Nature Watch
May 6, 2008
By Susan Benson, CNHM Director of Education
Could we have had a record snowfall in April this year? It surely felt like it, and let us hope that the snow is behind us, as May is perhaps the most exciting month for regional phenologists. Many northern Wisconsin bird species have returned and some of the later species such as warblers and shorebirds are on their way, either to develop territories here or rest briefly before heading to final destinations farther north. May forests are full of bird songs, most of them sung by males. In most cases, the males will stake out a territory and use their call to attract a female of that species to them. By now it’s likely that sandhill cranes have built a nest near open water in a grassy area. The fuzzy yellow-brown chicks are born within 30 days so should be hatching in mid-May. White-throated sparrow, tree sparrows, and song sparrows have arrived. May 7-15 is when Museum phenologists have recorded hummingbirds as having returned to this area.
Listen in the evening for the male American woodcock, which has the most elaborate display to attract females. One of my most favorite spring activities is to sneak up close enough to observe this ritual. The male gives repeated "peents" on the ground, stomps his feet, dips his bill, and then turns and repeats the sound and motion in several directions. After several buzzes the woodcock leaps into the air. As he gets higher, his wings begin to whistle using his outer primary wing feathers; he continues to climb in wide spirals until he's almost out of sight. He comes down in a zig-zag, diving fashion, chirping as he goes. After landing he buzzes again, and if he's lucky a female joins him. Males repeat this performance up to twenty times during an evening.
During some years (that have less April snow), a few species of flowers have already bloomed during April, while others make their first appearance in May. Dandelions are among the first plants to pop up in the spring, and I have observed them blooming in Ashland. Species such as hepatica and bloodroot should be blooming soon; other species such as starflower, trillium, lilac, blue-bead lily, Canada mayflower, forget-me-nots and marsh marigold will be seen during the coming weeks.
Keep your eyes out in the forest for one of my favorite signs of spring, the blooming leatherwood, a woody shrub that grows up to 8 feet, but is usually smaller. The small, yellow bell flowers are delicate and beautiful. As its name suggests, the stems are soft, leathery and very pliable, yet still very strong; the stems can actually be tied into knots. The bark is fibrous and can be peeled off in strips and woven into twine.
Most insects should be hopping, buzzing, crawling and flying around by now. The abundance of mosquitoes can be at its highest during May, due to the spring ponds, puddles and other wet areas where they lay their eggs. In Wisconsin, dragonfly nymphs change into adults two different times a year. The spring species emerge all at once in May and early June when the days grow longer and temperatures get warmer. The summer species develop at separate times throughout late June, July, and August.
When will you record your first mosquito this season? Email your spring observations to the Museum at info@cablemuseum.org and be sure to include information on the date observed, name, and the town in which you made your observations.
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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.
Tuesday, May 6, 2008
Thursday, May 1, 2008
Frogs & Butterflies
Nature WatchMay 1, 2008
By Susan Benson,
CNHM Director of Education
Although snow seems to want to stay, there are still many signs that tell us winter is coming to an end. Really! The loud, peeping chorus of spring peepers was heard last week. These frogs are among the very first to call and breed in the spring, often beginning when there is still ice on our lakes and snow on the ground. These frogs are found in temporary (vernal) spring ponds, or permanent ponds, marshes and ditches; following the breeding season they move into woodlands or fields. Peepers are easier to identify because they call out their name – peep, peep, peep. Sometimes peepers call while sitting under grass clumps or in crevices in the earth, allowing them to amplify their call; this technique also makes it difficult to track exactly from where the sound is coming. Other frogs to keep your ears out for include the western chorus frog that sounds like a person’s thumb pulling down a comb; the wood frog is said to sound a little like a squeaky duck quacking.
Last week’s warmth brought out a lot of butterflies. One of the most common during the warm spring days is the mourning cloak, black with yellow on the edges. These insects hibernate as adults, secreting natural antifreezes such as sorbitol into their bodies as the weather cools. They then find shelter under loose bark, in debris, or in a crevice under a roof overhang. Now, in the spring, mourning cloaks are the first to come out as their dark colors experience solar heating. Their spring food includes mostly tree sap, especially that of oaks. They walk down the trunk to the sap and feed head downward. Males will bask in the spring sun awaiting receptive females. Eggs are laid in groups circling twigs of the host plant. Caterpillars live in a communal web and feed together on young leaves, then pupate and emerge as adults in June or July. Due to their hibernation, the mourning cloak has a greatly extended adult span. While a period of about two weeks is a typical life span for most adult butterflies, mourning cloak adults live for up to eleven months. Other butterflies to keep an eye out for include the Milbert’s tortoise shell, red admirals, and the small blue spring azure.
