Data from: Maternal investment increases with altitude in a frog on the Tibetan plateau

Reproducing females can allocate energy between the production of eggs of different size or number, both of which can strongly influence fitness. Environmental conditions often drive these reproductive tradeoffs, because of direct influences on offspring survival. Many vertebrates show positive relationships between female body size and altitude, resulting in the production of larger clutches at higher altitudes. We report a different tradeoff in the high-altitude endemic frog Rana kukunoris (n=11 populations, 2000-3500 m): females living at higher altitudes produce heavier clutches of larger eggs without a concomitant increase in female body size or clutch size. Reproduction at high altitudes thus favours current reproduction at a cost to short-term maintenance and growth. The harsh environmental conditions at high altitudes can impose strong and opposing selection pressure on egg and adult life history stages.