[2] In appearance, it closely resembles the Empidonax flycatchers, and was formerly placed in that genus, but differs in anatomical and molecular characters.

Euler's flycatchers are inconspicuous birds, tending to keep to undergrowth perches from which they sally forth to catch insects; they are also capable of hovering flight to pick off prey from plants, but use it far less often.

[4] In subtropical montane forest in the south of its range, it breeds in the rainy summer months, with peak nesting activity in late October to November and extending to January–February.

The open cup nest is made of grass, leaves and plant fibre and placed in a tree fork.

[5] The typical clutch is 2–3 white eggs, which are marked with reddish brown mostly at the larger end, weigh about 1.7 grams (0.060 oz) each and measure roughly 18 by 13.5 millimetres (0.71 in × 0.53 in).