Mugger crocodile

Mugger crocodile
Chambal River, Uttar Pradesh, India
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Crocodilia
Family: Crocodylidae
Subfamily: Crocodylinae
Genus: Crocodylus
Species: C. palustris
Binomial name
Crocodylus palustris
Lesson, 1831[1]
Distribution of Crocodylus palustris

The mugger crocodile (Crocodylus palustris = "crocodile of the marsh"), also called the Indian, Indus, Persian, Sindhu, marsh crocodile, broad-snouted crocodile or simply mugger,[1][2] is found throughout the Indian subcontinent. It is one of the three crocodilians found in India, the others being the gharial and the saltwater crocodile.[3] It is a medium-sized crocodile that mostly inhabits freshwater lakes, ponds, sluggish rivers, swamps and marshes.[4] Males of the species are said to grow up to 4–5 m (13–16 ft) in length. As with other crocodilians, females are smaller.[5] The mugger crocodile has the broadest snout of any extant crocodile, giving it an alligator-like appearance. It is a more heavily armored species with enlarged scutes around the neck. Adults are dark grey or brown, while hatchlings are tan colored.

The mugger crocodile is a skilled predator that preys on a variety of species. Like other crocodilians they are ambush hunters and wait for their prey to come close. They wait camouflaged in the murky waters to launch the attack in the suitable moment. They mostly prey on fish, reptiles, birds and mammals. Reproduction takes place in winter months. Females lay eggs in nests that are holes dug in the sand. Temperature during incubation is the determinant of sex in the young. The mugger crocodile possesses the size to be a serious threat to humans, but they are not as aggressive as some other species, such as the sympatric saltwater crocodiles. They are also observed to usually avoid areas with saltwater crocodiles.[6] Muggers are a fairly social species and tolerate each other during basking and feeding.

Taxonomy and etymology

The name "mugger" is a borrowing of magar, the Hindi word for "crocodile".[7] This is in turn derived from makara, a Sanskrit name for a mythical water monster that is sometimes depicted as a crocodile.[8]

Characteristics

Mugger Crocodile Skull
Adult male mugger crocodile

Mugger crocodiles have 19 upper teeth on each side; a snout that is 1⅓ to 1½ as long as broad at the base; a rough head but without any ridges; mandibular symphysis extending to the level of the fourth or fifth tooth; pre-maxillo-maxillary suture, on the palate, transverse, nearly straight, or curved forwards; and nasal bones separating the pnemaxillaries above. Four large nuchals forming a square, with a smaller one on each side; two pairs of smaller nuchals on a transverse series behind the occiput. Dorsal shield well separated from the nuchal, the scutes usually in 4, rarely in 6, longitudinal series, those of the two median usually considerably broader than long; 16 or 17 transverse series. Scales on limbs keeled. Fingers webbed at the base; outer toes extensively webbed. A serrated fringe on the outer edge of the leg. Adult blackish olive above: young pale olive, dotted and spotted with black.

Size

The mugger crocodiles is considered a medium-sized species. Although much smaller than a saltwater crocodile on average, the mugger crocodile has the broadest snout of any extant true crocodile and may appear bulkier than many crocodiles of around the same length.[9][10] Sexual maturity is obtained at around 1.7–2 m (5.6–6.6 ft) and 2.6 m (8 ft 6 in) for females and males respectively.[11] The largest specimen in the British Museum measures 3.7 m (12 ft 2 in).[12] However, some mugger crocodiles are said to grow up to 4–5 m (13 ft 1 in–16 ft 5 in) long in exceptional cases.[11] The average size of adult mugger crocodiles in Manghopir, Pakistan was cited as 2.89 m (9 ft 6 in), with an estimated average weight of around 100 kg (220 lb).[13] However, some muggers of around 3 m (9 ft 10 in) may weigh 195 kg (430 lb), as was one male caught by Pakistani Forestry, Wildlife and Fisheries department.[14] An 5 m (16 ft 5 in) outsized mugger crocodile may scale up to 700 kg (1,500 lb).[13]

Distribution and habitat

Mugger crocodile
Marsh crocodiles in captivity in CrocBank

Mugger crocodiles are a freshwater species found in lakes, rivers and marshes. Muggers prefer slow-moving, shallower bodies of water rather than fast-flowing, deep areas. They are also known to thrive in man-made reservoirs and irrigation canals. Although they prefer freshwater, they have some tolerance to saltwater therefore are occasionally found in saltwater lagoons. The species is sympatric with the gharial (Gavialis gangeticus) in some areas of India and Nepal and with the saltwater crocodile (Crocodylus porosus) in other areas, but separated by habitat most of the time.

