The brown fantail warbler (scientific name: Cisticola juncidis) is a small bird with a body length of 9 to 11 cm. Male and female feathers are similar. Spring feathers are chestnut or chestnut brown with black-brown feathers, and the top of the head and pillow are black brown with a wide skin-yellow or chestnut brown feather margin, forming black-brown longitudinal stripes on the top of the head and pillow; the eyebrow lines are light brown or brownish white, sometimes inconspicuous. The eyes are brownish white, the cheeks and ear feathers are pale brown or maroon, the sides of the head and the back of the neck are light chestnut brown, and the back of the neck has or slightly light brown feathers. The upper back and shoulders are black, the upper back feather margin is chestnut brown, the outer shoulder feather margin is gray, and only the inner feather margin is chestnut brown; the lower back, waist and tail cover feathers are chestnut brown, the tail is convex, the central tail feather is the longest, and the outward is shortened sequentially, the tail feather color base is black, gradually becoming light brown with white end spots and black secondary spots, the central tail feather has a wide brown feather margin, black secondary spot and grayish brown or light brown end, and the outer tail feather has a narrow brown margin and a large brown spot in the middle of the inner wing. The winged coverts and tertiary flight feathers are black with a chestnut brown margin; the primary and secondary flight feathers are dark brown, and the outer feathers are chestnut brown. The underparts are white or milky white, the flanks and covert feathers are brownish yellow or light brown, the axillary feathers are white, and the underwing coverts are white and brown. Winter feathers have black markings on the forehead, black on the top of the head and pillow, sandy yellow feathers, darker tail, white brownish yellow underparts, and the rest resemble summer feathers. The iris is reddish brown, the upper mouth is reddish brown, the lower mouth is pink, and the feet are fleshy or flesh red.
China is mainly distributed in the middle and lower reaches of the Yangtze River, south of the Yangtze River, Fujian, Guangdong, Guangxi, Yunnan, Hainan Island and Taiwan provinces.
It inhabits lowland shrublands and grasses at the foot of mountains, hills and plains below 1000 m above sea level, but also in and out of farmland, grasslands, shrublands, swamps, low reed ponds and shrubs and grasses on the edge of the ground. During the breeding period, it is active alone or in pairs, with strong territoriality, and in winter, it is mostly a loose group of 3 to 5 or more than 10 animals. Sexually active, non-stop activity or foraging throughout the day. It is found in grasses, shrubs or weeds, and on plant stems, and sometimes rests on shrubs or power lines. During breeding, male birds often do unique flight performances in the field, soaring straight up in the sky when taking off, soaring at high altitude and doing circle flight, and then folding their wings, rapidly descending, turning to horizontal flight when approaching the ground, or burrowing into grass or perching on protruding grass stems, and making a sharp and continuous "ji~ji~ji" call when rushing into the sky, and issuing a "dza~dza~" sound when the wings fall. The tail is often fanned out and swings up and down during flight. Migration: Resident birds, some summer migratory birds. Feeding habits: Feeds mainly on insects and insect larvae, but also eats other small invertebrates such as spiders, ants and plant foods such as weed seeds.
The breeding season is from April to July. Nests usually nest in grass, 10 to 50 cm above the ground. The nest is pear-shaped, oval or sachet-shaped, open on the upper or upper side, mainly woven from torn grass blades, plant fibers, etc., and some are covered with cobwebs on the outside, and the inner cushion is lined with fluff and soft plants. The nest is 7 to 8 cm tall and about 5 cm in diameter, and the nest is borne by the female, and the male assists in carrying the nest material. Each clutch usually lays 4 to 5 eggs; occasionally as few as 3 and as many as 6. Egg white or pale bluish white