The impact of hunting on Victoria crowned pigeon (Goura victoria:Columbidae) in the rainforests of Northern Papua, Indonesia

Victoria crowned pigeon (Goura victoria) is an endemic bird and has been declared as protected species by Indonesian Government under Law Act No. 301/1991. This species with two other species of Goura (crowned pigeon) are endemic to New Guinea islands, and have been state as Restricted Range Species. IUCN Red List also has verified the entitre genus of Goura as the largest-body sized of pigeon in the world with status of vulnerable species due to hunting problems, beside listed on Appendix II of CITES as well. The workshop on Priority-Setting of Biodiversity Conservation in Papua has launched that the major threats on this bird included the large-scale forest conversion for logging, swidden-agriculture, plantation, transmigration, and settlement, also hunting and illegal trading. Local communities in Papua have been practicing hunting on wildlife especially on bird for subsistence, though it is moving towards commercial activities in some regions recently. Since hunting becomes the main threat to Goura spp, it is important to conduct a field study on the impact of hunting on Victoria crowned pigeon in tropical rainforests of the northern area in Papua-Indonesia. The published information on hunting activity and its impact are very limited, as well as the lack data on Victoria crowned pigeon population in its natural habitat in the northern Papua. More over, information on tree communities and vegetation structure in the habitat of Victoria crowned pigeon in this region is still very inadequate. Based on these conditions, it becomes very important to carry out such a research focusing on hunting practice, population of Goura victoria, and forest structure in the northern of Papua. The main aim of this study was to assess the impact of hunting on the population of Victoria crowned pigeon in the rainforests in Papua. The current research is intended to contribute the conservation action of Victoria crowned pigeon in the future. The specific aims of this study includes to investigate forest structure in four different areas inhabited by G.victoria and to estimate the population size and density of Victoria crowned pigeon in four different forest areas in northern Papua; The other aims of the study are to compare the population size of G.victoria in the given areas; to describe the activity of the bird’s hunters and their impact on the population of G.victoria in those forest areas and to create and increase awareness of the local people for the conservation of Victoria crowned pigeon. The study was concentrated in forests of four different regencies in the northern part of the Papua Province, which are forest of Buare (Mamberamo Raya), Supiori (Supiori), Unurumguay (Jayapura), and Bonggo forest (Sarmi). The detailed observations on population density on Goura victoria, composition and forest structure, also on hunting activity by local people, and its impacts on the population of Victoria crowned pigeon were conducted in those forest areas. Buare and Supiori forests are the parts of nature reserve become forest area with lower interference of local people activity compared with higher interference and pressures in Unurumguay and Bonggo forests. In each study site, as many as 25 randomly long lines transects for vegetation analysis of 20 x 100 meters with 20 m x 20 m plots were established for vegetation analysis. Measurement and identification within each plot were taken on each tree with a diameter at breast high more than 10 cm and more than a meter height. Furthermore, floristic structure was assessed quantitatively by calculating the Important Value Index (IVI) for each species in each study site. The IVI represents the sums of the value of Relative Density (RD), Relative frequency (RF) and Relative Dominance (RDo). Goura surveys were carried out at four sites using line transect method and 45 transects were set aside in all study sites. The researcher walked along the transect line and recorded the perpendicular distance between detection points and transect line. Surveys were done four days per week, between 06.00 in the morning to 16.00 in the afternoon each day by the field team. The semi structural interviews with questionnaires were used and the interviews were conducted on 151 respondents who live in 13 villages of four districts in four regencies. Important Value Index (IVI) and Shannon-Wiener Diversity Index (H’) were used to calculate the floristic composition and forest structure in each study site. Distance 5.0 release 2.0 program was used to estimate the population density and population of Victoria crowned pigeon. The Mann Whitney U test, Kruskall-Wallis test and Multiple Linier Regression Analysis using SPSS version 19.00 were used to illustrate the hunting activity by local people and predict the impact of hunting by local people to Goura victoria population. Then, the estimation of maximum sustainable annual harvest was compared to the value of maximum current annual harvest. Hunting practice on Goura victoria is unsustainable if the value of maximum current annual harvest exceeds the value of maximum sustainable annual harvest. All data analysis was processed using Excel program. Floristc composition in each study sites showed that the 58 species in 38 families in Buare and 57 species in 38 families were found in Supiori. These were quite different with 39 species in 25 families found in Unurumguay and 34 species in 22 families found in Bonggo, The tree diversity in each study site also varied, showed as H’= 3.55 in Buare forest, 3.45 in Supiori, 3.09 in Unurumguay and 3,00 in Bonggo. Although the diversity in Buare seems more diverse than that in other sites, it is statistically not significant, because the values of H’ of all study sites are in the range between 1– 4.5. The seven most dominant tree species based on the Important Value Index were varied between study sites. These species belong to different families, with Euphorbiaceae family as the most common family encountered in all study sites. The results showed that Pimeliodendron amboinicum Hassk become dominant tree species in forest area of Buare, Supiori and Unurumguay, while Pometia spp. (Pometia pinnata and Pometia sp.) dominated forest area in Buare, Unurumguay and Bonggo. Likewise, the measurements of diameter at breast height and tree height class distribution were used to describe structural composition of forest area in each study site. This result shows that about 80% of vegetation in all study sites was represented by trees with diameter at breast height less than 30 cm and Bonggo area has trees with small diameter and already loss the large trees. Trees from all diameter class in other three locations had descending trend quantity from small to big diameter, while all study sites showed similar forest structure in distribution of trees height. Population size of Goura victoria was varied, which depends on the size of hunting area with higher value of estimation on population density but has the least value population size of Goura victoria. The interviews with Papuan hunters about hunting practices showed that distance of hunting area, hunting using air gun, using dogs and using foot snares on hunting Victoria crowned pigeon were varied among each study sites. Hunters in Buare area prefer to hunt Goura victoria within the distance of less than 2 - 5 km, while mostly hunters in three other sites prefer to hunt Goura victoria within the distance of 3 km to more than 5 km. The used of air gun in Buare area, was not recorded, while in the three other study sites it was more common though in low level, not more than 22% of all hunting practices. Using dogs in hunting Goura victoria also occurred less frequent in all study sites, only about 12%. Hunters in all study sites tended to use foot snares in catching G.victoria. However, the estimation value of current annual harvest within the hunting area size for each study sites exceed from the allowable values on estimation of maximum sustainable annual harvest per each hunting area size. Goura’s hunting is already prohibited not only in Indonesia, but also in Papua New Guinea. Goura victoria as a high-valued bird, is mainly sold alive and usually being hunted for fresh money to fulfill daily needs of hunter’s family. Hunting activities in all study sites were relatively high compared to other areas of Papua, an example from hunting of G.victoria in Waropen showed the high frequency of hunting activity. Hunting activity on Victoria crowned pigeon’s was unsustainable and this practice by local people has negative effects of G.victoria population, although most of hunters using foot snares. The result from ths study showed that protection of Victoria crowned pigeon needs deep concern from the Governments. The related stakeholders should enhance and determine conservation areas with the factual boundaries, including protected forest, animal sanctuaries and nature reserves. It also necessary to establish and manage more buffer zones around protected area immediately, to reduce interference from local people. Papuan people need more socialization of the laws and regulations concerning wildlife protection. The law enforcements should be implemented together with strict sanctions. Further research on Goura victoria should be carried out on other part of northern Papua, including short and long terms in all ecological aspects of Goura victoria