China alligator, Yangtze alligator
The Chinese alligator (Alligator sinensis) is one of the smallest species of crocodilian. It has been a part of Chinese literature since the third century. In the late 1200s, Marco Polo became the first person outside of China to write about it. In some writings, the Chinese alligator has been associated with the Chinese dragon. Many pieces of evidence suggest that the Chinese alligator was an inspiration for the Chinese dragon.
The Chinese alligator is almost completely black or dark gray in color as an adult. It has a short and broad snout, which points slightly upwards and narrows at the end. Its head is robust, more so than that of the American alligator, with a bony septum dividing its nostrils. It has 72-76 teeth. The Chinese alligator is fully armored, including its belly. It contains up to 17 rows of scales across its body, which are soft on its belly and side and rougher on its back. Its upper eyelids have bony plates on them, a feature usually not present in the American alligator. Its tail is wider than that of the American alligator. It does not have webbed feet, in contrast to the American alligator, which has extensive webbing on its toes.
The Chinese alligator was once distributed widely throughout the eastern part of China’s Yangtze River system. Today it is primarily restricted to a reserve of 433 square kilometers in the Anhui province in the lower Yangtze and some parts of the adjacent provinces of Jiangsu and Zhejiang. This species lives in a temperate, subtropical region, in wetlands, swamps, ponds, lakes, freshwater rivers, and streams.
Chinese alligators are solitary and brumate over winter in a system of complex underground burrows, to emerge around May. They use the burrows throughout the year, more in the winter. These can be very elaborate, sometimes housing more than one alligator. On emerging in May, they spend most of their day basking in the sun in order to raise the temperature of their bodies. They are an aquatic species, and can also use water to thermoregulate either by being in the upper columns of water heated up by the sun, or by moving to shaded water to cool down. With their body temperature normalized, they can return to their usual nocturnal ways. A Chinese alligator makes a bellowing sound to communicate its location. Males and females both also use body language for communication, such as using their lower jaws to slap the water or snapping their jaws to convey a warning.
A Chinese alligator is a carnivorous predator. Adults mostly eat fish, snails, and clams, as well as water birds and small mammals, and sometimes turtles. Younger alligators eat small invertebrates such as insects.
Chinese alligators are polygynous and males mate with more than one female. Both males and females bellow or roar to signal their location and seek a mate. Both genders also have a musk gland under their lower jaw that produces a scent that is attractive and is used in mating. After mating in June, egg-laying takes place in mid-July. The female makes a mound nest from surrounding mud and vegetation and on land that surrounds lakes or rivers. The nest is often near a burrow so that during incubation a mother can attend to the nest. She lays 10-40 eggs in a hollow on the top of the mound, then covers them with more vegetation. She stays near the nest, and in 70 days the eggs hatch when the young alligators make a high-pitched croaking sound. Their mother quickly digs them out and looks after them throughout their first winter. They reach maturity after 5-7 years.
Habitat destruction is the primary threat to this species. Wetland areas are developed for agriculture in order to cope with the huge human population increase in the region. This animal now mainly lives in populated areas where inevitably it comes into conflict with the local farmers. The burrow systems where they hibernate cause problems for drainage in fields, and alligators also eat the farmers' ducks. Despite the lack of commercial value on the international market for the skin of the Chinese alligator, often these reptiles are killed when encountered, due to either fear or a threat to livelihood.
According to IUCN Red List, the total population size of the Chinese alligator is 136-173 individuals. Currently, this species is classified as Critically Endangered (CR) on the IUCN Red List, but its numbers today are stable.