White-Headed Marmoset

• Common Name: Geoffroy’s marmoset
• Taxonomy Classification Year: 1812
• Monkey Size: 19.8 to 19.8 cm (7.80 to 7.80 in)
• Skin Color(s): Dark or blackish brown
• Habitat: Rainforest
• Diet: Omnivorous
• Native Countries: Brazil

The Geoffroy’s marmoset^[1], also called Geoffrey’s marmoset, white-headed marmoset, or tufted-ear marmoset is a marmoset native to the forests of eastern Brazil, where it is native to Minas Gerais, Espírito Santo, and Bahia.

• Geoffroy’s marmosets are small primates, only around 20 cm long, with a tail of around 29 cm.
• Females typically weigh around 190 grams, while males weigh between 230 and 350 grams.
• The body is usually blackish or dark brown. The tail is surrounded by black and gray bands.
• Adults have white foreheads, temples, cheeks, and throats. Also, adults have black tufts of hair in front of their ears.
• Juveniles differ from adults because they lack both ear tufts and white markings on the face.
• Instead, juveniles grow their ear tufts at around two weeks and have full adult markings by five months.

The Geoffroy’s marmoset nourishes on Abas (Psidium guajava), Brazilian Pepper-Tree (Schinusus terebinthifolius), Black Mulberry (Morus nigra) and Strawberry tree (Muntingia calabura)^[¶].

• The dominant female and male in each group of Geoffroy’s marmosets form a monogamous pair. Therefore, only this pair will reproduce.
• Pre-copulatory courtship typically begins with sniffing each other’s genitals and object marking, grooming, licking, and cuddling.
• Geoffroy’s marmosets are said to follow swarms of army ants to catch insects expelled by the ants.
• They send out alarm calls when they sense a threat. Also, they have observed scent marking.
• Groups of Geoffroy’s marmosets respond to predator threats by increasing vigilance rates and decreasing rates of foraging and play.