As a private land manager the Tasmanian Land Conservancy needs long term data to better understand the natural variability of mammal populations over time, and to track their response to on-ground management. This is especially important for short-lived, wide-ranging carnivores like Tasmanian devil and spotted-tailed quoll, both now threatened with extinction. In 2014 the TLC commenced an annual mammal monitoring program across its 11,000 ha Five Rivers Reserve using camera traps at 44 sites. In four years we have established basal relative abundance and occupancy data for 15 terrestrial mammal species, and we have learned so much more. We have mapped the distribution of feral cats, tracked the spread of invasive fallow deer, confirmed the status of Tasmanian devil facial tumour disease and monitored the health of common wombats susceptible to sarcoptic mange. Our analysis has been aided by a citizen science program ‘Wildlife Spotter’ crowdsourcing hundreds of on-line volunteers from around the globe to remotely classify over 12,000 fauna images via a web-based interface. The simplicity of this monitoring program and the capacity for broader community involvement has translated into a significant conservation benefit for us, for others and for nature. This collaboration will help sustain our monitoring program into the future, and that’s what simple but effective ecological monitoring is all about.