Circus spilonotus

General description: 

Male similar to that of C.mailardi, but paler and more finely streaked. Female digger from from that C. aeruginosus in dark streaking on crown and nape. Immature said to be darker than C. aeruginosus. Race spilothorax polymorphic. Nomrmal morph usually has heavier streaking on head and neck, but Burda from Highland PNG have solid blackish throat. Dark morph mostly blakish with some pale streaking, pale primary windows and grey tail.

Conservation status: 

Not Threatened.

Diagnostic description: 

Male similar to that of C.mailardi, but paler and more finely streaked. Female digger from from that C. aeruginosus in dark streaking on crown and nape. Immature said to be darker than C. aeruginosus. Race spilothorax polymorphic. Nomrmal morph usually has heavier streaking on head and neck, but Burda from Highland PNG have solid blackish throat. Dark morph mostly blakish with some pale streaking, pale primary windows and grey tail.

Behaviour: 

Size: 

47-55 cm, 370-780 g

Phylogeny: 

Taxonomy:

    Circus spilonotus Kaup, 1847, Asia. Often considered a race of C. aeruginosus, with which it forms superspecies, along with C. ranivorus, C. approximans and C. maillardi. Race spilothorax possibly approaching species level. Two subspecies normally recognized. (source: Handbook of the Birds of World)
Distribution: 

Subspecies and Distribution:

    * spilonotus Kaup, 1847 - SE Siberia and Mongolia to Ussuriland, Sakhalin, NE China and N Japan; winters from S Japan and SE Asia and S China to Indonesia and Philippines. * spilothorax Salvadori & D'Albertis, 1875 - C & E New Guinea.
Habitat: 

Marshes, swamps, lake edges, aned especially large reedbeds. Also other open areas e.g. paddyfields and grassland. In NG mainly in highlands.

Trophic strategy: 

opportunist hunter. Captures disabled aquatic Burda , takes small terestrial passerines, nestlings nad eggs.

Reproduction: 

Latiny from mid-May to early Jun. Nest on ground in marshes, mainly in reedbeds. Nest is fairly large. Apparently sedentary in NG.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith