Nature Watch
April 30, 2009
By Susan Benson,
CNHM Director of Education
Robins hopping over lawns in search of food, singing from tree branches and utility wires, or bathing in rain puddles, are all familiar sights to most people. On the evening of April 16, I observed probably forty robins migrating through my yard. Museum staff often asked about robin behavior. “What do robins do for food when snow is on the ground,” is a common question. This week a call came into the Museum from a member asking, “What is happening with the robin in my back yard? It keeps pecking and flying against the windows of my house.” Robins exhibit many interesting behaviors throughout the year that are worth studying when outdoors.
Late winter seems to always bring a snowfall after the robins arrived. Most of us believe that robins must be struggling, but in truth, robins are not earthworm specific birds. In the late winter and early spring, when insects are not available, robins feed on ripe fruits and berries in trees and shrubs. During the breeding season robins will eat earthworms, beetles, snails, spiders, caterpillars, ants, grasshoppers and other ground-dwelling insects.
When breeding, male robins actively defend their territory, which is one-third of an acre up to several acres. If another male intrudes in his territory, he will fly at the trespasser to scare him away. If this doesn’t work, he will dive-bomb the bird, hitting the invader chest to chest. It is this behavior that occurs when a male mistakes his own image in a window for an opponent. Male robins will beat themselves against windows, thinking they are attacking another robin. They might also attack vehicle mirrors for the same reason. Other times, robins may see the reflective nature of a window, and simply fly into it thinking it is safe to do so. Robins are also known to attack red objects, such as socks or other items on a clotheslines, or ornaments or toys in the lawn, again mistaking them for an imposter. This behavior can go on for days or weeks, but usually the birds do not injure themselves seriously. Usually after the romance of the season ends, so do their territorial antics.
If we watch robins long enough in the spring, we might see several other different displays associated with courtship and territorial behavior. Robins will lift their tails when they believe there is danger. The male or female will lower their head and raise their tail to a forty-five degree angle and flick their tail repeatedly while calling out. They drop their wingtips so they are drooping after a dangerous encounter, and sometimes puff their breast feathers out. They also are known to sound their alarm call at a human approach when nesting. Robins will mob nest predators such as crows in areas where there are large numbers of robin nests. When you see a robin perched or flying in midair with a wad of mud or grass in its beak, or a line of mud across the female’s breast, she is nest building. The females work this mud into place with their feet and bill, molding it into that perfectly circular shape with their bodies. When we observe a robin flying off with food in its beak, which is a sign that there are young in a nearby nest. After breeding season is over, we can watch as robins gather for the night in communal roosts, located in trees, under bridges or barns, containing a few to several hundred birds. These are all behaviors worth watching for.
Sometimes we may observe robins “listening,” apparently for their food. It is believed that robins use sight rather than sound for finding food. When tilting their head they are most likely checking the ground with one eye, looking for worms or their castings. Another common thing to look for is when robins thump on the ground with their feet, trying to stimulate movements from the worms before catching them. If we took our shoes and socks off, stamped our feet on the soil a few times, would we be able to feel the movement of worms? What an amazing feat.
Robins have less reproductive success, with up to 80 percent of the young dying each year. Blue jays, ravens, crows, squirrels, chipmunks and raccoons eat robin eggs and nestlings. During the winter they are a favorite food for great horned and barred owls, and hawks and falcons will prey upon the adults in flight. Since they feed on the ground, young and old are exposed to domestic cats. Historically, robins suffered from the insecticide DDT (in the 1950s and 1960s) as they ate earthworms with higher levels of DDT in their bodies.
What can we do to aid robins’ success? Avoid using insecticides. Leave some “forest floor” in open soil by leaving leaf litter to provide for ground foraging. Plant native fruit and berry-producing trees and shrubs. If robins are attacking our car mirrors, place small paper sacks over the mirrors when parked. Where birds are striking windows, break up the window’s reflection by hanging strips of tape, string, or other material six inches apart on the outside of windows. Avoid using commercial silhouettes used to frighten birds, as robins quickly lose their fear of the shapes. Rubbing a bar of soap on the exterior surface of the window with a design that leaves no area six inches or larger uncovered, or cover windows with black netting.
Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.
