Publications

DENSITY OF BIRDS IN EUCALYPT WOODLAND NEAR ARMIDALE, NORTH-EASTERN NEW SOUTH WALES


Birds were counted along four 8-9 ha transects 50 m wide through 1981. Densities averaged 8.3 - 11.1 birds/ha., with the numbers tending to be highest in winter and lowest in spring. About 50% of individuals belonged to species that are insectivorous, 35% were honeyeaters (eating nectar and insects) and about 13% were of granivorous species. Frugivores and vertebrate-feeders were scarce. A total of 67 species were seen of which 40 were resident in one or more sites and 11 were breeding summer visitors. Numbers of several species , especially pardalotes and honeyeaters, increased in early autumn and declined in late winter.  Home ranges of seven species were mapped and these more accurate estimates of density were compared with those from the transect censuses. On average , densities were underestimated by the transect censuses by 15%, and up to 50% for individual species .  Estimates of density at one site were about 50% of those made nearby in 1978 and 1979. A severe drought had probably contributed to this decline. Results are compared with those from three other locations in south-eastern Australia. Although they span nearly 8 degrees of latitude the composition of the avifauna and its seasonality are very similar in all four localities.

>> Download Complete PDF | File Size: 3mb