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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.
By Susan Benson,
CNHM Director of Education
Although snow seems to want to stay, there are still many signs that tell us winter is coming to an end. Really! The loud, peeping chorus of spring peepers was heard last week. These frogs are among the very first to call and breed in the spring, often beginning when there is still ice on our lakes and snow on the ground. These frogs are found in temporary (vernal) spring ponds, or permanent ponds, marshes and ditches; following the breeding season they move into woodlands or fields. Peepers are easier to identify because they call out their name – peep, peep, peep. Sometimes peepers call while sitting under grass clumps or in crevices in the earth, allowing them to amplify their call; this technique also makes it difficult to track exactly from where the sound is coming. Other frogs to keep your ears out for include the western chorus frog that sounds like a person’s thumb pulling down a comb; the wood frog is said to sound a little like a squeaky duck quacking.
Last week’s warmth brought out a lot of butterflies. One of the most common during the warm spring days is the mourning cloak, black with yellow on the edges. These insects hibernate as adults, secreting natural antifreezes such as sorbitol into their bodies as the weather cools. They then find shelter under loose bark, in debris, or in a crevice under a roof overhang. Now, in the spring, mourning cloaks are the first to come out as their dark colors experience solar heating. Their spring food includes mostly tree sap, especially that of oaks. They walk down the trunk to the sap and feed head downward. Males will bask in the spring sun awaiting receptive females. Eggs are laid in groups circling twigs of the host plant. Caterpillars live in a communal web and feed together on young leaves, then pupate and emerge as adults in June or July. Due to their hibernation, the mourning cloak has a greatly extended adult span. While a period of about two weeks is a typical life span for most adult butterflies, mourning cloak adults live for up to eleven months. Other butterflies to keep an eye out for include the Milbert’s tortoise shell, red admirals, and the small blue spring azure.
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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.
Thursday, April 24, 2008
Phoebes & Juncos
Nature Watch
April 24, 2008
By Susan Benson,
CNHM Director of Education
Hellos and Goodbyes
I said “hello” this week to one of my best friends, and welcomed her back to my home in the woods. Her name is Phoebe. Some might know her as the Greek goddess of the moon, or the interesting character from the sitcom Friends. She arrived this past Wednesday, April 16, and will spend her next few months visiting me and talking with me every day. Technically, her name is Eastern phoebe. Any birder knows who I am talking of, the bold bird friend that can be observed from the arctic circle to the equator. Phoebe is one of the New World flycatchers and is a very aggressive insectivore, better known to me as the bird with a tremendous personality.
Phoebe’s color is a gray-brown, and she is a sparrow-like flycatcher with a light breast and a black bill. Every morning she greets me with her two syllable “fee-bee,” “fee-bee.” The first “fee-bee” goes down in pitch, and the second goes up. While some people might nod their heads at me in greeting, Phoebe has the habit of greeting me while bobbing her tail downward and upward again. She has a few places in my yard that seem to be her favorite perches every year, and she never appears to mind my human presence. This is one species that seems to thrive among any kind of development.
We share the same house. Every year Phoebe finds a sheltered spot under the eaves of my house to make her nest, although some birds will consider a porch or even inside a barn. Six inches square is about all she needs to build upon, and moss and mud seems to be two of her most common nest-building materials. She doesn’t like it when I get near her nest, but each year I check in on her young to make sure they’re doing well. Phoebes are common cowbird hosts, and to combat this parasitic bird species, phoebes sometimes will build a new nest floor over top of cowbird eggs.
The eastern phoebe is the first flycatcher to arrive up north in the spring. Why does the phoebe come back so early and how does it survive when there are no insects to eat? The first field guide I looked at says that phoebes also eat berries and seeds, mostly in winter; insects and the occasional small fish or frog during other times. Phoebes also don’t go very far south for the winter, flying only to the southern United States. All other flycatchers winter in Central or South America and do not show up here until May when insects are available here.
