Tuesday, 16 June 2009


by Michael Fay

Most readers of the Blueskin News will know by now that there is an
ongoing project to try and measure changes in the numbers of species
of birds in our gardens with the long term aim of trying to see if the
eco-sanctuary is having any effect on garden populations.

Those taking part in the survey sit in their garden for an hour and
record the maximum number of birds of each species that they see or
hear. The table lists the results from the first three surveys, which
was carried out in October 2007 and July and October 2008. The
different months plainly produce different results, largely due to all
the silvereyes clustered around feeders, but apart from this the small
variations seem to be random. This suggests that it may take some
years to see any effect, or that the technique is just not
sufficiently sensitive.

There are two new species around now, kaka and saddleback, but their
small numbers make it very unlikely they would be picked up during one
survey hour, although a Kaka did make a very brief visit to our garden
soon after their release. And, during an half-hour sitting at the
Sanctuary's viewing platform I saw six native species: pigeon, tui,
bellbird, rifleman, tom tit and fantail, and heard a fernbird whilst
walking back along the track. This number of native species is more
than we see in most months in our garden.

Average number of birds in the gardens per site (27 sites)

Species Oct 07 July 08 Oct 08 Species Oct 07 July 08 Oct 08

Blackbird 2.4 2.2 1.9 Skylark 0.2 0.0 0.1
Song-thrush 2.0 0.8 1.6 Fantail 0.2 0.5 0.1
Starling 1.5 2.0 1.1 Pukeko 0,2 0.3 0.0
Silvereye 1.4 9.7 0.3 Cuckoo 0.1 0.0 0.1
House sparrow 1.2 1.2 0.9 White-faced Heron 0.1 0.1 0.0
Bellbird 1.1 1.1 1.5 Paradise duck 0.1 0.1 0.1
Chaffinch 1.0 0.7 1.1 Brown creeper 0.1 0.2 0.0
Kereru (pigeon)0.9 0.6 0.3 Gull (black-backed)0.1 0.0 0.0
Dunnock 0.8 1.0 0.9 Harrier hawk 0.1 0.1 0.0
Goldfinch 0.8 0.4 0.4 Magpie 0.1 0.4 0.0
Redpoll 0.7 0.0 1.0 Spur-winged plover 0.1 0.1 0.1
Yellowhammer0.5 0.3 0.5 Rifleman 0.1 0.0 0.0
Greenfinch 0.4 1.4 0.5 Rosella 0.1 0.0 0.2
Mallard 0.2 0.2 0.1 All birds 16.2 25.0 13.9
Tui 0.4 0.8 0.5 Total species 30 24 24
Grey-warbler 0.3 0.3 0.4 Most birds 42 70 31
Kingfisher 0.2 0.1 0.1 Most species 14 14 12

The next survey will take place during the last week of July which
will allow us to make a direct comparison with last year's July
survey. This may give a hint towards seeing whether or not the safety
of the Eco-sanctuary is beginning to have an effect on bird numbers
outside the fence.

We will be in touch by email with all those already involved and would
welcome any others who would like to be. Survey forms and easy to
follow instructions can be obtained via a phone call to Mike Fay at
4822806 or by email to mikeandvalfay@paradise.net,nz.

If numbers warrant it, Derek will run a training session on bird
identification just before the survey is due to start. Just let us
know if you would be interested in participating; you will enjoy it.

Our survey takes place at the same time as Eric Spurr's national
survey which uses the same methodology. The web address (see below)
provides a great identification poster of most of the birds you are
likely to see. I will try and get some copies for the library to have
available too. www.landcareresearch.co.nz/research/biocons/garden

From blueskin.co.nz and 'Blueskin News' published by Blueskin Media:
voluntary/non-profit community publishers in Blueskin Bay (Seacliff,
Warrington, Evansdale, Waitati, Doctors Point), Dunedin, New Zealand.
All material sent to or published by us is "copyleft" in the public
domain and may be freely shared, archived, re-edited and republished.
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