Articles relating to in captivity Alberts, S., (1987). Parental care in captive siamangs (Hylobates syndactylus). Zoo Biology, 6.4. DOI: 10.1002/zoo.1430060414

Bennett, J., (1992). A glut of gibbons in Sarawak- is rehabilitation the answer?. Oryx, 26.3:157-164. DOI: 10.1017/S0030605300023590

Burns, B.L., Dooley, H.M., & Judge, D.S., (2011). Social dynamics modify behavioural development in captive white-cheeked (Nomascus leucogenys) and silvery (Hylobates moloch) gibbons. , 52.271. DOI: 10.1007/s10329-011-0247-5

Cheyne, S.M., (2006). Unusual behaviour of captive-raised gibbons: implications for welfare. Primates, 47.4:322-326. DOI: 10.1007/s10329-006-0190-z

Cheyne, S.M., & Brulé, A., (2004). Adaptation of a captive-raised to the wild. Folia Primatologica, 75:37-39. DOI: 10.1159/000073430

Cheyne, S.M., Campbell, C.O., & Payne, K.L., (2011). Proposed guidelines for in situ gibbon rescue, rehabilitation and reintroduction. International Zoo Yearbook, 46.1. DOI: 10.1111/j.1748- 1090.2011.00149.x

Cheyne, S.M., Chivers, D.J., & Sugardjito, J., (2008). Biology and behaviour of reintroduced gibbons. Biodiversity and Conservation, 17.1741. DOI: 10.1007/s10531-008-9378-4

Cooke, C.M., & Schillaci, M.A., (2007). Behavioral responses to the zoo environment by white handed gibbons. Applied Behaviour Science, 106.1-3:125-133. DOI: 10.1016/j.applanim.2006.06.016

Cunningham, C.L., Anderson, J.R., & Mootnick, A.R., (2006). Object manipulation to obtain a food reward in hoolock gibbons, Bunopithecus hoolock. Animal Behaviour, 71.3:621-629. DOI: 10.1016/j.anbehav.2005.05.013

Dooley, H. & Judge, D., (2007). Vocal responses of captive gibbon groups to mate change in a pair of white-cheeked gibbons (Nomascus leucogenys). Folia Primatologica, 78:228-239. DOI: 10.1159/000102318

Fischer, J.O., & Geissmann, T., (1990). Group harmony in gibbons: Comparison between white-handed gibbon (Hylobates lar) and siamang (H. syndactylus). Primates, 31.4:481-494. DOI: 10.1007/BF02382532

Geissmann, T., (1991). Reassessment of age of sexual maturity in gibbons (hylobates ssp.). American Journal of Primatology, 23.1. DOI: 10.1002/ajp.1350230103.

Geissmann, T., (2009). Door slamming: Tool-use by a captive white-handed gibbon (Hylobates lar). Gibbon Journal, 5.

Geissmann, T. & Orgeldinger, M., (1995). Neonatal weight in gibbons (Hylobates spp.). American Journal of Primatology, 37.3. DOI: 10.1002/ajp.1350370302

Gronqvist, G., Kingston-Jones, M., May, A., & Lehmann, J., (2013). The effects of three types of environmental enrichment on the behaviour of captive Javan gibbons (Hylobates moloch). Applied Animal Behaviour Science, 147.1-2:214-223. DOI: 10.1016/j.applanim.2013.04.021

Haraway, M.M., Maples, E.G., Tolson, S., (1981). Taped vocalization as a reinforcer of vocal behavior in a siamang gibbon (Symphalangus syndactylus). Psychological Reports. DOI: 10.2466/pr0.1981.49.3.995

Hark, H., Stevens, L., Margulis, S.W., & Petersen, J., (2016). Gibbon aggression during introductions: an international survey. Journal of Applied Animal Welfare Science, 19.3:260-270. DOI: 10.1080/10888705.2015.1130631

Jildmalm, R., Amundin, M., & Laska, M., (2008). Food preferences and nutrient composition in captive white-handed gibbons, Hylobates lar. International Journal of Primatology, 29.6:1535-1547. DOI: 10.1007/s10764-008-9314-1

Lanford, R.E., Chavez, D., Rico-Hesse, R., & Mootnick, A., (1999). Recombination and Evolution. DOI: 10.1128/JVI.74.6.2955-2959.2000

Liebal, K., & Kaminski, J., (2012). Gibbons (Hylobates pileatus, H. moloch, H. lar, Symphalangus syndactylus) follow human gaze, but do not take the visual perspective of others. Animal Cognition, 15.6: 1211-1216. DOI: 10.1007/s10071-012-0543-5

Lukas, K.E., et al. (2002). Longitudinal study of delayed reproductive success in a pair of white-cheeked gibbons (Hylobates leucogenys). Zoo Biology, 21.5. DOI: 10.1002/zoo.10040

Maheshwarf, H., et al. (2010). Fecal steroid profile of female Javan gibbons (Hylobates moloch) maintained in pairing-typed cage. HAYATI Journal of Biosciences, 17.1:43-49. DOI: 10.4308/hjb.17.1.43

