Abstract:
The East African root rat, Tachyoryctes splendens (Rüppell, 1835) is a solitary subterranean
rodent mole. The present study investigated breeding patterns in both sexes of T. splendens from
data collected at monthly intervals over an entire calendar year. The study focused on the
analyses from post mortem examination of males and females to assess the presence of foetuses,
gonadal histology, reproductive tract morphometrics, measurement of gonadal steroids (plasma
progesterone and oestradiol-17β in females and testosterone in males) and field observations
(i.e., the presence of infants, juveniles, sub-adults and lactating females). The objective of this
study was to assess if the reproductive biology of the root rat reflected the bimodal pattern of rainfall that is characteristic of East Africa. Rainfall has been suggested to trigger breeding in
many subterranean rodents and as a consequence, this study aimed to assess the relationship
between rainfall and reproductive characteristics of T. splendens. Peaks in mean gonadal mass,
increases in concentration of reproductive hormones and the presence of Graafian follicles and
corpora lutea in the ovaries of females, and testes mass, seminiferous tubule diameter and
testosterone titre mirrored the annual peaks of precipitation at the study area. Together with field
observations of the temporal occurrence of pregnancies, infants, juveniles and sub-adults, the
data show that T. spendens cues its breeding with the patterns of rainfall, such that offspring are
born in the latter half of each rainy season, from April to July and November to December.
