Reproductive rate, not dominance status, affects fecal glucocorticoid levels in breeding female meerkats

Non-invasive monitoring of glucocorticoid metabolites in banded mongooses (Mungos mungo) in response to physiological and biological challenges

“…The pattern shown here by banded mongooses was approximately similar to that shown in meerkats (Suricata suricatta) where female FGMs were low at conception and increased to parturition in females that did not have postpartum conception [4]. Female meerkats with postpartum conception, however, had lowered FGMs in the last 2 weeks of gestation [4]. In contrast, the captive female in our study did conceive after her first litter but her FGMs appeared to remain high until parturition.…”

“…These increases were possibly related to several correlated factors, including (1) increases in the female's glucocorticoid production associated with estrus, pro-estrus, parturition and lactation, (2) increases in male glucocorticoid production associated with guarding and mating the female, (3) increases in the troop's glucocorticoid production in response to other stressors brought about by the reproductive cycle: (a) attraction of predators to and depredation of juveniles, (b) post parturition attraction of invading male mongooses to the estrous female and (c) non-depredation-related juvenile mortality. The pattern shown here by banded mongooses was approximately similar to that shown in meerkats (Suricata suricatta) where female FGMs were low at conception and increased to parturition in females that did not have postpartum conception [4]. Female meerkats with postpartum conception, however, had lowered FGMs in the last 2 weeks of gestation [4].…”

Mean fecal glucocorticoid metabolites are associated with vigilance, whereas immediate cortisol levels better reflect acute anti-predator responses in meerkats

“…Meerkats forage in cohesive groups and therefore, within groups, individuals experience similar local environmental conditions including predation pressure.Sex, body condition, reproductive stage (Keay et al, 2006;Millspaugh and Washburn, 2004), and social context (Creel et al, 2013) are all likely to affect both adrenal activity and time required to respond to potential predators. In meerkats, dominance status (Carlson et al, 2004) and the presence of pups can influence plasma GC , and reproductive stage affects mean fGC concentrations (Barrette et al, 2012). By working only with young adult subordinate individuals we aimed to minimize all the above-mentioned sources of variation.…”

“…This procedure causes temporary elevation of plasma cortisol levels (within their natural range, Barrette et al, 2012) and reduction in foraging behavior over at least 2 hours following a single application (Satema et al, 2013). Intra-muscular injections were given in the thighs using a 1ml syringe with a 25G needle, while the meerkats were sunning, unrestrained, after emerging from their sleeping burrows and before they began foraging (for more details see .…”

“…To control for the potential confounding effects of age, dominance status and reproductive state on adrenal activity (Carlson et al, 2004, Barrette et al, 2012 we included only adult subordinate individuals aged between 1 and 2.5 years, in our study. Juveniles were excluded from the present study because they respond to threats differently compared with adults, due to their earlier developmental stage (Hollén and Manser, 2006).…”