Garden bird survey trial, July 2006
Introduction
A small-scale trial garden bird survey was undertaken in July 2006 based on similar surveys overseas, such as the Big Garden Birdwatch (www.rspb.org.uk/birdwatch/) in the UK, Great Backyard Bird Count (www.birdsource.org/gbbc/) in the US and Canada, and Backyard Birds Survey (www.birdsinbackyards.net/) in Australia. These surveys are very popular, with more than 470,000 people participating in the 2005 UK survey. The trial New Zealand garden bird survey had restricted publicity, so had restricted participation.
Methods
Participants were asked to spend 1 hour during the period 15–23 July 2006 watching birds in their home garden, local park, or school ground, and record the highest number of each bird species they saw at any one time. They could sit outside (e.g., on a verandah or garden seat) or they could sit inside (e.g., in the living room at home or classroom at school) and look out the window to watch for birds. It was suggested that if they had a bird feeder or water bath in their garden participants might like to watch an area of their garden that included that feature. Participants were provided with instructions, a data recording sheet, and an Excel spreadsheet (for those who had Excel), with the option of returning their results by post, fax, or email.
Results
People participating
Fourteen people or groups of people surveyed 16 gardens, ranging from Turangi in the north to Invercargill in the south. Most surveys were done in the Wellington region. Most were done by one person working alone, but three were done by two people working together. Seven people returned their results by post, four by email, and three by fax. Comments received included, “This was an interesting exercise”, “I found the format to be simple to use”, “Definitely wouldn’t like to be confined to counting from indoors”, and “Murphy must have come by in the night – not one bird have I seen – in any part of my garden, all day!”
Birds recorded
Twenty-two species of birds were recorded (Fig. 1). The average was 6.5 species per garden (range 0 to 16). Blackbirds were recorded in nearly 90% of gardens, silvereyes 81%, house sparrows 56%, hedgesparrows 50%, and other species in less than 50% of gardens.
House sparrows were recorded in the greatest number at any one time (average 7.7 per garden) (Fig. 2). However, the average was exaggerated by one garden with 84 house sparrows and another with 12. In both these gardens birds were fed bread, grain, and/or scraps. Silvereyes were the second most abundant species (average 6.3 per garden). This included gardens with up to 33 silvereyes around sugar-water feeders. Blackbirds had an average of 2.1 per garden, California quail 1.7, starlings 1.3, fantail 1.0, and other species less than 1.0 per garden. The average number of California quail was boosted by one garden that had 24 California quail.
Birds were fed in half the gardens surveyed, with more than one type of food in some gardens (viz. sugar-water in three gardens, seeds and grain in three gardens, bread and scraps in two, fat in one, and fruit in one). More birds were recorded in gardens where food was put out.
Fig. 1. Percentage of gardens with species present, July 2006
Fig. 2. Average number of birds of each species per garden, July 2006
Discussion
The results of this trial garden bird survey are affected by the small number of people participating and the limited area of the country covered. They should not be regarded as typical of New Zealand gardens. Nevertheless, the trial was a useful demonstration that the methods work. Some positive comments were received but no negative ones, though this may have been because people were just too polite.
A number of instruction details need to be finalised. For example, should participants record birds from inside their house (as in the UK) or outside (as most did in this trial)? Should they include birds heard but not seen? Should they include birds flying over (e.g., gulls and harriers)? Should people be given the option of counting annually, bi-annually, quarterly, or monthly? How can administration of the survey be supported financially? Your comments are welcome and will be considered by a multi-agency working group. Once details of the method and funding have been finalised, the next step will be to promote the survey nation-wide. The real value of garden bird surveys comes from mass participation over a number of years, providing long-term information on garden bird distribution and population trends, as well as enjoyment for participants.
Acknowledgements
Richard Gregory and Richard Bashford (RSPB) for assistance with devising the survey instructions, Nick Allen, Ian Armitage, and Mike Bell (OSNZ) for promoting the survey, and the people who volunteered to do the survey.
Primary contact
 | Eric Spurr Email  |
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