title: Excluding access to invasion hubs can contain the spread of an invasive vertebrate.
abstract: Many biological invasions do not occur as a gradual expansion along a continuous front, but result from the expansion of satellite populations that become established at 'invasion hubs'. Although theoretical studies indicate that targeting control efforts at invasion hubs can effectively contain the spread of invasions, few studies have demonstrated this in practice. In arid landscapes worldwide, humans have increased the availability of surface water by creating artificial water points (AWPs) such as troughs and dams for livestock. By experimentally excluding invasive cane toads (Bufo marinus) from AWP, we show that AWP provide a resource subsidy for non-arid-adapted toads and serve as dry season refuges and thus invasion hubs for cane toads in arid Australia. Using data on the distribution of permanent water in arid Australia and the dispersal potential of toads, we predict that systematically excluding toads from AWP would reduce the area of arid Australia across which toads are predicted to disperse and colonize under average climatic conditions by 38 per cent from 2,242,000 to 1,385,000 km(2). Our study shows how human modification of hydrological regimes can create a network of invasion hubs that facilitates a biological invasion, and confirms that targeted control at invasion hubs can reduce landscape connectivity to contain the spread of an invasive vertebrate.
authors.affiliation: School of Biological Sciences, University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: Daniel
authors.initials: D
authors.lastname: Florance
authors.forename: Jonathan K
authors.initials: JK
authors.lastname: Webb
authors.forename: Tim
authors.initials: T
authors.lastname: Dempster
authors.forename: Michael R
authors.initials: MR
authors.lastname: Kearney
authors.forename: Alex
authors.initials: A
authors.lastname: Worthing
authors.forename: Mike
authors.initials: M
authors.lastname: Letnic
mesh_terms: D000818:Animals; D002024:Bufo marinus / Q000502:physiology*; D003710:Demography; D017753:Ecosystem; D058865:Introduced Species; D015876:Northern Territory; D010571:Pest Control / Q000379:methods*; D045483:Rivers; D012621:Seasons