CSIRO Publishing blank image blank image blank image blank imageBooksblank image blank image blank image blank imageJournalsblank image blank image blank image blank imageAbout Usblank image blank image blank image blank imageShopping Cartblank image blank image blank image You are here: Journals > Emu   
  Journal of BirdLife Australia
blank image Search
blank image blank image
blank image
  Advanced Search

Journal Home
About the Journal
Editorial Structure
Online Early
Current Issue
Just Accepted
All Issues
Special Issues
Research Fronts
Rowley Reviews
Virtual Issues
Sample Issue
For Authors
General Information
Submit Article
Author Instructions
Open Access
Awards and Prizes
For Referees
Referee Guidelines
Review an Article
Annual Referee Index
For Subscribers
Subscription Prices
Customer Service
Print Publication Dates
Library Recommendation

red arrow Complete Archive
blank image
With the complete digital archive of Emu now online, we have selected some of the most interesting and significant papers for readers to access freely.

blue arrow e-Alerts
blank image
Subscribe to our Email Alert or RSS feeds for the latest journal papers.

red arrow Connect with BirdLife
blank image
facebook TwitterIcon LinkedIn

red arrow Connect with CP
blank image
facebook twitter logo LinkedIn


Article << Previous     |     Next >>   Contents Vol 98(3)

Density and Total Population Estimates for the Threatened Christmas Island Hawk-Owl Ninox natalis

F.A. Richard Hill and Alan Lill

Emu 98(3) 209 - 220
Published: 1998


Radio-tracking and territory mapping in plateau primary forests mainly during the dry season revealed that Christmas Island Hawk-Owls Ninox natalis occupied essentially exclusive territories with an average area of c. 18 ha. Estimates of home range size from radio-tracking data collected over a period of 10 to 67 d were smaller (males 13 ha, 10.6 ha, 10.1 ha, 9.5 ha and 5.5 ha; females 6 ha and 7 ha) but in general supported the conclusions from territory mapping data. Christmas Island Hawk-Owls were widespread on the island in both primary and disturbed habitats. Call-playback censusing of 22 sites repeated five times detected no significant difference in the relative abundance of owls between primary forests on the plateau and the surrounding terraces and scree slopes; significantly fewer owls were detected in regrowth forest. These results provide an estimate of 562 105 occupied owl territories on the island. From this we estimate that there may be fewer than 1000 mature Christmas Island Hawk-Owls remaining and recommend that this taxon remain listed as Vulnerable.

Full text doi:10.1071/MU98029

© Royal Australian Ornithologists Union 1998

blank image
Subscriber Login

PDF (282 KB) $25
 Export Citation
Legal & Privacy | Contact Us | Help


© CSIRO 1996-2016