The field work was carried out in four different periods; (1) August to November 2007 in Northern Supiori area, (2) March to April 2008 in Buare-Mamberamo areas, (3) August to November 2009 in Unurumguay area and (4) August to November 2010 in Bonggo area.
3.2.2. Habitat parameters
Habitat parameters were assessed in order to know the composition and vegetation structure of forest in each study site, and to describe the ecological and habitat quality of the site.
In each study site, as many as 25 randomly long-line transects for vegetation analysis of 20 x 100 meters with 20 m x 20 m plots were established.
Trees with a diameter at breast high > 10 cm and more than one meter height within each plot were measured and identified. Furthermore, floristic structure was assessed quantitatively by calculating the Important Value Index (IVI) for each species in each study site (Dumbois and Ellenberg 1994, Brower et al 1997).
The IVI represents the sum of the value of Relative density (RD), Relative frequency (RF) and Relative Dominance (RDo), which are determined by the following equation:
29
Forest structure of each study site was assessed by comparing the distribution of canopy heights and trunk diameter classes. Further analysis of height distribution and diameter distribution was followed Hadi et al (2009). In addition, Shannon-Wiener index (H’) and its variance of H’ (Magurran 1998) were calculated to determine the plant diversity between the study sites. Tree species were identified based on the information from taxonomist of Forest Research and Development Institute Manokwari. For the species that were unable to identify in the field, the voucher specimens were collected and sent to the Herbarium of Bogoriense, Bogor, Indonesia.
3.2.3. Population of Goura victoria
Goura surveys were carried out at four sites using line transect methods (Buckland et al, 2001) 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 on 06.00 - 16.00 by the field team.
Population density (D) of G.victoria was calculated using Line Transects Formula (Buckland et al 2009) as follows:
D = (N x 1000)/2LW
Where the width of the transect line W (in meters) is two times of the mean distance of transect line. L is line length in kilometers, and N is the number of bird seen or heard. The Distance 5.0 Release 2 program was used for data analyzing (Laake et al 2006, CREEM 2009).
3.2.4. Hunting activities by local people
In order to determine the activities of local hunter, used semi structural interviews with questionnaires. The study sites or villages were chosen purposively due to the most accessible and feasible reason. All sites should also secure enough to be studied according to the availability of time and resources.
All of the villages selected as study sites were situated around the forest area.
30 Selections of villages and hunters as respondents were taken based on the information from key informants (villages headmen, head of tribe or ‘Ondoafi’
and church elderly). The levels of hunting activity by local people were fluctuated seasonally therefore the interviews were conducted after the completion of survey on G.victoria.
The interviews were conducted on 151 respondents who live in 13 villages of four districts in four regencies. The location of those villages were mapped (figure 3.2), and the information of each village was described in table 3.2.
Table 3.2 The villages, individual surveyed, indigenous communities surveyed and belief system where the surveys were undertaken.
No Regencies District Villages
Surveyed Village name Individual
2. Jayapura Unurumguay 2 Guriath 17 Unurumguay Christianity
Sawesuma 16 interviewed. The questionnaire was focused on the following questions:
a. Frequency of hunting (categorized as : often, sometimes or rare) b. Number of person participating (single or groups)
c. Hunting distance (close : < 2 km, middle: 3-5 km, far: >5 km)
d. Frequency of bird meat consumed (commonly, occasionally and rarely) e. Hunting time (day or night)
f. Hunting season g. Other species hunted
31 h. Hunting methods (traps, gun, dogs)
i. Numbers of G.victoria captured
j. Hunting purposes (money, meat or both) k. Bird age and sex of G.victoria
l. Utilization of bird parts (all part or only carcasses) m. Permission, protection and ban of hunting on G.victoria n. The age of hunter
Information on all hunted animals was collected to gain insight into hunting patterns and determined the relative importance of G.victoria. Respondents were also asked about forthcoming hunting trips or orders from traders. In addition to G.victoria, all captured or killed animals were later identified, and if brought back to the community (with the hunter’s permission) their weight, actual price and selling price were noted as well.
Non parametric statistics include Mann-Whitney U test, Kruskal-Wallis test and Multiple Linier Regression followed Aiyadurai et al (2010) and O’Brien et al (1998) were used to assess several variables in hunting. All analysis was run with SPSS Release 17.
3.2.5. Estimation on the sustainable harvest of Goura victoria
The r-values for population growth were calculated in order to estimate the sustainable harvest rates of G.victoria. The r-value is the maximum intrinsic rate of population increase of a population that is not limited by food, space, resource competition, or predation. This value was calculated according to the following formula (Bodmer et al 1997, Robinson 2000):
1 = e-rmax + be-rmax(a) – be-rmax(w+1)
Where: e = 2.7128, a = the species-specific age at first reproduction, w = the age of last reproduction and b = the annual birth rate of female offspring. The value of a, w and b of G.victoria was obtained from studies on Goura in captivity (Belterman and Poot 2008, Gibbs et al 2001, Baptista et al 1997, Coates, 1985).
32 Afterwards, the finite rate of increase (λ) was calculated to estimate the population growth over time. This value was converted from the instantaneous rate of increase (λmax) according to formula from Noss (2000) and Robinson (2000):
λmax= λ , so as: λ= er
The λ-value is to estimate the maximum annual production at the observed density (Pmax(D)), using formula from Robinson and Bennett (2000b) and Robinson (2000)
Pmax(D) = [(0.6D × λmax) – 0.6D]
= (λmax-1) (0.6D)
Where D is represents the observed value from the population density of Goura in this study.
Specifically for G.victoria, the factor fRR is defined as 0.2 representing the production in long-lived species, for those whose age of last reproduction is over 10 years. Finally, all the earlier values were used to estimation the maximum sustainable harvest (based on Begazo and Bodmer 1998) follows:
Maximum sustainable harvest = (PmaxD) (0.2)
To assess hunting sustainability in each study site, the estimation of maximum sustainable annual harvest was compared with the value of maximum current annual harvest. Hunting practice on Goura is unsustainable if the value of maximum current annual harvest exceeds the value of maximum sustainable annual harvest.
All data analysis was run with Excel program.
33 CHAPTER 4: RESULT
4.1. Floristic and structural composition of the forest in each study site