The blue-throated bee-eater (Merops viridis) is a species of bird in the bee-eater family. They are found throughout southeast Asia in subtropical or tropical mangrove forests. Their diet consists mostly of bees, wasps, and dragonflies. Blue-throated bee-eaters are small with colorful plumage consisting of a red nape, dark green wings, light green breast, and their signature blue throat. Juvenile plumage contain dark green head and wings and light green breasts, only developing their full plumage in adulthood. They have a rich variety of songs and calls, including longcalls which allow them to communicate long distances in the forest.
Blue-throated bee-eaters practice asynchronous brooding, which means that chicks hatch at different times, often pairing with siblicide. Older chicks are not only larger and able to withstand larger wounds from other siblings, but also have the ability to monopolize the food they are fed by parents. There has been several observations of migration between islands in southeast Asia or onto mainland of Asia. One notable seasonal spring migration occurs from Sumatra, across the Strait of Malacca, and ending on the west coast of Malaysia. They also migrate from southeast Asia to breeding grounds in western China during breeding season.
Conservation status of the blue-throated bee-eaters is of "least concern" due to their large distribution and stability of its population as of 2016. However, deforestation may be its biggest threat, destroying its habitat and decreasing other bird diversities.
Taxonomy and systematics
Blue-throated bee-eaters are part of the family Meropidae, which are the bee-eaters, including 27 other birds. Another alternate common name they have is the chestnut-headed bee-eater.
Description
Adult blue-throated bee-eaters grow to around 21 cm, with an additional 9 cm including tail streamers. They weigh around 34 to 41 grams. Adults have spectacular plumage with a red crown and nape, dark green wings, blue tail, light green breast, white belly, and the signature blue throat. Juveniles develop their full plumage later, with mostly green coloration all over their body. They have a dark green head and wings and light green breast. Both adults and juveniles have black eye patches. Eye color can range between red and brown, or a combination.
Vocalizations
Blue-throated bee-eaters make a combination of vocalizations characterized as longcalls, alarm calls, chirps, low chirps, purrs, sharp coos, trills, and feeding calls. Longcalls have been observed to communicate long distances and are recognizable by their volume and intensity. A longcall is performed either during flight or on a perch by stretching and pointing their bill upwards, known as a “longcall” posture. Chirps are short and sharp with regular intervals, often used during digs.
Distribution and habitat
They have a wide distribution ranging from southeastern China to the Greater Sundas Islands. The most concentrated distribution is found in Singapore, Malaysia, southern Cambodia, and southern Thailand. Other locations with greater dispersal include Borneo and Java.On 26th May 2013, this species was sighted by sasidharan manekkara and photographed from, the breeding colony of blue-tailed bee-eater (Merops philippinus)near , Kannur, Kerala South India. They live in lower elevations between 0–670 meters. Their habitat includes a wide variety of flat plains, such as farmland, suburban gardens, riversides, dunes, and sandy clearings. In the winter, some blue-throated bee-eaters move to forest canopies and saltwater channels of mangrove forests. They often dig burrows horizontally into flat ground, allowing easier access compared to burrows in sand cliffs of other bee-eaters. Colony sizes range from 50 to 200 pairs or living completely solitary in the open country.