A team of biologists has discovered that green-rumped parrotlets engage in both infanticide and adoption behaviors, driven by competition for nesting sites. Adoption is found to be a non-violent means of getting genes into the next generation, with males who adopted unrelated offspring going on to nest with widowed females.
A new study in mice reveals that a middle-brain region controls aggression towards young animals, while another region promotes maternal behavior. The findings suggest that the brain mechanism behind infanticide by women may be similar to that in males.
A study of over 29,000 American women found that breastfeeding significantly reduces the risk of postpartum depression. Women who breastfed for longer periods had lower rates of postpartum depression, with those breastfeeding for 6-12 months showing the greatest reduction.
Infanticide by female mammals removes potential competitors for breeding space, milk, and social status. Researchers found that harsh conditions and territorial needs drive this behavior in various mammalian species.
Researchers found that adult males were responsible for most infanticides in a Ugandan chimpanzee community, with victims often under one week old. The study suggests that the sexual selection hypothesis is the key driver behind this high rate of infant killings.
Research by Harvard University's Catherine Dulac reveals that male mice engage in infanticide due to a combination of sensory cues, including the shape of pups and specific pheromone signals. These signals allow males to identify newborn infants and recognize their need for nurturing versus protection from attack.
Researchers found that mothers adjust their behavior when a mid-ranking male rapidly rises in rank, reducing association with him and seeking stable high-rank males for protection. This highlights the females' sensitivity to the relative risks posed by different males to their infants.
A new study from the University of Illinois provides video evidence of parental infanticide in dickcissel birds, challenging existing assumptions about this phenomenon. The researchers observed a female parent removing her own chick from the nest, raising questions about the ecological and evolutionary implications.
Researchers used open-source software and genetic analysis to identify the male brown bear that killed a female and her two cubs in the Italian Alps. The study provides new insights into infanticide in small populations, highlighting its impact on species conservation.
A study by University of Toronto researchers found that baby monkeys in groups with higher risks of infanticide develop faster. This accelerated growth may be triggered by stress hormones in maternal milk, allowing mothers and infants to better survive.
A study in mice reveals that specific brain areas control paternal versus infanticidal behavior. The activation patterns of these areas determine whether a male mouse will show caring or aggressive behavior towards newborn pups. This discovery could have implications for understanding societal problems such as child-directed aggression...
Researchers at RIKEN Brain Science Institute found that two forebrain regions determine whether males exhibit paternal or infanticidal behavior. Activity patterns in these regions were associated with paternal behavior and inhibited infanticide.
A new study reveals that females have evolved a highly-effective counter-strategy to stop males from killing their offspring: by having multiple mates in a short time, causing paternity dilution and reducing infanticide risk. This leads to increased testis size in male mouse lemurs as they produce more sperm to outcompete others.
In a study on banded mongooses, researchers found that older, dominant females kill entire litters if they did not contribute to them, but allow communal litters with their own young to survive. This coordination is crucial for the group's productivity.
Researchers found that subordinate female meerkats who have recently lost litters or been evicted are more likely to wet-nurse the dominant female's pups. This behavior may provide a survival benefit for the nursed offspring and the mother of the pups, allowing the subordinate female to remain in the group.
The study reveals that male infanticide is the key driver of monogamy in humans and other primates. By caring for young, fathers can protect infants from rival males and share childcare burdens. This leads to a reduction in infant dependency and allows females to reproduce more quickly.
Researchers found a rare case of non-parental infanticide in the black-billed magpie, where an adult bird attacked and killed nestlings. The suspected perpetrator was a female parent from a neighboring nest, due to aggressive interactions and territorial expansion.
In a study of moustached tamarins, researchers found that 75% of infants survive with male help, but only 41.7% without. Female infanticide occurs when mothers kill their own offspring due to social competition and high levels of prenatal stress.
A study suggests that 19th century infant deaths attributed to smothering and overlaying were likely caused by Sudden Infant Death Syndrome (SIDS). The analysis of mortality schedules from 1850-1880 found that these deaths shared similar characteristics with known SIDS cases, including age, gender, and racial patterns.
Researchers discover annual increase in anxiety and stress among male sifaka concurrent with birthing, suggesting complex social dynamics. The study found significant rise in stress-related hormones in male sifaka feces during the birth season.
Researchers report instances of three female-led infanticidal attacks in wild chimpanzee community, challenging the notion that infanticide is a male-dominated behavior. The findings suggest that deadly aggression may be part of the female behavior repertoire, possibly driven by demographic shifts and increased competition for resources.
The female European badger's ability to conceive during pregnancy is enabled by a reproductive strategy called embryonic diapause and superfetation. This unique trait allows females to mate with multiple males, benefiting them regardless of social system, according to Oxford biologists.
A recent study analyzed 6373 infants who completed a support program for parents experiencing SIDS. The findings suggest that most second and third unexpected infant deaths are due to natural causes. Eighty to ninety percent of cases were determined to be natural, with the remaining ten percent having unclear or suspicious circumstances.