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Encouraging and managing animals' social dynamics requires keepers to pick up on subtle cues.
By Devin Murphy
Getting animals to behave naturally is one of the great challenges of modern zoo keeping. Keepers, scientists, and curators work hard to encourage wild behaviors in a captive setting. What that takes can vary by animal. It may mean finding just the right diet or adjusting the layout of an animal’s enclosure.
Then again, sometimes what an animal needs most is very simple—other animals. Many species can’t behave naturally alone; they need a group. It may be a mated pair, an extended family, or a group of unrelated animals. In any case, each group has its own complex dynamics. Small cues—a call here, a body movement there—reinforce the dynamics and, if understood, give keepers a glimpse into the animals’ social network.
Part of the Zoo's flamingo flock (Mehgan Murphy/NZP)
Birds That Bicker
A familiar social group in the animal world is a mated pair. A mated pair has made a commitment to each other (for at least a breeding season) to work together to raise offspring. The Zoo’s flamingos live in a flock of 62 squabbling mated pairs. The birds begin to sidle up to each other in late December or early January.
“Usually around January, the whole flock starts displaying,” explains biologist Sara Hallager. “In that group display, you also have pairs.” Keepers can identify pairs through their body language. Birds that are interested in mating with each other in the coming months will stand near each other, feed together, and fend off rival pairs.
Flamingos’ social dynamics create an intriguing paradox. The birds need the social interaction of a flock to thrive; however, much of the social interaction within the flock is bickering. “One bird will be peacefully sleeping and another bird will come up and bump it on purpose,” says Hallager. She does not have a definite answer for why they fight, but it seems to be part of their nature. One reason may be territoriality within the flock; another may be to assert rank. Bickering seldom gets too heated, so keepers generally refrain from intervening.
The Zoo’s troop of western lowland gorillas enjoys a much more stable and peaceful social structure than the flamingos. Baraka, the 19-year-old, 375-pound silverback male, is the imposing figurehead of the group. The five other gorillas defer to him and respect his moods. He settles most disputes and can discipline anyone not behaving acceptably with an intimidating look or body movement.
Mandara and Kigali are the adult females in the Zoo's gorilla troop. (Mehgan Murphy/NZP)
Despite his imposing nature, however, keepers say Baraka is not hyper-vigilant. “He doesn’t rule with an iron fist,” explains keeper Amanda Bania. “He’s still kind of growing into his role. But for the most part the group is pretty respectful of him.” That may change as the troop’s younger males, Kwame and Kojo, begin to mature and become silverbacks themselves.
As the brothers get closer to adulthood, they will begin to challenge Baraka as the silverback of the troop. “The plan is to let them be a troop for as long as they can,” explains Bania. “Kwame, our 11-year-old, will probably be the first one to pose some kind of threat to Baraka.”
Keepers are monitoring interactions between Baraka and Kwame and keeping a detailed account of what transpires. They are watching closely to see if either ape shows aggression. Based on what they see, keepers will decide when it is time to pull Kwame and Kojo from the troop and make them an independent pair, known as a bachelor dyad.
The western lowland gorillas are not the only animals that have to grapple with maturing males. Age shapes the social dynamics of another mammal group at the Zoo: the three Asian elephants. Ambika, Shanthi, and Kandula live as a family spanning three generations on Asia Trail, even though all of them are not related.
At 62 years old, Ambika, a female, is the oldest elephant (and mammal) at the Zoo. Shanthi, another female, is 34. Kandula is the baby of the herd; he is 10. “Ambika and Shanthi are very closely bonded,” explains keeper Marie Galloway. The two females have a relationship more like equals rather than a matriarch and younger female in a herd.
Then there’s Kandula. As a maturing elephant, Galloway says, he is “very aggressive and very independent.” In the wild, young bulls usually leave their natal groups around 13, when they begin feeling urges to assert their male dominance. Older bulls then teach them how to behave like an adult.
Galloway explains that ideally the Zoo would have an older bull to show Kandula the ropes of social etiquette and some younger bulls with whom he could expend his extra testosterone-fueled energy. In the meantime, while a bigger herd complete with an older male role model is still a work in progress, Ambika has taken over as Kandula’s etiquette teacher.
