SCARES IGNORED

Otago Daily Times, Issue 26852, 17 August 1948, Page 6

SCARES IGNORED

"FEATHERED ENEMIES” CONTEMPTUOUS ATTITUDE ADOPTED NESTING IN SUB-STATIONS Daily Times Special Service. AUCKLAND, Aug. 16. Birds nesting in sub-station structures are causing trouble to the State Hydro-electric Department, but so far none of the scaring devices suggested by an ornithologist, scientists, Chinese market gardeners and a bird psy- * chologist has troubled the birds. This problem has grown to such proportions that the birds were included In the department’s last annual report as the cause, of • “ outages ” along with lightning and a haystacker. “ Outage ” is the technical term for a power interruption. A leading ornithologist suggested that a stuffed owl in a glass-fronted box or shelter might scare away the birds. The theory behind this was that the owl is a natural enemy of small birds and they instinctively avoid owls. A trial disposed of this theory. Apparently the birds know a dead owl when they see one. ’ . ■ . Reports appeared in many American semi-scientific publications of the, use of supersonic waves for scaring birds. The State Hydro-electric Department found that pollution of reservoirs by seagulls was exercising the attention .of the Department of Scientific and Industrial Research, and experiments were in progress on the production of a supersonic generator. A machine was built and tried in a small way, but was ineffective. This project was dropped on receipt of a scientific report from America which showed fairly conclusively that stories coming from there were pure invention. Then it was noted that Chinese market gardeners used a device consisting of a number of old sacks in which firecrackers were dispersed. The sets were set alight and smouldered slowly, setting off crackers at intervals and frightening the birds. This idea would not' be practicable in a high-voltage sub-station, but a variation was tried. A large electric bell was set up and connected to an electrical mechanism that gave it a , single impulse at odd intervals. -The birds soon got used to this and it was abandoned after a sparrow was observed to be completely oblivious to it at a distance of 4 feet. Besides, people in nearby cottages complained. A local psychologist had the idea of smearing likely perches with a sticky substance which would annoy the birds without actually hprting them, as bird lime would do. They would be discouraged from nest building, which is the real cause of the trouble. On trial, it was found that the sticky substance certainly annoyed the birds, but after a time a skin formed over it and the birds perched quite happily on this skin.

Another idea tried was closing up in fine mesh gauze of the areas in which the birds usually nest, and the fitting of spiked and serrated obstacles at all likely perching places. A further idea considered, but not actually tried, was the intermittent firing of cartridges or percussion caps. Unless the department’s officers can think of some more successful sticky, noisy, uncomfortable or fearsome surprises for their feathered enemies, it is likely that there will-be more crops of “outages” to report in the next annual review.