Effect of Brood Reduction on Nest Abandonment of Smallmouth Bass

Abstract

AbstractSmallmouth bass Micropterus dolomieu are well known for vigilantly guarding their nests, which is done solely by the males. Because parental care is costly, smallmouth bass are faced with a trade‐off between current and future reproduction. If the male foregoes current reproductive efforts and abandons his nest, he may be better able to prepare for future efforts. In this article, we present field data on the effect of brood reduction on nest abandonment and explore the role of male age, brood size, and brood age on nest abandonment. We removed 0, 25, 50, or 75% of the brood from males' nests in Lake Opeongo, Ontario, during the summers of 2007 and 2008 and observed the response (nest success or failure). Across all treatments, 22 of 105 nests (21%) failed and were abandoned, but there was no significant difference among treatments. However, fish that abandoned their nests were significantly younger and had fewer offspring at the time of abandonment than did those that did not. In addition, younger nests were more likely to be abandoned than older nests. Our results differ from those of previous brood reduction experiments, although they match parental care theory overall.