Biology subjects

Paredes, U. M.

Publications and source records attributed to Paredes, U. M..

3 recordsLinked to original sources

bioRxiv2025

Strategic rejection of newborns is associated with substantially extended lifespan in parents and increased lifespan in well-reared offspring in owl monkeys

Parental rejection of apparently healthy newborns is widely classified as a behavioural abnormality in captive primate colonies, yet its biological significance remains unclear. In owl monkeys (Aotus nancymaae), parental rejection, defined here as cessation of nursing leading to rescue nursery rearing, is typically lethal for offspring and is transmitted across generations despite reducing offspring survival. Here, we tested whether parental rejection is associated with lifespan and reproductive differences in parents and their surviving offspring. We analysed long-term demographic records from a captive colony of 962 individuals and compared survival and reproductive outcomes between rejector and non-rejector parents using survival analyses and regression-based models. Parents who rejected offspring lived significantly longer than non-rejectors, with an average lifespan advantage of approximately 4-4.5 years in both males and females. This survival difference was concentrated during the prime reproductive period (6-20 years). Well-reared offspring of rejector parents also lived longer than offspring of non-rejectors, with a mean lifespan difference of 1.26 years. Rejector parents produced more offspring overall, but this difference was explained by extended lifespan rather than higher reproductive output per year. Analyses stratified by rejection timing showed no longevity advantage in first-birth rejectors, whereas parents rejecting later-born offspring exhibited longer survival. Together, these findings show that parental rejection is associated with longer lifespan in parents and in their well-reared offspring under captive conditions. These patterns are consistent with altered allocation of parental investment under energetic or environmental stress.

evolutionary biology↗

bioRxiv2024

Parental rejection is associated with intergenerational inheritance of reduced survival, altered behaviours and miRNAs in Owl Monkeys

Parental rejection in captive primates represents severe early-life stress, yet intergenerational effects remain poorly characterised. We investigated spontaneous rejection in owl monkeys (Aotus nancymaae) across two generations using demographic records (n=1,372), behavioural observations (n=65), and blood miRNA profiling (n=47). Rejected individuals showed 51% reduced lifespan, decreased probability of reaching reproductive age, and increased morbidity throughout life. Critically, well-reared offspring of rejected parents exhibited similar reductions in survival to reproductive age and lifespan. Rejected adults displayed heightened fearfulness and aggression with reduced paternal care; offspring showed decreased locomotion and altered stress responses. Blood miRNA analysis revealed significant upregulation of mml-miR-30a-5p in female offspring-a miRNA associated with early-life stress and behavioural disorders in humans. These findings demonstrate intergenerational transmission of rejection effects on fitness and behaviour, with preliminary evidence suggesting epigenetic mechanisms are associated with this transmission, though multiple pathways likely operate.

animal behavior and cognition↗

bioRxiv2020

Rejection in early life is associated with high and long-lasting stress and higher incidence of infections in owl monkeys

1.BackgroundThe mothers of owl monkeys sometimes reject their new-borns. When this occurs in captive colonies, the rejected infants are manually raised by veterinarians, allowing them to survive. However, maternal rejection can induce chronic stress, which in turn is associated with infectious diseases. Rescued, rejected owl monkeys might experience high rates of stress and infections which go undetected. MethodologyTo test this hypothesis, we evaluated the connection between maternal rejection, stress and infections in owl monkeys (Aotus nancymaae) from the IVITA Center for Conservation and Reproduction of Primates (UNMSM, Peru). Specifically, we compared the stress rates and frequency of infection treatment in juveniles (19-24 months) rejected in the first month of life and controls. To assess stress, we compared cortisol levels in hair using a competitive ELISA and recorded behaviours using cameras. We analysed past medical treatments and medication to compare incidence of infection treatment in subjects. We then studied the correlation between the frequency of infection treatments and cortisol using a linear regression. ResultsRejected owl monkeys showed significantly higher cortisol levels (p=0.0123), a higher incidence of stereotypical behaviour and overeating (pacing p=0.0159; head twirling p=0.0476, eating p=0.0238) compared to controls. Rejected owl monkeys also received significantly more treatment for infections than controls per month lived (p=0.0009). Moreover, infection rates observed in this population were positively although weakly associated with concentration of cortisol in hair (R2=0.307, p=0.0075). ConclusionMaternal rejection in the first month of life is associated with high and long-lasting stress levels and infections in the IVITA owl monkey colony. IVITA owl monkeys will be a useful model for studying the long-term effects of early life stress at the population level.

neuroscience↗