Determine the effects of a hunting moratorium on the current population status of Scotts Tree Kangaroo, Dendrolagus scottae, in PNG's Torricelli Mountain Range

A project undertaken at The Zoological Parks & Gardens Board, Parkville, Victoria, and supervised by P Temple-Smith

The Scott’s Tree Kangaroo (Dendrolagus scottae) or Tenkile as it is known locally, was first described to science in 1989 by Dr Tim Flannery.  At the time it was already on the verge of extinction.  Its range was reduced to a 20-30 square kilometre area of the Torricelli Mountain Range in the north of Papua New Guinea. Although its habitat remains relatively unspoiled, the abandonment of many traditional practices and beliefs, such as the end to tribal warfare and belief in forest spirits, have allowed tribal hunters far greater access to Tenkile habitat increasing local hunting pressure on tree-kangaroos which has had dire consequences.  This, combined with an ever-increasing human population has compounded an already critical situation. As few as 100 animals remain.

Since the Tenkile’s discovery a recovery plan has been written for the species and is being implemented by the Tenkile Conservation Alliance (TCA).   Local villagers are aware of the need to conserve the Tree Kangaroo and in 1999 a hunting moratorium was agreed between the Tenkile Conservation Alliance and the fourteen villages that have ownership over Tenkile habitat.

The aim of this project has been to determine the effect of the two year hunting moratorium and assess current  population status and trends for Tenkile in the Torricelli Mountains using skilled PNG Nationals. A Pacific Biological Foundation grant has been pivotal in engaging villagers in the design and delivery of this conservation activity.

Priorities
  • Assess current hunting moratorium and implement a new moratorium if required.
  • Prepare distance sampling sites in at least three key areas.
  • Identify population estimate and geographic range.
  • Undertake distance sampling at all mapped sites and map language boundaries.
Progress

Assess current hunting moratorium and implement a new moratorium if required

  • Meetings with 15 villages indicated a willingness to extend moratorium beyond agreed date.
  • Villages resigned hunting moratorium in June 2002

Prepare distance sampling sites in at least three key areas.

  • Twenty transects have been prepared with 206 survey points in Tenkile habitat. GPS locations for base line and some point stations obtained.

Identify population estimate and geographic range.

  • Monthly surveys were conducted on the Sweipini Ridgeline in the Torricelli Mountains, Searches were performed on 206 search points. Dung density per km2 were obtained. Using the statistical software program DISTANCE (version 4.0), the average density estimate of D. scottae on Sweipini Ridgeline is approximately one individual per km2. D. scottae is thought to have a total range of 140 km2 (Vincent et al. 2000). Although there is now a population density estimate, the population density of the species throughout its total range cannot be estimated until more is known about its social structure.

Map language boundaries.

  • Language boundaries mapping completed. Waiting finalised report.

Undertake distance sampling at all mapped sites.

  • Due to high topographical constraints in the Torricelli Mountains eg much of the terrain within D. scottae’s estimated range is too precipitous for dung surveys, the transect lines could not be extended as far as planned. This is likely to lead to the failure of applying the methods used in the remainder of Tenkile’s range.
Conclusion

Now that an initial estimate of the population density of Tenkile has been achieved, the TCA are in a position to begin to assess the impact of the hunting moratorium and incorporate this into the extension and development of further field research and conservation efforts. The work undertaken so far has confirmed that the population size is critically low. Without a continuing input from the TCA and generous supporters like APBF, the chances for the long-term survival of the species are certainly low. Coupled with this program, an intrinsic part of the Tenkile recovery will be improved levels of trust and understanding between the people of the Torricelli Mountains and external organisations involved.

Scotts Tree Kangaroo, Dendrolagus scottae

Possible location of Scotts Tree Kangaroo in PNG

Estimated range of D. scottae in Torricelli Mountains, Papua New Guinea

Hunting Scotts Tree Kangaroo

Survey work

Signing a moratorium

Moratorium document