Connecting people with nature in Ontario's Mississippi Valley

Amazing Monarchs at MVFN

Jean Lauriault
Press Story
Amazing Monarchs at MVFN
January 24, 2008
by Sheila Edwards

A large crowd gathered January 17 for a Mississippi Valley Field Naturalists (MVFN) lecture on Monarchs presented by Jean Lauriault of the Canadian Museum of Nature. As one of Canada’s foremost Monarch experts and member of a tri-national committee for conservation of these animals, Lauriault knows Monarchs well. Monarchs (Danaus plexippus) have a very interesting life cycle, as short as 20 days, or 9 months long. During a hot summer the cycle is quick and thus more generations are born. From June to August, adults lay eggs on milkweed. In 3 to 15 days they hatch and there are 5 instars or molts of the caterpillar (larvae) taking up to 14 days, before the pupa or chrysalis (not cocoon) stage is reached. The adults emerge within 7-15 days and will live as little as 14 days or as long as 8-9 months for the late-season adults emerging in August. These are the adults which go into sexual diapause and begin the amazing migration south, remaining sterile until starting their return trip.

Monarch migration has always fascinated scientists, children, and nature lovers alike, but it wasn’t until 1975 that the site of their winter home in Mexico was discovered. As they leave Canada, Monarchs in Ontario gather at ‘staging’ areas to cross Lake Erie and Ontario. Then, covering distances of up to 100 km per day at heights of up to 1 km, they head to locations in southern US and remote areas in Mexico. Little is known about the stopover locations used during their trip, but upon arrival as many as 50 million butterflies may congregate within trees in a single hectare. They do not eat all winter but survive on stored Lipids. In March as the area gets drier, they mate and head north, with many stopping in Texas to lay their eggs and die, leaving the next generation to complete the return journey. Those arriving in Canada are the children of those that left in August.

It is hard enough to conserve a species that stays put, but conserving Monarchs, Lauriault noted, poses a ‘super challenge”, requiring the efforts of three countries. Concerns in Mexico include protecting the remote wooded area favoured by the Monarch, from illegal logging. When return migration commences clouds of butterflies fly low over the land and thousands/millions may be killed by vehicles. Important also are the stopover areas in the US, many not yet identified, where a generation may be raised in the spring, and where non-migrating Monarchs may also live.

What can we do here in Canada to conserve Monarchs? The staging areas in southern Ontario need continued protection. Secondly, Milkweed, the sole food of the caterpillar, is classified as a weed since it is toxic to cattle; action needs to be taken to remove this classification. A very aggressive invasive species that has gotten a strong foothold in Ontario is dog-strangling vine (Pale Swallowwort), also in the milkweed family. Adults can mistakenly lay their eggs on it, but the hatched caterpillars cannot eat this plants leaves. Dog-strangling vine should be eradicated whenever possible. Finally as Lauriault pointed out, the adult butterflies feed on nectar of various wild flowers and thus roadside flora need to be protected from mowing and herbicide application. On an up note, provide habitat by planting a butterfly garden, and enjoy!

To wrap up our evening, we presented Jean Lauriault with a Monarch T-shirt. He then drew a name for a second Monarch shirt, won by Teresa Peluso. Both shirts were donated by Neil Carleton, a local educator who often uses Monarchs for teaching biology and conservation in his classroom.

The next lecture in our series “Our Natural World: Conservation Challenges” on Thursday, Feb 21st will be “Ontario’s Birds” presented by Cliff Bennett, an MVFN founding member and Ontario East Director for Ontario Nature. For more information please contact Program Chair Joyce Clinton at 613-257-4879 or email . MVFNs Annual Winter Walk will take place February 17th. Learn about Winter Adaptations of Plants and Animals. For more information call Cliff Bennett at 613-256-5013 or refer to www.mvfn.ca for information on either of these upcoming events.

NOTES:

1. Further information on butterflies can be found in The Butterflies of Canada by Layberry, Hall and Lafontaine, parts of which can be found on-line at http://www.cbif.gc.ca/spp_pages/butterflies/index_e.php.

2. More information on dog-strangling vine may be found at http://www.swallow-wort.com, and http://www.ofnc.ca/fletcher/research/swallowwort/index_e.php.

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The Beaver, nature’s great watershed engineer

Press Release
Mississippi Valley Field Naturalists
September 21, 2006

by Sheila Edwards

Michael Runtz brings to life the work of one of nature’s great engineers in the watershed – the Beaver

BeaverA large crowd gathered on Thursday the 14th for Mississippi Valley Field Naturalists (MVFN) September lecture. Michael Runtz was the keynote speaker for the first of a series of talks exploring the “Mississippi Valley Watershed”.

