Family FALCONIDAE. 

 Circus aeruginosus (L). — Marsh-Harrier. 



(Plate 102, fig. a-c). 

 (Snouckaert: Avifauna Neerlandica, p. 65, No. 154). 



Colour of surface of shell: 



Colour of spots (if any) : 

 Average dimensions: 

 Average weight of shell : 

 Texture of shell : 

 Shape: 

 Nest: 



Site of nest: 



Number of eggs: 

 Breeding season: 

 Duration of incubation: 



white, tinged more or less bluish sea-green 

 when light shines through the eggshell it 

 shows through green. 



light havana-brown. 



48.6 > 37.9 millimetres. 



3.16 grams. 



finer grained than that of A. palumbarius. 



mostly bellied-spherical. 



consists of vegetable materials, lined with 

 a few feathers. (Also sometimes takes 

 possession of nests of Fulica atra). 



in tall reeds on old stubbles; on overhan- 

 ging willow bushes, etc., in bogs with a 

 dense growth of shrubs. 



4—6, usually 5 (after-set 3—4). 



May— June. 



about 3 weeks. 



