
1. Dominance Conflicts
In some monkey troops, high-ranking females may kill the infants of rivals to secure better resources for their own offspring. This is a form of reproductive competition.
2. Male Takeovers
When a new alpha male takes control of a troop, he may kill the existing infants. This triggers the mothers to return to fertility faster, allowing the new male to pass on his genes.
3. Stress-Induced Aggression
In captivity or overcrowded habitats, stress can drive monkeys to lash out, sometimes toward their own young if they perceive them as a burden or distraction from immediate survival.
4. Food Shortages
When resources are extremely scarce, some mothers may abandon or attack their infants if raising them would jeopardize their own survival.
5. Maternal Inexperience
First-time monkey mothers occasionally mishandle or unintentionally harm their infants. In rare cases, confusion or frustration can escalate to fatal aggression.
6. Sick or Weak Offspring
A mother may kill a baby that is severely ill or malformed, redirecting her energy to future offspring with better survival prospects.
7. Territorial Disputes
Fights between troops over territory can be brutal. In the chaos, infants are sometimes killed intentionally to weaken the enemy troop.
8. Infanticide by Siblings
Older juveniles in some species have been observed attacking newborns, often as a result of jealousy, competition for attention, or instinctual play turning violent.
9. Learned Behavior from Humans
In areas where monkeys come into regular conflict with people, abnormal aggression patterns can emerge, including violence toward their own young.
10. Misinterpreted Play
Young or inexperienced mothers sometimes play too roughly with newborns. Without knowing their own strength, this can lead to fatal injuries.