At the same time I am greeting the phoebes around my house, I am also saying goodbye to the slate-colored juncos. Sunday morning I went for a short walk and was serenaded by the flash and song of what seemed like 40 or more juncos. This bird is a delightful uniform pale gray bird with its upperparts sharply defined against its white belly, aptly described as "leaden skies above, snow below." During the fall these small birds will fly south to inhabit much of the United States and northern Mexico in their winter flocks. During winter they will become frequent visitors to the yards of homes where food has been put out, preferring to scratch the ground for an easier meal.
Spring migration begins in around April 7th-12th as juncos fly over much of the eastern and Midwestern states on their journey north to Alaska and Canada. These birds will build up fat reserves before migrating in the spring, and will move northward rapidly in flocks of up to 100 birds. They will sometimes be accompanied by other sparrows. Male juncos will usually arrive early to establish territory for their nests. I say goodbye to these birds now, knowing they will soon find themselves the summer companion of the canoeist in the Canadian forests.
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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.
April 24, 2008
By Susan Benson,
CNHM Director of Education
Hellos and Goodbyes
I said “hello” this week to one of my best friends, and welcomed her back to my home in the woods. Her name is Phoebe. Some might know her as the Greek goddess of the moon, or the interesting character from the sitcom Friends. She arrived this past Wednesday, April 16, and will spend her next few months visiting me and talking with me every day. Technically, her name is Eastern phoebe. Any birder knows who I am talking of, the bold bird friend that can be observed from the arctic circle to the equator. Phoebe is one of the New World flycatchers and is a very aggressive insectivore, better known to me as the bird with a tremendous personality.
Phoebe’s color is a gray-brown, and she is a sparrow-like flycatcher with a light breast and a black bill. Every morning she greets me with her two syllable “fee-bee,” “fee-bee.” The first “fee-bee” goes down in pitch, and the second goes up. While some people might nod their heads at me in greeting, Phoebe has the habit of greeting me while bobbing her tail downward and upward again. She has a few places in my yard that seem to be her favorite perches every year, and she never appears to mind my human presence. This is one species that seems to thrive among any kind of development.
We share the same house. Every year Phoebe finds a sheltered spot under the eaves of my house to make her nest, although some birds will consider a porch or even inside a barn. Six inches square is about all she needs to build upon, and moss and mud seems to be two of her most common nest-building materials. She doesn’t like it when I get near her nest, but each year I check in on her young to make sure they’re doing well. Phoebes are common cowbird hosts, and to combat this parasitic bird species, phoebes sometimes will build a new nest floor over top of cowbird eggs.
The eastern phoebe is the first flycatcher to arrive up north in the spring. Why does the phoebe come back so early and how does it survive when there are no insects to eat? The first field guide I looked at says that phoebes also eat berries and seeds, mostly in winter; insects and the occasional small fish or frog during other times. Phoebes also don’t go very far south for the winter, flying only to the southern United States. All other flycatchers winter in Central or South America and do not show up here until May when insects are available here.
At the same time I am greeting the phoebes around my house, I am also saying goodbye to the slate-colored juncos. Sunday morning I went for a short walk and was serenaded by the flash and song of what seemed like 40 or more juncos. This bird is a delightful uniform pale gray bird with its upperparts sharply defined against its white belly, aptly described as "leaden skies above, snow below." During the fall these small birds will fly south to inhabit much of the United States and northern Mexico in their winter flocks. During winter they will become frequent visitors to the yards of homes where food has been put out, preferring to scratch the ground for an easier meal.
Spring migration begins in around April 7th-12th as juncos fly over much of the eastern and Midwestern states on their journey north to Alaska and Canada. These birds will build up fat reserves before migrating in the spring, and will move northward rapidly in flocks of up to 100 birds. They will sometimes be accompanied by other sparrows. Male juncos will usually arrive early to establish territory for their nests. I say goodbye to these birds now, knowing they will soon find themselves the summer companion of the canoeist in the Canadian forests.
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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.
Thursday, April 17, 2008
April
Nature Watch
April 17, 2008
By Susan Benson,
CNHM Director of Education
April showers have not exactly been on our list of weather events so far this month, but we are all wishing for them! Here is the good news. 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 12 miles per day. Elevation and longitude also factor in, predicting spring’s later arrival at higher elevations and westward longitudes.
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. During 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. My own observations have been: April 3, turkey vulture; April 4, first robin and killdeers; April 7, great blue heron and kestrels; April 8, wood ducks and hooded mergansers; April 9, mallard duck; April 10, a pair of crows, the male flying a circle to attract the female; April 11, reports came in via the phone during the blizzard that red-winged blackbirds, grackles and many other bird species were flocking to bird feeders for sustenance.