Thursday, April 30, 2009
Thursday, April 16, 2009
Phenology Notes
Nature Watch
April 16, 2009
By Susan Benson,
CNHM Director of Education
Every day a friend, family member, or Museum visitor shares with me some exciting observation they have made related to spring phenology – “I saw my first robin”; “Look, it’s my first tick”; or “The mergansers are back,” are phrases I have been hearing. Phenology continues to provide joy to many people as they study the life cycles of plants and animals as they respond to seasonal changes. There are many events to keep an eye out in the last part of April.
Mid- to late-April brings the peak spring duck migration, and mallard hens begin nesting during the third week of April. Bald eagles begin nesting, and osprey should be migrating back as more open water becomes visible. Our first sandhill cranes and great blue herons can be observed any time now. Other birds to watch for are the eastern phoebe, yellow-bellied sapsucker, barn swallows (I saw my first on April 8,) bluebirds, house wrens, and brown-headed cowbirds. Spring bird migration is probably one of the most-watched phenological events.
Last week was the first mourning cloak butterfly I observed. The ticks are definitely back. We should also be seeing our first earthworms, evidenced by the robin’s avid search through open fields in town. We might even begin seeing our first bumblebees during the last few days of the month. At 40 degrees Fahrenheit, I even spotted my first spider of the season on Sioux Beach on Lake Superior on April 10. It is in April that we can also look forward to seeing our first black flies and getting our first mosquito bite. These are all events to look forward to!
Sometime in April, painted turtles begin emerging, spring peepers begin peeping, and American toads begin to sing. Hog-nosed snakes are also coming out of hibernation. Salamanders begin moving during the first warm, night rain. The phenology of reptiles and amphibians is very dependent upon temperature and moisture conditions, making it more difficult to predict when these animals might emerge. For example, wood frogs will not be present until night temperatures are over 50 degrees Fahrenheit. Many scientists are using amphibian data in current research on the effects of climate change because of their sensitivity to temperature and moisture. It is worth recording annual amphibian information in order to look at general patterns over a longer range of time.
There is much happening in the mammal world in April. Coyote pups and mink kits are born. Black bears leave their dens in mid-April. Little brown bats usually leave hibernation during the third week of April. Snowshoe hares begin turning brown. Raccoon kits are born in a hollow tree, brush pile, or other chosen site.
Plants begin their winter-free growth during April. Trees begin to flower. Bloodroot blooms. The first dandelions begin blooming by the end of the month. It is during this growing season that mature trees can increase their circumference by roughly one inch every year. Spring is a transition, a process that transforms the winter woods with its bare trees to the lush green of May. In the plant world, the process moves step by step, from the forest floor until it finishes with the explosion of growth in the tallest trees.
Each of us uses different phenological sightings as our signs of spring. For me it’s my first mourning cloak butterfly, or the eastern phoebe that visits my home to nest every spring. Please send your observations by Emailing the Museum at info@cablemuseum.org. Please be sure to include information about the observation, date, and location for our records.
Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.
April 16, 2009
By Susan Benson,
CNHM Director of Education
Every day a friend, family member, or Museum visitor shares with me some exciting observation they have made related to spring phenology – “I saw my first robin”; “Look, it’s my first tick”; or “The mergansers are back,” are phrases I have been hearing. Phenology continues to provide joy to many people as they study the life cycles of plants and animals as they respond to seasonal changes. There are many events to keep an eye out in the last part of April.
Mid- to late-April brings the peak spring duck migration, and mallard hens begin nesting during the third week of April. Bald eagles begin nesting, and osprey should be migrating back as more open water becomes visible. Our first sandhill cranes and great blue herons can be observed any time now. Other birds to watch for are the eastern phoebe, yellow-bellied sapsucker, barn swallows (I saw my first on April 8,) bluebirds, house wrens, and brown-headed cowbirds. Spring bird migration is probably one of the most-watched phenological events.
Last week was the first mourning cloak butterfly I observed. The ticks are definitely back. We should also be seeing our first earthworms, evidenced by the robin’s avid search through open fields in town. We might even begin seeing our first bumblebees during the last few days of the month. At 40 degrees Fahrenheit, I even spotted my first spider of the season on Sioux Beach on Lake Superior on April 10. It is in April that we can also look forward to seeing our first black flies and getting our first mosquito bite. These are all events to look forward to!
Sometime in April, painted turtles begin emerging, spring peepers begin peeping, and American toads begin to sing. Hog-nosed snakes are also coming out of hibernation. Salamanders begin moving during the first warm, night rain. The phenology of reptiles and amphibians is very dependent upon temperature and moisture conditions, making it more difficult to predict when these animals might emerge. For example, wood frogs will not be present until night temperatures are over 50 degrees Fahrenheit. Many scientists are using amphibian data in current research on the effects of climate change because of their sensitivity to temperature and moisture. It is worth recording annual amphibian information in order to look at general patterns over a longer range of time.
