Higher maternal care and tolerance in more experienced giraffe mothers

Further behavioural parameters support reciprocity and milk theft as explanations for giraffe allonursing

“…Moreover, the time devoted to (allo)nursing increased with the increasing parity of the female, and thus the more experienced females allonursed more than the less experienced ones, which contradicts the parenting hypothesis. In previous studies, a high effect of the parity on the nursing behaviour of captive giraffe was found; more specifically, the probability of successful suckling, the acceptance rate within the female-calf dyad 19 , as well as the allonursing bout frequency, and the total time devoted to nursing in all events (filial and non-filial), increased with increasing female parity 10 . Females are expected to change the rate of maternal care with their reproductive experience 52 , 53 , although, it can be can assumed that more experienced females are able to cope better with allosuckling and milk distribution, and realise that providing additional milk to other calves has no deleterious effect on their current filial offspring.…”

“…All suckling events were recorded, including successful suckling bouts and unsuccessful suckling attempts. An unsuccessful suckling attempt was defined as when the calf took the teat into their mouth for less than 5 s 10 , 19 , 21 , 23 , or when the calf just approached the udder of the female 10 , 19 , 60 . A successful suckling bout was defined as when the calf held the teat in the mouth for 5 s or longer 10 , 19 , 21 .…”

“…The transfer of milk is an elementary part of reproduction in all mammals, yet species differ considerably with respect to suckling strategies 6 – 8 . Allosuckling (allonursing), which is the suckling (nursing) of non-filial young 9 , undoubtedly belongs amongst the most interesting suckling strategies 10 – 12 . Many hypotheses were proposed to explain the occurrence of allosuckling 9 , 13 , and these hypotheses can co-occur (i.e.…”

“…Therefore, females may reciprocate the nursing the offspring of other females, and ensure that the members of the group will continue to nurse her filial offspring 13 , 30 . Typically, some individuals allonurse more than other females 10 , 30 – 32 .…”

“…Allosuckling in giraffes has been recorded in the wild 2 , 41 – 43 , and the nursing bout duration was highly variable (4–360 s) 2 , as well as in captivity 2 , 10 , 19 , 21 , 44 . Based on the rejection rate, a high occurrence of allosuckling was documented in captive giraffe 19 .…”