Assessing the spatial ecology and resource use of a mobile and endangered species in an urbanized landscape using satellite telemetry and DNA faecal metabarcoding

Abstract

The conservation of highly mobile species presents challenges to managers for assessment of threats to survival, given the difficulties in locating and observing such species. Here we evaluate satellite telemetry, DNA faecal metabarcoding and traditional field observations as three complementary techniques to acquire critical management information for an endangered species, Carnaby's Cockatoo Calyptorhynchus latirostris. Satellite telemetry of 23 birds resulted in 6026 location fixes accurate to within 500 m, and combined with extensive field observations and DNA faecal metabarcoding resulted in a more detailed understanding of how this species survives in an urbanized landscape. We identified 168 night roosts, 75% of which were previously unknown, which will contribute towards a more accurate population size estimate based on annual counts of roosting birds. We also determined the scale of daily movements (morning 5.4 ± 3.4 km from roost, afternoon 5.5 ± 3.3 km to roost; maximum distance between consecutive roosts 69.7 km) and the size of foraging areas around roosts (range 17-276 km2), and identified dependence on a variety of native and exotic food sources. Field observations identified 11 food-plant families, but combined with DNA faecal metabarcoding this was extended to 21 food-plant families. The three techniques were compared to assess their individual and collective values. By combining spatial ecology information from satellite telemetry with ecological knowledge from field observation and DNA faecal analysis, we gained deeper insights into the ecology of the species than would have been possible from any one technique alone. This information will lead to more strategic conservation planning to allow this species to persist within a rapidly expanding urban environment.