There is much happening in the mammal world in April. Coyote pups and mink kits are born. Black bears leave their dens in mid-April. Little brown bats usually leave hibernation during the third week of April. Snowshoe hares begin turning brown. Raccoon kits are born in a hollow tree, brush pile, or other chosen site.
Plants begin their winter-free growth during April. Trees begin to flower. Bloodroot blooms. The first dandelions begin blooming by the end of the month. It is during this growing season that mature trees can increase their circumference by roughly one inch every year. Spring is a transition, a process that transforms the winter woods with its bare trees to the lush green of May. In the plant world, the process moves step by step, from the forest floor until it finishes with the explosion of growth in the tallest trees.
Each of us uses different phenological sightings as our signs of spring. For me it’s my first mourning cloak butterfly, or the eastern phoebe that visits my home to nest every spring. Please send your observations by Emailing the Museum at info@cablemuseum.org. Please be sure to include information about the observation, date, and location for our records.
Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.
Wednesday, April 1, 2009
Swan Song
Nature Watch
April 1, 2009
By Susan Benson,CNHM Director of Education
Who can forget the classic tale of the ugly duckling, where a homely little chick grows into a beautiful white swan? That “duckling” in the story was really a mute swan chick passing through its natural brownish phase before turning white.
The mute swan, commonly found along the East Coast and in parts of the Midwest, is the swan typically featured in artwork and folklore as a symbol of grace and beauty. However, many people consider this nonnative bird undesirable in North America because it harasses native waterfowl and can uproot large quantities of aquatic vegetation.
Mute swans were brought to the United States from Eurasia in the 1800s as ornamental additions to estates, parks and zoos. Over the years, many were released or escaped captivity and, by the 1970s, a resident population had established itself in Wisconsin and has been growing ever since.
By contrast, trumpeter swans were almost wiped out during the nineteenth century when they were hunted for their meat and feathers. By 1930, fewer than 100 Trumpeters remained in the United States, but a national effort to save the bird seems to have paid off. In 1989, trumpeter swans were reintroduced to Wisconsin and placed on the state endangered species list, and are now making a slow comeback.
Both the trumpeter and mute swans can be found in marshes, lakes and prairies, and both are about the same size, with a wingspan of up to eight feet and weight of up to 30 pounds. How can you tell the difference?
The mute swan is best identified by its orange bill and prominent black fleshy knob extending from the base of the bill to the forehead. Additionally, mute swans typically hold their necks in an S-curve with the bill pointed downward. Contrary to its name, this
bird is not silent, but utters a variety of calls, including grunts and snorts.
The trumpeter swan, by contrast, has a broad, black bill and holds its neck erect and head upright. True to its name, the trumpeter’s voice sounds like a horn. Trumpeter swans form pair bonds that last their entire lives wherever they spend their winter, and usually arrive on their breeding grounds soon after the ice melt in early spring. Once a pair has spent at least two summers at the same nesting location, they form a strong attachment to that site. When we are fortunate to see them they can be a strong reminder of our own attachments to the north woods.
For anyone looking to observe this beautiful trumpeter swan, a short drive can bring successful results. They can be seen along Pacwawong, part of the Namekagon River wetlands along 63 between Seeley and Cable, or in the wetlands along Mosquito Brook Road. Bring along your binoculars for an exciting view!
Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.
April 1, 2009
By Susan Benson,CNHM Director of Education
Who can forget the classic tale of the ugly duckling, where a homely little chick grows into a beautiful white swan? That “duckling” in the story was really a mute swan chick passing through its natural brownish phase before turning white.
The mute swan, commonly found along the East Coast and in parts of the Midwest, is the swan typically featured in artwork and folklore as a symbol of grace and beauty. However, many people consider this nonnative bird undesirable in North America because it harasses native waterfowl and can uproot large quantities of aquatic vegetation.
Mute swans were brought to the United States from Eurasia in the 1800s as ornamental additions to estates, parks and zoos. Over the years, many were released or escaped captivity and, by the 1970s, a resident population had established itself in Wisconsin and has been growing ever since.
By contrast, trumpeter swans were almost wiped out during the nineteenth century when they were hunted for their meat and feathers. By 1930, fewer than 100 Trumpeters remained in the United States, but a national effort to save the bird seems to have paid off. In 1989, trumpeter swans were reintroduced to Wisconsin and placed on the state endangered species list, and are now making a slow comeback.
