Wambo Coal AEMR 2010-2011 - Peabody Energy

• Observer bias. Likely variation in the skill level of observers across the four years haslikely resulted in an unknown level of variability in the total number of speciesrecorded.The variability in the number of bird species recorded at each site is likely due to acombination of the above factors and as such is essentially a result of variability inherentin undertaking a single brief survey at each site.Species Diversity across SitesThe variation in the number of sites at which each species was recorded is likely due to:• Variation in the habitat preferences of each species;• Variation in the density of each species;• Variation in the detect-ability of each species.The variability in the number of bird species recorded at each site is likely due to acombination of the above factors and as such is essentially a result of the naturalvariability in the distribution of species across the sample sites. As such the RufousWhistler, Weebill and Yellow-faced Honeyeater are the most widely distributed speciesacross the sites sampled.Species Abundance in 2010The variation in the number of individuals across all sites is likely due to:• Variation in the habitat preferences of each species;• Variation in the natural density of each species;• The population structures of individual species. Some species move around in flocks,others in pair and others singularly. Additionally some species are resident and aremore likely to be recorded than migratory species.• Variation in the detect-ability of each species.The variability in the number of bird species recorded at each site is likely due to acombination of the above factors and as such is essentially a result of the naturalvariability in the distribution of species across the sample sites.3.3.3 Owl Call PlaybackNo threatened owl species were recorded during the 2007 and 2010 annual surveys. ThePowerful Owl was recorded once in 2008 and the Masked Owl was recorded once in2009. Due to the large home range area of the target owl species and the relatively few(four) call playback sessions undertaken each year, it is not unexpected that threatenedowls species are rarely detected. The variation in the results of owl call playback sessionsacross the years appears to be a result of the combination of the sampling methodologydesign and the natural distribution and abundance patterns of the target species.The Tawny Frogmouth and Australian Owlet Nightjar were recorded during spotlightingsurveys in all four years. Both species were recorded in low numbers and appear to bepresent at a relatively low density.2010 Annual Ecological Monitoring Report, Draft Report, January 2011 Page 21