Animal-borne sensor data, along with other types of sensor-based observations, provide a growing volume and proportion of documentation about biodiversity. These data differ from the traditional specimen, sampling and human observation records for which the Taxonomic Database Working Group (TDWG) originally designed the Darwin Core standard. The original intention of the new TDWG Machine Observations Interest Group is to facilitate a body of work combining the informatics expertise of TDWG with that of subject matter experts to document best practice guidelines for applying Darwin Core to bio-logging datasets. This session offers the opportunity to walk through some of the use cases developed so far, including a terrestrial GPS tracking and acceleration dataset from Movebank and a marine acoustic telemetry dataset from the Ocean Tracking Network using stationary as well as mobile acoustic receivers. Through these examples, we will describe the strategy and rationale for the approaches taken to the application of Darwin Core using typical animal tracking scenarios laced with some of the common complexities in bio-logging and other types of machine-based biodiversity observations.