Both the trumpeter and mute swans can be found in marshes, lakes and prairies, and both are about the same size, with a wingspan of up to eight feet and weight of up to 30 pounds. How can you tell the difference?
The mute swan is best identified by its orange bill and prominent black fleshy knob extending from the base of the bill to the forehead. Additionally, mute swans typically hold their necks in an S-curve with the bill pointed downward. Contrary to its name, this
bird is not silent, but utters a variety of calls, including grunts and snorts.
The trumpeter swan, by contrast, has a broad, black bill and holds its neck erect and head upright. True to its name, the trumpeter’s voice sounds like a horn. Trumpeter swans form pair bonds that last their entire lives wherever they spend their winter, and usually arrive on their breeding grounds soon after the ice melt in early spring. Once a pair has spent at least two summers at the same nesting location, they form a strong attachment to that site. When we are fortunate to see them they can be a strong reminder of our own attachments to the north woods.
For anyone looking to observe this beautiful trumpeter swan, a short drive can bring successful results. They can be seen along Pacwawong, part of the Namekagon River wetlands along 63 between Seeley and Cable, or in the wetlands along Mosquito Brook Road. Bring along your binoculars for an exciting view!
Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.
Wednesday, March 25, 2009
April Phenology
Nature Watch
March 25, 2009
By Susan Benson,CNHM Director of Education
The robins have returned! Museum members and Sawyer County Record readers have reported observations of having seen them Monday, March 16 (in Barnes) and Wednesday, March 11 (in Cable and Hayward.) Trumpeter swans were observed on Mosquito Brook Road on Tuesday, March 17. An American kestrel was observed in Ashland on Monday, March 16. Other observations of mergansers and mallards have filtered into the Museum. A flock of common loons was seen on Thursday, March 18 in Seeley. A first chipmunk was also reported to have been seen in Hayward early in the week. Spring is finally here, and April will bring along with it plenty of spring activities. Just how fast does spring move, and what can we have to look forward to seeing during the upcoming weeks?
March 20, dubbed as the first day of spring, is not the only indicator that spring has sprung. In the early part of the 20th century, an entomologist named Andrew Delmar Hopkins tried to describe the relationship of elevation, latitude and longitude to the coming of spring. Roughly speaking, Hopkins’ Law of Bioclimatics calculates that spring moves northward by about twelve miles per day. Elevation and longitude also factor in, predicting spring’s later arrival at higher elevations and westward longitudes. However spring travels, we are happy to see it arrive!
Bird migration is in full swing by April. During a typical spring, waterfowl and black bird species are usually the first birds back in large numbers. By late April, birdwatchers should be seeing new species just about every day. Some of the birds are seeking out nesting and breeding territories, while others are stopping to eat for a few days before continuing their northward journey.
Common loons should continue arriving in the north during April. These birds have been spending the winter along the Atlantic coast, but by mid- to end-March they will have ventured north of the Carolinas to begin their inland flight. During this flight loons need to follow rivers and lakes because they can’t land on anything other than water. The Great Lakes can also aid loon migration. The Great Lakes usually open up before our surrounding northern lakes, and loons gather on the Great Lakes, making frequent flights to search for open water. Consequently, a pair of loons might land on "their" lake minutes after the ice disappears because of these flights. The Great Lakes provide loons with a distinct advantage by offering them “first dibs” at choosing their preferred nesting habitat. Keep your eyes out as this bird flies overhead, presumably on their way to the great Lake Superior.
A few more signs of spring to watch for in April: spring peepers chirping, grouse drumming, bloodroot blooming, dandelions blooming, and ticks and mosquitoes biting. We want to hear about your phenological observations! Send your seasonal sightings to the Cable Natural History Museum through Email at info@cablemuseum.org. Please include information on the specific date and place in which you observed the natural sighting.
Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.
March 25, 2009
By Susan Benson,CNHM Director of Education
The robins have returned! Museum members and Sawyer County Record readers have reported observations of having seen them Monday, March 16 (in Barnes) and Wednesday, March 11 (in Cable and Hayward.) Trumpeter swans were observed on Mosquito Brook Road on Tuesday, March 17. An American kestrel was observed in Ashland on Monday, March 16. Other observations of mergansers and mallards have filtered into the Museum. A flock of common loons was seen on Thursday, March 18 in Seeley. A first chipmunk was also reported to have been seen in Hayward early in the week. Spring is finally here, and April will bring along with it plenty of spring activities. Just how fast does spring move, and what can we have to look forward to seeing during the upcoming weeks?
