For sexual selection to act on a given sex, there must exist variation in the reproductive
success of that sex as a result of differential access to mates or fertilisations. The …

The role of non-gametic components of the ejaculate (seminal fluid) in fertility and sperm
competitiveness is now well established. Surprisingly, however, we know far less about …

Evolutionary biologists have endeavoured to explain the extraordinary diversity of sperm
morphology across animals for more than a century. One hypothesis to explain sperm …

Mate choice can continue after mating via chemical communication between the female
reproductive system and sperm. While there is a growing appreciation that females can bias …

The lifespan of spermatozoa from externally fertilizing freshwater fish ranges from a few
seconds to several minutes, depending on the species. External factors, such as …

Background Predicting effects of rapid climate change on populations depends on
measuring the effects of climate stressors on performance, and potential for adaptation …

Mammalian sperm must spend a minimum period of time within a female reproductive tract
to achieve the capacity to fertilize oocytes. This phenomenon, termed sperm 'capacitation' …

In species with internal fertilization, females can favour certain males over others, not only
before mating but also within the female's reproductive tract after mating. Here, we ask …

Factors such as gamete quality can profoundly affect fertility, but the spawning micro-
environment that surrounds the spermatozoa and eggs during gamete contact has largely …

'Sperm competition'—where ejaculates from two or more males compete for fertilization—
and 'cryptic female choice'—where females bias this contest to suit their reproductive …