Bird population recovery 22 years after intensive logging near Eden, New South Wales

Abstract

Intensive logging for sawlogs and woodchips in south-eastern Australia is known to cause an immediate impact on bird populations. We measured bird abundance and species turnover during the medium term (13 and 22 years) after intensive alternate-coupe logging in a forest area that had been studied previously for short-term (0–4 years) impacts. The study provides a series of snapshots of bird population recovery following one of the most intensive logging operations in the region when, unlike the current practice, no old trees were retained in logged areas and no unlogged forest was retained in strips along all drainage lines. The aim was to assess the longer-term effects of logging on the bird assemblage and to determine whether recovery had occurred. We found that recovery had occurred for a large component of the avifauna within 22 years of intensive logging (as practised in 1976 when few or no old trees were retained in logged areas). Most bird species that forage among canopy foliage, in the air, among the understorey and on the ground had recovered. Five common forest birds were significantly more common on logged coupes than unlogged coupes. The Bell Miner, Manorina melanophrys, a honeyeater often associated with disturbed forest and implicated in eucalypt canopy dieback, had established colonies on some logged coupes 22 years after intensive logging. However, some hollow-nesting bird species (e.g. treecreepers, cockatoos) had still not fully recovered. A number of other common forest birds occurred so rarely in the study area (on both logged and unlogged coupes) that few conclusions could be made about their responses to logging. Evidence suggested that intensive logging may have had an effect at a local landscape (compartment) level as well as at the level of individual logged coupes. This was indicated by changes to the avifauna of the unlogged coupes over time (increasing numbers of species) as the forest regenerated on the adjacent logged coupes.