Nature Watch
June 25, 2008
By Sue Benson,
Director of Education, CNHM
What Makes a Lake?
The natural history of Wisconsin is a story of water, with the main characters being the glaciers, lakes and rivers that shaped and are still shaping the land. In fact, the word “Wisconsin” means “gathering of the waters.” In addition to wetlands, rivers, streams, and 1,000 miles of Great Lakes shoreline, Wisconsin is home to more than 15,000 inland lakes.
What makes a lake?
A lake is a body of standing water that can be formed naturally (by melted glacial ice, naturally dammed rivers, or other natural processes) or by human actions (reservoirs or farm ponds). Lakes are a critical part of the environment, serving as the collection point for all of the water that falls in its watershed — the surrounding rivers, streams and land that drains water into the lake. Lakes also provide important habitat for countless plants and animals, and provide us with aesthetic beauty and recreational opportunities.
Though we may come up to our favorite lake summer after summer, lakes don’t last forever. They get old naturally over time, filling with sediments, nutrients, plants and algae. The process usually takes thousands of years, though different human activities can either delay or speed the process.
Near the shores of the lake grow reeds and cattails and floating mats of sedges. Slowly, generations of sedge-mats die and sink to the bottom of the lake and decompose. Given enough time, the lake becomes a cattail marsh or sphagnum peat bog, where eventually there is no open water left. The lake has transformed from an aquatic community to a wetland community and will eventually become a wet meadow or perhaps a black spruce forest growing on peat.
As you travel the back country of the northland, keep your eyes open for “old” lakes — grassy lowland areas or depressions that may still be wet and spongy and are less thickly wooded than the surrounding land.
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.
Wednesday, June 25, 2008
Wednesday, June 18, 2008
Eggs Rule
Nature WatchJune 18, 2008
By Susan BensonCNHM Director of Education
Eggs Rule!
What is an egg rule? Is it the number of eggs we should have in the morning for breakfast? Maybe not, but there is an ecological concept called an egg rule that expresses that the average clutch size laid by songbirds and birds in several other orders that tends to increase as one moves north in latitude.
There are few natural objects more interesting than bird eggs. Birds lay hard-shelled eggs made mostly of calcium carbonate. The hard shell keeps an egg from dehydrating and allows parents to sit on the eggs during incubation. Although bird eggs are hard-shelled, they possess microscopic pores, which allow oxygen to pass into and carbon dioxide to exit the shell.
Eggs come in a variety of colors and patterns. Colored and speckled eggs are laid in areas where they need to be camouflaged. Blue or green eggs are laid by birds that nest in shady places such as trees or shrubs (robins). This makes them less visible in the dappled sunlight. White eggs are laid by birds nesting in cavities (owls, wood ducks,) thought to happen because the eggs are usually hidden from natural predators. Birds that lay white eggs in open nests hide the eggs because they begin to incubate with the laying of the first egg. Others such as ducks, geese and grebes cover their eggs with plants when leaving the nest. Patterned eggs blend in with grass or small stones and are laid by birds that nest on the ground (gulls, sandpipers).
The shape of the egg depends on where the bird nests. The most common shape for eggs is oval. Birds that lay their eggs on ledges need eggs with a pointed end so they will not roll off the ledge (vulture). Round eggs are generally laid by birds nesting in a protected area, such as a cavity (owl). Birds that lay many eggs typically have eggs that are pointed. This allows incubation of several eggs in a small area (bobwhite). The number of eggs laid varies by species from as few as one for a seabird to nearly 30 for the bobwhite. The bobwhite needs about 3-10 minutes to lay an egg, but the goose is reported to take 1-2 hours.
This time of year the Museum staff hears stories from visitors about bird eggs and their nests. I was startled myself this week to have scared my resident phoebe out of her nest. She had set up in the same spot under the eaves that she has been using for many years. Enjoy the nesting birds in your own back yard!
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 BensonCNHM Director of Education
Eggs Rule!
