Complex sentence: When rainfall is at its highest, a male red-eyed tree frog calls "chack" to get the attention of the female, which then carries him on her back around for up to several hours during the oviposition process.
Split into simpler sentences: When rainfall is at its highest, a male red-eyed tree frog calls "chack" to get the attention of the female. During amplexis, the female carries the male on her back for up to several hours during the oviposition process.