Rabu, 03 September 2008

Crocodile conservation


THE BEGINNING
Crocodilians were threatened in India due to indiscriminate killing for commercial purpose and severe habitat loss until enactment of the Wildlife (Protection) Act.1972. All three species of crocodiles (Gharial, Gavialis gangeticus; Mugger crocodile, Crocodylus palustris and Saltwater crocodile, Crocodylus porosus in the river systems of Orissa were on the verge of extinction by the seventies. Crocodiles were very few because of ever increasing human activity in the rivers and their other traditional habitats, and consequent reduction in the extent of habitable stretches. Also, the survival rate of the crocodile hatchlings in nature is low because of predation. Piecemeal efforts were being made from the sixties onwards to save the crocodile. FAO Expert, Dr. H.R.Bustard engaged by UNDP/FAO and Government of India studied the prospects of crocodile rehabilitation,

THE BEGINNING

MANAGEMENT OBJECTIVES

PROJECT SITES IN ORISSA

'BAULA' PROJECT: DANGAMAL

MUGGER PROJECT: RAMATIRTHA (more file)

GHARIAL PROJECT: TIKARPADA

CAPTIVE BREEDING OF CROCODILES AT NANDANKANAN

RESEARCH AND TRAINING

CONTRIBUTIONS

Interpreting visual signs

and based on his report and guidance a Crocodile Conservation Project was launched in 1975 in different States. The Gharial and Saltwater crocodile conservation programme was first implemented in Orissa in early 1975 and subsequently the Mugger conservation programme was initiated, since Orissa is having distinction for existence of all the three species of Indian crocodilians. The funds and technical support for the project came from UNDP/ FAO through the Government of India.

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MANAGEMENT OBJECTIVES.
The broad strategy adopted for rehabilitation of crocodiles was to protect them in their natural habitats, to rebuild the population quickly through captive breeding (rear and release), and to build up trained personnel for the job. The broad objectives of activities under crocodile project were the following.

(a) To protect the remaining population of crocodilians in their natural habitat by creating sanctuaries.

(b) To rebuild natural population quickly through 'grow and release' or 'rear and release' technique involving the following phases of operation.

· Collection of eggs from natural nests as soon as these were laid,
· Incubation of these eggs under ideal temperature and humidity maintained in artificial hatcheries,
· Hatching and rearing the young crocodilians in ideal captive-husbandry conditions,
· Marking and releasing young crocodiles in protected areas, and
· Assessing the result of release along with protection of the released crocodiles.

(c) To promote captive breeding.

(d) To take-up research to improve management. Some of the major research activities have been in the following directions.
· Interpretation of the various types of data collected during survey and census.
· Determination of parameters for maximum success in egg collection, egg incubation, hatching, rearing and release, including husbandry aspects on feeding, food conversion and growth.
· Study of habitat features and population structure.
· Study of behavioural biology including reproduction, thermo-regulation, feeding, water-orientation, locomotion etc.

(e) To build up a level of trained personnel for better continuity of the project through trainings imparted at the project-sites and through the erstwhile Central Crocodile Breeding and Management Training Institute, Hyderabad.

(f) To involve the local people intimately through the following:
· The development of a strong level of acceptance of the project by the people, by locating the projects in rural areas where people could both see and participate in the entire programme.
· Protect the immediate and long-term interests of fishermen who reside within the sanctuaries, and whose livelihood depends on fishing, by, if necessary, providing an alternative source of income that was not detrimental to the conservation aims.
· Extend the conservation programme to village-level, commercial crocodile farming, so that people could earn an income from conserving crocodiles and their habitats.

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PROJECT SITES IN ORISSA
During 1976, survey of (i) salt-water crocodiles and (ii) Gharial crocodiles was conducted in the river system of Bhitarkanika area and in the Mahanadi, respectively. The number of salt-water crocodiles in Bhitarkanika area was estimated to be 95, including 34 adults. The number of Gharials in Mahanadi was estimated to be 8, including 4 adults. No detailed survey was, however, conducted for Mugger crocodiles at that time, although the species occurred at several places in the State. The one breeding population of Mugger known at that time was in the Balimela Dam in Koraput district.

