The Black-headed Spider Monkey is arboreal and diurnal. It moves by climbing and brachiation. When mating, females may consort with a male for up to three days, or else mate with several males. Mating occurs with the male and female face to face, and can last for 5 to 10 minutes. The gestation period is between 226 and 232 days. The infant rides on its mother's back for 16 weeks, and is weaned at 20 months. Females attain sexual maturity at 51 months; males at 56 months. Females give birth every three years.
The Black-headed Spider Monkey is considered to be critically endangered by the International Union for Conservation of Nature (IUCN) due to an estimated population loss of more than 80% over 45 years, from hunting and human encroachment on its range of habitation.