March 20, dubbed as the first day of spring, is not the only indicator that spring has sprung. In the early part of the 20th century, an entomologist named Andrew Delmar Hopkins tried to describe the relationship of elevation, latitude and longitude to the coming of spring. Roughly speaking, Hopkins’ Law of Bioclimatics calculates that spring moves northward by about twelve miles per day. Elevation and longitude also factor in, predicting spring’s later arrival at higher elevations and westward longitudes. However spring travels, we are happy to see it arrive!
Bird migration is in full swing by April. During a typical spring, waterfowl and black bird species are usually the first birds back in large numbers. By late April, birdwatchers should be seeing new species just about every day. Some of the birds are seeking out nesting and breeding territories, while others are stopping to eat for a few days before continuing their northward journey.
Common loons should continue arriving in the north during April. These birds have been spending the winter along the Atlantic coast, but by mid- to end-March they will have ventured north of the Carolinas to begin their inland flight. During this flight loons need to follow rivers and lakes because they can’t land on anything other than water. The Great Lakes can also aid loon migration. The Great Lakes usually open up before our surrounding northern lakes, and loons gather on the Great Lakes, making frequent flights to search for open water. Consequently, a pair of loons might land on "their" lake minutes after the ice disappears because of these flights. The Great Lakes provide loons with a distinct advantage by offering them “first dibs” at choosing their preferred nesting habitat. Keep your eyes out as this bird flies overhead, presumably on their way to the great Lake Superior.
A few more signs of spring to watch for in April: spring peepers chirping, grouse drumming, bloodroot blooming, dandelions blooming, and ticks and mosquitoes biting. We want to hear about your phenological observations! Send your seasonal sightings to the Cable Natural History Museum through Email at info@cablemuseum.org. Please include information on the specific date and place in which you observed the natural sighting.
Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.
Wednesday, March 18, 2009
Last Two Weeks of March Events
Nature Watch
March 18, 2009
By Susan Benson,CNHM Director of Education
Will spring please come? If we ask very nicely, would it consider showing its face? Could we ask for above zero temperatures at night? These might be the thoughts many of us are sharing right now. As we enter the week of the spring equinox, there is truly cause for much celebration, so break out the bubbly, hiking boots, and binoculars. There are many events in the next two weeks that could occur that should cheer us with thoughts of spring.
Maple sap flows when daily temperatures reach above forty degrees Fahrenheit.
Wood frogs begin calling and breeding the first day and night we have over fifty degrees Fahrenheit.
The first robins are usually seen in the last two weeks of March! Along with this come the first red-winged blackbirds, mourning doves, cardinals, American kestrels, common grackles, Canada geese, herring gulls, great blue herons, wood ducks, hooded mergansers, killdeers, mallards, song sparrows and other bird species. Bald eagle and sandhill crane migration has already begun. Tom turkeys begin gobbling. The American woodcock performs its first peent. Eastern phoebes can begin arriving around our houses. First bird nest making can be observed.
Pussy willows begin to bloom (although a Museum member brought in blooming willows this year on February 17!) Skunk cabbage can begin poking itself through the snow. The first crocus can bloom.
First chipmunks emerge from hibernation. The first garter and red-bellied snakes can warm up enough to be seen as well. Indications that skunks have left their den are apparent through the smells in the air.
Snow fleas can be seen more often, peppering the snow around the base of trees.
The first butterflies can be seen flitting about in the sunlight.
The Madeline Island Ferry in Bayfield sometimes has their first open water day in March.
The first thunderstorm could arrive this month.
I’m saving my favorite for last – the first bike ride. We have already had our first 45 degree or better days, which is, as some may recall from last fall, my minimum temperature allowance for my own bike rides. I vow to get out and ride my bike by this month’s end, and hope readers will consider doing the same!
How do I know all this? The Museum’s substantial phonological database is great evidence of these events happening year after year. If you have an exciting phenological observation you would like to share, please Email the Museum at info@cablemuseum.org. Please be sure to include information about the observation, date, and location for our records.
Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.
March 18, 2009
By Susan Benson,CNHM Director of Education
Will spring please come? If we ask very nicely, would it consider showing its face? Could we ask for above zero temperatures at night? These might be the thoughts many of us are sharing right now. As we enter the week of the spring equinox, there is truly cause for much celebration, so break out the bubbly, hiking boots, and binoculars. There are many events in the next two weeks that could occur that should cheer us with thoughts of spring.
