Alternative mating tactics in the alpine newt Triturus alpestris alpestris

Sexual behaviors in dyadic encounters in the alpine newt, Triturus alpestri s alpestris, is described to test whether male behavior is influenced by ex ternal cues, that is, female responsiveness. Depending on this factor, a ma le exhibits one of the two following tactics during the sperm transfer phas e. The male either waits for a positive response from the female before ini tiating sperm transfer ("waiting" tactic), or creeps and deposits a spermat ophore in front of a nonresponsive female ("luring" tactic). The sperm tran sfer success rates of these tactics are 31% and 6%, respectively,and encoun ter success rates, 64% and 8%, respectively. The success of the second tact ic is linked to behaviors that lure the female, notably quiver and distal l ure. The same individual can exhibit both tactics, and neither body size no r condition appears to influence the tactic a male exhibits. These tactics can be interpreted as the result of a conditional strategy, that is, a stra tegy that allows an individual to incorporate information about its ability to obtain fitness through alternative tactics and then express the tactic that maximizes its fitness. More particularly, these tactics are examples o f a side-payment strategy, that is, a strategy that allows individuals to a chieve small gains by capitalizing on passing opportunities.