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 Structure
Contacts
Content
Online Early
Current Issue
Just Accepted
All Issues
Special Issues
Research Fronts
Rowley Reviews
Sample Issue
For Authors
General Information
Scope
Submit Article
Author Instructions
Awards and Prizes
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 LinkedIn

 

Article << Previous     |     Next >>   Contents Vol 109(2)

Do observer differences in bird detection affect inferences from large-scale ecological studies?

David B. Lindenmayer A C, Jeff T. Wood A B, Christopher MacGregor A

A Fenner School of Environment and Society, The Australian National University, Canberra, ACT 0200, Australia.
B Statistical Consulting Unit, The Australian National University, Canberra, ACT 0200, Australia.
C Corresponding author. Email: david.lindenmayer@anu.edu.au
 
PDF (122 KB) $25
 Export Citation
 Print
  


Abstract

Use of multiple observers in large-scale bird surveys is often unavoidable. But how significant are observer differences in bird detection? Do observer effects significantly influence inferences about environmental factors on birds? We conducted a field experiment to quantify differences between observers in the detection of birds at Booderee National Park, south-eastern Australia. We also re-analysed a large dataset from an observational study where multiple observers had participated in bird surveys. We identified highly significant observer differences for estimates of bird species richness and the probability of detection of three exemplar taxa. We demonstrated that observer effects would not substantially alter inferences we made about relationships between bird species and vegetation type or burning history. We believe that four features of our survey design and protocol limited the magnitude of observer effects on environmental inferences: (1) high levels of replication of classes of field sites – critical for relative comparisons of site (vegetation) types; (2) pre-survey screening to ensure that only experienced ornithologists participated in surveys; (3) repeat sampling of field sites by a different observer on a different day to reduce the impacts of observer heterogeneity and ‘day’ effects; and (4) precluding surveys during poor weather or long after dawn, also to limit ‘day’ effects.

   
Subscriber Login
Username:
Password:  

    
Legal & Privacy | Contact Us | Help

CSIRO

© CSIRO 1996-2015