Does rat control benefit forest invertebrates at Moehau, Coromandel Peninsula? S.R. Rate
DOC Research & Development Series 316. 25 p
What's it about? Many of New Zealand’s indigenous invertebrates are predated on by introduced mammals, but the impacts of this on their populations remain little understood. The effect of rat (Rattus spp.) control on invertebrates was examined in two forest types near Moehau, Coromandel Peninsula, between 2002 and 2007. Rat control had no effect on the relative abundance, diversity and body length of pitfall-trapped invertebrates, except for a significant reduction in numbers of ants (Formicidae). There was strong spatial and temporal variation in several of the invertebrate indices measured, and site and sample date were the main factors separating samples based on invertebrate community composition. These results suggest that rat control has not benefited invertebrate populations at Moehau. However, it is possible that some invertebrates that are susceptible to predation by rats were not adequately sampled, that predatory pest mammals were not reduced to low enough levels to elicit a measurable invertebrate response, or that invertebrate responses would only be measurable over a longer time span. Therefore, further research into the effect of rodent control on mainland invertebrate populations is required. Several recommendations are made to improve future studies.
The above new publication is now in press and can be downloaded from:
http://www.doc.govt.nz/upload/documents/science-and-technical/drds316entire.pdf (345 KB)
