Lifestyle and Lifespan
The papio genus of "savanna" baboons has five old-world baboons: Hamadryas, Anubis, Yellow, Chacma, and Guinea. The different species have varying coat colors but have a similar build. Males will generally have a mane or ruff. Both genders in baboon species have ischial callosities, forming padding for long periods of sitting and playing a role during reproduction. Social structures are complex and full of intricate behaviors. They are primarily fruit-eaters. These baboons are capable of interbreeding with each other.
The hamadryas baboon is more dramatically sexually diamorphic in size than other old world monkeys. Both sexes are smaller than their other Papio counterparts. Males are gray-brown in color while the females are an olive-brown. Their color sets them apart from the other Papio baboons, as well as their northern range in Africa. The others are further south.
Females reach adult size at 6 years of age. Males reach adult size at 10 years of age. Secondary male sex characteristics will not appear until after full size has been reached. These include the silver mane, white cheeks, and red/pink buttocks. Males will fully develop their testes before this, however, which indicates they may be secretly breeding without being the dominant male. Baboons' primary sense is their excellent vision. Their eyes are set closely together, giving them good depth perception for spotting predators and seeing other baboons' body language.
Hamadryas baboons are found in many kinds of habitats, provided there are sufficient watering holes and cliffs for sleeping. These includes subdesert, steppe, alpine grass meadows, and short-grass savannahs.
A one-male unit may travel a few miles during daylight foraging for food but they will return to the same cliffs for sleeping.
Diet consists of mostly fruit, as well as grasses, insects, seeds, and flowers. Baboons have a unique ability to survive on a low quality diet when the habitat cannot provide anything more than grasses.
Hamadryas baboons are a prey animal for hyena, leopards, and eagles.
They spend the night on rocky cliffs, sometimes foraging miles during the day but returning to the cliffs to sleep. The mornings are spent with other families, sometimes hundreds of hamadryas baboons, playing, grooming, and chasing. The family units will then leave to forage separately. Before retiring for sleep, the families will engage in social grooming again.
Hamadryas baboons have many kinds of communication, such as vocalizations, visual and tactile signals, and gestures. Grooming is an extremely important behavior. It effects bonds between individuals. Hamadryas baboons are unique in that the females groom the dominant male more often than the other females. This may help them keep their place in the hierarchy and keep him loyalty. The act of grooming also releases beta-endorphins which induce a very relaxed state. This can help to ease tensions within the family.
Hamadryas baboons utilize a one-male unit. One adult male will mate with multiple females and be dominant over the other individuals. Males are related to each other and females move between groups. A family group will be one dominant male with four or five females and their offspring. Those groups will come together to travel and may form bands of up to 50 or 100 individuals. These bands often form with related dominant males bringing together their family units. To form an intial harem, a male may take a young female from her mother and finish raising her himself. This bonds the pair together very strongly. A male may also follow a harem and either breed with the females without the dominant male's notice or try to depose him through combat. However, often males will respect the relationship between the dominant male and the females in his family. Females leave their natal group between 1.5 and 3.5 years of age and have been seen to join groups that contain females they already know.
When there is a takeover by a new dominant male, females may go through a "deceptive" sexual cycle. They will appear to be fertile and will mate with the new dominant male. This places them in a high social rank and may protect their current offspring from the new male.
At birth, the pelage is black. At six months of age, it turns olive-brown. The mother provides care for the first few months of life, as the offspring is unable to walk or eat solid food. Offspring are weaned at about 239 days. Other members of the group are interested in the offspring and may even be groomed by adults other than their mother.
The hamadryas baboon is listed as "Least Concern" by the IUCN and its population is increasing. This may be due to loss of predators and small-scale agriculture. CITES has this species listed on Appendix II and under the African Convention it is listed as a vermin.
In the past, huge numbers of Hamadryas baboons were taken from the wild for medical research. However, this is not done anymore and the population has rebounded. In ancient times they were present in Egypt but they are extinct now in that country.
Oakland Zoo participates in the Species Survival Plan for Hamadryas baboons.
The Hamadryas baboon was sacred in ancient Egypt. They have been found mummified and entombed. They were associated with the sun. They were called sacred, mantled, or Arabian baboons.
The way that dominant males continue to socialize with their male kin throughout their lives with the forming of bands is unique to Hamadryas baboons. Other baboons will leave their natal family and fight for dominance with other males. Hamadryas males will often seek each other out and unite against unrelated bands.
University of Michigan. Animal Diversity Web. "Papio: baboons." http://animaldiversity.org/accounts/Papio/
University of Michigan. Animal Diversity Web. "Papio hamadryas." http://animaldiversity.org/accounts/Papio_hamadryas/
Barrett, Louise. "Baboons: survivors of the African continent." London:BBC, 2000.
Red List. The IUCN Red List of Threatened Species. "Papio hamadryas." http://www.iucnredlist.org/details/16019/0
San Diego Zoo Global. "Hamadryas Baboon." http://animals.sandiegozoo.org/animals/hamadryas-baboon
About Our Baboons
Currently at Oakland Zoo we have a troop of 14 Hamadryas baboons. Our baboons are very genetically valuable and many of them are recommended to breed by the SSP (Species Survival Plan). The smallest social unit for Hamadryas baboons is the ‘One Male Unit’, or OMU, which consists of a dominant male, several females, the immature offspring, and sometimes adult ‘follower’ males. Our long-time OMU consists male, Martijn, females Krista and Maud, and their juvenile offspring as well as the offspring of Martijn’s former female, Maya, who moved to San Diego Zoo with her daughter, Akila, in February 2019. Brothers Kusa and Milo came to the Oakland Zoo at age 2 in 2015 with the intention of creating their own OMUs with Martijn’s offspring. Kusa and Milo are now forming their own OMUs after being a part of Martijn’s for the last several years. Males will often ‘kidnap’ a female baboon from another unit to be a part of their OMU. This can often look very violent and can result in some injury, but for the most part it looks worse than it is. In our troop, Kusa has taken a liking to Kodee (daughter of Martijn and Krista) and are very solid in their relationship. Milo has taken a liking to Mimi (daughter of Martijn and Maya) and are also very solid in their relationship. Kabili, daughter of Martijn and Krista, is still unestablished. She currently associates more with Kusa, most likely due to her sister being a part of his OMU which is very natural.
Guests often ask if Martijn will be violent towards Kusa or Milo for taking his daughters or for being aggressive towards them. Hamadryas baboons are unique in that the males ‘respect’ the social bond between other males and their female affiliates. These multiple OMUs form a ‘clan’ or ‘band’. Within the band, the OMU leader males coordinate where they will meet up at midday, usually around a watering hole. Then they will go about their day outside of vocal and visual range and reconvene at the established location. So although Martijn, Kusa, and Milo have their own OMUs, they will continue to coordinate and work together as one group without very much aggression.