The Zoo's three elephants: Kandula, Shanthi, and Ambika. (Jessie Cohen/NZP)
“Ambika has very little tolerance for Kandula,” explains Galloway. But her impatience is not a bad thing. “Hopefully, that will help him to learn to behave more socially appropriately with other elephants.” Ambika has no qualms about telling Kandula it is time to settle down. If his bull behavior is annoying her, she has several direct ways to communicate her displeasure—a shove, a kick, or a mad dash in his direction.
Scientists are still learning about Asian elephant social behavior. Much more is known about African elephants, which live in matriarchal herds. It is possible that Asian elephants do not live in herds with such a strict social structure. “We might know more about them physically, but we know less about them behaviorally,” explains Galloway about Asian elephants. “As we learn more, I believe we are going to find more and more differences.”
Older females living with younger males is also a pattern among the Zoo’s white-cheeked gibbons. Longtime residents Mae and Muneca are the Zoo’s two geriatric female gibbons. Mae is 41, and Muneca is 44. Even though they are too old to breed, it is still important for them to have social bonds. So they are housed with much younger male companions.
Mae is housed with Sydney, a 12-year-old very playful male. His rambunctious nature does not bother the aging Mae. Primate curator Lisa Stevens describes him as more independent than his fellow gibbons—and at times a bit of a pest. Mae does not put Sydney in his place when he wants to play rough. “I think he gets away with a lot because he’s living with a geriatric female,” says Stevens. The two companions get along well, and age is not a problem, but Sydney may have to have a crash course in social etiquette if he is placed with a younger breeding female.
Muneca has mesh access to Mickey, a 25-year-old male. This means that the two apes can interact and even touch through a mesh door, giving them the social interaction they need. Yet they remain separated. This is because of Mickey’s shadowed past, a reminder that wild animal behavior is never totally predictable.
Mickey originally came to the Zoo as a potential mate for Siam, an older gibbon who had lost her mate—and thus much of her social interaction. “He came in, and we introduced them, and everything went really well,” says Stevens. “Then one day he jumped on her and inflicted a lethal wound to her neck.” Keepers immediately intervened and separated the two, rushing Siam to the veterinary hospital. Unfortunately, she died of her wound.
Although the attack saddened Stevens and the primate staff, there is still hope that Mickey will become half of a mated pair. (Muneca would not be a suitable mate for him though since she is no longer breeding.).
One key lesson of studying animal dynamics is to be wary of generalizations. Take the Zoo’s three sloth bears, for instance. Each has a distinct personality that influences how social the animal is.
Hana, a female, generally prefers to interact very little with Khali (another female), Francois (a male), or her keepers. “She is a very independent bear who likes to spend time alone,” says keeper Mindy Babitz. Hana is more social during the breeding season, when she solicits attention from Francois.
Hana’s solitary nature is not typical of Khali or Francois. “Khali is the most social of the three bears and enjoys spending time interacting with her keepers every day,” says Babitz. Francois is very social and likes to play with other bears. If no one is interested in playing with him, he will turn to his keepers for some attention and entertainment.
Things change during the breeding season. Then, Hana shows more interest in Francois and seeks out his attention. “Hana has been alone all winter, because she has not shown much positive interest in Francois and has been aggressive towards him when they’ve had the chance to socialize,” says Babitz.
“We are keeping an eye on her behavior, though, since she will start becoming more interested in him and more social the closer we get to breeding season. When we see these positive social behaviors, we’ll start giving her opportunities to interact with Francois, and based on how it goes, we’ll decide if and when to put them together.” Meantime, keepers separate Khali and Francois, who are not a recommended breeding pair.
Kwame and Kojo are the Zoo's young male gorillas. (Mehgan Murphy/NZP)
Social networking at the Zoo does not require a Facebook or Twitter account (though some birds do tweet). It takes real face-to-face time and perhaps a Species Survival Plan recommendation. Animals’ behaviors tell keepers when breeding season has arrived, when they would rather be alone, or when they are growing up—which is why keepers go to such great lengths to understand and foster social dynamics.
—DEVIN MURPHY is the editorial intern for Smithsonian Zoogoer.
If you have a comment about Smithsonian Zoogoer magazine, please email it to us.Smithsonian Zoogoer 40(3) 2011. Copyright 2011 Friends of the National Zoo. All rights reserved.