Assessing the projected impact of invasive species is a leading issue for scientists today. A major question for ecologists is determining which characteristics will predispose a species to be a good or bad colonizer when introduced into an ecosystem. New research from John Drake, an assistant professor at UGA’s Odum School of Ecology, adds another piece to the invasive species puzzle.

In a recent issue of the publication Functional Ecology, Drake demonstrated that in fish invasive species were more successful in relation to higher parental investment—meaning fish that bear live offspring or guard their eggs are more likely to be successful colonizers than those that lay eggs and do not guard them.

“This study will help scientists better predict establishment success in future introductions,” said Drake. “Wildlife managers will benefit from this information because they can better identify traits predisposing species to successfully establish, making invasive species management plans more effective.”

Drake was influenced to begin his study after research showed that successful establishment of birds linked with larger relative brain size. It wassuggested that this could apply to all vertebrates, but Drake’s research found no correlation between the two. Besides brain size, Drake’s research also debunks another theory relating successful colonizers with higher numbers of total offspring.

“Classical theory predicts that colonizing ability should increase with the lifetime number of offspring,” said Drake. “However, for these fish introductions, this was not the case. In fact, the chance of successful establishment actually declined with fecundity.”

Data for the study was obtained from FishBase 2000, an online database with extensive information on fish establishment success by region.

“This study was only possible because of the worldwide number of contributors to this very popular meta-database,” said Drake.