Movements and burrow use of newly emerged juvenile and adult female platypuses

The platypus, a unique mammal endemic to freshwater ecosystems in eastern Australia, faces population declines owing to various anthropogenic pressures. Despite its ecological importance, substantial knowledge gaps exist concerning juvenile movements and adult–juvenile interactions. We investigated total range, burrow range, active range, and burrow usage of platypuses in Coranderrk Creek, Victoria. We radio-tracked three adult female and three juvenile platypuses, recording the location of their resting burrows during the day and their movements during the night. Our results showed that juveniles exhibited significantly larger total ranges (mean juvenile 1473 ± 735 m; adult 920 ± 373 m) and daily ranges than did adults (mean juveniles 568 ± 407 m; adult 306 ± 226 m). Juveniles also had larger burrow ranges and travelled further from their burrows each night. Although no significant differences were observed in total number of burrows used between adults and juveniles, juveniles tended to use more moderate-use burrows (used 2–9 times), whereas adults favoured frequent-use burrows (used >10 times). Additionally, juvenile–adult dyads demonstrated the greatest total range (burrow and active range combined) overlap, and several instances of burrow sharing between adults and juveniles were observed. These findings suggest that juvenile platypuses are more exploratory, with larger ranges and more diverse burrow use patterns than adults. Our study has provided new insights into the spatial behaviour and social interactions of the platypus.