mugger
- Also called:
- mugger crocodile or marsh crocodile
- Related Topics:
- apex predator
mugger, (Crocodylus palustris), species of freshwater crocodile known for its broad head and snout, robust body (which gives it a superficial resemblance to the American alligator [Alligator mississippiensis]), and use of tools to attract prey. Muggers inhabit freshwater streams, ponds, and marshes, as well as saltwater lagoons, in South Asia. The mugger’s geographic range extends from extreme southeastern Iran eastward to Bangladesh and from Nepal and northern India south to Sri Lanka. The crocodile’s common name comes from magar, which translates loosely to “water monster” in the Hindi and Urdu languages.
Natural history
Muggers have a fearsome look, even when compared with other crocodiles. Like several other species of crocodiles, their coloration is a mix of grays and browns. In some adults, some of the scales on the top and sides of the body may appear darker than others, forming charcoal-colored patches and faint dark bands, especially on the tail. In hatchlings and juveniles, whose color ranges from dull green to golden brown, such dark patches and bands are more pronounced. Muggers can grow to 4–5 meters (13–16.5 feet) long. Although the largest adults can weigh as much as 700 kg (1,540 pounds), most weigh about 450 kg (990 pounds). The mugger has the broadest snout of any crocodile, and the upper jaw overlaps the lower—two characteristics, along with the animal’s size, that have earned it comparisons to the American alligator.
Muggers split their time between land and water. Like many other reptiles, muggers bask in the sun to raise their body temperature, which lifts their metabolism to allow them to become active enough to hunt and move. They nest in burrows, which provide refuge from the heat during the day and from the colder temperatures that occur at night. They hunt by sitting and waiting in the water until prey ventures close enough to be ambushed by a sudden strike of their jaws. They also will seek out prey on land, in some cases galloping at speeds as fast as 13–14.5 km (8–9 miles) per hour to chase down their quarry. In 2007 muggers were observed using sticks and twigs as hunting lures to attract birds that were in search of materials for their nests, the first evidence of tool use by a reptile.
Muggers function as apex predators in the ecosystems they inhabit, and some individuals also scavenge dead carcasses for food in some locations. In addition to birds, muggers eat fishes, amphibians, deer, monkeys, and even other crocodiles. They also attack livestock and people, most of their human victims being fishermen. Between 2008 and 2013 there were 110 documented attacks by the species on people, and approximately one-third of those attacks resulted in death of the victims. Once muggers become large enough, they essentially have no natural predators other than humans; however, some sources note that adults are sometimes prey for tigers and other crocodiles. Mugger eggs and hatchlings are sometimes consumed by other animals, including crows and wild dogs, and people collect mugger eggs for food as well.
Mugger habitat is divided up into territories, and the species uses a polygynous mating system (in which one male mates with several females). Breeding males appear to tolerate one another during the dry season, when habitat is more limited. However, they become more territorial during the middle of the rainy season when mating takes place. At the beginning of the dry season, female muggers deposit about 25 to 30 fertilized eggs in their burrow, and they incubate their eggs for roughly two months before the eggs hatch. Females can produce up to two clutches per year, and hatchlings that emerge are carried to the water by their parents. Young remain in the care of their mother, father, and other nearby adult muggers for about one year before they disperse.
Female mugger crocodiles become sexually mature at about age six, when they have grown to 1.7–2 meters (about 5.6–6.6 feet) long. Males, in contrast, do not start to breed until some four years later, when they reach roughly 2.6 meters (about 8.5 feet) in length. Muggers can live for more than 30 years in captivity, and some sources suggest that the species lives between 30 and 40 years in the wild.
Conservation status
The International Union for Conservation of Nature and Natural Resources has classified the mugger as a vulnerable species since 1982. Limited population studies conducted during the late 1980s reported that between 2,000 and 3,000 muggers remained worldwide. More-comprehensive studies conducted since then estimate that adults and juveniles combined (though excluding hatchlings) number between 5,700 and 8,700, and populations, though largely isolated from one another, occur in many parts of South Asia. The species is considered to be extinct in the wild in Bhutan and Bangladesh, but both countries report having successfully bred some individuals in captivity. Long-term mugger survival continues to be threatened by habitat loss stemming from agricultural and urban land-use change, conflict with people over fish, poaching, and accidental drowning in fishing nets.