Maple sap flows when daily temperatures reach above forty degrees Fahrenheit.
Wood frogs begin calling and breeding the first day and night we have over fifty degrees Fahrenheit.
The first robins are usually seen in the last two weeks of March! Along with this come the first red-winged blackbirds, mourning doves, cardinals, American kestrels, common grackles, Canada geese, herring gulls, great blue herons, wood ducks, hooded mergansers, killdeers, mallards, song sparrows and other bird species. Bald eagle and sandhill crane migration has already begun. Tom turkeys begin gobbling. The American woodcock performs its first peent. Eastern phoebes can begin arriving around our houses. First bird nest making can be observed.
Pussy willows begin to bloom (although a Museum member brought in blooming willows this year on February 17!) Skunk cabbage can begin poking itself through the snow. The first crocus can bloom.
First chipmunks emerge from hibernation. The first garter and red-bellied snakes can warm up enough to be seen as well. Indications that skunks have left their den are apparent through the smells in the air.
Snow fleas can be seen more often, peppering the snow around the base of trees.
The first butterflies can be seen flitting about in the sunlight.
The Madeline Island Ferry in Bayfield sometimes has their first open water day in March.
The first thunderstorm could arrive this month.
I’m saving my favorite for last – the first bike ride. We have already had our first 45 degree or better days, which is, as some may recall from last fall, my minimum temperature allowance for my own bike rides. I vow to get out and ride my bike by this month’s end, and hope readers will consider doing the same!
How do I know all this? The Museum’s substantial phonological database is great evidence of these events happening year after year. If you have an exciting phenological observation you would like to share, please Email the Museum at info@cablemuseum.org. Please be sure to include information about the observation, date, and location for our records.
Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.
Wednesday, March 11, 2009
Light Under Snow
Nature Watch
March 11, 2009
By Susan Benson,CNHM Director of Education
Sunlight. Daily, we feel its heat more strongly. It warms our hearts with thoughts of spring. Daylight savings springs ahead to give us more of that terrific sunlight. Even for life under the snow, interesting activities can still occur in the plant and animal world.
No matter how we look at or measure it, there is very little light that reaches underneath the winter snowpack. However, snow can absorb red light most effectively, and blue and blue-green light can reach even greater depths into the snowpack. As the snowpack density increases as snow and ice grains get closer together, more surfaces are created to scatter light and thereby increase light absorption lower into the snowpack. March is a time when this light penetration is often at its highest. It is sunlight absorption that is believed to assist in the spring germination of algae in alpine regions. Research of lichens in polar areas have shown that lichens can absorb water from snow and photosynthesize even in temperatures below 14 degrees Fahrenheit. Conifers have been observed taking in water during the winter – a study in Norway injected dye into a tree just above the snow surface, and found water moving upward. Dye has also been observed moving through roots of a silver birch that was in solid, frozen soil. Scientists still are not sure if the water was absorbed from frozen soil or if there are other ways in which this water movement occurs. Finally, seed germination of many plant species can occur even under the snow. This plant germination leads to some interesting events in the animal world as well.
Winter breeding can occur for some of our small mammals that live in the world under the snow (the subnivean layer.) Although having young might seem strange in the winter, this event might be tied to plant-animal interactions. As seeds germinate under the snow, gibberellic acid, a plant growth hormone is found inside those seeds. It is possible that the stimulus for winter mammal breeding might come from these seeds as they are eaten by an animal. All of this can happen from just a little more sun!
This information brings some new thoughts. Are plants under the snow that seem to still be green in the spring photosynthesize throughout the winter? For animals that never go through daylight savings changes, how do the lower light levels under the snow surface affect daily activity patterns? These are questions for the ecologists to continue to find answers. In the meantime, we can focus on getting outdoors and enjoying that sun!
Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.
March 11, 2009
By Susan Benson,CNHM Director of Education
Sunlight. Daily, we feel its heat more strongly. It warms our hearts with thoughts of spring. Daylight savings springs ahead to give us more of that terrific sunlight. Even for life under the snow, interesting activities can still occur in the plant and animal world.
