Alternative mating tactics in the alpine newt Triturus alpestris alpestris

Sexual behaviors in dyadic encounters in the alpine newt, Triturus alpestris alpestris, is described to test whether male behavior is influenced by external cues, that is, female responsiveness. Depending on this factor, a male exhibits one of the two following tactics during the sperm transfer phase. The male either waits for a positive response from the female before initiating sperm transfer ("waiting" tactic), or creeps and deposits a spermatophore in front of a nonresponsive female ("luring" tactic). The sperm transfer success rates of these tactics are 31% and 6%, respectively,and encounter success rates, 64% and 8%, respectively. The success of the second tactic is linked to behaviors that lure the female, notably quiver and distal lure. The same individual can exhibit both tactics, and neither body size nor condition appears to influence the tactic a male exhibits. These tactics can be interpreted as the result of a conditional strategy, that is, a strategy 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 of a side-payment strategy, that is, a strategy that allows individuals to achieve small gains by capitalizing on passing opportunities.