摘要:SummaryLife history theory predicts a trade-off between the quantity and quality of offspring. Short interbirth intervals—the time between successive births—may increase the quantity of offspring but harm offspring quality. In contrast, long interbirth intervals may bolster offspring quality while reducing overall reproductive output. Further research is needed to determine whether this relationship holds among primates, which have intensive parental investment. Using Cox proportional hazards models, we examined the effects of interbirth intervals (short, normal, or long) on infant survivorship using a large demographic dataset (n = 15,852) of captive callitrichine monkeys (marmosets, tamarins, and lion tamarins). In seven of the nine species studied, infants born after short interbirth intervals had significantly higher risks of mortality than infants born after longer interbirth intervals. These results suggest that reproduction in callitrichine primates may be limited by physiologic constraints, such that short birth spacing drives higher infant mortality.Graphical abstractDisplay OmittedHighlights•Callitrichines are unusual primates; they breed cooperatively and birth litters•We analyzed 15,852 births with known interbirth intervals in captive callitrichines•Short interbirth intervals were associated with increased mortality risks•Callitrichines seem to face trade-offs between offspring quality and quantityBiological sciences; Zoology; Animals; Animal physiology