Perhaps it is the giraffe’s lofty stature that explains its reputation for being an aloof and solitary creature.
But a study now suggests that the species has been misunderstood. Wild giraffes, it argues, live in sophisticated social groups comparable to those of elephants or killer whales, with older “grandmothers” helping to raise the young and serving as repositories of wisdom.
The findings raise fresh concerns about trophy hunters who often target the oldest giraffes on the basis that they no longer contribute to reproduction, scientists said yesterday.
Giraffe numbers have declined by an estimated 40 per cent since 1985. The species is listed as vulnerable by the International Union for Conservation of Nature.
For decades they were thought to have only fleeting relationships with each other. In recent years, however, evidence has emerged to suggest a rich social life.
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The latest study looks at how female giraffes can live for as long as a decade, or about 30 per cent of their lifespan, after they are no longer capable of producing young.
Something similar is seen in other animals with highly complex social structures, such as elephants and killer whales, which respectively spend around 25 to 35 per cent of their lives in a post-reproductive state.
In these species, it has been demonstrated that the presence of post-menopausal females offers survival benefits for related youngsters. This has given rise to the so-called “grandmother hypothesis”, which suggests that females live long past menopause so that they can help raise successive generations of offspring, contributing to the preservation of their genes.
The researchers behind the new study are proposing that older female giraffes perform a similar role. “There must be some evolutionary advantage,” said Dr Zoe Muller of the University of Bristol, who led the study.
“My proposal is that it’s about care of the young, and the retention of information and knowledge for group survival.
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“In southern Africa, [hunters] tend to select older individuals, and adult females are perceived to not be contributing anything to the population because they’re not bearing offspring anymore. So if it is true that older females are the ones helping the survival of the rest of the herd, then that’s obviously a big concern for conservation and wildlife management.”
The new study drew together information from more than 400 pieces of previous research. It also showed that female and young giraffes live in matriarchal groups, with childcare often shared between the female adults.
Groups of up to about 65 animals have been observed, Muller said, adding that giraffes’ sedate pace of life had contributed to them being largely ignored by researchers.
“They have travelled under the radar,” she said. “It is baffling to me that such a large, iconic and charismatic African species has been understudied 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.
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“I hope that this study draws a line in the sand from which point forwards giraffes will be regarded as intelligent, group-living mammals that have evolved highly successful and complex societies. These have facilitated their survival in tough, predator-filled ecosystems.”
