In zoo and laboratory colonies of marmosets and tamarins (Callitrichidae) there has been an increasing need to adopt breeding control methods. In zoos, this need has been driven by a growth in populations. In laboratories, increased interest in control options has followed from the requirement to improve welfare by housing potential breeding animals together. Progestagen-containing contraceptive implants or depot-injections, prostaglandin injection regimes, vasectomy and various group-management methods have been used to control reproduction in marmoset and tamarin colonies. There is a need for advances in control techniques suitable for use in zoos. In the meantime, a policy of selective euthanasia or the use of vasectomy are recommended as control methods. In laboratories, although improved control methods are required, a number of techniques have been found to be satisfactory. When there are surplus marmosets and tamarins, the alternatives for their utilization include movement to other colonies, use for studies within zoos or in laboratories, sale to private keepers or euthanasia. Selling these animals privately is not recommended, except in exceptional circumstances. The preferred control option will differ in each circumstance and guidance is given in this paper.

Members of the New World primate genera Callithrix and Cebuella have specialisations for eating plant exudates. Exudates are also an important component of the diets of many other callitrichid species in the wild, especially at times of nutritional stress. Gum arabic is fed daily to all marmosets and to some tamarins in Jersey Zoo's collection. This study investigated species differences in liking for gum and the effects of the concentration of gum solutions on palatability. As predicted from field data, Callithrix species consumed more gum than other species; Saguinus also showed quite a strong liking for gum. In parallel with data from the wild, lion tamarins (Leontopithecus spp.) consumed the least, and Callimico also took relatively little. The two marmoset species tended to like stronger solutions of gum more than weak solutions and, therefore, the provision of smaller amounts of stronger concentrations is likely to be the most cost-effective way of incorporating gum into the diet. Providing gum to callitrichids on a regular basis can have significant welfare benefits.

Although there is a growing recognition that the transfer of diseases between humans and non-human primates can be of great significance for conservation biology, there have been only a few studies focusing on parasites. In this study, saddleback (Saguinus fuscicollis) and moustached tamarin (Saguinus mystax) from the rainforest of the Peruvian lowlands were used as models to determine helminth parasite associations between canopy-dwelling primate species and a nearby human settlement. The human population showed high prevalences of infestation with a number of nematodes, including Ascaris lumbricoides (88·9%), Trichuris trichiura (37%) and hookworms (55·6%). However, the ova of these geohelminths were not detectable in tamarin faeces. Thus, no direct parasite transfer from humans to non-human primates could be documented. However, tamarin groups with more frequent contact to humans and their facilities had significantly higher prevalences and egg output of Prosthenorchis elegans, an important primate pathogen, than a forest group. In contrast, a cestode was significantly more common with more egg output in sylvatic than in human-associated groups. Human alteration of the habitat is likely to play a major role in determining the occurrence, prevalence and intensity of helminth infestation of wild non-human primates.

The present study provides comparative data on the types and microhabitats of animal prey captured by associating saddleback Saguinus fuscicollis and moustached Saguinus mystax tamarins. The main prey items were katydids (Tettigoniidae, Orthoptera), stick grasshoppers (Proscopiidae, Orthoptera) and spiders (Araneida), although lizards (Squamata) and frogs (Anura) were also taken. The tamarins foraged for, and captured prey from, significantly different substrates. This resulted in a significant partitioning of the prey spectrum between the two species. Sylvan katydids (Pseudophyllinae) accounted for most of the prey of both species, but the moustached tamarins captured more bush katydids (Phaneropterinae) than the saddlebacks. The degree of dietary overlap was less for animal prey than the plant-based portion of the tamarins' diet.