The two studied sibling species of African mole-rats, Fukomys anselli and F. kafuensis, are blind, subterranean rodents that live in an eusocial families with only a single pair breeding whilst its offspring exhibit prolonged philopatry and do not breed. The reproductive skew is caused by incest avoidance through individual recognition of family members. The aim of the study is to contribute to basic understanding of priming capacities of olfactory stimuli and reproductive activity on biological state of a female. We compared hormonal profiles (normalized urinary estradiol- and progesterone concentration (mg/crea) and their temporal changes in females throughout three different test phases: I. Five week phase without manipulation; II. Five day phase with olfactory stimulation with odours of potential repreductive partners; III. Five day phase wih reproductive stimulation with respective partners. Colpocytology was performed to correlate spontaneous or induced estrus with vaginal cytological findings. There was a strong correlation between sexual activity of females (queens) on one side and high mean estradiol and progesterone levels on the other side as well as estradiol increase triggered by mating. No correlation was found between estrus phase and typical estrus like cells in colpocytological examinations.
A recent study (H e t h et al. 2002) challenged the idea of “blind” foraging in herbivorous underground dwellers by showing that subterranean rodents of several species use olfaction to discriminate between soils in which plants had or had not been growing. Here we address additional questions about odour-based foraging underground. We tested responses of Zambian mole-rats (Cryptomys anselli and C. kafuensis) to putative carrot kairomones using tunnel T-mazes. Mole-rats distinguished peat moistened with hydroponic as well as filtered hydroponic “carrot water” from peat moistened with distilled water. Furthermore, mole-rats detected carrot kairomones that percolated over the course of a week through the soil to a distance of 30 cm. These results demonstrate that 1) Attractiveness of soil is given by contents of primary root kairomones not caused by microbial activity in planted soil. 2) Carrot-kairomones are water-soluble molecules of less than 0.6 μm diameter. 3) Carrot-kairomones diffuse around the plant, making plants detectable from a distance.