The Crocodile Project started with the objective of building the population to a stage when incidence of sighting could be 5 to 6 crocodiles per KM length of water. The Project sought to make up the natural losses by death and predation through rear and release operation. This involved collection of eggs from the nests as soon as these were laid, incubation and hatching of these eggs in hatcheries under regulated conditions of temperature and humidity, rearing the young juveniles, marking and release of the young crocodiles into Nature in protected areas, and assessment of the degree of success in restocking any protected area with crocodiles released from the hatcheries. To accomplish these tasks, 3 separate research units were established at Tikarpara, Dangmal and Ramatirtha for the Gharial, Salt Water Crocodile and the Mugger, respectively. At the Nandankanan Biological Park, captive breeding plans for all three species were pursued.

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'BAULA' PROJECT AT DANGAMAL
‘Baula’ is the Oriya term for Saltwater Crocodile. At Dangmal in Bhitarkanika sanctuary, salt-water crocodile eggs have been collected locally; and young crocodiles have been released in the creeks and the estuaries; and more than 2200 crocodiles have been released in phases since 1977.

This operation has been reasonably successful and the crocodile population in the Bhitarkanika river system has gradually been built up. Above 50 released female Saltwater Crocodiles have bread successfully and are laying eggs in the wild.

The annual census conducted in the river systems of Bhitarkanika wildlife sanctuary in Jan.2004 indicated that there were 1308 Saltwater crocodiles and the crocodile population is on increasing trend. The details about the census results are as under:

Size class and number of crocodiles

Hatch-lings

Year-lings

Juvenile

Sub-adult

Adult

Total

525

303

210

100

220

1358

38.60%

22.30%

15.50%

7.40%

16.20%




Comparison of census results (2000-2004)


Census year and no. of crocodiles

2004

2003

2002

2001

2000

1358

1308

1330

1098

914



Range wise crocodile number (2004)

Forest ranges and no. of crocodiles

Kanika

Rajnagar

Mahakalapada

Chandbali

Total

1149 (84.6%)

172 (12.67%)

19 (1.40%)

18 (1.33%)

1358

Results indicate the followings:

There are 220 full grown adults among 1358 crocodiles counted;

There is an increase of 3.8% over 2003-04 results;
Six adults are above 18’ length.
Kanika range holds 84% of the entire present population.
The areas having higher concentration of crocodiles have:
(I) Good mangrove cover / fringing mangrove vegetation,
(ii) Less human disturbances (little or no illegal fishing activities), and
(iii) A network of the river, creeks and creek lets.

Thus, above 70% of the entire crocodile population are restricted into only approximately 30% areas /habitat i.e. Khola-Brahmani river confluence to Bhitarkanika-Pathasala river confluence of the Bhitarkanika National Park.

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MUGGER PROJECT AT RAMATIRTHA
The Ramatirtha center, meant for Mugger crocodiles, initially started with eggs and juveniles of Mugger procured from Tamilnadu. Since 1984 breeding of Muggers and the release of young ones into the nature in Similipal have been carried out, and so far more than 600 crocodiles have been released in Similipal.

Census was conducted to ascertain the population status of Mugger crocodiles in the prominent rivers/waterbodies inside the Similipal. The river wise census results have been indicated below.

The census results indicate the followings:

  • In West Deo river, two stretches namely UBK-Patbil and Kandadhenu- Lower Barhakamuda hold 27 out of 42 (64.28%) of total muggers in about 15 km of the river.

  • In river Khairi, the stretches between Jenabil and Ransa, about 15 km long,hold 13 (65%) out of 20 Muggers.

  • This is the situation / trend continuing since late 1980s during which regular monitoring of the crocodiles has been carried out.

River and size / length wise distribution of Crocodiles-2004.