No matter how we look at or measure it, there is very little light that reaches underneath the winter snowpack. However, snow can absorb red light most effectively, and blue and blue-green light can reach even greater depths into the snowpack. As the snowpack density increases as snow and ice grains get closer together, more surfaces are created to scatter light and thereby increase light absorption lower into the snowpack. March is a time when this light penetration is often at its highest. It is sunlight absorption that is believed to assist in the spring germination of algae in alpine regions. Research of lichens in polar areas have shown that lichens can absorb water from snow and photosynthesize even in temperatures below 14 degrees Fahrenheit. Conifers have been observed taking in water during the winter – a study in Norway injected dye into a tree just above the snow surface, and found water moving upward. Dye has also been observed moving through roots of a silver birch that was in solid, frozen soil. Scientists still are not sure if the water was absorbed from frozen soil or if there are other ways in which this water movement occurs. Finally, seed germination of many plant species can occur even under the snow. This plant germination leads to some interesting events in the animal world as well.
Winter breeding can occur for some of our small mammals that live in the world under the snow (the subnivean layer.) Although having young might seem strange in the winter, this event might be tied to plant-animal interactions. As seeds germinate under the snow, gibberellic acid, a plant growth hormone is found inside those seeds. It is possible that the stimulus for winter mammal breeding might come from these seeds as they are eaten by an animal. All of this can happen from just a little more sun!
This information brings some new thoughts. Are plants under the snow that seem to still be green in the spring photosynthesize throughout the winter? For animals that never go through daylight savings changes, how do the lower light levels under the snow surface affect daily activity patterns? These are questions for the ecologists to continue to find answers. In the meantime, we can focus on getting outdoors and enjoying that sun!
Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.
Wednesday, March 4, 2009
Snowshoe Hike
Nature Watch
March 4, 2009
By Susan Benson,CNHM Director of Education
This past week the third grade from Hayward Community Schools visited the Cable Natural History Museum for a Museum visit and snowshoe trek. The outdoor exploration began at the North End Trail, where there is an excellent snowshoe Ridge Trail that I highly recommend to other snowshoe fanatics. The goal of this experience was for the students to learn how to snowshoe while discovering animal tracks and signs. We discovered some really neat animal tracks that others out in the forest could experience themselves. We used signs and clues the animals left behind to determine what they were.
The first signs we discovered were very small tracks from an animal that hops from tree to tree making shallow imprints in the snow. Sometimes the tracks vanished in the snow as if the animal disappeared into thin air. Some of the tracks we observed had prominent trail drags between their legs, and in other tracks the trail marks were less visible. Using these clues, we determined that two different animals were moving through the forest: voles and white-footed mice. Following these observations, I did a little research on these two common critters that seemed worth sharing.
Voles are small rodents a little larger than a mouse that are active during the day or night, and in winter are more often moving during the day. Two species in this area are the red-backed vole and meadow vole. These small mammals can reach speeds up to 5 or 6 miles per hour. Meadow voles are known as great swimmers, where they can end up as prey for musky and pike. As an extremely common species in the northwoods, there can be several hundred voles per acre as they can have large litters, several times per year.
In the winter both species of voles live under the snow where it is warmer than the open air. They eat vegetation, and gnaw on the bark of shrubs for food, often leaving behind tiny tooth marks. At North End Trail, there were tiny tracks on the snow surface marking where they had been. The third graders also observed the vole tracks disappearing as they entered a hole in the snow to head down to the ground, or subnivean layer below. It is under the snow where they create a large number of runways or tunnels throughout the winter as they forage for food or huddle together for warmth.
Other tracks the third graders observed this week were likely that of the white-footed mouse. This mouse can be quite acrobatic, able to climb trees, and sometimes finding an old bird’s nest to rebuild and use as its own throughout winter. The white-footed mouse is active at night except during times of scarce food supplies. They do not make tunnels under the snow like voles, but will use vole tunnels for their own travel. When traveling on land (or snow) they gallop, leaving a tiny track that resembles a tiny rabbit. Their tail drag between their feet is quite noticeable.
One of the most interesting habits of the white-footed mouse is their winter food and feeding behaviors. This time of year they eat nuts from shrubs and trees such as pine, spruce, hazelnut, walnut, beech, oak, and a variety of wildflower seeds. They also find beetles, moths, or flies in their adult or larval stages they find while traveling through the tunnels of other rodents. Food is important in winter, as small rodents such as the white-footed mouse need more food in proportion to their weight than do larger warm-blooded animals in order to conserve heat. They make caches during all parts of the year, but particularly in the fall. They often take the outer husk off and store the inner nut or tree seeds, sometimes leaving up to a pint or quart of food in their cache. Evidence of these caches can be found in log piles, knotholes, or under rocks (sometimes in our houses as well.) Sometimes the caches are two to four inches underground in small piles. One large cache found had eight quarts of nuts. What a store of winter food that must be!