Muggers are better adapted to terrestrial life than most other crocodilians, like their cousin the Cuban crocodile, but they are ecologically most similar to the African Nile crocodile. Muggers are known to be more mobile on land, can migrate considerable distances over land in search of a more suitable habitat, and can chase prey on land for short distances. They are also known to dig burrows as shelters during the dry seasons.

The mugger crocodile can be found in India, Bangladesh, Sri Lanka, Pakistan, Nepal, and the southern tip of Iran. They are probably also found in Indo-China. This crocodile is the most common and widespread of the three species of crocodiles in India, far outnumbering the much larger saltwater crocodile within the country (and most likely within neighboring countries). The mugger is the only crocodilian found in Iran and Pakistan.

In the 1980s, the largest population of wild crocodiles in Tamil Nadu, South India lived in the Amaravathi Reservoir, and in the Chinnar, Thennar and Pambar rivers that drain into it. Their total population was estimated to be 60 adults and 37 sub-adults.

The Amaravati Sagar Crocodile Farm, established in 1975, is the largest crocodile nursery in India. Eggs are collected from wild nests along the perimeter of the reservoir to be hatched and reared at the farm. There were up to 430 animals maintained in captivity at one time. Hundreds of adult crocodiles have been reintroduced from there into the wild.[15] The estimated population in Pakistan is between 400 and 450 animals found in the coastal areas and rivers of Sindh and Baluchistan provinces. They are indigenous to the Sarbaz River, Bahu Kalat River, Kaju and Pishin river basins. The mugger crocodile is the national reptile of Pakistan.[16]

On the Iranian Makran coast, above Chabahar, there is a population of around 200 mugger corocodiles. Due to human activity and a long drought in the late 1990s and early 2000s, the mugger had been pushed to the brink of extinction over the past few years. Following several tropical cyclones, such as the Cyclone Gonu and Cyclone Yamyin in 2007, and Cyclone Phet in 2010, much of the habitat of the Iranian mugger crocodiles has been restored as the dry lakes and hamuns have flooded once again. The animal is known as gando in the local Iranian vernaculars.

Biology and behavior

Mugger crocodiles can achieve speed of around 8 mph over a short distance in pursuit of prey. They can swim much faster than they can run—achieving speeds of 10 to 12 mph in short bursts—and can cruise at about 1 to 2 mph.

Hunting and diet

Mugger crocodile (Gando) in Chabahar, Iran

Being a large carnivorous reptile and a highly opportunistic (but not voracious) predator, the mugger crocodile eats fish, snakes, turtles, birds and mammals. Young crocodiles eat mainly insects such as beetles as well as crabs and shrimp but graduate to vertebrate prey fairly quickly.[17][18] While fish are often favored by crocodiles of various sizes, the mammalian prey are usually small to medium-sized for both subadults and adults. Such prey includes monkeys, squirrels, other rodents and otters as well as ungulates up to the size of chitals.[19] In fact, most vertebrates that approach to drink are potential prey, and may suffer being seized and dragged into the water to be drowned and devoured when the opportunity arises. Studies have indicated the importance of turtles, including even land-based tortoises, to the diet of adult muggers.[20][21] Large adults will sometimes prey on larger mammals, such as large deer, like sambar, and large bovines, like cattle and domestic water buffalo, but such large prey are not common prey as in the case of sympatric saltwater crocodiles. At night, they sometimes hunt on land, lying in ambush near forest trails.[22] There is evidence that they when hunting large prey such as deer they will sometimes leave it to rot while wedged underwater to make it easier to pull apart.[23] During their nocturnal hunts, they often steal kills from other predators, such as leopards,[24] sometimes (albeit very rarely) preying on the predators as well.[25] This species is generally considered to be occasionally dangerous to humans.[26] Given their less aggressive dispositions and more modest size, fatal attacks on humans (though poorly studied for this species) are probably considerably less frequent than those by saltwater crocodiles. Nonetheless, large muggers are formidable creatures that should be given a considerable amount of space.[27][28] Large mugger crocodiles are capable predators of nearly any variety of human livestock or domestic animal, which can in turn worsen the perception of this species and increase conflict.[18][29][30]

Tool use

Mugger crocodiles have been documented using lures to hunt prey such as birds.[31] This means they are among the first reptiles recorded to use tools. By balancing sticks and branches on their heads, Mugger crocodiles are able to lure birds looking for suitable nesting material. This strategy, which is shared by the American alligator, is particularly effective during the nesting season, in which birds are more likely to gather appropriate nesting materials.[32][33]

