Can chainsaw carved hollows provide an effective solution to the loss of natural tree cavities for arboreal mammals?

• Tree hollows carved by chainsaws have potential to restore degraded forest habitat. • Two mammal species were detected more often in carved hollows than in nest boxes. • Tree species differed in their response to carved hollows and inserted faceplates. • Some tree species had relatively rapid growth of bark over faceplates. • Further study of changes in carved hollow condition is required. Constructing hollows or cavities in trees with chainsaws is an emerging approach to manage hollow-dependent species in hollow depleted landscapes. Small-scale experiments are required to refine this approach before implementing on a broad scale. We addressed two questions: i) are chainsaw hollows used by the regionally threatened brush-tailed phascogale (Phascogale tapoatafa) and the non-threatened sugar glider (Petaurus notatus) , ii) do chainsaw hollows retain their integrity over time. We paired 45 chainsaw hollows with nest boxes of equivalent internal dimensions in southeastern Australia and inspected these on 20 occasions over 2.5 years. Camera traps revealed phascogales visited some cavities within hours of installation and monthly inspections revealed rapid uptake of these hollows by both target species. Overall, phascogales and sugar gliders used 32% and 84% of the chainsaw hollows respectively, and 21% and 82% of the nest boxes. We used multi-method occupancy to compare detection within the two types of cavities. Detection models that included cavity type had more support than those without. Detection of both species was substantially higher in the chainsaw hollows compared to the nest boxes. Over the 2.5-year monitoring period the faceplates of some chainsaw hollows showed signs of deformity. Callous regrowth over the faceplate was pronounced on some trees suggesting the need for periodic maintenance. Our study confirms the potential of chainsaw hollows to restore habitat for hollow-dependent mammals but highlights periodic maintenance is likely to be a feature of this approach as it is with nest boxes. [ABSTRACT FROM AUTHOR]