Variation in bird species abundance in a commercial pine plantation in New Zealand

Authors: Richard Seaton, Edward O. Minot, John D. Holland
Publication: New Zealand Journal of Forestry, Volume N.Z.J.For. 2009, Issue N.Z.J.For. 54(4) 2010, pp 3-11, Jan 2010
Publisher: New Zealand Institute of Forestry

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Abstract: The abundance of bird species in a commercial radiata pine plantation in New Zealand was studied to determine how different aged tree compartments affect birds. We found that exotic bird species were found in greater numbers than indigenous species in young and intermediate aged pine stands, but both were recorded in similar abundances in mature stands. Stand edges had higher overall densities of birds than the interiors of stands. Eight of the 31 bird species observed made up 89 % of birds recorded. We found that the application of poison bait (1080) for pest control had no significant effect on bird density overall. The density of exotic bird species, however, was greatest where bait was applied from the ground over a small, localised area. Moreover, some individual indigenous species were recorded in their highest numbers in areas where bait had been aerially broadcast over a large area. Higher densities of birds were recorded at the start and end of the breeding season. Our results indicate that in commercial pine forests, maximum avian diversity and density will result from a mosaic of pine stand ages with high local heterogeneity. Within this mosaic, stand edges and pine stands over 20 years old are particularly important. If conservation of indigenous bird species is the management aim, then older stands must be well represented throughout, and broadcast application of pest control over a wide area may be beneficial.

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