Getting to Know One of the Most Unique Animals on Earth

Analysis by Dr. Karen Shaw Becker

Story at-a-glance -

  • A new study suggests that giraffes — a very understudied mammal — are a highly complex and social species similar to elephants and killer whales
  • Among the study’s findings are that giraffes spend up to 30% of their lives in a post-reproductive state; known as the “Grandmother hypothesis,” it suggests that females live long past menopause so that they can help raise successive generations of offspring, thereby ensuring the preservation of their genes
  • Study co-authors hope that their findings will encourage scientists and conservations to regard giraffes as intelligent, group-living mammals that have evolved highly successful and complex societies

Giraffes are a beloved, instantly recognizable species, but until very recently, their social behavior was essentially unknown. Once thought to be “socially aloof, forming no lasting bonds with its fellows and associating in the most casual way,"1 new research suggests we’ve missed the boat in terms of our understanding of these graceful creatures.

Researchers at the University of Bristol’s School of Biological Sciences in the U.K. published their study results this past August in the journal Mammal Review, and believe their findings suggest giraffes are a highly complex and social species.2

‘Grandmother Hypothesis’ Applies to Giraffes

Over the last decade, research has shown that giraffe social organization is much more advanced than we knew. The University of Bristol study suggests that giraffes spend up to 30% of their lives in a post-reproductive state. According to ScienceDaily:

“This is comparable to other species with highly complex social structures and cooperative care, such as elephants and killer whales which spend 23% and 35% of their lives in a post-reproductive state respectively. In these species, it has been demonstrated that the presence of post-menopausal females offers survival benefits for related offspring.

In mammals — and including humans — this is known as the 'Grandmother hypothesis' which suggests that females live long past menopause so that they can help raise successive generations of offspring, thereby ensuring the preservation of their genes.

Researchers propose that the presence of post-reproductive adult female giraffes could also function in the same way, and supports the author's assertion that giraffes are likely to engage in cooperative parenting, along matrilines, and contribute to the shared parental care of related kin.”3

Future Research Goals

Study co-author Zoe Muller is puzzled by why such a “large, iconic and charismatic African species” as the giraffe has been ignored for so long.

“This paper collates all the evidence to suggest that giraffes are actually a highly complex social species, with intricate and high-functioning social systems, potentially comparable to elephants, cetaceans and chimpanzees,” Muller said in a university news release.

"I hope that this study draws a line in the sand, from which point forwards, giraffes will be regarded as intelligent, group-living mammals which have evolved highly successful and complex societies, which have facilitated their survival in tough, predator-filled ecosystems."4

Muller suggests eight key areas for future research to establish giraffes as a socially complex species:

  1. How does habitat influence giraffe social structure?
  2. What are the fitness benefits of group living in giraffes?
  3. What is the genetic structure of giraffe social groups?
  4. How do giraffes communicate?
  5. What is the role of older females in giraffe society?
  6. What is the role of older males in giraffe society?
  7. What is the impact of disturbance on giraffes?
  8. Are there species or subspecies differences in behavior?

Answering these questions and establishing that giraffes have a complex cooperative social system will further understanding of their behavioral ecology and conservation needs, says Muller.

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More Fascinating Facts About Giraffes

  • Giraffes are the world’s tallest mammals, reaching 14 to 19 feet in height and up to 2,800 pounds. Their long necks give them a unique advantage in spotting predators at a great distance as well as allowing them to feast on leaves from treetops that other animals can't reach.
  • While their height has its advantages, it has also a few drawbacks, such as when they need to drink water from a ground source. To reach a watering hole, giraffes must spread their legs wide and bend down awkwardly, making them vulnerable to predators. After taking a nice, long drink (which they only attempt once every several days), they often must quickly jerk their heads upward to avoid falling forward into the water.
  • No two giraffes have exactly the same coat pattern, though those living in the same area have a similar pattern.
  • They give birth standing up, which means newborn giraffes drop more than five feet to the ground at birth. Within 30 minutes they’re standing, and within 10 hours, they’re able to run.
  • As adults, giraffes can gallop at up to 35 miles per hour, which is useful when trying to escape predators. They also have a powerful kick — strong enough to kill a lion. Male giraffes may also battle with one another by butting their necks and heads. These displays don't typically result in injury and end when one animal gives up and walks away.5

Aside from predators like lions and crocodiles, giraffes are also threatened by humans, who hunt them for their hides and meat, and sometimes only for their tails, which are used as good-luck bracelets, fly whisks, thread, and more. Unfortunately, the animals make easy targets for poachers.

Giraffe habitat is also being threatened by agriculture, settlement expansions, and the construction of roads. As acacia trees, which are giraffes' main food source, are destroyed, wild giraffe habitat and populations in the wild are shrinking.

Organizations like the African Wildlife Foundation are working with local communities to implement sustainable practices for agricultural and settlement growth. They're also working on reforestation projects in West Africa to plant more acacia trees and allow giraffes to expand their habitats.6