Population change and demographic parameters in wamba forest
Year  Social situation The number of groups Population size Group size*1 of E1 Source Mortality rate Sources Birth rate*2 Sources  
Infants & juveniles (0-7 yrs.) Adolescent males (8-13 yrs.) Adults (>14 yrs.) Memo
1976   6   18 [94], [97] 0.027 0 0.006 [98] 0.12 Calucurated from [97] Low frequency provisioning 
1977       18 0.35
1978       19 0.47
1979       21 0.05
1980       21 0.30
1981       21 0.14
1982       22 0.18
1983       24 0.19
1984       25 0.36
1985       28 0.08
1986       28 0.21
1987       32 0.056 0.083 0.05 0.19
1988       31 0.25
1989       30 0.10
1990       27 0.28
1991 Disorder 6 around 280 30 0.033 0.194 0.144 0.19  
1992     28 0.15  
1993     22 0.17  
1994       22 0.094 0 0.05 0.25  
1995       23 0.21  
1996 First Congo War 6 106 19         0.20  
1997                    
1998 Second Congo War                    
1999                    
2000                    
2001                    
2002                    
2003                    
2004   3 around 60 17              
*1 The group size was recorded on January 1st of each year.
*2 The number of birth / the number of mature female the was identified in E1 and E2 group.
Source: 
[94] Furuichi T. (2004) Current situation of bonobos endangered. Primate Res. 20: 67-70 (in Japanese)
[97] Furuichi T., Hashimoto C., Idani G., Ihobe H., Tashiro Y. & Kano T. (1999) Current situation of studies of bonobo (Pan paniscus) at Wamba, D.R. Congo. Primate Res. 15: 155-127 (in Japanese)
[98] Furuichi T., Idani G., Ihobe H., Kuroda S., Kitamura K., Mori A., Enomoto T., Okayasu N., Hashimoto C. and Kano T. (1998) Population dynamics of wild bonobos (Pan paniscus) at Wamba. Int. J. Primatol. 19: 1029-1043