Blue-tailed Forest Hawk

Appears a more vivid light blue than the Orthetrum albistylum (Common Skimmer)

Scientific name	Orthetrum triangulare melania
English name	Blue-tailed Forest Hawk
Japanese name	大塩辛蜻蛉
Class	Insecta
Order	Odonata
Family	Libellulidae
Genus	Orthetrum
Species	triangulare
Subspecies	melania
Full length	50-60mm
Distribution	Throughout Japan

Blue-tailed Forest Hawk Characteristics and Morphology

A dragonfly that looks like a slightly larger version of the Common Skimmer (Orthetrum albistylum).
Eyes are dark brown. The wings have black veins and black pterostigmata (wing spots) toward the tips. The wing tips are dark brown. The base of the wing has a triangular brown patch, which is the origin of its scientific name. It is somewhat difficult to identify because it lives in similar places to the Common Skimmer and has very similar coloring. Compared to the Common Skimmer, the thickness of the abdomen remains consistently thick from the base. In the Common Skimmer, the abdomen narrows abruptly right after the base. The black portion at the end of the Common Skimmer's abdomen also appears longer. Since it is hard to distinguish them in flight, it is best to observe them closely when they perch on leaves or the ground.

Male

Overall a light, watery blue. Like the Common Skimmer, the blue area is covered in a white, powdery wax.

Female

Body colors are yellow and black.
The abdomen is yellow up to the middle, while the tip is black.

Blue-tailed Forest Hawk Ecology

Habitat

Distributed throughout Japan. Inhabits watersides at low altitudes. They appear in almost any watery environment, including ponds, marshes, and small streams.

Food

Feeds on small insects.

Life Cycle

They mate on vegetation or similar surfaces. They overwinter in the larval stage.

Blue-tailed Forest Hawk Photos

Blue-tailed Forest Hawk Photos are introduced.
Tap the photo to open the detail page.

The thickness of the abdomen does not change much throughout its length.

The body is covered in fine hairs and has no gloss.

Blue-tailed Forest Hawk Behavior

If they sense danger while mating, they will fly away while maintaining their coupled position.

Blue-tailed Forest Hawk Information

Naming

The species name "triangulare" means "triangular," referring to the shape of the colored patches at the base of the wings. The subspecies name "melania" means "black," derived from the fact that the populations found in Japan and surrounding areas are darker than the nominate subspecies.

Blue-tailed Forest Hawk Found Locations

Katakura Castle Ruins Park, Hachioji City

Photographed perching on a wooden boardwalk in Katakura Castle Ruins Park. At the time of shooting, I could not distinguish between the Common Skimmer and this species, so I thought they were all Common Skimmers. Two or three males perched about 1m away from me, repeating a movement of retreating slightly as I approached. Excluding the Jumbo Dragonfly (Anotogaster sieboldii), it is among the larger dragonflies in the park, flying around quite leisurely.

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