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GHARIAL PROJECT AT TIKARPADA
At Tikarpara, Gharial eggs were obtained at different points of time from Narayani and Kali rivers in Nepal and Chambal sanctuary in Madhya Pradesh, Rajasthan and Uttar Pradesh. The eggs collected from Mahanadi were infertile. Some hatchlings of Gharial were obtained from eggs incubated in Royal Chitwan National Park of Nepal and Katarniyaghat sanctuary in Uttar Pradesh. All Gharials reared at Tikarpara and those produced from captive breeding at Nandankanan zoo, numbering more than 700, were released in the river Mahanadi between Boudh and Katrang.

One of the assessments of the rear and release operation in respect of Gharials was made during December, 1987 - January, 1988, when only 25 Gharials were found to be surviving in the entire stretch of the river Mahanadi and down stream of Hirakud Reservoir over a length of 400 Kms. In January, 2003 census, one male and two female Gharials were sighted / counted in and outside of the sanctuary, respectively. A study was carried out to assess the reasons for poor survival of the Gharial in Mahanadi. For increasing the Gharial population to more viable levels it is absolutely essential to minimize fishing and navigation at least on certain stretches of the river. It has been under consideration to rehabilitate Gharials in Mahanadi up-stream of Hirakud reservoir, and some stretches of the river Brahmani.

The census conducted in winter-2004 in the river system of Mahanadi within the limits of Satkosia Gorge Sanctuary indicated survival only one male Gharial (3-3.5m length). This Gharial was located between Binikei and Majhipada of the river Mahanadi / SatkosiaGorge.

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MANAGEMENT IN THE WILD
Since the prime objective of crocodile project is to rebuild their population in the wild, restocking the sanctuaries with captive reared crocodiles is an ongoing programme. The resident and released populations of crocodiles are periodically monitored and the trend of nesting is also assessed.

Protection of crocodiles is a round-the-year activity. Measure threats are from intruding fishermen using nylon set nets.

Because of occasional reappearance of crocodiles in their former habitat that is now shared by increasing human population, there are occasional instances of nuisance crocodile. Such crocodiles are generally captured and shifted to some other river/creek or are brought back to captivity after careful consideration of the case histories and field conditions.

CAPTIVE BREEDING OF CROCODILES AT NANDANKANAN
Captive breeding units on all the three crocodilian species have been established at Nandankanan Zoo. Muggers bred at Nandankanan Zoo have also been released in Satkosia Gorge. Although Gharials have failed in establishing in Satkosia Gorge, Muggers have settled down well in this stretch of Mahanadi River. As per survey carried in January to March 2004 there are 64 Muggers in Mahanadi system and 83 Muggers in the rivers in Similipal.

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RESEARCH AND TRAINING
In-house research has been conducted to standardise 'the rear and release' technique. Studies have been carried out to determine the appropriate method of population assessment, egg collection, egg incubation, hatching, and husbandry of the young crocodiles and various aspects of behavioural biology of the three species of crocodiles and their habitat features. The baseline data on Indian crocodilians and their management has been possible because of over 300 publications produced from these conservation projects.

Training has been imparted to all field staff employed in the project to help them to discharge their duties efficiently. Local people have been trained on how to bring live food for the hatchling in the pools. The Research Officers of this organisation have availed of overseas training and have also conducted courses through the UNDP/FAO Programme. Based on their performance and contribution they have been in the steering committee and membership of the IUCN/ SSC Crocodile Specialist Group.

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CONTRIBUTIONS
All the three species of crocodiles have been saved from the brink of extinction, and many of their habitats have been brought under the protected area network of the State. The crocodile project that has since long come to a slow-pace in the State has contributed handsomely to develop the know-how and spreading of awareness. Future of the crocodiles can be secured with adequate protection of their habitats.

Apart from producing a large number of crocodiles in a short span, the Crocodile Project has contributed in various ways to the entire approach of wildlife conservation, research and training.

  • Local people have been intimately involved in the management of crocodiles.
  • Full time research personnel have been inducted into the wildlife wing to carry out research on crocodiles and other associated wildlife.
  • Some important wetland sanctuaries have been created with crocodiles as the flagship-species.
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