One sign of a great educator is when an audience doesn’t realize how much they are learning. In his presentation “Beaver Ponds in the Watershed”, Michael Runtz showed he is one such educator. His enthusiastic delivery style brought to life information based on his astute observations of nature. A well respected naturalist, nature photographer, and author, Runtz captivated his audience with stories about beavers, the topic of his next natural history book. Based on the response Thursday, it should prove as popular as his other Canadian best-sellers such as Wild Wings, Algonquin Seasons and Moose Country .

Runtz showed us how beavers play the role of engineer when it comes to creating nutrient rich ponds, teeming with life. Water levels are raised, new species are attracted, and the forest gradually acquires a pond, marsh, and ribbon of grassland. The habitats thus created by this impressive rodent are vital to the health of our watershed.

As the seasons change, a beaver pond changes as well. In the spring, nutrients will be washed out, enriching the water downstream; frogs will be at their noisiest, many birds will be arriving to nest in the forest and on dead trees standing in the pond; and the beavers will be busy feeding and working on their dams and lodges. Beavers feed on tree bark, the soft layer under the bark, and also herbaceous plants like pond lilies. As fall approaches, the beaver becomes more visible during the day as it works on creating a food pile for the winter and does fall maintenance on its structures; the lodge’s insulation is upgraded by piling more mud on top and the dam must be high enough to ensure the pond does not completely freeze. The lodge’s exits are about 1.5 m below the water’s surface, at a depth which hopefully will remain unfrozen throughout the winter. The beaver swims underwater to the food pile, eating the branches that are weighed down by less edible wood like alder. Beavers keep the lodge’s upper chamber clean for sleeping by eating and defecating in the lower chamber. Like the rabbit, the beaver has a ‘two-pass’ digestive system to maximize the nutritional benefit of its high-roughage diet.

If you are interested in observing beavers, Runtz had some good suggestions. For the paddler, beaver can stay underwater for as long as 15 minutes, so if they startle and dive down, they could be gone a long time. For the XC-skier, if the hole at the top of the lodge is open, and surrounded by frost; the occupants are alive and well. When watching a beaver cutting wood, they may use their tail as a stool by leaning back on it; they will also use either their front teeth or side teeth depending on whether they are eating or cutting respectively.

On Thursday October 19th, MVFN welcomes guest speaker Aquatic Ecologist, Brian Potter (OMNR) who will discuss “Wetland Habitats in the Watershed” (7:30 p.m. Almonte United Church, 106 Elgin Street). For more information on the lecture series please contact Program Chair Joyce Clinton at 613-257-4879/email , or visit our website at www.mvfn.ca . For those interested in an MVFN nature walk, the next one will be hosted and led by Joel Byrne at his property “Big Creek” near Watsons Corners, Sunday October 15th. If interested, and for more information, please contact Mike McPhail at 613-256-7211 or email .

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Stromatolites Unknown

Submited by Sheila Edwards
December 20th 2005

Stromatolites Unknown

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During September’s MVFN meeting, Jim Bendell mentioned the stromatolites near Champlain Bridge. Chris Hume and I were intrigued, so after getting an idea of where they were, off we went. Not really knowing what to look for all we saw were concentric circles, slightly mounded, split by fissures, with odd little tuffs of grass. Not nearly as entrancing as watching a Great Blue Heron or having frogs leaping away while paddling, or spotting a salamander in the glare of a flashlight. The day was nice, the surroundings calm, we didn’t get lost, the picnic went well – just not as earth shattering as it could have been.

Back to the drawing board. What were we looking at? Why were they so important? There are some things one can appreciate without much knowledge, like the butterfly greenhouses at Carleton, or seeing a Great Grey Owl; not so the stromatolites. These odd mounds turned out to be heavily eroded, extremely old fossils; in fact, the oldest type of fossil known.

They are not the tiny fossils found on the shores of Lake Ontario, but a whole connected area of fossils. They were created by communities of cyanobacteria (blue-green algae) and other microbes, when this area was covered by warm salt water. The calcite produced by the cyanobacteria and the normal sedimentation of minerals becomes trapped within the sticky cyanobacteria, which then settle and start to harden each night.

Over time, a solid mound is formed, with a new cyanobacteria colony growing on top. Mounds form on top of mounds, which eventually fossilize. Glaciations and other erosion mechanisms resulted in our stromatolites becoming relatively flat. Looking at the stromatolites one sees concentric circles, indicative of the cycle of colony growth and sedimentation. The pattern of the rocks is reflective of the tides and currents.

There are other, smaller, examples of stromatolites along the Carp River near Fitzroy, along the Ottawa River near Dunrobin Shores, and along the Jock River. Today living stromatolites can be seen off the west coast of Australia and in the Bahamas.

Only by seeing the stromatolites were we led to further study, and through further study we understood and thus appreciated what we saw. Some things one need only see to appreciate but the circular pattern of learning and seeing results in a richer experience; an increasing appreciation of nature.

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