Study area

Our research was conducted largely along the Eastern Goldfields Pipeline (EGP) at 11 sites up to 60 km west of Tropicana Gold Mine (TGM), located at 29°14′55″S, 124°33′21″E, and at one site 60 km south of TGM (Fig. 1; Supplementary Data SD1) in the Western Australian Great Victoria Desert (WAGVD). The WAGVD study site is classified as “Plains and dunes (longitudinal and ring dunes) with interdune corridors and plains; occasional salt pans” at an average (± SD) elevation of 402 ± 22 m a.s.l. (DAFWA 2014) and is dominated by T. desertorum and T. basedowii hummock grasslands with scattered eucalypts including marble gums (E. gongylocarpa) situated over wattle scrub (Acacia spp.) and mallee (Eucalyptus spp.—Beard et al. 2014). The study site soils are “Yellow deep sand, Soil Group 446” except for “Mulga” habitat class soils where a variable depth sandy loamy clay crust is present (Schoknecht and Pathan 2013). Ambient temperature (T_A) and weather data were recorded by the TGM weather station during the study. Mean maximum (T_A.max.r) and minimum (T_A.min.r) ambient temperature ranges were calculated for both reproductive seasons. Annual long-term weather data of mean maximum temperature (T_LT.max), mean minimum temperature (T_LT.min), highest temperature (T_LT.hi), and lowest temperature (T_LT.lo) were compared from the nearest available Bureau of Meteorology weather stations with long-term data sets to the study site and the two other S. psammophila populations (BOM 2020).