What is an egg rule? Is it the number of eggs we should have in the morning for breakfast? Maybe not, but there is an ecological concept called an egg rule that expresses that the average clutch size laid by songbirds and birds in several other orders that tends to increase as one moves north in latitude.
There are few natural objects more interesting than bird eggs. Birds lay hard-shelled eggs made mostly of calcium carbonate. The hard shell keeps an egg from dehydrating and allows parents to sit on the eggs during incubation. Although bird eggs are hard-shelled, they possess microscopic pores, which allow oxygen to pass into and carbon dioxide to exit the shell.
Eggs come in a variety of colors and patterns. Colored and speckled eggs are laid in areas where they need to be camouflaged. Blue or green eggs are laid by birds that nest in shady places such as trees or shrubs (robins). This makes them less visible in the dappled sunlight. White eggs are laid by birds nesting in cavities (owls, wood ducks,) thought to happen because the eggs are usually hidden from natural predators. Birds that lay white eggs in open nests hide the eggs because they begin to incubate with the laying of the first egg. Others such as ducks, geese and grebes cover their eggs with plants when leaving the nest. Patterned eggs blend in with grass or small stones and are laid by birds that nest on the ground (gulls, sandpipers).
The shape of the egg depends on where the bird nests. The most common shape for eggs is oval. Birds that lay their eggs on ledges need eggs with a pointed end so they will not roll off the ledge (vulture). Round eggs are generally laid by birds nesting in a protected area, such as a cavity (owl). Birds that lay many eggs typically have eggs that are pointed. This allows incubation of several eggs in a small area (bobwhite). The number of eggs laid varies by species from as few as one for a seabird to nearly 30 for the bobwhite. The bobwhite needs about 3-10 minutes to lay an egg, but the goose is reported to take 1-2 hours.
This time of year the Museum staff hears stories from visitors about bird eggs and their nests. I was startled myself this week to have scared my resident phoebe out of her nest. She had set up in the same spot under the eaves that she has been using for many years. Enjoy the nesting birds in your own back yard!
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, June 11, 2008
Mosquitoes
Nature Watch
June 20, 2008
By Sue Benson,
Director of Education, CNHM
Buzzzzzzz! This is a familiar and irritating sound heard around our ears this spring, one we have gotten less used to last year with the extremely dry conditions. As they fly around us, we slap them, shoo them, spray ourselves and in general try everything we can do to avoid them and their bites.
The intense itching and swelling is an allergic response to the mosquito's salivary secretions. Mosquitoes are attracted to carbon dioxide, perspiration, body odor, lactic acid, light and heat to find their hosts. Some fragrances and dark colors may attract some mosquitoes. The most efficient way of reducing numbers of mosquitoes in your yard is to try to remove standing water in discarded tires, bird baths, plant saucers, and even gutters and flat roofs.
Mosquitoes begin life in aquatic environments. The eggs are laid on the surface of the water or sometimes are laid in moist soil that will eventually be flooded. The larvae hatch within about 48 hours. A larva lives in the water and comes to the surface to breath and shed its skin four times, growing larger each time. During the fourth shed the larva changes into a pupa.
The pupal stage is spent resting; they do not feed but are capable of movement, responding to light changes, moving with a flip of their tails towards the bottom or protective areas. Some mosquito species spend about two days as a pupa in the summer, and the skin splits, allowing the adult mosquito to emerge.
There are many kinds of mosquitoes, preferring different habitat, behavior and source of blood. It takes about two weeks after water is available for adults to appear, and more than 60 percent of these adults will migrate up to 20 miles from their breeding habitat. Only the female mosquitoes are blood sucking (the blood meal obtains the protein necessary for the development of her eggs) while the males feed on nectar and other plant juices. In the summer they can sometimes go through their entire life cycle in one week. Adult females will live for three to six weeks and can take several blood meals during this time. Temperatures below 50 degrees F prevent mosquitoes from flying.
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.