Common loons should be arriving in the north this month. These birds have been spending the winter along the Atlantic coast; by the end of 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.
In spite of all this spring snow, there are a few more signs of spring we should continue to look forward to seeing or hearing soon: spring peepers chirping, grouse drumming, bloodroot blooming, dandelions blooming, and our favorites – ticks and mosquitoes biting. Do you have your own spring phenology observations you have been recording? Send your Email to the Museum to info@cablemuseum.org and we will include your data in our phenology database. Please be sure to record your name, name of observation, the date sited, and town in which you observed the animal or plant species.
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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.
April 17, 2008
By Susan Benson,
CNHM Director of Education
April showers have not exactly been on our list of weather events so far this month, but we are all wishing for them! Here is the good news. 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 12 miles per day. Elevation and longitude also factor in, predicting spring’s later arrival at higher elevations and westward longitudes.
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. During 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. My own observations have been: April 3, turkey vulture; April 4, first robin and killdeers; April 7, great blue heron and kestrels; April 8, wood ducks and hooded mergansers; April 9, mallard duck; April 10, a pair of crows, the male flying a circle to attract the female; April 11, reports came in via the phone during the blizzard that red-winged blackbirds, grackles and many other bird species were flocking to bird feeders for sustenance.
Common loons should be arriving in the north this month. These birds have been spending the winter along the Atlantic coast; by the end of 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.
In spite of all this spring snow, there are a few more signs of spring we should continue to look forward to seeing or hearing soon: spring peepers chirping, grouse drumming, bloodroot blooming, dandelions blooming, and our favorites – ticks and mosquitoes biting. Do you have your own spring phenology observations you have been recording? Send your Email to the Museum to info@cablemuseum.org and we will include your data in our phenology database. Please be sure to record your name, name of observation, the date sited, and town in which you observed the animal or plant species.
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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.
Wednesday, April 9, 2008
Sandhill Cranes
Nature Watch
April 9, 2008
By Sue Benson,
Director of Education, CNHM
Six-million-year-old fossils unearthed in Nebraska make sandhill cranes the oldest living species of bird in the world, according to the International Crane Foundation (ICF). And it’s not hard to think of these animals as living fossils. With large bodies, long necks, stilt-like legs, and wingspans that can exceed six feet, the sandhill doesn’t have a lot of avian contemporaries on the Wisconsin landscape.
To many people, the distinctive, repeated k-r-r-r-oo call of early migrating sandhills ranks with the cry of the loon or the howl of a wolf as one of the fundamental resonances of nature. Wallace Grange, the early Wisconsin wildlife biologist whose personal land restoration effort later became the state’s Sandhill Wildlife Area, understood all this when he described a flock of sandhills as “a trace of colorful arrows gliding across time.”
These surprisingly graceful birds were once nearly relegated to fossil status in the state. Sixty-five years ago, it is believed that Wisconsin’s population had fallen to perhaps only 25 breeding pairs, centered in a few south-central counties. Their population had plummeted in response to excessive hunting and the loss of the wetland habitats upon which they depend for food and nesting sites.
Fortunately, with protection from hunting, greater protection and restoration of the state’s wetlands, and perhaps some behavioral changes by the birds themselves (adapting to breed in smaller wetlands and forage in agricultural fields), this tenuous population slowly began to expand. The expansion accelerated, and in the last 25 years a substantial rebound has taken place. In 2007, the Annual Midwest Sandhill Crane Count, sponsored by the ICF, tallied 13,764 cranes in Wisconsin and a total of 14,662 in Wisconsin and neighboring states.
The Sandhill Crane does not breed until it is two to seven years old. It can live up to the age of 20. Mated pairs of cranes participate in unison calling, a complex and extended series of coordinated calls. While calling, cranes stand in an upright posture, usually with their heads thrown back and beaks skyward during the display. Mated pairs stay together year round, and migrate as a group with their offspring. In some areas, wild sandhills preen iron-rich mud into their feathers, creating a rusty brown color which lasts throughout spring and summer. During fall these colored feathers molt and the birds return to their grayish appearance.
