Giraffe Social Circles and What They Mean for Conservation
November 14th, 2021
What do Sabrina the Teenage Witch, Gilmore Girls, and Giraffes have in common? The women are the stars of the show.
Despite being one of the most popular animals on Earth, giraffes are not studied as much as you might expect. You might think that is totally fine. After all, giraffes are not known for being super complicated creatures. Aside from being adorable, their unique geometric pattern, and having purple tongues, their biggest flex is that they stand as tall as 3 Dwayne “The Rock” Johnson’s and sometimes fight each other with their Kevin Hart-sized necks. But now, a pair of researchers at the University of Bristol in England, Zoe Muller and Stephen Harris, have discovered that longstanding beliefs about giraffe social lives just do not measure up, and their findings may have huge implications on saving these creatures.
Only now, thanks to field cameras and other technologies, are we learning that Giraffes have complex social relationships similar to chimps, whales, and elephants. Giraffes live in “matrilineal” societies. If we break up that word into its parts, we get matri- which means mother, and -lineal which means line. Giraffe society is grouped according to motherly lines. When a giraffe has her young, they stay together for a surprisingly long time, at least 15 years! For context, female giraffes only live about 30 years. Of course, any boys will someday strike out on their own, often flying solo and sometimes joining up with other males. While male groups consist of related members about one-third of the time, female groups are so for a majority. A group may have 3 to 9 members made up of sisters, a grandmother, and offspring. But relatedness is not the only thing that defines these matrilineal groups.
You may have heard the saying, “it takes a village”. Well, giraffes take that to heart. Giraffes form what are called crèches. It is basically a giraffe daycare. If one mother giraffe needs to spend a little more time foraging, the others will watch out for the little one. Females in the group will nurse each other’s young, protect them, and show shared distress at the loss of a youngling.
These types of societies are common in mammals and for good reason. Matrilineal societies are a smart bet. This setup reduces the risk of young giraffes becoming a meal for a hungry predator. Plus, they help relieve the mother of the energetic burden of raising young. Raising young is a group effort. This is of course great in the short term, but its impact extends much further. It’s all a part of evolution.
Evolution by natural selection is dependent on survival. Yet survival means nothing if you do not make it to the age of reproduction. Being able to reproduce means passing on your genes. Passing on your genes and shifting the proportions of genes in the population is what drives evolution. Young giraffes have far more to gain than lose by staying with their mothers for a third of their lives. For the adults, they benefit by sharing the energetic burden that comes with raising young. But even this evolutionary ingenuity may not be enough in the face of a changing landscape, climate, and conflicts with humans.
It may come as a surprise to learn, but giraffe populations are in free-fall. Since 1985, their populations have declined by more than 40%. The IUCN lists giraffes as a vulnerable species with some subspecies fairing worse than others. But even the number of giraffe species has been a topic of debate. At the moment, scientists seem to agree there are 4 distinct species and 5 subspecies of giraffes all ranging from vulnerable to critically endangered.
In Tanzania, researchers discovered that the home range of adult female giraffes grows the closer they are to towns while their social networks are virtually nonexistent. In the Rift Valley where the giraffe population is highly affected by humans, their social groups have fewer and shorter connections and the population growth is at a trickle. Then there is hunting.
The color of a Giraffe is a signal. It says how old they are, their social status, and how fit they are, especially in males. The darker they are, the older they are. These tall, dark, and handsome giraffes are the bachelors of the savanna, roaming around looking for a female companion. Remember, the younger males are usually a part of closely related groups for over one-third of their lives. The roaming romantics serve the important role of diversifying the gene pool. It just so happens they are also the ones most often targeted by trophy hunters.
On occasion, older females are killed, mistaken for an old bull. It is known that losses of matriarchs in elephants have devastating consequences for the herd, including a loss of vital information helpful for survival that has been carried through the years. Are the consequences the same for giraffes? We do not know. But that is the thing, is it not? We do not know what we do not know. When it comes to Giraffes, the list of things we are learning we did not know is only growing while the time to learn about them continues to shrink. There are more questions than there are answers, and you can bet that scientists will be craning their necks to find them.
References
- Muller, Z., & Harris, S. (2021, August 02). A review of the social behaviour of the giraffe Giraffa camelopardalis: a misunderstood but socially complex species. Mammal Review. https://doi.org/10.1111/mam.12268
