We observed 19 male replacement events involving 17 OMUs and 16 adult males. The dataset (presented as a table) includes detailed information of social circumstances during male takeover events occurred, such as new male name, name of dependent offspring in the social unit, individual number in that social unit, Residency of the mother, and fate of fetal or unweaned infant. Furthermore, the dataset also included other information which would be useful for evaluate female counter-strategies against infanticide. For example, when male takeover events occur if the females in the social unit were pregnant; if new male attacked the pregnant female or unweaned infant after male takeover. These data might be important for the readers who hope to know the context of the male takeover except the interest were mentioned in the manuscript.

These data were collected on a daily basis at distances 5 - 50 m from 0800 to 1800 in winter-spring or 0700-1900 in summer-autumn between January 2006 and April 2021. The data were collected when we conducted a long-term study for a population of golden snub-nosed monkeys (Rhinopithecus roxellana). Golden snub-nosed monkeys (Rhinopithecus roxellana) are Asian colobines endemic to China living in a multi-level society, in which females reside in core social units consisting primarily of one male unit (OMU) with multiple females, and multiple such OMUs associate and forage together as one larger social band. All adult members were individually identifiable based on a unique set of physical features, such as body size, pelage color, evidence of injuries or scars, the shape and size of a female’s nipples, and the shapes of granulomatous flanges which are present of fleshy nodules on both sides of the upper lip in adult males. The monkeys are strictly seasonal breeders with most conceptions occurring between late August and early November and births occurring between March and May. However, male takeover events occurred around year. We recorded all social circumstance during and after male replacement till the end of mating season. All instances of births, abortions, copulations and male takeovers were observed using all-occurrence sampling. Once a male takeover event had taken place, male attacks on pregnant females, infants or mothers with infants, as well as any abortions, infanticide events were observed in a focal animal sampling. This focal animal sampling extended to the end of the mating (potential conception) season (late November) of the year of the takeover. All events were recorded via continuous all-occurrence sampling once an event began. Detailed social circumstances in the file are listed as:

• Events: sequence list according to its occurred;
• New male ID: Name of the male who replace the (old) resident male in the social unit (one male, multifemale unit, OMU) where male takeover events occur;
• ID of dependent offspring: Name of unweaned infant when male takeover events occur.
• Is the mother pregnant during the takeover event: ‘Yes’ means that female is pregnant when male takeover event occurred; ‘No’ means that female is not pregnant.
• OMU size that except infant: Number means the individuals (except infants) in that OMU when male takeover events occurred.
• Male attack on pregnant female: ‘Yes’ means new male had attacked pregnant after male replacement. ‘-’ means no observation; ‘/’ means unrelated.
• Male attack on infant: ‘Yes’ means new male had attacked unweaned infant after male replacement. ‘No’ means not. ‘-’ means no observation.
• Female's coalition: The number of adult females involved collective defense are presented in brackets which are not included the repeatedly attack in #1, #6 and #9. "a", means the mother is the initiator of collective defense; "b" means the other females except the mother are the initiator of collective defense; "c" means that the initiator of collective defense is unclear.
• Residency of the mother following male replacement: "New male" means the mother and unweaned infant stay with; "Old male" means the ousted male; "Transfer" means the mother and unweaned infant transfer to other OMU; A, the mother and unweaned infant initially stay with new male and return to stay with old male; B, the pregnant female initially stay with new male, she returned to stay with old male after giving birth.
• Fate of the fetal or unweaned infant: ‘Abortion’ means the pregnant female terminates pregnancy after male takeover events. ‘Infanticide’ means the unweaned infant was killed by new male. ‘-’ means unrelated. ‘Survive’ means the unweaned infant at least survive to weaned.

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