Table 1. Orang-utan site information.

Site(start of study)	Coordinates/habitat	No. hrs of focal observation	Individuals observed nesting (# making calls)	Mother-infant pairs observed (making call)	No. of sequenced individuals
Tuanan (B) (2003–)	2° 09′ S 114° 26′ E/Peat swamp	>15,000	21 (21)	8 (8)	20
Sg. Lading (B)(2005–2007)	2° 15′ S 114° 22′ E/Peat swamp	>2,000	6 (0)	4 (0)	24
Sabangau (B) (2003–)	2° 19′ S 114° 00′ E/Peat swamp	>3,000	19 (18)	4 (0)	21
Ketambe (S) (1971–)	3° 41′ N 97° 39′ E/Dryland	>15,000	20 (0)	6 (5)	16
Suaq (S) (1994–)	3° 04′ N 97° 26′ E/Peat swamp/dryland	>10,000	28 (25)	12 (0)	15

Note: (B)  =  Borneo, (S)  =  Sumatra. For the number of individuals making nests, we only included individuals that were followed for more than 10 nights, because after this number of night nests most orang-utans that occur in sites were they make nest calls were found to have made a nest call. At sites where mother-infant calls were heard, they occur once every 7.8 mother-infant follow hours for Ketambe (994 total follow hours) and 42.6 follow hours for Tuanan (5827 total follow hours). At the three sites were these calls were not heard, many more follow hours have been collected (Sabangau: 1709 hrs; Sg. Lading: 2140 hrs; and Suaq: 7665 hrs).