Abstract
Humans have an extremely long history of transporting and introducing mammal species outside their native geographic range. The characteristics of the species introduced (taxonomy, life-history, ecology, environment) can all influence which traits are available (and selected) for establishment, and subsequent invasive spread. Understanding the non-randomness in species introductions is therefore key to understanding invasions by alien species. Here, we test for selectivity in the identities and traits of mammal species introduced worldwide. We compiled and analysed a comprehensive database of introduced mammal species, including information on a broad range of life history, ecological, distributional and environmental variables that we predicted to differ between introduced and non-introduced mammal species. Certain mammal taxa are much more likely to have been introduced than expected, such as Artiodactyls in the families Bovidae and Cervidae. Rodents and bats were much less likely to have been introduced than expected. Introduced mammal species have significantly larger body masses, longer lifespans and larger litter sizes than a random sample of all mammal species. They also have much larger native geographic ranges than expected, originate from significantly further north, from cooler areas, and from areas with higher human population densities, than mammal species with no recorded introductions. The traits and distributions of species help determine which have been introduced, and reflect how the evolutionary history of mammals has resulted in certain species with certain traits being located in the way of human histories of movement and demands for goods and services. The large amount of unexplained variation is likely to relate to the intrinsically stochastic nature of this human-driven process.
Highlights
Humans have deliberately transported a large number of species beyond the limits of their native distributions, to areas where they have subsequently escaped, or been released, into environments where they do not naturally occur
Examples include angiosperms and Pinaceae introduced in Britain (Williamson 1993, 1996), fish, bird and mammal species introduced from Europe to North America (Jeschke and Strayer 2005), bird species introduced from North America to Europe (Jeschke and Strayer 2005), and amphibians introduced to Australia (García-Díaz and Cassey 2014)
We searched the following online databases to determine the status of the species recorded in Long (2003): the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, Delivering Alien Invasive Species Inventories for Europe (DAISIE) and the Invasive Species Specialist Group (ISSG)
Summary
Humans have deliberately (and accidentally) transported a large number of species beyond the limits of their native distributions, to areas where they have subsequently escaped, or been released, into environments where they do not naturally occur (here termed introductions or introduced). These species are only a small fraction of those that could potentially be introduced. Around 15% of parrots (54 out of c.350 species; Cassey et al 2004), 10% of birds (973 out of c.10,000 species; Blackburn et al 2015) and 3% of amphibians (179 out of c.6,000 species; Tingley et al 2010) are known to have been introduced. A recent study by Capellini et al (2015) identified 232 mammal species as having been introduced (c.4% of the total mammal species richness) based on data in Long (2003) and other sources
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
