A new book is coming that aims to improve the standard of monitoring for Australia’s threatened biodiversity and I had the opportunity to contribute to one of the chapters.
Update: The book received the 2018 Whitley Award commendation for Conservation Zoology!
Chapter 21: Determining trends in irruptive desert species
Populations of many desert-dwelling organisms show ‘boom and bust’ dynamics, irrupting briefly following rain-driven pulses of productivity before collapsing again to low numbers. Determining population trends for such organisms poses unique challenges. This chapter describes population booms and busts in two species of dasyurid marsupials monitored over 22–27 years at nine sites in arid central Australia and uses these species to gain insight into how population trends in irruptive species might be discerned. The brush-tailed mulgara Dasycercus blythi increased predictably after heavy rainfall at all sites before again becoming scarce, whereas the lesser hairy-footed dunnart Sminthopsis youngsoni fluctuated asynchronously at all sites, with no population drivers identified. These disparate patterns indicate that monitoring programs (survey timing, number and placement of monitoring sites) should be designed with respect to the natural history of the target species to reveal trends in their populations. Environmental factors and known or putative threats to the target species also should be monitored, and appropriate models to assess the robustness of population trends and key drivers should be constructed to assist in making decisions about management intervention. More resources and input from stakeholders are needed to lift monitoring of threatened, irruptive desert species above current levels.
Reference:
Dickman C. R., Greenville A. C. & Wardle G. M. (2018). Determining trends in irruptive desert species. In: Monitoring threatened species and ecological communities (eds S. Legge, D. B. Lindenmayer, N. Robinson, B. Scheele, D. M. Southwell and B. Wintle) pp. 281-92. CSIRO Publishing, Melbourne.