Remove/control non-native invertebrates
Overall effectiveness category Unknown effectiveness (limited evidence)
Number of studies: 1
Background information and definitions
Non-native invertebrates can affect mammals in a number of ways. Alterations to habitats and predation on other species could reduce feeding resources available to mammals and, in some cases, direct predation on mammals can occur (Masser & Grant 1986). Such effects can lead to mammals avoiding areas occupied by non-native invertebrates (Killion & Grant 1993). Control of such species may be carried out in an attempt to reverse these impacts.
Masser M.P. & Grant W.E. (1986) Fire ant-induced trap mortality of small mammals in east-central Texas. The Southwestern Naturalist, 31, 540–542.
Killion M.J. & Grant W.E. (1993) Scale effects in assessing the impact of imported fire ants on small mammals. The Southwestern Naturalist, 38, 393–396.
Supporting evidence from individual studies
A replicated, controlled, before-and-after study in 1989–1990 in coastal grassland and shrubland in Texas, USA (Killion et al. 1995) found that after the control of red imported fire ants Solenopsis invicta, capture rates of northern pygmy mice Baiomys taylori increased. Northern pygmy mouse capture rates increased more where red fire ants were controlled (from 6–9/plot during first three months (over winter) of ant control to 19–25/plot nine months later) than in uncontrolled areas (8–9/plot during first three months of ant control to 11–15/plot nine months later). Captures were similar between plots in the summer before treatments began (19–27 mice/plot). In June 1989, two 110 × 130-m plots were established at the Welder Wildlife Foundation refuge. Each plot was divided into a treatment area and an untreated area. In treatment areas, an aerosol insecticide (active ingredient 0.7% pyrethrin) was injected directly into ant mounds while a bait insecticide (active ingredient 0.88% amidinohydrazone) was deployed monthly, from November 1989 to October 1990. Between June 1989 and October 1990, mice were sampled for four days/month using 108 baited Sherman live traps/plot. Animals were marked at first capture, and only included in analysis when caught for a second time.Study and other actions tested