Skip to main content

Advertisement

Log in

Unexpected overlapping use of tree hollows by birds, reptiles and declining mammals in an Australian tropical savanna

  • Original Paper
  • Published:
Biodiversity and Conservation Aims and scope Submit manuscript

Abstract

Tree hollows are a critical resource for many arboreal vertebrates, including many threatened species. In northern Australia’s vast tropical savannas, arboreal mammals are of particular conservation concern, as many have exhibited rapid population declines in recent decades. To understand the extent to which arboreal vertebrates compete for tree hollows in these savannas, we used motion-activated cameras to estimate rates of hollow visitation (i.e. individuals seen at the hollow entrance) and hollow use (i.e. individuals seen entering or exiting a hollow) by all vertebrate species at 29 hollows over a nine-month wet season period in the tropical savanna of Melville Island, Australia. We assessed the frequency of interactions between vertebrate species at the tree hollows. We recorded 21 vertebrate species visiting hollows, with larger hollows most frequently visited: 84% with entrance diameter > 10 cm. Larger-bodied mammal species were more likely to use larger hollows, in larger trees, at greater heights. However, smaller-bodies species also visited and used large hollows. The brush-tailed rabbit-rat (Conilurus penicillatus) used relatively shallow hollows close to the ground, and these hollows were most frequently visited by monitors (Varanus spp.) and snakes. This arboreal rodent has declined severely in recent decades, most likely due to predation by feral cats, and it is noteworthy that their hollow selection behaviour may be associated with increased predation risk. Our study highlights the importance of large tree hollows for a range of taxa in the tropical savannas of northern Australia and the potential impact of reductions in the density of large hollows on hollow-dependent species. Frequent, intense fires are a threat to large hollow-bearing trees, with appropriate fire management needed to conserve this resource and help to stem mammal declines.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Subscribe and save

Springer+ Basic
EUR 32.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or Ebook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5

Similar content being viewed by others

Data availability

The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request. All analysis was conducted in R a freely accessible software.

References

Download references

Acknowledgements

We would like to thank the Tiwi Land Council and the Traditional Owners of the Tiwi Islands for their ongoing support of scientific research on their land. This research was primarily conducted on Munupi, Marrikawuyanga and Wulirankuwu Country. We thank the Tiwi Land Rangers for their on-ground assistance and sharing of knowledge, in particular Willy Rioli, Collin Kerinaiua and Willie Roberts, Brien Austral, and Edward Henry-Whiting and Tiwi College staff and students. This study was funded by the Australian Research Council (LP150100615 and FT170100004) and the Western Australian Department of Biodiversity, Conservation and Attractions, with in-kind support provided by Plantation Management Partners. Permission for animal use was Granted by the Charles Darwin University Animal Ethics Committee (A16002) and the Northern Territory Department of Flora and Fauna (Permit to Interfere with Protected Wildlife No. 58472). We thank the Australian Government’s National Environmental Science Program (funded through the Threatened Species Recovery Hub) for support to LAW and BPM. We also thank Kelsey Johnson, David Penton, Kathleen Penton, and Billy Ross for ensuring CEP never got stuck in a tree. We are grateful for the anonymous reviewers for their careful reading and constructive input.

Funding

This study was funded by the Australian Research Council (LP150100615 and FT170100004) and the Western Australian Department of Biodiversity, Conservation and Attractions.

Author information

Authors and Affiliations

Authors

Contributions

CP and LW contributed to the study conception and design. Material preparation, data collection and analysis were performed by CP and BT. The first draft of the manuscript was written by CP and all authors commented on subsequent versions of the manuscript. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Cara E. Penton.

Ethics declarations

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

Permission for animal use was granted by the Charles Darwin University Animal Ethics Committee (A16002) and the Northern Territory Department of Flora and Fauna (Permit to Interfere with Protected Wildlife No. 58472).

Additional information

Communicated by Dirk Sven Schmeller.

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Below is the link to the electronic supplementary material.

Supplementary file1 (DOCX 5096 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Penton, C.E., Radford, I.J., Woolley, LA. et al. Unexpected overlapping use of tree hollows by birds, reptiles and declining mammals in an Australian tropical savanna. Biodivers Conserv 30, 2977–3001 (2021). https://doi.org/10.1007/s10531-021-02231-6

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10531-021-02231-6

Keywords

Navigation