Table 4.

Orangutan male reproductive success

Male ID	No. of offspring	%TTL	Dom. res. male
Sumatran male reproductive success (Ketambe, Utami et al. 2002)
Aldo	1	10	Jon/Erik
Bobby	1	10	unknown
Boris	3	30	Jon/Jon/Nur
Jon	1	10	Jon
Nur	2	20	Nur/Nur
X	2	20	Boris/Jan
Bornean male reproductive success (Kinabatangan, Goossens et al. 2006)
14f	1	11
I16	1	11
I16f	1	11
I19f	2	22
Ss12f	2	22
SsL2.3f	1	11
SsL2.4uf	1	11

Paternity has been determined for orangutan males at two research sites, Ketambe in Sumatra and Kinabatangan in Borneo. At neither site is paternity concentrated in any one male, as shown by the percent of total paternities per male (%TTL). Behavioral data from Ketambe show that dominant resident males (Dom. res. male) are not consistently sires. Although paternity at both sites is distributed across males for which genetic samples were analyzed, both studies reported that they did not sample all potential fathers; neither study reported the corresponding behavioral mating data that would include the number of potential fathers or the total number of males in the area. As a result of this, we do not know for either site how many additional males have a zero chance of paternity and therefore may be potentially infanticidal