Pup Shoving by Adult Naked Mole‐Rats

Abstract

Adult naked mole‐rats (Heterocephalus glaber) characteristically perform an unusual behavior toward young: they shove small pups frequently and vigorously around the nest. We studied 15 litters in five captive colonies to quantify which adults shove pups, changes in shoving frequencies as pups develop, how external disturbances affect pup‐shoving frequencies, and behavior of juveniles that were not shoved as pups. In all litters and colonies the breeding female shoved pups significantly more often than any other individual. Breeding females also shoved adult colony mates, but at far lower rates than they shoved pups. Breeding males shoved pups about half as often as did breeding females. Together, the parents shoved pups ten times more often than did nonbreeders. Frequencies of pup shoving peaked when pups were 3–4 wk old, roughly coincident with weaning. When colonies were disturbed experimentally, frequencies of pup shoving increased dramatically, whereas rates at which nonbreeding adults were shoved decreased sharply. We separated four newly‐weaned litters and raised half the pups apart from their colony. When these litters were reunited 4–9 wk later, the unshoved (experimental) pups were the same size as the frequently shoved (control) pups, but the unshoved pups were significantly less likely to flee from a disturbance. Shoving of small pups encourages them to flee from danger, and also may enforce weaning.

The re-emergence of felid camouflage with the decay of predator recognition in deer under relaxed selection

“…If foot-stamping functions as a conspecific warning signal (Caro et al 2004), we would expect increased foot-stamping when fawns were present so as to warn them of the potential danger or to potentially sensitize them to the threat (e.g. Stankowich & Sherman 2002). This evidence appears contradictory to previous results (Caro et al 2004) showing that foot-stamping occurs more often in species living in intermediate and large groups.…”

Altruism in insect societies and beyond: voluntary or enforced?

“…For example, the relative importance of enforcement in promoting and maintaining cooperation in vertebrate including human societies largely remains to be determined [51,52,57,61]. However, it is clear that coercion is often important in promoting altruism in extant insect societies, and the realization of this brings a full understanding of worker altruism within our grasp.…”

“…In vertebrate societies, enforcement can take varied forms: in cooperatively breeding cichlid fish, subordinates that do not help are evicted and thereby prevented from inheriting the natal territory [57]; monkeys punish individuals who do not share food [58], police disruptive individuals in the group [59] and enforce fairness by not cooperating with others perceived as unfair [60]; naked mole rat queens shove pups to stimulate them to work [61]. A particularly ruthless example of enforcement is found in meerkats, in which the dominant female suppresses the reproduction of subordinates [62].…”

Parental aggression against dependent young results in task partitioning in a cooperatively breeding bird

“…Parental aggression often occurs at weaning and signals the end of care for offspring (Leonard et al 1988(Leonard et al , 1991Malm & Jensen 1997;Stankowich & Sherman 2002). In some cooperative species, however, aggression might signal the end of care from specific subsets of adults.…”