Together they are powerful: Like us humans, life increases in a group of female giraffes’ chances of survival. This is now confirmed by a study conducted on wild giraffes in Tanzania. Accordingly, female giraffes who mate with some species and forage together live and raise their young for longer. The benefits of group life have a greater impact on the survival of animals from their habitat or proximity to human settlements.
Humans are not just considered social beings – primates like chimpanzees and gorillas also live in larger groups and have social bonds. Marine animals such as dolphins, whales, and sharks also form complex social structures and work together. Even birds like thieving magpies support fellow species. The reason for this is that individuals in a community often have a higher chance of survival.
What about giraffes?
Researchers working with Monica Bond of the University of Zurich (UZH) investigated a long-term study of whether female giraffes also benefit from their social behavior and life in groups. They also wanted to see if social behavior had a greater impact on giraffes’ chances of surviving the natural environment and humans as a potential disruptive factor. To this end, the team documented the social behavior of more than 500 female wild Maasai giraffes (Giraffa camelopardalis tippelskirchi) in Tanzania for five years, who lived together in several social communities with about 60 to 90 adult females each. With the help of algorithms to analyze animal populations, the researchers examined individual and group effects on animal survival.
It turns out that giraffes lived longer in larger groups than about 50 socially isolated female animals. Researchers note that giraffes get together repeatedly to form other groups throughout the day. However, they have maintained specific friendships over a long period of time. “Living with more females is associated with increased survival rate for female giraffes, even if they change their groups a lot,” Bond explains. The researcher adds, “The social contact of animals is more important than environmental factors such as vegetation or proximity to human settlements.” It appears that the female giraffes that lived near the city had a somewhat lower survival rate due to poaching. However, the main causes of animal death were socially affected factors such as disease, stress or malnutrition.
To search for food, protection and cooperation
But how exactly does social contact reduce the risk of survival? “Social relationships can improve foraging efficiency,” explains Bond colleague Barbara Koenig. For this purpose, female giraffes will likely collaborate with the optimum number of at least three other females in order to exchange information on the best food sources. Additionally, union with other females helps overcome competition with specific species, the imminent danger from predators, disease risks and psychosocial stress, Koenig continues. Other benefits of group life could be that females are less disturbed than males wanting to mate, that they care for and protect their young together, or that the presence of familiar females reduces stress.
The following applies: The more bonds they have with other females, the less stress and competition they feel and the higher their chances of survival. Bond summarizes: “It seems that female giraffes have an advantage in communicating with many other females and thus develop a feeling for a larger community, but not for one small group.” Similar social habits also occur in different species of monkeys such as rhesus monkeys (Macaca mulatta) and decorative monkeys (Cercopithecus).
Quelle: University of Zurich, Fachartikel: Proceedings of the Royal Society B: Biological Sciences, Doi: 10.1098 / rspb.2020.2770