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   
Emu
http://www.birdlife.org.au
  A Journal of BirdLife Australia
 
blank image Search
 
blank image blank image
blank image
 
  Advanced Search
   

Journal Home
About the Journal
Editorial Board
Contacts
Content
Online Early
Current Issue
Just Accepted
All Issues
Special Issues
Research Fronts
Rowley Reviews
Sample Issue
For Authors
General Information
Notice to Authors
Submit Article
For Referees
Referee Guidelines
Review an Article
Annual Referee Index
For Subscribers
Subscription Prices
Customer Service
Print Publication Dates

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 youtube

 

Article     |     Next >>   Contents Vol 98(2)

Social Organisation and Nesting Biology of the Cooperatively-breeding Varied Sittella Daphoenositta chrysoptera in North-eastern New South Wales

Richard A. Noske

Emu 98(2) 85 - 96
Published: 1998

Abstract

In north-eastern New South Wales, Vried Sittellas occur in sedentary groups or clans holding weakly-defended territories of 13-20 ha. Average group size at one site where several birds were colour-banded was 5.4, while groups observed elsewhere in the region averaged 4.9. Simple pairs occurred in 20% of cases. However, group size varied over the year, some breeding groups amalgamating into ‘clans’ during the non-breeding season. Density in the region varied from 0.2 to about 0.5 birds ha –1. Sex ratios were skewed towards males in samples from two separate districts. Five distinct vocalisations were recognised. Roosting was communal, one colour-banded group using 13 different trees over 120 nights. The group roosted consistently earlier, and awoke later, than other local small passerine species. The breeding season was long, from August to January and second broods were occasionally attempted. Because five out of eight birds disappeared in September–October, mortality and/or dispersal seemed highest during the early breeding season. Most nests were built on dead branches of Broad-leaved Stringybarks Eucalyptus caliginosa. Most clutches (74%) of the species were of three eggs, the remainder being two. Nest success was low (20%; n = 49). Nesting attempts in two groups failed four times per season, although some nests were abandoned before laying. Large territories, feeding of the incubating female, and long periods of incubation, nestling and juvenile dependency, as well as a specialised foraging niche and cryptic prey all suggest that food may be limiting for this species. Thus, helpers may normally be required to provide young with sufficient food. However, I argue that group-living and philopatry in this species probably developed to increase foraging efficiency and reduce vulnerability to predators. The species offers exceptional scope for studies of the influence of habitat on sociality and cooperative breeding, and the effects of group size on foraging success.



Full text doi:10.1071/MU98009

© Royal Australian Ornithologists Union 1998

blank image
Subscriber Login
Username:
Password:  

 
PDF (323 KB) $25
 Export Citation
 Print
  
    
Legal & Privacy | Contact Us | Help

CSIRO

© CSIRO 1996-2014