388 THE OWLS 



it is a migrant, breeding locally in suitable ground to within the Arctic Circle and 

 south to the Mediterranean, but absent as a breeding species from the Iberian 

 Peninsula and Greece. In Great Britain it is also somewhat sparingly and locally 

 distributed in moorlands and marshes as a breeding species, but chiefly on the 

 northern moors, although a few pairs breed south of the Pennines, e.g. in the 

 Devonian Peninsula, East Anglia, Lincolnshire, Wales, etc. It also nests in the 

 Inner and Outer Hebrides, Orkneys and Shetlands, and has bred in the Isle of Man, 

 but not in Ireland apparently, although the country seems well suited to its habits. 

 [F. c. E. j.] 



3. Migration. A resident in variable but generally small numbers, a winter 

 visitor in large but also variable numbers, and probably also a bird of passage to a 

 slight extent. The distribution of the British-breeding stock is both local and 

 variable, but in winter the species is common and generally distributed throughout 

 the British Isles, including Ireland, where it is not known to remain to nest. The 

 immigration takes place from Northern Europe on the eastern seaboard of Great 

 Britain, including the northern isles. It becomes noticeable in the last days of 

 September, and persists till the middle of November or later. The spring emigra- 

 tion is less noticeable, but takes place in March and April. October to January is 

 the period in which it is abundant in Ireland (cf . Ussher and Warren, B. of Ireland, 

 1900, pp. 116-17). There is some evidence of an autumnal passage through Kent 

 and across the Straits of Dover, with a corresponding return journey in spring (cf. 

 Ticehurst, B. of Kent, 1909, pp. 251-52). As regards habits, it may be said that 

 this owl migrates both by night and by day ; on the Yorkshire coast, for instance, 

 it is noted as arriving " at all hours of the day, from early morn till late afternoon " 

 (cf. Nelson, B. of Yorks., 1907, p. 299). It is commonly seen about the lanterns of 

 lighthouses at night, not striking against it like other birds, but preying on the 

 thrushes and other migrants attracted by the glare (cf. Gatke, Vogelwarte Helgoland, 

 Eng. trans., 1895, pp. 195-96 ; Nelson, op. cit., p. 298 ; and Rintoul and Baxter, 

 Ann. Scot. Nat. Hist., 1909, p. 16). As a migrant, the shorteared-owl is gregarious 

 to a very considerable extent : on the Yorkshire coast it often arrives in parties 

 of from ten to twenty (cf. Nelson, loc. cit.) ; on Heligoland, in flocks of twenty or 

 more (cf. Gatke, loc. cit.) ; and in the autumn of 1907, on Fair Isle (Shetlands), "on 

 two occasions from forty to fifty were observed " (cf. Clarke, Ann. Scot. Nat. 

 Hist., 1908, p. 83). The variability of the numbers of this species from year to 

 year, both as a resident and as a winter visitor, and the interesting connection of 

 this with the numbers of the common field-vole (Microtus agrestis), is discussed 



