday. “I’m not sure if pine grosbeak are irruptive, but maybe that is part of the equation as they only show up in the valley like this once every 10 years.”
Irruptive bird migrations occur when there is an irregularity in the food supply. Pine grosbeak typically feed on the seed cones of conifer trees, but may also utilize alders, river birch and Douglas fir.
“Irruption is a mass movement of birds that get into geographic areas you wouldn’t expect to see every year like a typical migration,” said John Parker of Sacajawea Audubon Society. “When it happens it is kind of exciting because it is unpredictable.”
Winter birders looking for unusual birds often pursue irruptive species. Red crossbills, white-winged crossbills and hoary redpolls are irruptive species that have made an appearance in the Gallatin Valley this winter.
While rare and irruptive species are undeniably appealing to avid birders, the winter also provides a great time to see a variety of more common but no less fascinating species. From red-tailed hawks to chickadees, there’s always a bird that piques the interest.
Wolcott said birding during the winter requires a few changes from the warmer months. Instead of being keyed into bird song, Wolcott said birders must listen instead for calls.
“Bird song is breeding behavior,” Wolcott said. “But birds have calls they make at other times of year that alert you to their presence. So we are still birding by ear, but winter birding tends to be a bit more visual.
“In the spring you really want to be out there early because that is when the birds are most active,” Wolcott said. “In the winter they are foraging and talking all day. In the summer I am happy to be out at 6 a.m., but you couldn’t drag me out there in the winter.”
The rise of eBird has made the process of locating birds a communal affair. Birders use the database to enter observations that can be viewed by others. Each entry includes the location, date, time and number of birds seen, along with optional notes added by birders.
As an eBird editor, Wolcott reviews observations made by birders in Gallatin and Madison counties. She said rare sightings cause a buzz among the birding community the way an observation of two sandhill cranes in Belgrade did last Saturday. The cranes, typically long gone by this time of the year, were spotted in flight near Dry Creek Road.
“That was huge,” Wolcott said. “I know the birder that saw those cranes and he is a reliable source. It seems like there have been a lot of interesting sightings this winter.”
Wolcott said eBird has revolutionized birding.
“Instead of writing down an observation that disappears when I die, it is available to the public today and 100 years from now,” Wolcott said. “We all become contributors to the public knowledge and it is making real changes in the world.”
Data from eBird has been used to monitor shorebirds in California’s Central Valley. Conservationists have used the data to identify farmers in the valley and paid them to flood their fields during migration periods, creating a benefit for the landowners and wildlife.
Wolcott said contributing to eBird gives birders purpose, but experiencing nature and the chance to see something amazing are all the motivation she needs.
“I love birding because it gets me outside and gets me exercise,” Wolcott said. “And there is always a rare bird out there and if you get it, it makes you a star.”
An AP member exchange.