Vietnam Adventure Tours & Travel, Trekking, Bird Watching, Cycling Tours

Circus is a genus of birds in the family Accipitridae. The genus includes most harriers which are of the several species of diurnal hawks.

1/ Pallid Harrier (Diều Bụng trắng, Circus macrourus)
2/ Eastern marsh harrier (Diều đầu trắng, Circus spilonotus)
3/ Pied harrier (Diều mướp, Circus melanoleucos) 
4/ Hen harrier (Circus cyaneus)

accipitrinus Latin accipitrinus hawk-like (accipiter: hawk).
In both Latin and Greek, the root of the word "circus" means "ring" or "circle". The Latin word circus comes directly from the Greek word κίρκος (kírkos), which also means "circle" or "ring". This etymology describes the shape of the ancient Roman arenas and the modern performance spaces where circuses are held. 

Eastern marsh harrier (Diều đầu trắng, Circus spilonotus)

The eastern marsh harrier (Circus spilonotus) is a bird of prey belonging to the marsh harrier group of harriers.

The breeding range of the bird covers north-east China, Mongolia and south-east Siberia (as far west as Lake Baikal), and with some in northern Japan.
The wintering range of this species includes southern China, Taiwan, Korea, southern Japan, northeast India, Bangladesh and Southeast Asia.

accipitrinus Latin accipitrinus hawk-like (accipiter: hawk).
In both Latin and Greek, the root of the word "circus" means "ring" or "circle". The Latin word circus comes directly from the Greek word κίρκος (kírkos), which also means "circle" or "ring". This etymology describes the shape of the ancient Roman arenas and the modern performance spaces where circuses are held. 
Spilonotus is a Greek-derived term for a biological name that means "spot-backed".
The origin is from the Greek words spilos (σπίλος), meaning "spot," and notos (νῶτος), meaning "back". 

Hen harrier (Circus cyaneus)

The hen harrier (Circus cyaneus) is a bird of prey in the family Accipitridae. 
The bird breeds in Eurasia, winters in southern Europe and southern temperate Asia.

Traits:
- White patch on rump;
- Five finger tips (five prominent primaries on the wings);

accipitrinus Latin accipitrinus hawk-like (accipiter: hawk).
In both Latin and Greek, the root of the word "circus" means "ring" or "circle". The Latin word circus comes directly from the Greek word κίρκος (kírkos), which also means "circle" or "ring". This etymology describes the shape of the ancient Roman arenas and the modern performance spaces where circuses are held. 
The term "cyaneus" is a Latin word meaning "dark blue" or "sea blue". It is derived from the Ancient Greek word kuáneos (κυάνεος), which also refers to a dark blue color, sea blue, and was used to describe dark blue enamel or lapis lazuli. 
The term "hen harrier" refers to its former habit of preying on free-ranging fowl.

Pallid Harrier 
(Diều Bụng trắng, Circus macrourus)

The pallid harrier (Circus macrourus) is a species of harrier, a bird of prey in the family Accipitridae. 
This bird species breeds in southern parts of eastern Europe and central Asia and Iran and winters mainly in India and southeast Asia.

accipitrinus Latin accipitrinus hawk-like (accipiter: hawk).
In both Latin and Greek, the root of the word "circus" means "ring" or "circle". The Latin word circus comes directly from the Greek word κίρκος (kírkos), which also means "circle" or "ring". This etymology describes the shape of the ancient Roman arenas and the modern performance spaces where circuses are held. 
Macrourus is derived from the Ancient Greek words makros ("long") and -ouros ("-tailed"), meaning "long-tailed". The term is not Latin; it was borrowed from Koine Greek. 

Pied harrier (Diều mướp, Circus melanoleucos) 

The pied harrier (Circus melanoleucos) is a bird of prey in the family Accipitridae, named for the male's white and black colouration.
The bird is a migratory bird endemic to Asia, ranging roughly from southern Siberia to the Philippines.

The breeding range of this species extends east roughly from Lake Baikal in southern Siberia through Mongolia and Northeast China, as far south as North Korea. 
The wintering range is from eastern India and Sri Lanka, through South East Asia to the Philippines and Borneo.

Traits:
- Male: Black-hooded;

accipitrinus Latin accipitrinus hawk-like (accipiter: hawk).
In both Latin and Greek, the root of the word "circus" means "ring" or "circle". The Latin word circus comes directly from the Greek word κίρκος (kírkos), which also means "circle" or "ring". This etymology describes the shape of the ancient Roman arenas and the modern performance spaces where circuses are held. 
 Melanoleucos comes from the Greek words melas and leucos, meaning black and white respectively.