Mootnick, A., (1997). Management of gibbons Hylobates spp at the International Center for Gibbon Studies, California: with a special note on pileated gibbons Hylobates pileatus. International Zoo Yearbook, 35.1. DOI: 10.1111/j.1748-1090.1997.tb01220.x

Mootnick, A.R., (2006). Gibbon (Hylobatidae) species identification recommended for rescue or breeding centers. Conservation, 5.1987:103-139. DOI: 10.1896/0898-6207.21.1.103

Mootnick, A.R., & Baker, E., (1994). Masturbation in captive Hylobates (gibbons). Zoo Biology, 13.4. DOI: 10.1002/zoo.1430130408

Mootnick, A.R., Baker, E., Nadler, R.D., & Merker, B., (2006). Hostile presenting in captive gibbons. International Journal of Primatology, 27.3:809-825. DOI: 10.1007/s10764-006-9040-5

Mootnick, A.R., Baker, E., & Sheeran, L.K., (2005). Familiarity during immaturity: implications for the captive propagation of gibbons. International Journal of Primatology, 26.6:1417-1433. DOI: 10.1007/s10764-005-8860-z

Mootnick, A.R., & Nadler, R.D, (1998). Sexual behavior of maternally separated gibbons (Hylobates). Developmental Psychobiology, 31.2. DOI: 10.1002/(SICI)1098-2302(199709)31:2<149::AID- DEV8>3.0.CO;2-K

Morino, L., et al. (2017). Tube task hand preference in captive hylobatids. Primates, 58.3:403-412. DOI: 10.1007/s10329-017-0605-z

Newberry, R.C., (1995). Environmental enrichment: Increasing the biological relevance of captive environments. Applied Animal Behaviour Science, 44.2-4:229-243. DOI: 10.1016/0168- 1591(95)00616-Z

Nijman, V., (2006). In-situ and ex-situ status of the Javan gibbon and the role of zoos in conservation of the species. Contributions to Zoology, 75.3-4:161-168.

Olson, D.A., Ellis, J.E., & Nadler, R.D., (1990). Hand preferences in captive gorillas, orang-utans and gibbons. American Journal of Primatology, 20.2. DOI: 10.1002/ajp.1350200203

Orgeldinger, M., (1997). Protective and territorial behavior in captive siamangs (Hylobates syndactylus). Zoo Biology, 16.4. DOI: 10.1002/(SICI)1098-2361(1997)16:4<309::AID-ZOO3>3.0.CO;2-E

Palombit, R.A., (1995). Longitudinal patterns of reproduction in wild female siamang (Hylobates syndactylus) and white-handed gibbons (Hylobates lar). International Journal of Primatology, 16.5:739-760. DOI: 10.1007/BF02735718

Pirovino, M., et al. (2011). Fecal glucocorticoid measurements and their relation to rearing, behavior, and environmental factors in the population of pileated gibbons (Hylobates pileatus) held in European zoos. International Journal of Primatology, 32.1161. DOI: 10.1007/s10764-011-9532- 9

Schessler, T., & Nash, L.T., (1977). Food sharing among captive gibbons (Hylobates lar). Primates, 18.3:677-689. DOI: 10.1007/BF02383142

Shepherdson, D., Bemment, N., Carman, M, & Reynolds, S., (1989). Auditory enrichment for Lar gibbons Hylobates lar at London Zoo. International Zoo Yearbook, 28.1. DOI: 10.1111/j.1748- 1090.1989.tb03294.x

Smith, K.N., & Kuhar, C.W., (2010). Siamangs (Hylobates syndactylus) and white-cheeked gibbons (Hylobates leucogenys) show few behavioral differences related to zoo attendance. Journal of Applied Animal Welfare Science, 2:154-163. DOI: 10.1080/10888700903579895

Supriatna, J., (2006). Conservation programs for the endangered Javan gibbon (Hylobates moloch). Primate Conservation, 15.3:155-163. DOI: 10.1896/0898-6207.21.1.155

Wallace, E.K., Kingston-Jones, M., Ford, M., & Semple, S., (2013). An investigation into the use of music as potential auditory enrichment for moloch gibbons (Hylobates moloch). Zoo Biology, 32.4. DOI: 10.1002/zoo.21074

Wells, D.L., & Irwin, R.M., (2009). The effect of feeding enrichment on the moloch gibbon (Hylobates moloch). Journal of Applied Animal Welfare Science, 12.1:21-29. DOI: 10.1080/10888700802536533

Woolery, A., (2012). Effects of environmental enrichment and natural substrates on increasing species- specific behavior of captive northern-white cheeked gibbons (Nomascus leucogenys leucogenys). McNair, 6.1. DOI: 10.15760/mcnair.2012.50

Yang, P., (2000). Reproduction of held in captivity. Sichuan Journal of Zoology, 19.2:88-89.