Sparrow droppings

Konrad Zehnder <zehnder [at] arch__ethz__ch> writes

>The painted stones of the main portal of the Berne cathedral
>(Switzerland) are affected by excrements of pigeons and sparrows. A
>wire fence has been installed which keeps off the pigeons, however,
>it is not efficient to keep off the sparrows which are still soiling
>the oil painted figures.

We had a similar problem with a large oval bronze sculptural relief
"The Seal of the National Gallery of Victoria" by Norma Redpath
which is about 7 meters wide and 4 meters high and is placed about
15 meters above the main entrance to our building.  Sparrows used
its interstices for nesting and the build up of bird droppings
became quite extraordinary.  We considered many solutions including
various sticky substances that birds hate to get on their feet- you
might want to look into these- they are essentially grease and in
some cases mixed with hot chili to make the experience even more
unpleasant for the birds- I recall this one was called "Hot-foot"
and the other something like Yuk off.  I was never very happy about
them for several reasons.  Another solution used by colleagues here
on outdoor 19th C. bronze sculptures involved the placement of
needles to prevent the birds from landing on the heads and shoulders
of the sculptures and this seems to work well in some cases.

Our eventual solution for our large bronze "Seal" was to use black
plastic bird netting used by the wine industry to cover their vines-
this has about 15mm opening.  It is available in 5 meter widths on
rolls of something on the order of 100m, but we buy it by the meter
from the neighborhood hardware and garden suppliers.

The netting has been a complete success.  It lasts about 5 years
before beginning to embrittle in sunlight, costs very little and in
position against the patinated bronze oval "dish", is virtually
invisible from street level.  We stretch it across the sculpture and
hold it in place with black foam inserts. It is removed every year
or so for washing of the sculpture and put back into position.

For a flat architectural use such as ours, it seems just about perfect.

Thomas Dixon
Chief Conservator
National Gallery of Victoria
Melbourne Australia


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                  Conservation DistList Instance 14:18
               Distributed: Thursday, September 14, 2000
                       Message Id: cdl-14-18-003
                                  ***