Lake Eyre Basin Rivers 68 drought, but irrupted within a few months of each of the major rainfall events (Fig. 6.4b). Sandy inland mouse populations were similar but were always detectable, even in dry periods (Fig. 6.4c). This species also showed a small response to moderate rainfall in the summer of 1997, contrasting with the lack of effect on spinifex hopping-mouse populations at that time. These two rodent species had different-sized responses to summer rainfalls, although the highest capture rates were in the most recent irruptions (Fig. 6.4b and c). These population booms were triggered by increases in primary productivity due to rainfall, providing food for breeding (Dickman et al. 1999 Breed and Leigh 2011). 0 50 100 150 200 250 300 350 19 90 19 91 19 92 19 93 19 94 19 95 19 96 19 97 19 98 19 99 20 00 20 01 20 02 20 03 20 04 20 05 20 06 20 07 20 08 20 09 20 10 Mo nthl y ra in fa ll ( mm ) (a) 0 10 20 30 40 50 60 19 90 19 91 19 92 19 93 19 94 19 95 19 96 19 97 19 98 19 99 20 00 20 01 20 02 20 03 20 04 20 05 20 06 20 07 20 08 20 09 20 10 20 11 Captures (100 trap nights ) (b) Fig. 6.4. (a) Monthly rainfall (mm) at Ethabuka Reserve, Simpson Desert, western Queensland from 1990 to 2012 (mean annual rainfall for this site is less than 200 mm), and mean capture rates s.e.) expressed as captures/100 trap-nights for (b) spinifex hopping-mouse (Notomys alexis).
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