The blue-breasted blue flycatcher (Cyornis herioti), also known as the blue-breasted flycatcher, is a species of bird in the family Muscicapidae. It is endemic to the Philippines found only north and central parts of Luzon. Its natural habitat is tropical moist lowland forests. The Rufous-breasted blue flycatcher (Cyornis camarinensis) was formerly considered to be a subspecies.[1]
Ebird describes this as "An attractive flycatcher of forest understory from the lowlands to low mountains in northern and central Luzon. Male has a deep blue throat, chest and upperparts, blackish face, and pale blue forehead and eyebrow. Female has a brown back, rufous wings and tail, gray head, orange throat and pale eyebrow. Male is somewhat similar to Blue-and-white Flycatcher, but Blue-breasted Blue has orange-fringed white belly. Female somewhat similar to Mugimaki female but has a gray head. Song is a high-pitch, shrill “tsiiiiiiiii!” followed by a variety of lower notes.."[2]
It was formerly conspecific with the Rufous-breasted blue flycatcher from SouthLuzon. It was split as a separate species based on the male's eponymous Blue breast. As the Rufous-breasted flycatcher is an extremely rare bird and there are barely and specimens, the differences between the two species' females are poorly understood.
This species is poorly known. Stomach contents from specimens taken contained insects. This species forages close to the forest floor in the dense understorey. It is extremely unobstrusive and is usually alone or in a pair.
Its exact breeding season is still unknwon. Males found in breeding condition with enlarged testes found in May to July. A juveniles was seen in April to May. The only recorded nest was recorded in May in a shalllow cavity on a rock along a stream. This nest was cup shaped lined with ferns and an outer layer of moss and contained 3 eggs [3]
Its natural habitat is tropical moist lowland forest up to 1,200 m. It is often seen in lowland and foothill forest and secondary forest with bamboo,. The IUCN Redlist has classified this species as near threatened. Its threats are mainly habitat loss due to deforestation for lumber, mining and farmlands. There are no known targeted conservation actions for this bird, but it will indirectly benefit from the conservation of other North Luzon species like the Critically Endangered Isabela oriole. The stronghold of the Isabela oriole in Baggao is being proposed as a protected area and will thus preserve key habitat for this bird.
It is found in a few protected areas includings Mount Makiling, Quezon Protected Landscape, Northern Sierra Madre Natural Park, Aurora Memorial National Park and Kalbario–Patapat Natural Park but actual protection from deforestation is still lax.[4]