Table 4. Bonobo population density and number of adult individuals in 2011, 2012, 2013, respectively, as estimated with Distance 6.0.

	% CV	D	D LCL	D UCL	N	N LCL	N UCL
Global estimation1	14.38	0.41	0.32	0.56	39	30	53
Mpelu 2011	36.5	0.56	0.27	1.13	31	15	61
Mpelu 2012	27.08	0.21	0.12	0.35	11	7	19
Mpelu 2013	26.24	0.32	0.19	0.53	17	11	28
Nkala 2011	27.85	0.63	0.36	1.12	20	12	36
Nkala 2012	22.65	0.51	0.32	0.79	16	11	25
Nkala 2013	33.54	0.55	0.28	1.07	17	9	35
Lokoso&Mankere 2011	0	0	0	0	0	0	0
Lokoso&Mankere 2012	0	0	0	0	0	0	0
Lokoso&Mankere 2013	0	0	0	0	0	0	0

We modelled data with a half normal cosine function and used a truncation distance of 35 m. We obtained an effective strip width (‘ESW’) of 19.1 m and a mean probability of detection of 0.55. %CV =  Coefficient of Variation for the density estimate. D = density estimate. D LCL =  Lower confidence limit (95%) of the density estimate. D UCL =  Upper confidence limit (95%) of the density estimate. N =  community size estimate (number of adults). N LCL =  Lower confidence limit (95%) of the community size estimate. N UCL =  Upper confidence limit (95%) of the community size estimate (¹the global estimate was derived by weighting data with the area of the three parts of the study site).