The Eurasian hobby – Falco subbuteo
or just simply hobby, is a small slim falcon. It belongs to a rather close-knit group of similar falcons often considered a subgenus Hypotriorchis. Adults are slate-grey above with a dark crown and two short black moustachial stripes. The throat is unstreaked white, thighs and undertail coverts are unstreaked rufous and rest of the underparts are whitish with black streaks. Close views enable the red “trousers” and vent to be seen. Sexes are similar. Juveniles are generally much browner, with scaled upper parts and streaked buffy thighs and undertail coverts.

The hobby has a distinct first-summer plumage.

This falcon is 29–36 cm (11–14 in) in length with a wingspan of 74–84 cm (29–33 in) and a weight of 175–285 g (6.2–10.1 oz).

This species breeds across Africa, Europe and Asia. It is a long-distance migrant, wintering in Africa and Asia.

It sounds like this
Recording by Lars Edenius from Xeno Canto