The Yellow-bellied Flycatcher (Empidonax flaviventris) is a common New Brunswick summer resident. It migrates here in May and leaves in the fall. It is a bird of the northern boreal forest and can be found throughout the province. It likes dense spruce woods and dense understory with brushy vegetation.
First let's review flycatcher classification from a New Brunswick perspective. Knowing where the species fits and what are its close relatives helps with identification. More broadly speaking, there are 3 major categories of flycatchers: Tyrant Flycatchers, Old World Flycatchers and Silky Flycatchers. The Old World Flycatchers act like the New World Flycatchers but they are not closely related. The Silky Flycatchers are flycatchers of Middle America and are different from the Tyrant Flycatchers, which is the group that this post deals with.
The Tyrant Flycatchers, family Tyrannidae, include the Empidonax and Myiarchus flycatchers as well as the Phoebes and the Kingbirds. The Empidonax and the Myiarchus flycatchers present some of the most difficult identification challenges in birding. For identification one must pay attention to the overall shape, head shape, bill structure, primary projection, and wing feather formula. This group eats insects with a few eating small fruits during migration or on the wintering grounds. Most sit on a perch and fly out to grab an insect. Some return to the perch to eat the insect; some to another perch; some hover before grabbing the prey; some fly out from the perch to grab the insect on the ground. Differences in foraging methods can be used to help identify the species.
The plumage of males and females is usually the same in Tyrant Flycatchers. This family is very large and is exclusively found in the New World. Although found in most of the New World, there are by far the most member species in the tropics. Of 425 member species altogether, 45 species are found in North America; 35 of these breed here and 10 are vagrants. Flycatchers are threatened species caused by loss of habitat, fragmentation of habitat and habitat degradation.
So what flycatchers do we have in New Brunswick and how does the Yellow-bellied Flycatcher fit in? The Tyrant Flycatchers we have are grouped as follows:
Peeweees - Olive-sided Flycatcher - Contopus cooperi
Eastern Wood-Pewee - Contopus virens
Empids - Yellow-bellied Flycatcher - Empidonax flaviventris
Alder Flycatcher - Empidonax alnorum
Willow Flycatcher - Empidonax traillii
Least Flycatcher - Empidonax minimus
Phoebes - Eastern Phoebe - Sayornis phoebe
Say's Phoebe - Sayornis saya
Myiarchus Flycatchers - Ash-throated Flycatcher - Myiarchus cinerascens
Great Crested Flycatcher - Myiarchus crinitus
Kingbirds - Eastern Kingbird - Tyrannus tyrannus
Western Kingbird - Tyrannus verticalis
Scissor-tailed Flycatcher - Tyrannus forficatus
Fork-tailed Flycatcher - Tyrannus savana
There are many more members of these groups in North America. I have included most of the species we find here in summer with a few vagrants that often show up here.
The Yellow-bellied Flycatcher is a small bird, 14 cm long. It is mostly yellow all over. It appears short-tailed and big headed. The head has a round crown (some species have a flat crown). It has a moderate primary projection (in the folded wing, the distance from the end of the primary feathers to the tip of the tertial feathers). The bill is broad-based with a pale yellow-orange to pink lower mandible. The adult bird is mostly olive above and yellow below. There is an olive green wash over the sides of the breast. The bold eyering is even all around and yellowish in colour. It can be slightly thicker behind the eye. The wings are black with bright white wing bars. Similar species include the Acadian Flycatcher and the Least Flycatcher. The Acadian Flycatcher does not occur here but the Yellow-bellied Flycatcher is smaller with a shorter primary projection and smaller bill. The olive wash on the breast also helps identify it as a Yellow-bellied Flycatcher. In the fall when the birds' feathers are more worn, the Yellow-bellied Flycatcher can be mistaken for the Least Flycatcher but the throat of the Yellow-bellied Flycatcher is a more blended colour and the mandible is uniformly pale.
Flycatchers are not noted for their song. This is due to the anatomy of the syrinx. The call of the Yellow-bellied Flycatcher is a sharp, whistled chiu. The song is a che-bunk like the Least Flycatcher but softer and lower in tone. It is not as 'snappy' as the Least's song, according to David Sibley.
Yellow-bellied Flycatchers occur in summer on their breeding grounds all across Canada from Newfoundland and the Maritimes to Yukon, but not including most of British Columbia and southern Alberta and Saskatchewan. In the fall they migrate back to their wintering grounds in eastern Mexico and Panama using the overland route. They do not fly over the Gulf of Mexico.
Yellow-bellied Flycatcher nest in the boreal forest close to the ground. The nest is usually built within 2 feet of the ground usually on top of a hillock or stump or among rootlets or fallen trees. The nest is made of twigs, rootlets, weeds, and moss and lined with thin rootlets, grass and fresh leaves. Three to five white eggs spotted with brown are laid and incubated by the female.
The Yellow-bellied Flycatcher species was first described by an American, Spencer Fullerton Baird, in 1843. By some sources the Yellow-bellied Flycatcher is described as the easiest of the Empidonax flycatchers to identify. I would add that this group is very difficult! One very interesting fact about this species is that it winters in semi-open habitats including coffee plantations and that shade-grown coffee plantations have higher densities of this species than do sun-grown coffee plantations. This also is true for other avian species. Do your research on where coffee is grown and support shade-grown coffee products in order to save our avian species.
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