Implications for Invasive Bird Species
For future analyses, understanding the population structure from across the vast native range of European starlings may enable the identification of the precise parent population for the US introduction, especially with the use of museum specimens from the native range around the time of the initial introductions. In another invasive bird, the monk parakeet, there was a similar global study on three separate introductions (Edelaar et al., 2015). They were able to pinpoint the parent populations for each invasion using mtDNA and microsatellites (Edelaar et al., 2015). They also found decreased genetic diversity within invasive populations, leading to the conclusion that low genetic diversity does not likely inhibit the success of an invasive species, a conclusion also reached by reviews of this topic (Dlugosch & Parker 2008; Rollins et al. 2013). In order to understand why certain invasive bird populations are more successful than others, it is useful to compare these large-scale invaders to one another. This is not the only study to determine the ancestral origins of an invader. Across a wide range of taxa, studies of mtDNA have successfully determined the ancestral origins of invasive populations (e.g. in birds Jackson et al., 2015; in invertebrates Perdereau et al., 2013). These studies further show that mtDNA data are useful for understanding both the origins of introductions and the role of genetic diversity in invasion success. There is still much to learn about the invasion history of European starlings across the world, but using mitochondrial data to begin to compare these successful invasions can help us to gain a better understanding of the evolutionary history and expansion potential of invasive species. Especially with continued global climate change, closely monitoring invasive species and understanding their outsized adaptive flexibility will be increasingly important in years to come.