June 20, 2008
By Sue Benson,
Director of Education, CNHM
Buzzzzzzz! This is a familiar and irritating sound heard around our ears this spring, one we have gotten less used to last year with the extremely dry conditions. As they fly around us, we slap them, shoo them, spray ourselves and in general try everything we can do to avoid them and their bites.
The intense itching and swelling is an allergic response to the mosquito's salivary secretions. Mosquitoes are attracted to carbon dioxide, perspiration, body odor, lactic acid, light and heat to find their hosts. Some fragrances and dark colors may attract some mosquitoes. The most efficient way of reducing numbers of mosquitoes in your yard is to try to remove standing water in discarded tires, bird baths, plant saucers, and even gutters and flat roofs.
Mosquitoes begin life in aquatic environments. The eggs are laid on the surface of the water or sometimes are laid in moist soil that will eventually be flooded. The larvae hatch within about 48 hours. A larva lives in the water and comes to the surface to breath and shed its skin four times, growing larger each time. During the fourth shed the larva changes into a pupa.
The pupal stage is spent resting; they do not feed but are capable of movement, responding to light changes, moving with a flip of their tails towards the bottom or protective areas. Some mosquito species spend about two days as a pupa in the summer, and the skin splits, allowing the adult mosquito to emerge.
There are many kinds of mosquitoes, preferring different habitat, behavior and source of blood. It takes about two weeks after water is available for adults to appear, and more than 60 percent of these adults will migrate up to 20 miles from their breeding habitat. Only the female mosquitoes are blood sucking (the blood meal obtains the protein necessary for the development of her eggs) while the males feed on nectar and other plant juices. In the summer they can sometimes go through their entire life cycle in one week. Adult females will live for three to six weeks and can take several blood meals during this time. Temperatures below 50 degrees F prevent mosquitoes from flying.
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.
Wednesday, May 28, 2008
May Birds
Nature Watch
May 28, 2008
By Susan Benson,
CNHM Director of Education
This past week has been enjoyable, watching the indigo buntings feeding at the bird feeders. The male, a brilliant blue while the female is a duller brown, migrates at night, using the stars as guidance. Scientists believe they gain knowledge of the night sky from their experience as a young bird observing the stars. They’re so good at navigation, in fact, that experienced adults have been known to return to their previous breeding sites even after being held captive and released away from their normal wintering sites.
Indigo buntings prefer brush along woods, roads or in open deciduous forests and old fields. They eat small insects, spiders, seeds and berries, and glean their insects off branches. When nesting, they create a open cup nest in shrubs close to the ground, and held in pace with spider webs. Their songs are a sequence of notes that are similar between males when they are close by; if the males are separated by more distance, they will have different songs.
Another favorite bird I listen for every spring is an ovenbird. Ovenbirds are rarely seen, but often heard. Their loud song, “teacher, teacher, teacher,” rings throughout the forests of our area. They are perhaps more well-known to birders because the neighboring males sing together in the spring; one male begins singing and others will join in after, sometimes for as many as forty different songs. The ovenbird is an interior forest warbler species that nests on the ground of mixed deciduous or coniferous forests. Ovenbirds get their name from their nest; they use Pennsylvania sedges that curl over, making a dome that resembles a Dutch oven. They focus on uplands or sloped area habitat, leaving the steep slopes and lower elevated areas for other warblers. Ovenbirds feed on insects off leaf litter on the forest floor.
Large forest areas are important to the Ovenbird, as they can require 30 to 250 acres to sustain populations. The Ovenbird is considered to be one of the most fragmentation-sensitive birds in the northeast, possible because the bird is a ground nester, making it more vulnerable to predators. Fragmented forests allow more predators into the forest, negatively affecting ground nesters. Studies estimate that only half of adult ovenbirds survive each year. This knowledge makes listening to the sound of ovenbirds even more special. Enjoy the songs of our forest bird species on your next trip outdoors.
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.
