It’s late November. The temperature is dropping. Where should you go birding?

How about a grocery store parking lot? Last week, Team eBird converged for meetings in Ithaca, New York. In between meetings they managed to find an Audubon’s Warbler in just a narrow strip of shrubs and trees next to Wegman’s (home of the best bagels in Ithaca)! This subspecies of Yellow-rumped Warbler is annual in the Northeast, but still quite rare, with only a handful of records this year. Check out the eBird map and read on to get our take on some of the hottest November birding.

The Audubon’s Warbler wasn’t a fluke. So far in November, this seemingly random spot has produced an impressive haul of late lingering migrants: Yellow Warbler, Chipping, Lincoln’s and White-crowned Sparrows, Gray Catbird, and House Wren. This parking lot has earned hotspot status, so check out its Hotspot Details page. There are some nice illustrated checklists from 14 November and 21 November.

What’s going on? This is only one example of an unexpected and underbirded location that produces good birds. The same phenomenon happens in towns and cities across the country, on coasts and inland. These locations tend to get “hot” (for birds), right around now as the ambient temperature starts to get cold. There are a few factors at play, so let’s first take a look at the satellite image of where Ithaca birds were found.

At first glance, this might not seem like a particularly great birding destination. It’s the edge of a grocery store parking lot, surrounded by other parking lots and suburbs. The habitat along the canal is narrow and not particularly unique: there are some larger trees, lots of weeds, some denser thickets, and a few strips of cattails. However, even these small areas of habitat near water produce warm microclimates, especially since warmer water is discharged into the canal from the surrounding town and from the grocery store. With temperatures dropping significantly as we head in to winter, any slightly warmer area has a higher likelihood of holding surviving insects. For an insectivorous warbler or flycatcher, finding bugs is the only hope for survival, which is why lingering fall migrants or vagrants are often concentrated in these small patches.

Another good example of urban birding is Portland, Maine. The Maine coast is full of beautifully scenic birding locations, but one of the most consistent spots to find unusual birds in the fall is right in the middle of the city. Check out the hotspot page and overhead view below.

This is a tiny section of the city, showing two of the most productive spots for fall birding. Birds like Orange-crowned Warbler and Yellow-breasted Chat, both generally thought of as rare fall strays in Maine, are nearly annual in these two locations alone! While these particular locations aren’t close to open water, they are among tall buildings and provide shelter from wind. They are also on a hillside that faces south, collecting sun all day long and sheltering the thickets from colder winds from the north. Imagine if every backyard, every lot, every patch of bushes in Portland were checked every day. Our perception of the abundance of these, and other, fall strays and lingering migrants could be drastically changed.

The important thing to keep in mind is that these spots are not that unique. Take another look at the first map above. Birders have only been checking a short stretch of the canal at the edge of the large parking lot. What about that patch of trees in the bottom right of the map? What about the other canal that heads southeast? In Portland, how many more Orange-crowned Warblers are tucked into scrubby lots between houses? How many vagrant Hammond’s Flycatchers are we missing in the east in these spots that are rarely, if ever, birded? We know that many eastern warblers show up on the California coast in the fall, but how many go undetected in tiny patches of habitat in the suburbs? We challenge you to answer these questions. Go find a strip of weeds next to open water, or a sunlit hillside in the morning, or an abandoned lot. City parks that ordinarily host only House Sparrows can be remarkably consistent magnets for rare warblers when checked regularly in November and December. Try to think like a bird and pick the warm microclimates that might have late flying insects. We’re looking forward to your eBird submissions as we broaden our understanding of the true scale of vagrancy and migration.

Here are a few other favorite urban and suburban parks that have a clear track record for late-season insectivores. Check out their hotspot pages and be sure to click the bar chart link to see what late-season treats each one has had. If you know of others, let us know on Facebook or via email and we’ll update this story.

Contributed by Luke Seitz, Cornell 2016