Sympatric predators

Apart from other crocodilians[3] and the leopard,[24] many formidable predators with an overlapping prey base are sympatric with the mugger crocodile, including Asiatic lions (in the Gir Forest National Park in Gujarat), dholes, Indian pythons (as well as Burmese and reticulated pythons in the far eastern parts of the muggers range), and the Bengal tiger.[4][34] The latter big cat is the only sympatric top carnivore known to habitually forage around watery habitats and is bold enough to fight mugger crocodiles off prey and even, rarely and if extremely hungry, endeavor to prey upon muggers including adults. Tigers have been documented to have preyed on the crocodile in Ranthambore National Park in Rajasthan. However, after a tiger was killed by a crocodile in 2016, Bivash Pandav of the Wildlife Institute of India's Endangered Species Department said "this is the first time we have heard of an attack by crocodiles on a tiger," adding that it was common for the opposite to happen.[35] The mugger crocodile overlaps occasionally in distribution with such large crocodilians as saltwater crocodile and gharial but normally is able to avoid direct conflict with these by favoring different habitats. Muggers barely enter the brackish and saltwater homes of the formidable saltwater species and tend to forage on more diverse prey and in different micro-habitats (shallower waterways being preferring by the mugger) than the slender-snouted gharial.[29][36][37][38]