Although still an infrequent breeder in Wisconsin’s northern counties, local observations of sandhills are not the unlikely happenstance that they were just a decade ago. Sandhills are most active at dawn and dusk. Look and listen for them in wetlands, or nearby agricultural fields where they may forage for newly sprouting corn or worms and insects in the soil. Scan fields carefully with binoculars or look for movement; despite their size they blend in remarkably into a background of recently tilled soil, especially when the light is low. In flight, cranes fly with their necks extended and their legs trailing, in what has been called a “flying cross.”
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. They invite you to visit their facility in Cable on 43570 Kavanaugh Street or at the website at http://www.cablemuseum.org/ to learn more about their exhibits and programs.
April 9, 2008
By Sue Benson,
Director of Education, CNHM
Six-million-year-old fossils unearthed in Nebraska make sandhill cranes the oldest living species of bird in the world, according to the International Crane Foundation (ICF). And it’s not hard to think of these animals as living fossils. With large bodies, long necks, stilt-like legs, and wingspans that can exceed six feet, the sandhill doesn’t have a lot of avian contemporaries on the Wisconsin landscape.
To many people, the distinctive, repeated k-r-r-r-oo call of early migrating sandhills ranks with the cry of the loon or the howl of a wolf as one of the fundamental resonances of nature. Wallace Grange, the early Wisconsin wildlife biologist whose personal land restoration effort later became the state’s Sandhill Wildlife Area, understood all this when he described a flock of sandhills as “a trace of colorful arrows gliding across time.”
These surprisingly graceful birds were once nearly relegated to fossil status in the state. Sixty-five years ago, it is believed that Wisconsin’s population had fallen to perhaps only 25 breeding pairs, centered in a few south-central counties. Their population had plummeted in response to excessive hunting and the loss of the wetland habitats upon which they depend for food and nesting sites.
Fortunately, with protection from hunting, greater protection and restoration of the state’s wetlands, and perhaps some behavioral changes by the birds themselves (adapting to breed in smaller wetlands and forage in agricultural fields), this tenuous population slowly began to expand. The expansion accelerated, and in the last 25 years a substantial rebound has taken place. In 2007, the Annual Midwest Sandhill Crane Count, sponsored by the ICF, tallied 13,764 cranes in Wisconsin and a total of 14,662 in Wisconsin and neighboring states.
The Sandhill Crane does not breed until it is two to seven years old. It can live up to the age of 20. Mated pairs of cranes participate in unison calling, a complex and extended series of coordinated calls. While calling, cranes stand in an upright posture, usually with their heads thrown back and beaks skyward during the display. Mated pairs stay together year round, and migrate as a group with their offspring. In some areas, wild sandhills preen iron-rich mud into their feathers, creating a rusty brown color which lasts throughout spring and summer. During fall these colored feathers molt and the birds return to their grayish appearance.
Although still an infrequent breeder in Wisconsin’s northern counties, local observations of sandhills are not the unlikely happenstance that they were just a decade ago. Sandhills are most active at dawn and dusk. Look and listen for them in wetlands, or nearby agricultural fields where they may forage for newly sprouting corn or worms and insects in the soil. Scan fields carefully with binoculars or look for movement; despite their size they blend in remarkably into a background of recently tilled soil, especially when the light is low. In flight, cranes fly with their necks extended and their legs trailing, in what has been called a “flying cross.”
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. They invite you to visit their facility in Cable on 43570 Kavanaugh Street or at the website at http://www.cablemuseum.org/ to learn more about their exhibits and programs.
Wednesday, April 2, 2008
Spring Migration
Nature Watch
April 2, 2008
By Susan Benson,
CNHM, Director of Education
The days are longer, snow is melting, and temperatures are rising. For many of us, though, spring isn’t official until we see the return of our favorite migratory birds. Perhaps yours may be the American robin or the redwinged blackbird, or maybe you scan the thawing waterways for returning mallards, goldeneyes or mergansers. Bird migration has mystified humans for a long time. The Greek philosopher Aristotle believed that redstarts actually changed into robins in the winter. As recently as 200 years ago, it was thought that swallows and other migrants spent the winter in hibernation. Only recently have we begun to understand what migrating birds have been doing and why. We now know that almost the entire planet is criss-crossed by migration routes that lead in all directions, not just north and south. Each year some birds nearly encircle the globe in their travels from winter quarters to summer breeding areas and back again. Some of your human neighbors spend winter in the south, most likely because they prefer warm weather. A bird’s seasonal movements — and for that matter the migratory motivation of many other creatures including insects, fishes and mammals — are not strictly related to the temperature. In fact, most birds are well equipped to survive the cold. Migration is motivated by a search for food. In the fall, many birds depart northern regions in search of more reliable food sources. Come spring, these birds return north with the increasing availability of the tasty insects, fruits or small animals they eat. It might seem that birds would do well to stay in warm regions with plentiful food year-round. They return northward, however, for good reasons. Tropical days are only 12 hours long, but days in the north may reach 16 hours or more — that means more time for gathering food. Northward migration also expands a bird’s available nesting and food gathering area. Some birds do stay in the south, but merely expand their range to the north in summer.
