What’s been seen: November has really thrown South Shore birders for a loop, and I mean in a good way. In what has been a terrible year in many ways, the birding community in southeastern Massachusetts is being treated to a once-a-decade (or so) multiple species irruption. Birds of the North have invaded our forests and yards. Red crossbills, pine siskins, evening grosbeaks, common redpolls, hoary redpolls, and red-breasted nuthatches are sending birders scurrying about, chasing sightings they might not get for another seven to 10 years. Common redpolls and pine siskins were seen at Straits Pond on Nov. 8, and another winter rarity, a razorbill, was seen from Summit Avenue. A red-breasted nuthatch was seen by the high school on Nov. 21, as were 21 wild turkeys, tempting fate just before Thanksgiving. But the most unusual sighting of all took place on the southern side of Straits Pond at the end of the month when a bullock’s oriole appeared at local feeders in Cohasset. The species is a true western resident, rarely coming east of central Texas, yet somehow it found its way here, driven by storms, confusion, or, perhaps, escaping from a private menagerie.
What to expect this month: It will be worth keeping an eye out for the irruptive species. Irruptions are usually driven by food shortages or population overages, or the combination of both factors. A good seed crop up North can lead to breeding success, with second and third broods; a resultant abundance of mouths to feed can then lead to shortages that send young birds into new territories to fend for themselves. The same can happen with snowy owls, with a third trophic level mixed in, lemmings that feed on those seeds. Offshore, look for the oversized great cormorants to start mixing in with the double-crested cormorants, which should slowly start vanishing to the South. Long-tailed ducks, common goldeneyes, common loons, and many more species of waterfowl should be offshore. The horned larks and snow buntings that have been seen on the Hull Redevelopment Authority land should be regular visitors for the next two or three months.