Taxonomic status and sex identification from single follicle hairs in endangered Pyrenean Ibex (Capra pyrenaica pyrenaica)

Abstract

Seasonal variations in the horn development and testicular activity of the Spanish ibex (Capra pyrenaica hispanica) (n = 6) and European mouflon (Ovis orientalis musimon) (n = 5) were monitored to determine the role of increasing testosterone concentration on the arrest of horn growth during the rutting season. Marked seasonal variations in the rate of horn growth (P < 0.01) and testicular activity (P < 0.001) were seen in both species, although the magnitude and timing of these changes were different (P < 0.01). Horn growth rate was inversely correlated to seasonal levels in testosterone plasma concentration in both species (ibex: R = −0.45, P < 0.01; mouflon R = −0.51, P < 0.01). In the mouflon, the increase in plasma testosterone concentration recorded in September (P < 0.05 compared with the lowest concentration) coincided with a significant reduction in horn growth (P < 0.05). In the ibex, the increase in plasma testosterone concentration in October (P < 0.05 compared with the lowest concentration) was associated with a significant arrest of horn growth in November (P < 0.05). These results appear to support the hypothesis that high peripheral plasma levels of testosterone are linked with the seasonal arrest of horn growth during the rutting period.