Aj. Bradley, REPRODUCTION AND LIFE-HISTORY IN THE RED-TAILED PHASCOGALE, PHASCOGALE-CALURA (MARSUPIALIA, DASYURIDAE) - THE ADAPTIVE-STRESS SENESCENCE HYPOTHESIS, Journal of zoology, 241, 1997, pp. 739-755
A population of the red-tailed phascogale (Phascogale calura), a marsu
pial with a restricted distribution, was studied during a three-year p
eriod at a small reserve in the South-Western Wheatbelt of Western Aus
tralia. This species shows a life-history pattern which is typical of
many Antechinus species and is characterized by a synchronized winter
mating period followed by a complete male post-mating mortality. Matin
g occurs during a three-week period in July. In the field, males live
only 11.5 months while females may live up to 36 months. Females are m
onoestrous and polyovular and have eight teats which are usually all o
ccupied by pouch young. The production of supernumerary young is commo
n. Pregnant females become aggressive toward the males. To explain the
semelparous life history in this species, an adaptive-stress-senescen
ce hypothesis is proposed. As males enter the mating period they make
major physiological adjustments which are beneficial to the success of
mating. However, there may be a longer-term cost, that of hormonally
accelerated ageing and senescence, which is finally expressed in impai
rment of feedback control of adrenocortical function.