Data from: Testing the Mammalian Cues Hypothesis for Infant Corpse Carrying across Primate Species

One of the most frequently documented reactions that primates show toward the death of conspecifics is the carrying of infant corpses, yet the factors driving this behaviour remain unclear. Although mothers are most often observed transporting deceased infants, the behaviour also occurs in non-maternal group members and can even be directed at the corpses of other species. To investigate why non-mothers exhibit this behaviour, we proposed the mammalian cues hypothesis, which argues that evolutionary pressures shaping maternal care may produce a broader sensitivity to features characteristic of mammals. To test this idea, we presented six captive primate species -- ring-tailed lemurs (Lemur catta), golden-headed lion tamarins (Leontopithecus chrysomelas), black-capped squirrel monkeys (Saimiri boliviensis), white-naped mangabeys (Cercocebus atys), western lowland gorillas (Gorilla gorilla), and chimpanzees (Pan troglodytes) -- with a set of scaled objects varying in their degree of mammalian traits and recorded how individuals interacted with them. This record provides the data and R code for the analyses. Data columns in the data file (zoo_cues_data.txt): Obs_species: species observed Obs_id: numeric, order of observation for a given species indicating total exposure Interaction_duration: duration (s) that an object was interacted with Obs_Duration: duration (s) of the total observation Object: categorical, indicated the type of object presented Presentation_num: numeric, order of presentation for a given object to the indicated species Biting: duration (s) of biting Carrying: duration (s) of carrying Cradling: duration (s) of cradling Grooming: duration (s) of grooming Handling: duration (s) of handling Investigate: duration (s) of investigating Pulling: duration (s) of pulling Group_size: number of individuals in the group for that species Juvenile: binary, indicating whether the group for that species contained only adults (0) or juveniles and adults (1) prop_handle: proportion of interaction time spent handling the object prop_groom: proportion of interaction time spent grooming the object prop_aggress: proportion of interaction time spent aggressing the object cues: the number (numeric) of mammalian cues on the object (range 1-4) fur: binary, indicating whether the object was made of faux fur (1) or calico (0) bauplan: binary, indicating whether the object was pillow shaped (0) or bear shaped (1)