Understanding reproductive timing in seasonal breeders could illuminate evolutionary pressures that shape fertility windows across mammalian species, including patterns that may inform human reproductive health research. The rock hyrax presents an extreme case study, with males maintaining peak fertility for only weeks each year before sperm quality rapidly deteriorates. Researchers developed electroejaculation protocols to collect semen from 70 wild and captive male rock hyraxes across three years, achieving successful collection in nearly 90% of procedures during peak season. Analysis revealed sperm averaging 56 micrometers in length with ultrastructure similar to other placental mammals, but dramatic seasonal fluctuations in quality metrics. During peak mating season, males showed significantly higher sperm concentration, motility rates, and normal morphology compared to samples collected just 2-4 weeks later. Post-peak specimens exhibited extensive structural abnormalities including midpiece defects and principal piece malformations, alongside clear signs of disrupted spermatogenesis and compromised epididymal maturation processes. This research represents the first comprehensive characterization of hyrax reproductive biology and demonstrates how quickly mammalian fertility can shift from optimal to severely compromised. The findings highlight evolutionary trade-offs between energy allocation and reproductive timing, suggesting that seasonal species have developed highly synchronized but fragile fertility windows. For comparative reproductive biology, these patterns may offer insights into understanding fertility timing mechanisms and the cellular processes that govern sperm quality maintenance across different environmental and temporal contexts in mammalian reproduction.