Callithrix flaviceps
buffy-headed marmoset

Callithrix flaviceps is endemic to the Atlantic rainforests of southeastern Brazil. It is found at altitudes greater than 400 meters. It is currently limited to mostly privately owned pockets of remnant rainforest in the Brazilian states of Espirito Santo and Minas Gerais. (Ferrari 1998)

Buffy-headed marmosets prefer densely vegetated forest edge habitats, such as secondary and disturbed forests that are either natural or man-made.

Buffy-headed marmosets share many characteristics with other New World monkeys, including long tails and downward-flaring nostrils. As they are marmosets, they are among the world's smallest primates. Buffy-headed marmosets can be readily distinguished from other marmosets by white tufts of hair that flare horizontally from the sides of the head, and a face that is mostly white aside from darker hair immediately surrounding the eyes and nose. Additionally, they are darker in general coloration, with the dorsal side being darker than the ventral side, and the tail possessing alternating bands of black and lighter colored hair. They have non-opposable thumbs and their nails are claw-like (Ferrari 1998). Males and females are similar in size. Marmosets range from 180 to 300 mm in total body length, from 172 to 405 mm in tail length, and 230 to 453 grams in weight (Nowak, 1991).

Lifespan in the genus Callithrix seems to be about 10 years in the wild and up to 16 years in captivity (Nowak, 1991).

Buffy-headed marmosets live in social groups of multiple individuals, with larger groups consisting of up to fifteen or so marmosets. These groups consist of related individuals, and display matriarchal dominance. Each group usually contains only one breeding female. However, recent studies have shown that in at least one group of buffy-headed marmosets polygyny, polyandry and monogamy all occur, with monogamy occurring most often. They are primarily active during the day and maintain family group home ranges. (Ferrari 1987, 1998)

While buffy-headed marmosets do eat insects and fruit, they are noted for their ability to extract nutrition from plant gums. For most of the year, fruit (the staple of most New World monkey diets) is scarce in the marmoset's habitat. Due to their reliance on gum, marmosets have developed multiple specializations. Firstly, gum is produced by plants in relatively small amounts. Therefore, marmosets are small (rarely weighing more than a pound) and possess claw-like nails, sharp incisors (outward facing, narrow incisors that lack enamel on the interior side to increase sharpness) and a rough tongue for efficient gum extraction. Secondly, the bulk of gum's carbohydrate content is found as complex polysaccharides. Therefore, the marmosets have specialized digestive systems to process this food source, consisting of a specialized caecum and specialized gut bacteria that contribute to fermentation. The majority of gum that buffy-headed marmosets feed on is extracted from acacia trees, Acacia paniculata, which dominates the marginal and secondary forests the marmoset lives in. It is especially interesting to note that , instead of continually gouging new holes in the acacias, marmosets regularly use established feeding sites, which maintains the freshness and therefore nutritional value of the gum they are ingesting, as well as minimizing the energy expended acquiring the gum. Plant gum makes up 72.5% of their plant diet and fruits, seeds, nectar, and flowers makes up 15.9% of their plant diet. (Ferrari 1998)

Buffy-headed marmosets display many anti-predator adaptations common to New World monkeys as well as other marmosets, such as sociality marked by altruistic behaviors such as alarm calls and relatively small size. They are also nimble and fast in their arboreal habitat. Their main predators are raptors and small cat species, such as ocelots, they may also fall prey to large snakes. (Ferrari 1998)

Buffy-headed marmosets may be important as seed dispersers. They influence plant growth through foraging on plant gums.

There are no adverse effects of buffy-headed marmosets.

Buffy-headed marmosets are important as a focus of ecotourism. Unfortunately, some animals are taken for the exotic pet trade.

Buffy-headed marmosets are IUCN endangered primarily because of the small range of their habitat and small effective population size which, as of 2000, was expected to show at least a 20% decline in the next five years. The main threat to this marmoset species is the destruction of its habitat, along with human predation (capture for the exotic pet trade). It should be noted that buffy-headed marmosets are the rarest of all marmoset species. (IUCN 2000)