Biology subjects

Aviles de Diego, A.

Publications and source records attributed to Aviles de Diego, A..

3 recordsLinked to original sources

bioRxiv2026

Post-mortem infant-directed behaviours in wild Guinea baboons

The growing field of comparative thanatology aims to shed light on how and why the understanding of death evolved. Observations across different nonhuman primate species have reported care-taking behaviour of dead infants, but also cannibalism. Various hypotheses have been put forward to explain these infant-directed behaviours, ranging from responses to infantile cues to an understanding of death. To aid comparative analyses and test some of these hypotheses, we report behaviours directed at dead infants in a wild population of Guinea baboons (Papio papio) living in the Niokolo-Koba National Park, Senegal. During 12 years of field observations (2014-2025), 67 infants died before reaching 1 year of age. In 4 cases, we could not establish when the infants had died because the field station was closed due to the COVID-19 pandemic. In 22 of the remaining 63 cases, mothers, but occasionally also other group members, carried, protected, groomed, and dragged dead infants. In 6 cases, cannibalism occurred. None of the mothers expressed any signs of emotional distress in response to infant death. We suggest that a concept of death in Guinea need not be invoked to explain the observed behaviours. Instead, selection appears to have favoured post-mortem caretaking behaviours to avoid abandoning an infant that might temporarily be unresponsive. The lack of infant responses to maternal behaviour and the disintegration of the corpse may drive the transition from perceiving the infants as an object that evokes caretaking to one that resembles food, which ultimately facilitates occurrences of cannibalism.

animal behavior and cognition↗

bioRxiv2026

Maternal style does not predict infant growth and survival in wild Guinea baboons

Primate infants depend on their mothers for nursing, transportation, and survival, but also benefit from other behaviours such as contact, protection, and the mother serving as a model for social learning. During infancy, variation in maternal care ("maternal style") can have profound consequences for infant development and survival. We investigated the link between maternal style and infant growth and survival in wild Guinea baboons (Papio papio). This species lives in a tolerant social system with female-biased dispersal. We used data from N = 80 infants to assess variation in maternal style. The final statistical models comprised data from N = 50 infants for the growth analysis based on Parallel Laser Photogrammetry (PLP) measures of forearm length, and N = 63 infants for the survival analysis. To account for heterogeneity in data, we applied a recently established statistical framework that controls for variation in maternal behaviour with infant age. We found only moderate variation among mothers and no evidence for a link between maternal style and infant growth or survival. Neither infant sex, maternal age, nor NDVI variation, a measure later shown to be a poor indicator of food availability, predicted infant growth or survival. We suspect that, in this population living in a habitat with high carrying capacity, disease and predation have greater effects on infant growth and survival than maternal behaviour. Future studies should consider the interplay between infant behaviour and maternal responses in greater detail to better understand variation in early social development.

animal behavior and cognition↗

bioRxiv2023

Overcoming Pitfalls when Estimating Variation in Parental Investment: A Simulation Study

1. BackgroundIn many animal species, parents allocate resources to enhance offspring survival and thereby reproductive success ( parental investment). Parental care behaviors are a crucial part of parental investment, and one critical question in behavioral ecology is to which degree variation in parental care affects offspring development and survival. Crucially, parental care behaviors vary with offspring age, which creates non-trivial problems for statistical analyses, specifically when sampling is incomplete or biased. 2. MethodsWe conducted a simulation study to illustrate the problem when analyzing average parental care behaviors while not correcting for offspring age ( conventional approach), and propose a modeling approach to correct for offspring age and sampling biases. We simulated a set of different scenarios, varying with regard to sample size, sampling scheme, and variation in parental behavior. To model parent behavior as a function of offspring age, we fitted a Generalized Linear Mixed Model to each simulated data set. We included offspring age as a fixed effect and extracted Best Linear Unbiased Predictors (BLUPs) for the random intercept of parent identity. These BLUPs represent the parental behavior corrected for offspring age. Finally, we assessed how our proposed modeling approach compares to the conventional approach. 3. ResultsThe proposed modeling approach was superior to the conventional approach. More specifically, the conventional approach clearly overestimated the variation between parents, and even diagnosed appreciable variation when there was none in the simulated data. This bias was exacerbated in incomplete or unbalanced sampling schemes. 4. Conclusion.Our simulation study clearly demonstrates the necessity of correcting for offspring age in analyses of parental behavior. We strongly suggest including random slopes of offspring age within parent-offspring dyads, because doing so can reveal parent-specific trajectories of the modeled behavior against offspring age. Our approach allows for the inclusion of further categorical and continuous predictor variables that may affect parental behavior, such as parity or ecological conditions. In summary, the proposed modeling approach has several advantages over conventional methods.

animal behavior and cognition↗