Pig-nosed Turtles of the Kikori
Science in support of sustainable indigenous harvest
The pig-nosed turtle is important to the people of the Kikori region. It is important because of the value placed on its meat and eggs for food. Many turtles and eggs are eaten in the villages where they are caught or collected. Many are sold or traded through the markets and the monies used to purchase other foods or goods. This project aims to gather strategic data on the nesting biology and harvest of the pig-nosed turtle in the Kikori to inform effective community action for conservation and for sustainable use of this important resource.
The pig-nosed turtle, Carettochelys insculpta, is the sole remaining species of its Family, is very distinctive, and is restricted to the southern rivers of the island of New Guinea and the major rivers of the Northern Territory in Australia. Its taxonomic distinctiveness and limited distribution has generated considerable interest from the scientific community since its discovery in 1886 in the Fly River of Papua New Guinea. Unfortunately, these attributes have also engendered great interest in turtle fanciers and, more recently, the Chinese food market where large turtles of other species are becoming hard to obtain. Globally, pig nosed turtles are regarded as threatened.
In Papua New Guinea, the contemporary pressures of global trade in turtles comes on top of concerns about pressures internal to the country, brought about by a changing relationship between the local people and their traditional resources. The pig-nosed turtle is widely and heavily exploited for its meat and eggs and is an important component of the subsistence economies in New Guinea. Stereotyped nesting habits render the pig-nosed turtle (like sea turtles) extremely susceptible to over-exploitation. The IUCN Red Data Book lists traditional hunting of turtles and harvesting of eggs in southern New Guinea as the principal threat to the species.
Levels of exploitation in the Gulf and Western Provinces have been exacerbated in recent times by the introduction of modern technology, principally outboard motors and because, as clan warfare has decreased, people have moved from the hinterland to more convenient locations along the river banks. Populations of the pig-nosed turtle in New Guinea are reported to have declined sharply between 1960 and 1980. More recent surveys indicate that the level of harvest of nesting females and eggs remains very high. The volume of turtles and eggs passing through the Kikori markets in 2008 compared to 1982 indicate that the decline of this species has continued unabated. The pig-nosed turtle is in trouble in the Kikori, and if trends recorded over past decades continue, we could see a collapse of an important resource in the subsistence economy of the local people, and a collapse in one of a diminishing number of strongholds for the pig-nosed turtle within its already restricted range.
Decisions on whether to take action and what action to take is largely a matter for Kikori communities. They need to decide how important the pig-nosed turtle is to them, whether they are concerned to ensure that the turtle populations are there for future generations, whether they wish to respond to concerns from the global community, and what opportunities might be created by virtue of the spectacular and interesting species in their backyard.
These decisions need to be made on an informed basis. WWF has been very active in working with local communities to raise awareness of the problem and to chart effective action. They have identified the pig-nosed turtle as a priority species, and will be working with the communities in the future to address its conservation as a resource for the community and as a threatened species globally.
Our research is designed to inform this process.
There are many things about the pig-nosed turtle that we do not know, or until recently, did not know. Are they really in decline? Our research, published in the journal Biological Conservation, suggests that they have declined dramatically since the 1980s. We have recently learned that the sex of the young turtles depends on how hot the eggs are in the nest -- hot nests produce all females, cold nests produce all males. This means that some places in the Kikori may be special for producing males and other places special for producing females. Where are these places, and how do they fit into the places where eggs are heavily harvested? Harvesting adult females may have a great impact on the turtle population, but what about harvest of the eggs? Can we work out what the best way is to moderate the impact of harvest, if in fact the population is declining?
These are all questions that cannot be answered without further research, conducted at the same time as the community develops its plan of action with the help of WWF.
This work is funded by the petroleum industry, with additional logistic support from WWF (PNG).
1. Eisemberg, C.C., Rose, M., Yaru, B. and Georges, A. 2014. Spatial and temporal trends in pig-nosed turtle (Carettochelys insculpta) harvest in Papua New Guinea. Oryx, in press
2. Eisemberg, C.C., Rose, M., Yaru, B. and Georges, A. 2011. Demonstrating decline of an iconic species under sustained indigenous harvest - the pig-nosed turtle (Carettochelys insculpta) in Papua New Guinea. Biological Conservation 144:2282-2288.
3. Georges, A., Alacs, E.,Pauza, M. Kinginapi, F., Ona, A. and Eisemberg, C. 2008. Freshwater turtles of the Kikori Drainage, Papua New Guinea, with special reference to the pig-nosed turtle, Carettochelys insculpta. Wildlife Research 35:700-711.
4. Georges, A., Doody, J.S., Eisemberg, C., Alacs, E.A. and Rose, M. 2008. Carettochelys insculpta Ramsay 1886: Pig-nosed Turtle, Fly River Turtle. Chelonian Research Monographs 5:9.1-9.17 [doi:103854/crm.5.009.insculpta.v1.2008]