posted April 12th, 2013; last edited April 12th, 2013 –– David Sibley
Flycatcher identification by the calendar
Here are some eBird maps showing all records for the month of April for several species of small flycatchers in eastern North America. A glance at these maps will show which species are possible in your area in the next few weeks, and this greatly simplifies flycatcher identification. For most of the east, through most of April, small flycatcher identification can be summed up in one short phrase – “It’s a phoebe” (see Eastern Phoebe map at the end of this post below).
Anything is possible, of course, and spring migration is getting earlier each year, but if you think you have found, for example, an Alder Flycatcher in Pennsylvania in April, you’ll need some photo or audio documentation to verify it.
Alder Flycatcher records in the month of April – very few!
Yellow-bellied Flycatcher records in the month of April – very few!
Willow Flycatcher records in April. Only a handful of records scattered north and east of Texas. Assuming that these are correctly identified, the fact remains that any Willow Flycatcher in those areas in April is an extreme rarity.
Least Flycatcher records in April. The second-earliest Empidonax (after Acadian), and getting farther north by the end of April. This map was made on April 10th, the orange markers indicate records in the current year (i.e. the first ten days of April), blue markers show records from past years. Virtually all of the blue markers shown represent records from late April.
Acadian Flycatcher records in the month of April – this species arrives on its southern breeding grounds in mid- to late-April, and is generally the earliest Empidonax.
Eastern Wood-Pewee records for the month of April, showing as purple rectangles because there are over 2000 total records in view. Note that there are very few records north of about Missouri, southern Ohio, and Maryland. North of there any April reports of this species should be very carefully identified.
Eastern Phoebe records in April. This species is the earliest flycatcher by far. Many winter in the southern US, and spring migrants arrive as far north as New England during March, with a big influx there in early April. This map represents a nearly fully-occupied breeding range in April.