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Chairman Bruce Linton is also listed as a past president of the Carleton University Students Association.</html> | Chairman Bruce Linton is also listed as a past president of the Carleton University Students Association.</html> | ||
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| + | == Monarch butterfly numbers drop to new lows == | ||
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| + | <html>Beginning in March, after spending the winter literally hanging out in the Oyamel forest's coniferous fir trees, those long-distance fliers head north in search of milkweed plants on which to lay their eggs.<br> | ||
| + | Last winter's annual survey of monarch numbers, which actually measures the area occupied by monarch colonies, found the numbers were at their lowest since measurements began 20 years ago.<br> | ||
| + | While monarch numbers have fluctuated dramatically over the years, for the past 16 years the trend has been downward. Last year's unfavourable climatic conditions — a hot spring followed by the drought in the U.S. Midwest — had monarch watchers hoping for a recovery in 2013.<br> | ||
| + | "This year it was again too warm in March in Texas and too cold in April to June. In the northeast it was not only cold it was raining,[http://www.trutamil.com/images/Custom-New-York-Jets-Jerseys.html <em>Cheap Custom New York Jets Jerseys</em>]," Chip Taylor, the head of the citizen-scientist group Monarch Watch told CBC News. Taylor, who founded Monarch Watch in 1992, is also an insect ecologist at the University of Kansas.<br> | ||
| + | "What we're seeing is the result of two years in which the reproduction of monarchs has been limited because of the physical conditions, weather conditions," he says. | ||
| + | "We've also seen a decline in monarchs because of loss of habitat. So those two things together mean monarch numbers are much lower than they've ever been in the past."<br> | ||
| + | Sharon Burkhard, a Monarch Watch citizen-scientist in Tottenham, 70 kilometres north of Toronto, says she has seen just one monarch this year and that wasn't until the second week of September,[http://dpitsolutions.com.au/webdesignports.aspx <span style="font-weight: bold">Cheap Custom 49ers Jerseys</span>], an absence she describes as "very scary."<br> | ||
| + | "Based on what I saw this year, I'm very concerned they're not going to bounce back that well, and my fear is I'm going to see them extinct within my lifetime," Burkhard said. | ||
| + | New understanding of monarch migration | ||
| + | A study published last month, by University of Guelph biologist Ryan Norris and other scientists, describes "for the first time" the migratory patterns of monarchs during the entire breeding season in Eastern North America.<br> | ||
| + | They found that the overwintered butterflies came from all over the breeding zone. The next few short-lived generations showed a northern progression until August, when the journey south begins.<br> | ||
| + | They found that most of the monarchs that make it to Canada were born in the Corn Belt of the U.S. Midwest, followed by another Canadian-born generation.<br> | ||
| + | Their major finding, Norris told CBC News, is that "the Corn Belt really acts as a central hub for the expansion later on in the breeding season." | ||
| + | In this "key region" for monarchs, from June onwards, the population explodes around the Corn Belt, radiating outwards. After June, the monarchs not only move north but east and northwest as well.<br> | ||
| + | Norris says it's not surprising that monarch numbers in Ontario are near zero this year. "You're going to see the largest fluctuations in the northern part of the breeding range because when the population's low, you're going to get really low numbers."<br> | ||
| + | Egg-laying monarchs gain a reproductive advantage from fewer competitors, so Norris's theory is that when there are really low numbers, the monarchs don't need to come as far north to be free from competition. That's also why, "in years of low numbers we don't see them up here until really late."<br> | ||
| + | Norris says that although we don't have the full story yet, understanding the migration patterns is one of the steps towards figuring out how to help conserve the species. | ||
| + | At tipping point? | ||
| + | So what does all this portend for monarchs? Could they indeed become an endangered species?<br> | ||
| + | Both Howard and Taylor point out that, as insects,<b>[http://dpitsolutions.com.au/webdesignports.aspx Custom 49ers NFL Jerseys]</b>, monarchs have the capacity to bounce back. "The really good thing about monarch butterflies is they have a very robust reproductive capacity and that means if conditions are favourable they can recover very fast," Taylor notes.<br> | ||
| + | He predicts they will recover. "The conditions can't be like this forever and they will turn around, we will see favourable conditions for reproduction sometime in the future. The question is when." | ||
| + | Elizabeth Howard of Journey North says their migration records at this point make her quite concerned that monarch butterflies will again be at record low numbers this winter in Mexico. Howard poses in the monarchs' overwintering area. (Mary Housier/Courtesy Elizabeth Howard)<br> | ||
| + | Howard is less certain. "I wouldn't want to say that all they need is the right climate conditions because they also have disease and parasite effects as well."<br> | ||
| + | For next year at least, Howard says, "our migration records make me at this point quite concerned that we won't see more than the record low."<br> | ||
| + | She doesn't foresee extinction, but does worry that the monarch numbers may be at a tipping point.<br> | ||
| + | For Norris, "It's looking like a long-term decline." | ||
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| + | Loss of habitat | ||
| + | The three scientists all stress the loss of habitat for monarchs needs to be reversed.<br> | ||
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| + | Monarch Watch and Journey North are trying to promote monarch habitat restoration by planting milkweeds, which is the main food source for monarch larvae. | ||
| + | But Taylor says "the difficulty is that the loss of habitat is so great that the effort that we're making at this point needs to be ramped up probably a thousand-fold to get the kind of impact that we want." | ||
| + | Although it fluctuates from year to year, the monarch butterfly population overwintering in Mexico seems to be on a downward trend. (WWWF-Telcel-CONANP)</html> | ||
