Effects of early-life competition and maternal nutrition on telomere lengths

20 Early-life adversity can affect health, survival and fitness later in life, and recent evidence 21 suggests that telomere attrition may link early conditions with their delayed consequences. 22 Here, we investigate the link between early-life competition and telomere length in wild 23 meerkats. Our results show that, when multiple females breed concurrently, increases in the 24 number of pups in the group are associated with shorter telomeres in pups. Given that pups 25 from different litters compete for access to milk, we tested whether this effect is due to 26 nutritional constraints on maternal milk production, by experimentally supplementing 27 females’ diets during gestation and lactation. While control pups facing high competition had 28 shorter telomeres, the negative effects of pup number on telomere lengths were absent when 29 maternal nutrition was experimentally improved. Shortened pup telomeres were associated 30 with reduced survival to adulthood, suggesting that early-life competition for nutrition has 31 detrimental fitness consequences that are reflected in telomere lengths. Dominant females 32 commonly kill pups born to subordinates, thereby reducing competition and increasing 33 growth rates of their own pups. Our work suggests an additional benefit of infanticide may be 34 that it also reduces telomere shortening caused by competition for resources, with associated 35 benefits for offspring ageing profiles and longevity. 36 37