Vigilant couple have the measure of bush pests
Luring rats and other pests with tasty titbits on the end of a cardboard sheet in order to count them, is something a Timaru couple has done four times a year since 2006.
Margaret and Malcolm McPherson have just finished their latest three-day census at Kakahu Forest - finding six rats, and three mustelids (stoats, weasels or ferrets).
They spend about three hours a session laying the cardboard sheets and tunnels at 100-metre intervals, then add a little peanut butter.
The next day they remove the sandwich spread and replace it with a piece of meat. On the third day they collect the telltale footprinted cardboard.
Though the same animal could leave more than one set of footprints, the data are gathered and sent for analysis. Based on the estimations, the regularity of poison-laying is determined to protect the bird and bat life.
Excel Pest is just starting back into its spring poisoning operation, funded by Ecan under the biodiversity aspects of the Pest Management Strategy.
"They [the pests] look like they have been dancing on the cardboard," Mrs McPherson said.
The couple, who are friends of the South Canterbury Conservation Trust which funds the counting aspect, record the pests' movements in February, May, August and November. The number of pests varies from year to year, but there has been a gradual improvement, with fewer pests recorded.
"As the number of pests declines the bird count has gone up," Mrs McPherson said.
In 2006, before the June snow that wiped out a lot of vermin, the McPhersons recorded a total of 20 mustelids and 25 rats at Kakahu compared with one mustelid and 76 hedgehogs in 2011.
Mrs McPherson said even hedgehogs could be a pest, though they did not consider them to be as much of a problem as mustelids.
"You'd be surprised how clever hedgehogs are - they can get in a henhouse and dispose of a chicken," she said.
The couple take their lunch with them on their expeditions and enjoy the geology and bush as they set the lures - but it has not been without its occasional challenges.
About four years ago Mrs McPherson wandered off the track for a toilet stop and when she returned Mr McPherson and a friend were nowhere to be seen.
Meanwhile, Mr McPherson and his mate were getting worried about their missing companion.
After both parties walked out of the bush at separate times then went back in to search for each other, Mr McPherson was close to calling in a search party when his wife appeared none the worse for wear. "I was a faster walker than they were," she said.
Mr McPherson said he had since given his wife a whistle.
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