Finally, migration helps protect birds from predation. A predator that relies on a certain bird for its prey will not thrive if that prey regularly leaves for months at a time. We still have much to learn about how birds pull off their amazing migratory journeys. How do they find their way, year after year, on trips that can cover hundreds or thousands of miles? Most researchers agree that birds use a variety of navigational tools, including visual recognition of geographic features like rivers, coastlines and mountain ranges; sensitivity to earth's magnetic field using tiny grains of a mineral called magnetite found in birds’ heads; use of the sun and stars for guidance; and simply by following other birds.
The first birds are already arriving; trumpeter swans were in Pacwawong just north of Seeley on March 17, Canada geese on March 30, and many reports are coming in to the Museum about bald eagles, first robins, and other animal species. Keep your eyes out and upward to make your own observations!
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. They invite you to visit their facility in Cable on 43570 Kavanaugh Street or at the website at www.cablemuseum.org to learn more about their exhibits and programs.
April 2, 2008
By Susan Benson,
CNHM, Director of Education
The days are longer, snow is melting, and temperatures are rising. For many of us, though, spring isn’t official until we see the return of our favorite migratory birds. Perhaps yours may be the American robin or the redwinged blackbird, or maybe you scan the thawing waterways for returning mallards, goldeneyes or mergansers. Bird migration has mystified humans for a long time. The Greek philosopher Aristotle believed that redstarts actually changed into robins in the winter. As recently as 200 years ago, it was thought that swallows and other migrants spent the winter in hibernation. Only recently have we begun to understand what migrating birds have been doing and why. We now know that almost the entire planet is criss-crossed by migration routes that lead in all directions, not just north and south. Each year some birds nearly encircle the globe in their travels from winter quarters to summer breeding areas and back again. Some of your human neighbors spend winter in the south, most likely because they prefer warm weather. A bird’s seasonal movements — and for that matter the migratory motivation of many other creatures including insects, fishes and mammals — are not strictly related to the temperature. In fact, most birds are well equipped to survive the cold. Migration is motivated by a search for food. In the fall, many birds depart northern regions in search of more reliable food sources. Come spring, these birds return north with the increasing availability of the tasty insects, fruits or small animals they eat. It might seem that birds would do well to stay in warm regions with plentiful food year-round. They return northward, however, for good reasons. Tropical days are only 12 hours long, but days in the north may reach 16 hours or more — that means more time for gathering food. Northward migration also expands a bird’s available nesting and food gathering area. Some birds do stay in the south, but merely expand their range to the north in summer.
Finally, migration helps protect birds from predation. A predator that relies on a certain bird for its prey will not thrive if that prey regularly leaves for months at a time. We still have much to learn about how birds pull off their amazing migratory journeys. How do they find their way, year after year, on trips that can cover hundreds or thousands of miles? Most researchers agree that birds use a variety of navigational tools, including visual recognition of geographic features like rivers, coastlines and mountain ranges; sensitivity to earth's magnetic field using tiny grains of a mineral called magnetite found in birds’ heads; use of the sun and stars for guidance; and simply by following other birds.
The first birds are already arriving; trumpeter swans were in Pacwawong just north of Seeley on March 17, Canada geese on March 30, and many reports are coming in to the Museum about bald eagles, first robins, and other animal species. Keep your eyes out and upward to make your own observations!
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. They invite you to visit their facility in Cable on 43570 Kavanaugh Street or at the website at www.cablemuseum.org to learn more about their exhibits and programs.
Friday, March 28, 2008
Bats
Nature Watch
August 13, 2008
By Susan Benson,
CNHM Director of Education
While sitting out on a pleasant summer night, you might hear the whisper of wings or catch a glimpse of small dark objects careening through the sky. To many, the fleeting sight of a bat evokes a range of fears, most of which are unfounded.
