About Ceyx erithaca (Linnaeus, 1758)
The black-backed dwarf kingfisher (Ceyx erithaca) is one of the smallest known kingfisher species. It is only slightly larger than a medium-sized hummingbird, measuring 12.5–14 cm (4.9–5.5 in) in total length including the bill and tail. Females usually weigh 14–16 g, while males weigh 14–21.5 g, so males are slightly larger. Aside from size difference, the two sexes look identical, with no other marked sexual dimorphism. Both adult males and females share the same plumage and physical traits: a black spot on the forehead, blue and white patches on the side of the neck, a lilac-rufous crown, rump, and tail, dark blue back and wings, a white chin and throat, pale yellow-orange underparts, a dark brown iris, and red legs, feet, and bill. Juvenile birds have duller coloration with less lilac marking, a white chin, throat and belly, a yellow-orange bill with a pale tip, and blue scapulars and wing-coverts. This species has three toes, which is why it is sometimes called the three-toed kingfisher, though other kingfisher species also have three toes. Toe count does not appear to be an adaptive trait in these kingfishers. Its vocalization is a high-pitched, shrill "tsriet-tsriet" or a soft "tjie-tjie-tjie" given in flight. The black-backed dwarf kingfisher is a forest and wetland-associated species endemic to parts of the Indian subcontinent and Mainland Southeast Asia. Its breeding range covers eastern Bangladesh, northeastern India, Myanmar, extreme southern China, Laos, Cambodia and Thailand. There is a separate disjunct population in the Western Ghats of western India and in Sri Lanka. During winter, some individuals migrate south to the Malay Peninsula and Sumatra. It is most commonly found in deciduous and evergreen primary and secondary forests, but also occurs in alluvial forests, mangroves, overgrown rubber plantations, and dense stands of palms, bamboos, or shrubs. The birds tend to stay close to forest streams and ponds, but their nests are often located well away from water. They stay low to the ground, perching and flying within 1–2 m of the forest floor. Their preferred habitat is densely shaded lowland forest near small streams or ponds, and the lowlands they occupy generally do not exceed 1000–1300 m in elevation. The diet of the black-backed dwarf kingfisher consists primarily of insects, including mantises, grasshoppers, flies, water beetles, winged ants, and mayflies. It also eats spiders, oligochaete worms, small crabs, fish, frogs and lizards. Black-backed dwarf kingfishers forage alone. They perch in low vegetation or on rocks, then fly out to capture prey from the ground or within foliage. They can remove spiders from their webs and catch insects mid-flight, and can also dive into water to seize prey at or just below the surface without fully submerging. Larger prey items are typically carried back to a perch, where the bird strikes them repeatedly with its bill before swallowing.
