Should a parasite expose itself? (some theoretical aspects of begging and vigilance behavior)

This paper examines the evolutionarily stable (ESS) solution of the begging conflict in cases involving nest parasitization. As expected, the presence in the nest of a parasite chick leads to a more intense begging conflict, with the parasite displaying a more selfish behavior than the host chicks. The model also predicts opposite responses by the host and the parasite to changes in the number of nestmates. While a larger number of nestmates entails a reduced ESS begging intensity for each of the host chicks, it entails an increased begging intensity for the parasite. Consequences of the parasite's ability to disguise itself are compared to analogous results for the vigilance game: whereas in the begging game a parasite should conceal itself, exposure can be selectively advantageous for a defector in the vigilance game.