Research Report

Eliminating an avian pest (House Sparrow Passer domesticus) population:
the role of trapping at a homestead scale

David B McGregor and Bruce A McGregor

Abstract
In the absence of Australian data about methods to control House Sparrows Passer domesticus this paper investigates the role of harbour removal and trapping to eliminate a House Sparrow infestation from a farm property near Mansfield, Victoria. Over 23 years, 630 House Sparrows were captured and the property has had no resident sparrows for 13 years. Benefits from the removal of House Sparrows are listed. Over the past 10 years, records of captured dispersing House Sparrows from other locations indicate that 85% of these birds arrived during summer and less than 1% during midwinter to late spring. Once resident sparrow numbers were reduced to zero, birds arriving appeared nervous and usually dispersed before the trap was set. Based on this work, trapping is most effective during the dispersal period. These findings should encourage others to view House Sparrows as pests that can be eliminated with judicious trapping (care, skill and observation) and the removal of harbors. It is proposed that the effective use of trapping over a catchment scale based on homestead action should be able to reduce or eliminate House Sparrows from Australia. (The Victorian Naturalist 125 (1), 2008, 4-10)
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Distribution of clonal and non-clonal wetland plants at Clydebank Morass, Gippsland Lakes,
in relation to elevation and salinity gradients

Matthew J Hatton, Paul I Boon and Randall W Robinson

Abstract
A review of the published literature suggested that plants with a clonal growth habit dominated the vegetation of wetlands in many parts of the world. To test whether this pattern held in Australia, the distribution of plants with clonal and non-clonal growth habits was examined in Clydebank Morass, a brackish-water wetland of the Gippsland Lakes in south-eastern Victoria. Nineteen of the twenty species of aquatic or semi-aquatic plants present in the wetland were clonal. In terms of both species number and percentage cover, clonal plants dominated the vegetation in wet and intermittently damp parts of the Morass whereas non-clonal plants were progressively more common as elevations increased. This elevational effect was due more to changes in soil moisture content than in soil salinity. These results not only confirmed the prediction that clonal plants were the dominant growth habit in the wetland but were consistent with predictions made in the 1960s as to likely vegetation changes as the Gippsland Lakes became progressively salinised. Understanding the dominance of wetlands by clonal plants has implications for assessments of plant fitness and the maintenance of plant biodiversity and habitat heterogeneity; it is central also to improving the success with which degraded wetlands are rehabilitated. (The Victorian Naturalist 125 (1), 2008, 11-18)
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Leaf litter invertebrate assemblages in box-ironbark forest:
composition, size and seasonal variation in biomass

Sarah G Taylor

Abstract
Ground-dwelling invertebrates are an important component of the box-ironbark forest ecosystem, but have been relatively little studied. This study quantified the composition, size and seasonal variation in biomass of leaf litter invertebrates in a box-ironbark forest in Victoria over a period of two years. Invertebrates were extracted using Tullgren funnels in one year and by hand-sorting in a subsequent year. Seven classes of arthropod were identified. Hymenoptera was the most numerous taxon comprising 22% and 29% of the invertebrates extracted in each year. Most invertebrates were small: 81% extracted using Tullgren funnels (minimum length 0.1 mm) and 77% extracted by handsorting had a body length of less than 5.0 mm. There was significant seasonal variation in the biomass of the leaf litter invertebrates, with a short peak of one to two months’ duration from the end of winter, that is, at the end of the coldest and wettest period of weather. The time of lowest biomass was during the summer months (December, January and February), the hottest and driest period of the year. The biomass of leaf litter invertebrates was significantly correlated with the moisture content of the leaf litter. (The Victorian Naturalist 125 (1), 2008, 19-27)
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