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Crocodiles in Pakistan
Muhammad Sharif Khan 306 N. Morton Ave Morton, Pa 19070, USA
[email protected]
October, 2015
2 These characteristic large aquatic heavily built carnivorous reptiles are represented in Pakistan by two genera each with single species. Genus Crocodylus Laurenti, 1768 Snout long, broad, flat, about 60% wider than long.; post-occipital plates small, Arranged in a transverse series, followed by 5 large nuchals. Single species.
Crocodylus palustris Lesson (The Mugger: Magar machh) 1831 Crocodilus palustris Lesson, Bull. Sci. Nat. Paris 25, 2:121. Type locality: Plains of India. Diagnosis: 1. Snout long, flat, about 60% wider than long. Teeth in sockets, 19 in upper and 15 in lower jaw, 4th and 10th longest. 2. Neural plates sculptured, 18 from base of neck to the level of vent. 3. Abdominal plates rectangular, 16 across mid-belly. 4. Fingers webbed at base, toes completely webbed, emarginate; a serrated fringe along the outer side of limbs. Maximum total size 3 m. Color: Dorsum light brown, with darker mottling to almost uniformly black.
3 Natural history notes: The mugger inhabits rivers and lakes from plains up to 600 m of elevation; are extremely shy, quickly takes to water. Bask on the sandy river banks, in early and late winter, facing river with wide open mouth. A silent swimmer, floats quietly at the surface of 2 to 3 m deep water, on land rests at its belly; while walking drags it along, however, when running it lifts it off the ground. Burrows are excavated along banks of rivers to rest and lay eggs. A silent hunter; all huntings are done in water, the water visiting animals are dragged into deep water. Several muggers tear the prey into pieces A bad tempered animal, when disturbed hisses loudly, lunges furiously, violently lashing its tail. Male roars resembling bellow of cattle. Short grunts are typical form of communication between hatchlings and adult. Lives in colonies, with a dominant male, breeding season extends from January to March. The breeding males and females locate each other by the secretions from their scent glands. 3-45 eggs, depending on age and size of the female, measuring 71-74 x 46-50 mm, weighing 92-105 g, are laid in a 50-cm deep and 30-cm wide pitcher-shaped nest, which is excavated by the female, 2-500 m away from the water, on sandy earth or the gravel bank of the water body. The eggs are covered with vegetation and the female keeps a constant watch. Young are hatched within 4-6 weeks, depending on the warmth in the nest. At the time of hatching, young muggers utter characteristic calls. In answer, the mother who is close by, removes the vegetation cover from the nest and helps the young in cracking the hard eggshells. Juveniles soon scramble out of the nest. Distribution: Mugger range from Assam through India, from Sri Lanka to westernmost Balochistan and eastern Iran. In India it inhabits all river systems and their connecting streams and all sizable ponds. While in Pakistan it is reported to inhabit the lower Indus Valley.
A note on Mangopir Crocodiles
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The 700-year old Mango Pir shrine, 25 kilometers southwest of the Karachi city, is the only definite permanent habitat in Pakistan where about 150+ freshwater crocodile Crocodylus palustris or muggers are kept in an isolated freshwater six feet deep lake. The lake is fed by water from a spring close by. The lake spread over an area of 1200 feet. Protected by a brick-wall around the lake. When lake overflows during monsoon rains, crocks roam out of the parameter endangering inhabitants around. While during draught (winter and early summer) the lake water gets foul and stinky, threatening crock’s and visitor’s health, since the lake is not regularly cleared of the debris. Recently caring of the shrine is responsibility of Sindh Auqaf department, and of crocodiles under Zoological Survey Department and WWF-Pakistan, the conditions have improved. The number of crocs is increasing by breeding.
Family Gavialidae Genus Gavialis Oppel, 1811
5 Gavialis gangeticus (Gmelin) (Gharial: Gharial: Sassar) 1789 Lacerta gangetica Gmelin, partim, Linn. Syst. Nat. (13)1:1057. Type locality: Senegal, Africa, and Ganges, India. Diagnosis: 1. Snout long, narrow, its length 5 times its breadth. 2. Teeth 27-29 teeth in the upper, 25-26 in the lower jaw on each side, first 3 fitting into notches in upper jaw. 3. A continuous series of 21-22 transverse rows of plates from nuchal to level of vent. 4. A pair of small postoccipital scutes. 5. Fingers webbed. Males longer than females. During breeding season the male develops a large hollow cartilaginous protuberance at tip of its snout, known as "ghara" from which name “gharial” is derived. Maximum length 6.5 m. Color: Dark olive or brownish above, whitish or yellowish below. Young with spots or crossbars. Natural history notes: Restricted to deep fast-flowing rivers. About 100 years back they were plentiful in the rivers of the Indo-Gangetic plain. Its range extends from throughout the Gangetic system to the Indus Delta. Decline in population of these big reptiles is due largely to uncontrolled all-season hunting for hides, meat, medicine, and sport. Moreover, loss of habitat due to human activity and encroachment has led to the present deteriorating conditions, which will quickly lead to the extinction of these fascinating reptiles. An agile swimmer; however, clumsy on land, propels body with laterally extended limbs dragging heavy body along. It rarely ventures far from water. Muggers groan when disturbed, bellow and groan when in distress. Breeding males develop large lumpy excrescence known as ghara at the tips of their snouts, which are said to act as resonators of bellowing and hissing. Mating season extends from December to January. Nesting measure 30-37 cm deep and 22 cm wide excavated in sand along the banks. Clutch size varies from 10 to 96 hard-shelled white eggs, measuring 85-90 x 65-70 mm. Incubation period 72-92 days. Hatchling grunt from within the egg, and the mother, which is guarding the nest, helps the young in breaking shells of the eggs. Distribution: The gharial occurs in pockets throughout the Gangetic plains in India. Extremely rare in Pakistan, if not absent. This is why nothing definite can be said about its distribution in Pakistan. There is evidence in support of the existence of a population in the lower Indus, the East Nara in Sanghar District, Sindh.
6 References Khan, Muhammad Sharif (2006). Amphibians and Reptiles of Pakistan. Krieger Publishing, Malabar, Florida.
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