2010 Garden Bird Survey - 26 June to 4 July

Landcare Research, in collaboration with Forest & Bird and the Ornithological Society, established a garden bird survey to monitor the distribution and population trends of common garden birds in New Zealand.
Garden bird survey results for Dunedin
1. Top 10 species
The top 10 species (in terms of number of birds per garden) in Otago (mainly Dunedin) has differed from the national average in all 3 years of the survey. For example, in all 3 years, the silvereye was the most abundant species in Otago but was only second-most abundant nationally. The bellbird was 5th most abundant species in Otago but did not make the top 10 nationally. The kereru (New Zealand pigeon) was also more abundant in Otago than the nationally.
Table 1. Number of birds per garden in Otago and nationally in 2009
Top 10 species in Otago Top 10 species nationally
Silvereye 8.8 House Sparrow 12.1
House Sparrow 8.6 Silvereye 6.3
Blackbird 2.4 Starling 3.3
Starling 2.3 Blackbird 2.7
Bellbird 1.7 Tui 1.4
Greenfinch 1.4 Myna 1.0
Dunnock 1.3 Fantail 1.0
Chaffinch 1.2 Chaffinch 0.9
Tui 1.1 Song Thrush 0.9
Fantail 0.5 Goldfinch 0.8
2. Comparison with other cities
Silvereye numbers were higher and house sparrow numbers were lower in Dunedin than in more northerly cities in all 3 years of the survey. Bellbirds were also more common in Dunedin than in more northerly cities, and blackbirds and song thrushes less common.
3. Decline in silvereye numbers
Silvereye numbers have declined over the last 3 years, especially in Otago and Southland. This could be a result of disease. Several people in Dunedin noticed silvereyes with growths around the bill, eyes, and legs. The growths could have been avian pox, a virus that can be transmitted by contact with infected birds, when they congregate around bird feeders, for example, or by ingestion of contaminated food or water.
4. Number of people feeding birds
The percentage of people in Otago that feed birds is higher than further north. In particular, more people feed sugar-water to birds in Otago than further north. This may be because winters are colder in the south than in the north and people take pity on the birds.
Table 2. Percentage of gardens in which birds were fed in 2008
Region Sample size %
Northland 17 41
Auckland 95 38
Bay of Plenty 37 51
Waikato 92 59
Gisborne/Hawke's Bay 49 61
Taranaki 16 69
Manawatu 107 76
Wellington 793 76
Nelson/Marlborough 184 69
Westland 34 62
Canterbury 678 79
Otago 296 84
Southland 16 75
5. Number of participants
Only 121 people in the whole of Otago took part in the survey in 2009 (7% of the national total) compared to 296 (13% of the national total) in 2008. Come on Dunedin, you can do better than that!
Thanks to Landcare Research for providing the information
To complete the survey
http://www.landcareresearch.co.nz/research/biocons/gardenbird/
Further information
The Ornithological Society of New Zealand: http://www.osnz.org.nz/
Forest & Bird: http://www.forestandbird.org.nz/