Behaviour of kennelled dogs

The naked mole-rat is a subterranean Hystricomorph rodent with a eusocial reproductive strategy resembling that of the social insects, and where reproduction, in colonies of up to 300 individuals, is monopolised by a single dominant female, the 'queen', and one to three large males. The remaining mole-rats in a colony usually show no signs of sexual behaviour; these are classed as non-reproductive, and show a behavioural division of labour. In non-breeding female naked mole-rats, reproductive suppression was found to result from a failure of ovulation, associated with reduced circulating LH concentrations and an apparent inhibition of hypothalamic GnRH secretion. In male naked molerats, the endocrine cause of reproductive suppression was less clear-cut, because while breeding males had higher urinary testosterone and plasma LH concentrations than non-breeding males, the latter still produced mature spermatozoa. The reproductive block in non-breeding naked mole-rats is readily reversible. Non-breeders removed from their colonies and housed singly, or paired with an animal of the opposite sex, became reproductively active approximately 8 days after removal from their colonies. Reproductive suppression in naked mole-rats did not appear to he mediated by pheromones, because maintaining odour contact between separated animals and their parent colonies by daily transfer of soiled bedding and litter, neither delayed nor prevented the onset of reproductive activation in either sex. Likewise, rotation of groups of non-breeding animals between separated non-breeding females and their parent colonies every 2 days, together with daily bedding transfer, did not prevent reproductive activation in the permanently separated females. Thus the extreme socially induced suppression of reproduction in naked mole-rats may be predominantly mediated by a mechanism involving direct contact with the breeding queen. Behaviour of kennelled dogs