A Comparison of Growth-Rates in Dependent Juveniles of Planigale-Gilesi and Planigale-Tenuirostris (Marsupialia, Dasyuridae)

Abstract

Growth rates are compared from birth to early weaning in Planigale gilesi and P. tenuirostris, by means of linear regression of body parameters plotted against age. Pouch young of each species had similar growth rates; an equation is given for the aging of pouch young of P. gilesi. Juveniles of P. gilesi grew faster than those of P. tenuirostris; in both species there was a trend for males to grow faster than females. Eye opening and the end of weaning were two important developmental stages, associated with changes to reduced growth rates. Changes in body condition of the juveniles indicated that the weaning process was initiated by the mother. The different growth rates between the species and sexes produced a range of body sizes in juveniles at independence. This has important implications for partitioning of food and for community structure.