Douc Langurs (Pygathrix spp.) Fact Sheet: Reproduction & Development

• Both males and females solicit copulation before and after ovulation.
• Female solicits copulation by intently staring at the male with mouth closed, chin thrust out. She moves her head from side to side. She then presents her Anogenital region and crouches down in front of him.
• Male responds with a vocal grunt. He then looks to a copulation site. The female moves to the site indicated and is followed by the male and copulation occurs.

• Female menstrual cycle is 28-30 days
• Cycling females exhibit a reddened inguinal/perineum area. If impregnated the area remains red throughout pregnancy. Color returns to white when estrogen level falls prior to delivery.
• During pregnancy females become increasingly calm and quiet; don't participate in social activities. Sit at the side of the enclosure, close to a protective female
• Pregnant females exhibit care-taking behavior of all infants in the group until approximately 2 weeks before delivery when such behavior abruptly ceases (there may be a correlation with drop in estrogen level)
• Female becomes extremely restless just before birth, touching vagina and whipping tail back and forth
• Births occur year round; peak occurs between February and June
• Females from established groups often give birth in the same month, even same week
• In Cologne Zoo, most births occur between 19:00 and 20:00 hours

Gestation

• 200-205 days

Birth

• Birth interval: 11-38 months
• Birth of single young after 90 minutes of labor; twins rare
• Placenta detaches after 1-2 days

Infant stage 1: Birth-8 months

• Birth weight: around 460 g (16.2 oz)
• Eyes open at birth
• Natal coat - light chestnut with wide black stripe from shoulders to rump
• Black face. Eyes underlined with light stripes
• Clings to mother in first months - brief exploratory trips
• Day 7 - leaves mother
• Day 18 - takes food from other animals
• Day 60 - milk teeth fully developed. Leaves and fruit eaten in small quantities.

Infant stage 2: 8-18 months

• Adult coat - Infant face black
• Male develops white spots on either side of rump patch
• Testicles descend. Scrotum fully developed. Brown penis becomes pink
• Weaning begun by 12-13 months. Still some non-nutritive suckling
• Greater independence from mother
• Solid food important
• Males spend time in rough play. Females spend time grooming

Infant stage 3: 19-24 months

• Adult coat - infant face fades to color of adult
• Weaning tantrums frequent in both sexes

Juvenile: 2-4 or 5 years

• Body size and facial color clearly distinguishable from infant.

Adults: Sexually mature individuals

• 4-6 years in females, 4-9 years in males
• Lengthening of white hairs around face of male

Managed care

• No AZA estimates

A douc langur mother grooms her young.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.

Lippold (1977, 1981, 1989)
Ruempler (1998)