A team of researchers has found that wild chimpanzee mothers benefit from the use of “babysitters” because it speeds up the weaning process. Since their babies become independent faster and stop nursing, the mothers can prepare for their next pregnancy. The findings are in a paper that was just published in the journal Royal Society Open Science.
When a mother allows another individual to care for her offspring, scientists refer to it as alloparenting. Alloparenting is found throughout the animal kingdom, especially among bird and mammalian species. While there are some potential risks in entrusting offspring care to another individual, some possible benefits include maternal energy conservation, faster infant development, and earlier weaning.
Researchers led by a scientist from the University of Toronto studied wild chimpanzees (Pan troglodytes schweinfurthii) at the Kibale National Park in Uganda. The team observed 42 chimpanzee mothers and their offspring. They found that infants who spent more time with a babysitter became independent and were able to be weaned much faster. This allowed mothers to spend more time and energy on their next pregnancy, increasing overall reproductive success. The team found that early weaning did not negatively affect offspring survival. The authors noted that not all chimpanzee mothers utilize babysitters; alloparenting behaviors may be absent in some populations. Alloparenting is just one of many parenting strategies. For chimpanzee mothers that used the strategy, the biggest benefit was being able to wean infants at a faster rate.
The team’s findings show that alloparenting offers a huge benefit to chimpanzee mothers. They can wean their infants rapidly and start their next pregnancy earlier, leading to shorter inter-birth intervals. The research team found no evidence of negative effects from early weaning. Alloparenting increases the number of offspring a chimpanzee can raise to maturity in their lifetime. These findings give researchers a better understanding of babysitting behaviors and the benefits of getting some extra help when raising infants.
Bădescu et al. Alloparenting is associated with reduced maternal lactation effort and faster weaning in wild chimpanzees. Royal Society Open Science (2016).