(1724) Falco subbuteo subbuteo.
Falco subbuteo Linn., Syst. Nat., 10th ed. i, p. 89 (1758) (Sweden) ; Blanf. & Oates, iii, p. 422 (part.).
Vernacular names. Morassani (Oude).
Description. Upper parts slaty-grey, darkest on the head and upper back, palest on the lower back, rump and upper tail-coverts, the feathers of these parts black-shafted: outer tail-feathers barred on the inner webs with darker slate and dull rufous-grey ; a collar on the hind-neck white, sometimes tinged with rufous; primaries and outer secondaries almost black with a fine edging of whitish ; inner webs with half-bars of dull rufous ; round the eye, cheeks, ear-coverts and a broad moustachial stripe blackish-slate ; forehead, lores and a small supercilium whitish; chin, throat, front and sides of neck pure white; thighs and under tail-coverts rufous ; remainder of lower parts white, more or less tinged with rufous, especially on the lower abdomen and flanks, and broadly streaked throughout with black.
Colours of soft parts. Iris bright hazel to deep brown ; bill pale slate with black tip and sometimes a yellowish tinge at the base of the lower mandible; cere and orbital skin greenish-yellow; legs-orange, claws black.
Measurements. Wing, 245 to 265 mm., 273 to 280 mm.; tail, 129 to 142 mm., 146 to 148 mm.; tarsus about 30 to 35 mm.; culmen 17 to 18 mm.
Young birds are much darker above, almost black and generally with a brown rather than a slaty tinge; each feather is broadly edged with white, fulvous-white or pale rufous; the bars on the lateral tail-feathers extend to the outer webs; the underparts are white or fulvous-white, nearly always tinged with rufous and sometimes all pale rufous broadly streaked with blackish.
Distribution. Europe and Asia, East to Japan; South in Winter to Africa, India and China.
Hobbies in poor condition are often very difficult to determine but undoubtedly a very large number of our Indian cold weather birds cannot be distinguished from the European typical race.
Nidification. The Hobby breeds during June, generally in the first half of that month, depositing its eggs in old nests of Crows, Magpies or Herons, occasionally in a Book's nest or in a squirrel's drey. The tree selected is most often one in a hedge or on the extreme edge of a spinney, whence the bird can observe intruders from a considerable distance. The number of eggs laid is nearly always three, sometimes only two, whilst on the continent four are not very rare. The ground-colour is a pale dull yellowish or pinkish-clay, the whole surface profusely speckled all over with reddish-brown, almost obliterating the ground-colour. Rarely the eggs are more boldly marked with larger blotches and are then very like Kestrels' eggs, from which, indeed, it is impossible to distinguish them with certainty. Fifty eggs average 41.5 x 32.7 mm.: maxima 45.5 X 31.8 and 44.1 x 35.7 mm.; minima 38.1 X 31.1 and 38.8 x 31.0 mm. Incubation is said to take 28 days and both parents share in this duty, though the female does the greater part.
Habits. The Hobby is a bird of well-wooded country living principally on small birds, bats and the larger insects. Its flight is very powerful and swift and in character very like that of the Peregrine. It has been recorded as catching Swifts on the wing on several occasions and it frequently captures dragonflies and the quickest flying butterflies, etc. It is a very bold courageous bird and in former time was much used for hawking thrushes, larks, pipits and other small birds. When not busy feeding their young they are rather crepuscular in their habits, hawking principally in the mornings and evenings.