Bengal roof turtle
The Red-crowned roofed turtle (Batagur kachuga) is a freshwater turtle native to South Asia. Historically, this turtle was found in central Nepal, northeastern India, Bangladesh, and probably Burma, but it has suffered declines in population due to various factors. Currently the International Union for Conservation of Nature rates this turtle as being "critically endangered".
Males of this species usually reach only half the length of females. At the end of the rainy season, their heads and necks develop a brilliant courtship coloration of red, yellow, white, and blue, with 6 distinctive bright red stripes on top of the head. The carapace of the young is strongly keeled. The keels are tubercular posteriorly on the second and third vertebral shields. The posterior margin is strongly crenulated. The marginal serrature disappears in adolescent specimens and the vertebral keel, after being reduced to a series of low knobs, vanishes entirely in the full-grown, the carapace of which is very convex. The nuchal shield is small, trapezoidal and broadest posteriorly. Plastron is angulate laterally in the young. The anterior and posterior lobes are rather narrow and shorter than the width of the bridge, truncate anteriorly, and are openly notched posteriorly.
The National Chambal Sanctuary portion of the Chambal River is India's only protected riverine habitat and it is believed to be one of the last viable habitats for Red-crowned roofed turtles, though even here these turtles are rare.
Females lay eggs in March and April. They excavate nests in which they lay clutches that vary from 11 to 30 eggs. The eggs are 64-75 mm (2+1⁄2-3 in) long by 38-46 mm (1+1⁄2-1+3⁄4 in) wide.
The main threats to Red-crowned roofed turtles include poaching for their meat and shells, accidental drowning in fishing gear, water pollution, hydroelectric infrastructure projects, habitat destruction by sand mining, and egg predation by jackals.
According to the IUCN Red List, the total population size of the Red-crowned roofed turtle is unknown but the total population size of adult breeding females in Chambal River is estimated to be about 500 individuals. Currently, this species is classified as Critically Endangered (CR) on the IUCN Red List, and its numbers today are decreasing.