Biology of Amphibians by Duellman and }Tueb writes:
"Spermatophore covering is common in Ambystoma. Many males vie for one female, and males deposit many spermatophores. In species such as A. maculatum, in which courtship involves only nudging, males not only deposit spermatophores on top of other spermatophores, including their own, but nudge females trying to pick up spermatophores and rival males depositing spermatophores. Sometimes in A. maculatum a male has been observed to follow another male that is depositing spermatophores and then to cover each one with a spermatophore of his own. In some instances a male has been observed to circle behind his follower and deposit another spermatophore on top of that deposited by the follower, thus triple spermatophore results".