It was a glorious October morning, and we hoped to rack up an impressive list of late migrants. One of those migrants, however, had other plans as we started out around the trails at Blendon Woods. “I see a few Yellow-rumps”, called one of the birders, “so we won’t get skunked on warblers today.”
“Be careful what you wish for”, I countered. I had memories of picking through Myrtle Warblers (the old name for Yellow-rumps) in Florida and Ohio, and suddenly had a premonition of how this morning might play out. Sure enough, the next 99 warblers were all Yellow-rumps. We seemed to have hit their peak migration, and felt extremely lucky to glean out a Palm and Black-throated Green Warbler from the hordes of Yellow-rumps. They show up later than most warblers, but when the waves of Yellow-rumps hit, it’s nearly “game over” for locating other warbler species. There’s a reason “It’s just another butterbutt” is not exactly a term of endearment among birders.
It’s really a shame that we tend to look past the Yellow-rumps in our quest to find other warblers. Even in their non-breeding plumage, they have lots of field marks – a gray vest of streaks on either side of their whitish breast, a tiny daub of yellow on each side near where the wings attach, a cute gray mask, tail spots, and, of course, their bright yellow rump. This is a warbler with panache, with very distinctive behaviors, too: they often make short, flycatcher-like flights to nab flying insects, they tip forward on their perch to look at you or under a leaf (often giving you a great view of their tail spots), they like to hang around poison ivy vines to eat the berries. And last, but not least, they have a distinctive husky ‘chip’ call. Once you learn it, you’ll hear them everywhere because they use this chip to stay in large loose feeding flocks. If you want a good ‘crash course’ in butterbutts, watch some of the beginning of this feedercam, as a flock descends on a feeder station in Florida:
It’s probably good that they have so many fieldmarks, because we’d go crazy with the fieldguide if they were less identifiable.
What really sets butterbutts apart, however, is that this is a warbler that seems to think it’s a waxwing or a robin. They migrate later than other warblers, they migrate during the daytime in flocks, they tolerate the cold better, and they even switch their cold-weather diet to small fruits and some seeds. This is a warbler that is a temperate migrants, wintering in much of the southern U.S., with a few even hanging out here in Ohio over the winter. They usually favor bayberry or wax myrtle bushes, which can be abundant in some areas along the Atlantic or Gulf Coasts. These are native shrubs, but are often used as yard plantings in areas with sandy soils (see here for the Yellow-rump-Wax Myrtle link).
Around big stands of these bushes, the flocks of Yellow-rumps can reach epic proportions. Here in Ohio, we only see flocks later in migration, usually after the waves of neotropical migrants have passed through. In winter, there are usually small numbers that stay close to areas with large amounts of poison ivy. Few other birds eat the berries, so Yellow-rumps use this as their fall-back winter larder. They’re not averse to eating other small berries and the occasional frozen insect as well. You can see them snacking on poison ivy berries in the video on this page (scroll down the page for the video).
Where can you get in on this Fall butterbutt bonanza? The better question is where could you NOT see them. In October and early November, flocks of Yellow-rumps will move south through Ohio, already starting to seek out stands of small berries and poison ivy. Since they mostly migrate in the morning, look for them around these food sources then, or look for places that might funnel migrating flocks. I’ve found them along the shores of many reservoirs like Alum Creek Lake or Hoover Reservoir, especially where woods and berrybushes and ivy co-exist, like New Galena at the former and Maxtown Boat ramp at the latter. Isolated forest blocks like Blendon Woods and Blacklick Woods also seem to garner quite a few flocks. Blacklick Woods will even hold some deep into winter because of the abundance of poison ivy there. Flocks of Yellow-rumps also seem to congregate around where open flatlands run up against the hilly forests of unglaciated Ohio, like Great Seal State Park in Chillicothe, or Alley Park and Wahkeena Preserve south of Lancaster. But really, you don’t need to go that far; you probably have a flock of Yellow-rumps around your neighborhood as you read this. Just find some buggy area with berries, and look for the fluttering and listen for the chips. Don’t go expecting to find many other birds – just enjoy these rollicking, tough little warblers for themselves.
