1. Understanding the patterns of distribution and environmental responses in Australian grasshoppers based on historic field survey notebooks
- Abstract
What constitutes a species’ environment and distribution is of vital importance in ecology. Our understanding of the patterns of biogeographic distribution and their connection to the environmental responses of insects has been limited due to a lack of baseline data. The baseline distribution data for all species of a given group in a region can provide fundamental insights into biogeographic questions about historic patterns of diversity, endemism, and adaptive strategies to variable environments. Grasshoppers are one major group of insects for which a continent-wide perspective on distribution and response to environmental conditions can be obtained. This is because they were extensively surveyed in Australia for 54 years (1936-1989) as part of Commonwealth scientific expeditions for the Australian National Insect Collection. Field notebooks recorded by Dr Key and associates from those surveys can help fill the hole in our knowledge of invertebrate distribution patterns in Australia. In this thesis, I developed a database of historic occurrences of Australian grasshoppers based on those field notebooks. I transcribed and carefully geocoded field notebooks corresponding to surveys conducted in Western Australia (WA) and Tasmania. I collected 8975 geographic coordinates for 506 species having a confirmed or putative taxonomic name, based on our transcription and geolocation for 47 notebooks containing 590 pages (~24%, out of 2486 pages altogether). Of the 506 species identified from the notebook transcription, only 177 species had complete formal taxonomic names. I analyzed the occurrences that were recorded from WA using species distribution models (SDMs) to provide insights on the patterns of grasshopper diversity in Australia as well as their strategies of adaptation in response to variable climatic conditions. Overall, in this thesis I aimed to achieve the following goals: (i) digitize field notebooks and save them in a digital repository; (ii) transcribe and co
- Published
- 2022