Lake Eyre Basin Rivers 66 Heavy local rains or floods arising from deluges in the northern Desert Channels recharge wetlands and swamps, and sustain the extensive networks of riparian vegetation that line the major watercourses and their braided networks of minor channels (Fig. 6.1). These events provide windows of opportunity for mass flowering and seeding of grasses and herbs, recruitment of perennial shrubs and trees, and surges of vegetative growth (Brock et al. 2006 Wardle 2010 Wardle et al. 2015). In turn, these pulses of primary productivity drive booms in populations of consumer organisms such as herbivorous insects, many birds (Kingsford et al. 1999 Kingsford et al. 2004 Kingsford et al. 2010) and mammals (Letnic and Dickman 2010). Population booms usually subside within a year unless further rains fall, and give way to bust or dry periods that can last for several years. Organisms can survive these periods by dispersing to wet areas outside the desert, by retreating to refuges within the arid landscape, or by weathering conditions as drought-resistant seeds or eggs (Boulton et al. 2006 Brock et al. 2006 Robin et al. 2010). Mammals of the desert channels environment We have monitored vegetation, invertebrates, small vertebrates and weather in the far western part of the desert channels environment since 1990 (Dickman et al. 2014). This area in the north-eastern part of the Simpson Desert has long red sand dunes that run in a north-north- westerly to south-south-easterly direction, ~0.5–1.0 km apart. The valleys and sides of the dunes are dominated by hard spinifex (Triodia basedowii) with small areas of gidgee (Acacia georginae) woodland in patches of heavy clay soil (Wardle et al. 2015). We began catching small animals at Ethabuka Station (now Ethabuka Reserve) in the drought of 1990, using lines of pitfall traps (PVC pipes sunk into the ground). Mammals (and small reptiles) were trapped three to six times a year, usually for three days and nights each time, with captured animals identified, measured, marked and then released (Dickman et al. 2014). We have caught more than 40 species of lizard and 14 species of small mammal, with perhaps 30 more species of mammals and reptiles occurring in habitats just outside the sand dune system (Dickman and Wardle 2012). We show how populations of the two most abundant species of native rodent – the spinifex hopping-mouse (Notomys alexis, 30 g Fig. 6.2) and the sandy inland mouse (Pseudomys hermannsburgensis, 12 g) – and a common marsupial, the brush-tailed mulgara (Dasycercus blythi,100 g Fig. 6.3), have changed between 1990 and 2012 (Fig. 6.4). The rodents are omnivores, although a large part of their diet comprises seed, whereas the brush-tailed mulgara hunts invertebrates, rodents and other small vertebrates (Chen et al. 1998 Murray et al. 1999). Their dynamics are represented as catch-per-unit-effort (i.e. a trap-night is one pitfall trap open for one night), standardised as numbers of captures/100 trap-nights. After a period of prolonged drought in 1990, large rainfall events occurred in the summers of early 1991, 1992, 2000, 2007 and 2010, with other reasonable summer rainfall events in 1995, 1997, 2009 and 2011 (Fig. 6.4a). Spinifex, the dominant vegetation, fluctuated with rainfall, ranging in ground coverage from under 20% during dry periods to over 50% in the months following exceptionally heavy summer rain (Dickman et al. 2014 Nguyen et al. 2015). Populations of the three mammal species rose and fell with rainfall (Fig. 6.4a–d). Spinifex hopping-mouse populations were often undetectable during periods of