Monarch butterfly numbers drop by an “ominous” 59%
The number of Monarch butterflies making it to their winter refuge in Mexico dropped 59 per cent this year, falling to the lowest level since comparable record-keeping began 20 years ago, scientists reported Wednesday.
It was the third straight year of declines for the orange-and-black butterflies that migrate from the United States and Canada to spend the winter sheltering in mountaintop fir forests in central Mexico. Six of the last seven years have shown drops, and there are now only one-fifteenth as many butterflies as there were in 1997.
In the Hamilton region, Monarchs have been faced with a loss of habitat for many years said Jen Baker, Head-of-the-Lake Land Trust Program co-ordinator for the Hamilton Naturalists’ Club. Milkweed, the Monarchs’ main food source as well as where they lay their eggs, has been decreasing in the region.
“Milkweed can’t necessarily grow in fields that are sprayed for weeds. It might be good for crops, but it’s bad for milkweed,” she said, adding that invasive species also pose a risk.
“Dog Strangling Vine is an invasive plant that is a cousin of the milkweed. We’ve found some females will lay their eggs on the vine and the babies die because that’s not their food.”
Both planting milkweed and trying to control the Dog Strangling Vine population are both efforts the Naturalists’ Club encourages, Baker added.
The decline in the Monarch population now marks a statistical long-term trend and can no longer be seen as a combination of yearly or seasonal events, the experts said.
But they differed on the possible causes.
There are issues facing Monarchs south of the border, too, according to experts. Illegal logging in the reserve established in the Monarch wintering grounds was long thought to contribute, but such logging has been vastly reduced by increased protection, enforcement and alternative development programs in Mexico.
not a good sign..and its not caused by global warming..well..they haven’t found an exact way to blame it yet is probably more precise!
we watch the monarch butterfly a great deal..monarch programming..