See also

References

  1. 1 2 3 Choudhury, B.C. & de Silva, A (2013). "Crocodylus palustris". IUCN Red List of Threatened Species. Version 2009.6. International Union for Conservation of Nature. Retrieved 27 April 2017.
  2. ↑  Rines, George Edwin, ed. (1920). "Marsh Crocodile". Encyclopedia Americana.
  3. 1 2 Hiremath, K.G. Recent advances in environmental science. Discovery Publishing House, 2003. ISBN 81-7141-679-9.
  4. 1 2 Da Silva, A. and Lenin, J. (2010). "Mugger Crocodile Crocodylus palustris, pp. 94–98 in S.C. Manolis and C. Stevenson (eds.) Crocodiles. Status Survey and Conservation Action Plan. 3rd edition, Crocodile Specialist Group: Darwin.
  5. ↑ Mugger (Crocodylus palustris). Arkive. Retrieved on 2013-04-13.
  6. ↑ Current Distribution of Crocodylus palustris. Crocodile Species List. Retrieved on 2013-04-13.
  7. ↑ Mugger | Define Mugger at Dictionary.com. Dictionary.reference.com. Retrieved on 2011-03-19.
  8. ↑ "mugger, n.3". Oxford English Dictionary Online. December 2012. Oxford University Press.
  9. ↑ Chang, M. S., Gachal, G. S., Qadri, A. H., & Shaikh, M. Y. (2012). Bio-ecological status, management and conservation of Marsh Crocodiles (Crocodylus palustris) in Deh Akro 2, Sindh–Pakistan. Sindh University Research Journal-SURJ (Science Series), 44(2).
  10. ↑ Grigg, G. (2015). Biology and evolution of crocodylians. Csiro Publishing.
  11. 1 2 Britton, Adam. "Crocodylus palustris (LESSON, 1831)". Crocodilian Species List. Crocodile Specialist Group. Retrieved 21 July 2015.
  12. ↑ Boulenger, G. A. (1890) Fauna of British India. Reptilia and Batrachia.
  13. 1 2 Chang, M. S., Gachal, G. S., Qadri, A. H., Khowaja, Z., Khowaja, M., & Sheikh, M. Y. (2013). Ecological status and threats of marsh crocodiles (Crocodilus palustris) in Manghopir Karachi. International Journal of Biosciences, 3, 44-54.
  14. ↑ Siddiqui, R., Jeyamogan, S., Ali, S. M., Abbas, F., Sagathevan, K. A., & Khan, N. A. (2017). Crocodiles and alligators: Antiamoebic and antitumor compounds of crocodiles. Experimental parasitology, 183, 194-200.
  15. ↑ "Status and Distribution of the Mugger Crocodile in Tamil Nadu". Archived from the original on 3 August 2008. Retrieved 21 January 2018.
  16. ↑ "The Official Web Gateway to Pakistan". www.pakistan.gov.pk. Archived from the original on 2016-11-28. Retrieved 2016-10-23.
  17. ↑ McCann, C. (1935). The Mugger (Crocodilus palustris) feeding on large water beetles (Cybister sp.). Journal of the Bombay Natural History Society 38, 409.
  18. 1 2 Bhatnagar, C., & Mahur, M. (2010). Observations on feeding behavior of a wild population of marsh crocodile in Baghdarrah Lake, Udaipur, Rajasthan. Reptile Rap, 10, 16-18.
  19. ↑ Vyas, R. (2010). Mugger (Crocodylus palustris) population in and around Vadodara city, Gujarat state, India. Russian Journal of herpetology, 17(1), 43-50.
  20. ↑ Ranjitsh, M. (1989). MUGGER CROCODYLUS-PALUSTRIS EATING SOFT-SHELL TURTLE. Bombay Natural History Society, 86: 107.
  21. ↑ de Silva, M., Amarasinghe, A. A., de Silva, A., & Karunarathna, D. M. S. (2011). Mugger crocodile (Crocodylus palustris Lesson, 1831) preys on a radiated tortoise in Sri Lanka. TAPROBANICA: The Journal of Asian Biodiversity, 3(1).
  22. ↑ Dinets, V.L. (2010). "On terrestrial hunting in crocodilians" (PDF). Herpetological Bulletin. 114: 15–18. Archived from the original (PDF) on 2011-10-15.
  23. ↑ Bhattarai, S. (2016). Notes on Mugger Crocodile Crocodylus palustris (Lesson, 1831) hunting on Axis axis in Bardia National Park, Nepal. Hyla: Herpetological bulletin, 2015(2), 41-44.
  24. 1 2 "Sri Lankan Leopard". Arkive.org.
  25. ↑ Bhatnagar, C., & Mahur, M. (2010). Observations on feeding behavior of a wild population of marsh crocodile in Baghdarrah Lake, Udaipur, Rajasthan. Reptile Rap, 10, 16-18.
  26. ↑ "7 Crocodilian Species That Are Dangerous to Humans". britannica.com. Retrieved 7 January 2018.
  27. ↑ Vyas, R. (1993). Recent cases of man-eating by the Mugger (Crocodylus palustris) in Gujarat State. Hamadryad 18: 48-49.
  28. ↑ Sideleau, B., & Britton, A. R. C. (2012). A preliminary analysis of worldwide crocodilian attacks. In Crocodiles: Proceedings of the 21st Working Meeting of the IUCN–SSC Crocodile Specialist Group (pp. 22-25).
  29. 1 2 Da Silva, A., & Lenin, J. (2010). Mugger crocodile Crocodylus palustris. Crocodiles. Status survey and conservation action plan, 94-98.
  30. ↑ De Silva, A. (2010). Crocodiles of Sri Lanka: preliminary assessment of their status and the human crocodile conflict situation. Unpublished report to Mohamed Bin Zeyed Species Conservation Fund, Gampola, Sri Lanka.
  31. ↑ Dinets, V; Brueggen, JC; Brueggen, J.D. (2013). "Crocodilians use tools for hunting". Ethology, Ecology and Evolution. 1: 74. doi:10.1080/03949370.2013.858276.
  32. ↑ "Crocodiles are cleverer than previously thought: Some crocodiles use lures to hunt their prey". ScienceDaily. December 4, 2013. Retrieved December 8, 2013.
  33. ↑ Venugopal, P. D. (2006). Observations on Mugger Crocodylus palustris Lesson feeding on birds in Ranganthittu Bird Sanctuary, Karnataka, India. JOURNAL-BOMBAY NATURAL HISTORY SOCIETY, 103(1), 105.
  34. ↑ Nowell, Kristin; Jackson, Peter (1996). Wild Cats: Status Survey and Conservation Action Plan (PDF). Gland, Switzerland: IUCN/SSC Cat Specialist Group. pp. 1–334. ISBN 2-8317-0045-0.
  35. ↑ Dean Nelson. "Fifteen-foot Bengali crocodile claims king of jungle title from tiger". The Telegraph. Retrieved 8 March 2016.
  36. ↑ Whitaker, R., & Daniel, J. C. (1980). The status of Indian crocodilians. Journal of the Bombay Natural History Society, 75(4), 369.
  37. ↑ Martin, S. (2008). Global diversity of crocodiles (Crocodilia, Reptilia) in freshwater. Hydrobiologia, 595(1), 587-591.
  38. ↑ Whitaker, R. (2007). The Gharial: going extinct again. Iguana, 14(1), 25-32.
  • Mugger crocodile at the Encyclopedia of Life Edit this at Wikidata
  •  "Mugger". New International Encyclopedia. 1905.
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