Become a track detective. When you are next out for your own snowshoe trek, or a walk along the road, see if you can find tracks and traces of these two small mammals. Another thing to look for is their long snow tracks, visible as a mound of snow, where voles have made their runways under but closer to the surface of the snow. Some winter evening, when you are outside in the quiet woods, listen for soft scratching on a tree trunk or in leaf litter. It might be a white-footed mouse searching for his midnight snack. This spring, watch for vole runways near the ground as the snow melts. While on the search for vole or mice tracks who knows what else you might discover!
Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.
March 4, 2009
By Susan Benson,CNHM Director of Education
This past week the third grade from Hayward Community Schools visited the Cable Natural History Museum for a Museum visit and snowshoe trek. The outdoor exploration began at the North End Trail, where there is an excellent snowshoe Ridge Trail that I highly recommend to other snowshoe fanatics. The goal of this experience was for the students to learn how to snowshoe while discovering animal tracks and signs. We discovered some really neat animal tracks that others out in the forest could experience themselves. We used signs and clues the animals left behind to determine what they were.
The first signs we discovered were very small tracks from an animal that hops from tree to tree making shallow imprints in the snow. Sometimes the tracks vanished in the snow as if the animal disappeared into thin air. Some of the tracks we observed had prominent trail drags between their legs, and in other tracks the trail marks were less visible. Using these clues, we determined that two different animals were moving through the forest: voles and white-footed mice. Following these observations, I did a little research on these two common critters that seemed worth sharing.
Voles are small rodents a little larger than a mouse that are active during the day or night, and in winter are more often moving during the day. Two species in this area are the red-backed vole and meadow vole. These small mammals can reach speeds up to 5 or 6 miles per hour. Meadow voles are known as great swimmers, where they can end up as prey for musky and pike. As an extremely common species in the northwoods, there can be several hundred voles per acre as they can have large litters, several times per year.
In the winter both species of voles live under the snow where it is warmer than the open air. They eat vegetation, and gnaw on the bark of shrubs for food, often leaving behind tiny tooth marks. At North End Trail, there were tiny tracks on the snow surface marking where they had been. The third graders also observed the vole tracks disappearing as they entered a hole in the snow to head down to the ground, or subnivean layer below. It is under the snow where they create a large number of runways or tunnels throughout the winter as they forage for food or huddle together for warmth.
Other tracks the third graders observed this week were likely that of the white-footed mouse. This mouse can be quite acrobatic, able to climb trees, and sometimes finding an old bird’s nest to rebuild and use as its own throughout winter. The white-footed mouse is active at night except during times of scarce food supplies. They do not make tunnels under the snow like voles, but will use vole tunnels for their own travel. When traveling on land (or snow) they gallop, leaving a tiny track that resembles a tiny rabbit. Their tail drag between their feet is quite noticeable.
One of the most interesting habits of the white-footed mouse is their winter food and feeding behaviors. This time of year they eat nuts from shrubs and trees such as pine, spruce, hazelnut, walnut, beech, oak, and a variety of wildflower seeds. They also find beetles, moths, or flies in their adult or larval stages they find while traveling through the tunnels of other rodents. Food is important in winter, as small rodents such as the white-footed mouse need more food in proportion to their weight than do larger warm-blooded animals in order to conserve heat. They make caches during all parts of the year, but particularly in the fall. They often take the outer husk off and store the inner nut or tree seeds, sometimes leaving up to a pint or quart of food in their cache. Evidence of these caches can be found in log piles, knotholes, or under rocks (sometimes in our houses as well.) Sometimes the caches are two to four inches underground in small piles. One large cache found had eight quarts of nuts. What a store of winter food that must be!
Become a track detective. When you are next out for your own snowshoe trek, or a walk along the road, see if you can find tracks and traces of these two small mammals. Another thing to look for is their long snow tracks, visible as a mound of snow, where voles have made their runways under but closer to the surface of the snow. Some winter evening, when you are outside in the quiet woods, listen for soft scratching on a tree trunk or in leaf litter. It might be a white-footed mouse searching for his midnight snack. This spring, watch for vole runways near the ground as the snow melts. While on the search for vole or mice tracks who knows what else you might discover!
Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.
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