Moucherolle des aulnes— Quebec wildlife

The alder flycatcher (Empidonax alnorum) is a small insect-eating bird in the tyrant flycatcher family. The genus name Empidonax is from Ancient Greek empis, "gnat", and anax, "master". The specific alnorum is Latin and means "of the alders".

Description

E. alnorum is one of the larger Empidonax species, attaining a length of 13–17 cm (5.1–6.7 in), and a weight of 12–14 g (0.42–0.49 oz). The wingspan ranges from 21–24 cm (8.3–9.4 in). The upperparts of E. alnorum are dull greenish-olive. The crown is a slightly darker olive-green than the back. The throat is white, with a darker breast band. Thin white rings surround the eyes. The bill is wide and moderate in length, with pinkish or yellow-orange lower mandible and black upper mandible. Wings are generally black, with white wing bars and white edges of the innermost secondaries (tertials). Juveniles have brownish upperparts, yellow underparts, and yellowish brown or buff wingbars. E. alnorum is similar in appearance to the eastern wood pewee (Contopus virens) and the eastern phoebe (Sayornis phoebe), as well as the nearly identical willow flycatcher (Empidonax traillii) but E. alnorum can be distinguished by its smaller size and upward tail flicking behavior. Birds in the genus Empidonax are notoriously hard to identify. Novel approaches to identification have been employed to try and increase the accuracy of species identification of mist-netted individuals, such as using ratios of and differences between the measured lengths of various body parts, including wings and beaks. Vocalizations are often relied upon for identification to species in the field when birds cannot be manipulated by hand. The ratio of the lengths of the primary feathers is a useful distinction with birds in the hand or on good quality profile photographs.