Contributor list; Part I. Fossil History, Zoogeography and Taxonomy of the Pitheciids: 1. Pitheciidae and other Platyrrhine seed predators; 2. The misbegotten: long lineages, long branches and the interrelationships of Aotus, Callicebus and the Saki-Uacaris; 3. A molecular phylogeography of the Uacaris (Cacajao); 4. Taxonomy and geographic distribution of the Pitheciidae; 5. Zoogeography, genetic variation and conservation of the Callicebus personatus group; Part II. Comparative Pitheciid Ecology: 6. Morphological and ecological adaptations to seed predation - a primate-wide perspective; 7. Pitheciines: use of time and space; 8. Functional morphology and positional behaviour in the Pitheciini; 9. Male cooperation in Pitheciines: the reproductive costs and benefits to individuals of forming large multimale/multifemale groups; 10. Evolutionary ecology of the pitheciinae: evidence for energetic equivalence or phylogenetically structured environmental variation?; 11. Competition between Pitheciines and large Ara macaws, two specialist seed-eaters; 12. On the distribution of Pitheciine monkeys and Lecythidaceae trees in Amazonia; Part III. Genus Reviews and Case Studies: 13. Why we know so little: the challenges of fieldwork on the Pitheciids; 14. Ecology and behaviour of Uacaris (genus Cacajao); 15. Annual variation in breeding success and changes in population density of Cacajao calvus ucayalii in the Lago Preto Conservation Concession, Peru; 16. Cacajao ouakary in Brazil and Colombia: patterns, puzzles and predictions; 17. Ecology and behaviour of titi monkeys (genus Callicebus); 18. Costs of foraging in the Southern Bahian Masked Titi Monkey (Callicebus melanochir); 19. Insectivory and prey foraging techniques in Callicebus - a case study of Callicebus cupreus and a comparison to other pitheciids; 20. Seed eating by Callicebus lugens at Caparu Biological Station, on the lower Apaporis River, Colombian Amazonia; 21. Callicebus in Manu National Park: territory, resources, scent marking and vocalizations; 23. Feeding ecology of Uta Hick's Bearded Saki (Chiropotes utahickae) on a man-made island in southeastern Brazilian Amazonia: seasonal and longitudinal variation; 24. The behavioural ecology of Northern Bearded Sakis (Chiropotes satanas chiropotes) living in forest fragments of Central Brazilian Amazonia; 25. Ecology and behaviour of saki monkeys (genus Pithecia); 26. Finding the balance: optimizing predator avoidance and food encounters through individual positioning in Pithecia pithecia during travel; 27. Testing models of social behaviour with regard to inter- and intra-troop interactions in free-ranging white-faced sakis; 28. Comparative socioecology of sympatric, free-ranging white-faced and bearded saki monkeys in Suriname: preliminary data; 29. Pair-mate relationships and parenting in Equatorial Saki Monkeys (Pithecia aequatorialis) and Red Titi Monkeys (Callicebus discolor) of Ecuador; 30. Vocal communication in Cacajao, Chiropotes and Pithecia: current knowledge and future directions; Part IV. Conservation of the Pitheciids: 31. The Guyana Shield: Venezuela and the Guyanas; 32. Pitheciid conservation in Ecuador, Colombia, Peru, Bolivia, and Paraguay; 33. Brazil; 34. Pitheciines in captivity: challenges and opportunities, past, present and future; 35. The challenge of living in fragments; 36. Communities and Uacaris: conservation initiatives in Brazil and Peru; Appendix - country factsheets; Index.