Bats are the only flying mammals – in fact, the 950 different species of bats worldwide represent about 20 percent of all the planet’s mammal species. As with other mammals, bats nurse their young on milk. Bats also are quite clean; they groom themselves frequently, much as a cat does.
“Eek! They want to get caught in my hair, or suck my blood” is a common misconception. Only three bat species eat blood, and only very rarely is that human blood. The two main groups of bats include the “mega-bats,” or fruit bats, that eat fruit, nectar and pollen. The larger group of “micro-bats” eats insects. They navigate and hunt by a system called echolocation, whereby they emit sound waves that bounce off of objects and return as an echo, allowing the bat to fly about safety and locate prey. Wisconsin is home to seven bat species, all of them insect eaters.
On warm summer nights, you might consider the little brown bat, a Wisconsin native, an ally because it can catch and consume up to 600 mosquitoes per hour. Little brown bats (Myotis lucifugus) are the most common Myotis species in the northern two-thirds of the United States. Often found in tree hollows and buildings during the summer, it can roost with big brown bats. It is most likely found near water sources. In winter, it hibernates. The big brown bat is another common and widespread species of bats throughout North America. It roosts in colonies in tree hollows and buildings. As it is more tolerant of cold conditions than other resident bats, it is the only one that overwinters in walls and attics.
Bats cause humans little harm, especially compared to the disturbances they’ve suffered as a result of human activity. Many bats die from eating contaminated insects. Fear and ignorance have led to bat eradication campaigns by individuals and even governments. Some logging, development and agricultural practices can drastically reduce bats’ natural habitat.
Bats may find their way into buildings, looking for safe roosting habitat. If a bat should get into your home, open a window or door and allow it to find its own way out. If it cannot, wait until it has landed, then using a glove or towel, gently catch the bat and release it outside. The best way to remove roosting bats from attics or other areas is to find and seal their entry points after they have left for nightly feeding or in the fall after they have migrated.
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 43570 Kavanaugh Street or on the web at http://www.cablemuseum.org/ to learn more about exhibits and programs.
August 13, 2008
By Susan Benson,
CNHM Director of Education
While sitting out on a pleasant summer night, you might hear the whisper of wings or catch a glimpse of small dark objects careening through the sky. To many, the fleeting sight of a bat evokes a range of fears, most of which are unfounded.
Bats are the only flying mammals – in fact, the 950 different species of bats worldwide represent about 20 percent of all the planet’s mammal species. As with other mammals, bats nurse their young on milk. Bats also are quite clean; they groom themselves frequently, much as a cat does.
“Eek! They want to get caught in my hair, or suck my blood” is a common misconception. Only three bat species eat blood, and only very rarely is that human blood. The two main groups of bats include the “mega-bats,” or fruit bats, that eat fruit, nectar and pollen. The larger group of “micro-bats” eats insects. They navigate and hunt by a system called echolocation, whereby they emit sound waves that bounce off of objects and return as an echo, allowing the bat to fly about safety and locate prey. Wisconsin is home to seven bat species, all of them insect eaters.
On warm summer nights, you might consider the little brown bat, a Wisconsin native, an ally because it can catch and consume up to 600 mosquitoes per hour. Little brown bats (Myotis lucifugus) are the most common Myotis species in the northern two-thirds of the United States. Often found in tree hollows and buildings during the summer, it can roost with big brown bats. It is most likely found near water sources. In winter, it hibernates. The big brown bat is another common and widespread species of bats throughout North America. It roosts in colonies in tree hollows and buildings. As it is more tolerant of cold conditions than other resident bats, it is the only one that overwinters in walls and attics.
Bats cause humans little harm, especially compared to the disturbances they’ve suffered as a result of human activity. Many bats die from eating contaminated insects. Fear and ignorance have led to bat eradication campaigns by individuals and even governments. Some logging, development and agricultural practices can drastically reduce bats’ natural habitat.
Bats may find their way into buildings, looking for safe roosting habitat. If a bat should get into your home, open a window or door and allow it to find its own way out. If it cannot, wait until it has landed, then using a glove or towel, gently catch the bat and release it outside. The best way to remove roosting bats from attics or other areas is to find and seal their entry points after they have left for nightly feeding or in the fall after they have migrated.
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 43570 Kavanaugh Street or on the web at http://www.cablemuseum.org/ to learn more about exhibits and programs.
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