"Dry" season surveys
This month Range to Reef staff visited Christmas Island to undertake a flora and vegetation assessment and Abbott’s booby survey, of specific areas adjacent to mining lease on the central plateau, for Phosphate Resources Limited (PRL).
Western Australia lacks significant areas of rainforest so the EPA’s technical guidelines for flora and vegetation assessment are tailored to more arid environments. On Christmas Island, we used Queensland’s standard methodology as described by Neldner et al. (2017) which assesses a larger ground area and includes basal area measurements as an indicator of biomass.
The Department of Environment has also released survey guidelines for Australia’s threatened birds this year. The survey was timed to coincide with the nesting period for the Endangered Abbott’s booby and entailed a search for nests, droppings or calling birds. Luckily a period of several dry days coincided with the survey since June was otherwise much wetter than usual, receiving over 500 mm of rain.
Abbott’s booby (Papasula abbotti) is a graceful seabird but is not evolved for the land, requiring a run-up or a drop-off to take off. Occasionally Abbott’s booby can become stuck below the rainforest canopy where there is no way to return to the sky.
This adult was found and rescued from the rainforest floor by Range to Reef during the survey and returned to the skies after a check-up by Parks Australia and a dose of electrolytes.
The local fauna was inquisitive during the survey with an Endangered Christmas Island goshawk (Accipiter fasciatus natalis) following staff for a couple of hours and coming close enough to touch. Rain towards the end of the survey also brought out the robber crabs (Birgus latro) and much time was spend removing them from tracks to enable safe passage.
Staff also paid a visit to the Christmas Island District High School to see how hawk-owl (Ninox natalis) nest-box construction was going. The project is a collaborative project funded by PRL, with assistance from Christmas Island District High School and Range to Reef, to assess the effectiveness of nest boxes to provide supplementary nest sites for hawk-owls. The nest boxes were coming along well with 33 ready for installation in July and more underway.