May 28, 2008
By Susan Benson,
CNHM Director of Education
This past week has been enjoyable, watching the indigo buntings feeding at the bird feeders. The male, a brilliant blue while the female is a duller brown, migrates at night, using the stars as guidance. Scientists believe they gain knowledge of the night sky from their experience as a young bird observing the stars. They’re so good at navigation, in fact, that experienced adults have been known to return to their previous breeding sites even after being held captive and released away from their normal wintering sites.
Indigo buntings prefer brush along woods, roads or in open deciduous forests and old fields. They eat small insects, spiders, seeds and berries, and glean their insects off branches. When nesting, they create a open cup nest in shrubs close to the ground, and held in pace with spider webs. Their songs are a sequence of notes that are similar between males when they are close by; if the males are separated by more distance, they will have different songs.
Another favorite bird I listen for every spring is an ovenbird. Ovenbirds are rarely seen, but often heard. Their loud song, “teacher, teacher, teacher,” rings throughout the forests of our area. They are perhaps more well-known to birders because the neighboring males sing together in the spring; one male begins singing and others will join in after, sometimes for as many as forty different songs. The ovenbird is an interior forest warbler species that nests on the ground of mixed deciduous or coniferous forests. Ovenbirds get their name from their nest; they use Pennsylvania sedges that curl over, making a dome that resembles a Dutch oven. They focus on uplands or sloped area habitat, leaving the steep slopes and lower elevated areas for other warblers. Ovenbirds feed on insects off leaf litter on the forest floor.
Large forest areas are important to the Ovenbird, as they can require 30 to 250 acres to sustain populations. The Ovenbird is considered to be one of the most fragmentation-sensitive birds in the northeast, possible because the bird is a ground nester, making it more vulnerable to predators. Fragmented forests allow more predators into the forest, negatively affecting ground nesters. Studies estimate that only half of adult ovenbirds survive each year. This knowledge makes listening to the sound of ovenbirds even more special. Enjoy the songs of our forest bird species on your next trip outdoors.
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, May 21, 2008
Ephemerals
Nature Watch
May 21, 2008
By Susan Benson,
CNHM Director of Education
Locals like to call the time between when the snow melts and when the trees leaf out “mud season,” and with good reason. We may have had a short mud season this spring, but get out into the woods to discover a flowering spring treat: ephemerals.
Spring ephemerals are short-lived wildflowers that take advantage of a narrow window of opportunity when the sun rises higher in the sky and stays out longer, but before trees completely leaf out and block sunlight from reaching the forest floor. These opportunistic flowers will sprout, flower, wither and die back all in the space of about a week.
Often the first wildflower noticed by casual walkers is the trillium, a plant belonging to the lily family that has a large, often white, three-petaled flower above three broad bracts that look like leaves. These white flowers slowly turn into a shade of purple in the middle of spring.
Another ephemeral is hepatica, named from its leaves, which, like the human liver have three lobes. As part of the doctrine of signatures, it was once believed that plants were created for the use of human beings and as such, each plant displayed a signature of the purpose for which it was created - hepatica was thought an effective treatment for liver disorders. In marshy areas, look for skunk cabbage, a strong-smelling plant that Henry David Thoreau once called the “hermit of the bog.” Other spring wildflowers include spring anemone, spring beauty, wild geranium, marsh marigold, and bloodroot.
Being among the very first plants to grow and on the drab forest floor, spring ephemerals’ flowers stand out and attract pollinators like bees. Ants also play a role in the life cycle of these plants; after flowering, the spring ephemerals typically produce a small black seed with an energy-rich sac attached to it. Seeking food, ants gather the sacs and carry them to underground nests, leaving behind the seeds underground in their “garbage pile”, and essentially planting the seeds.
Watch for the flowers of spring ephemerals on woodland spring hikes, but avoid picking the flowers or digging up the plants, which are often rare or fragile and play an important role in the woodland ecosystem. If you are looking for some great places to hike and find spring ephemerals, try out the Forest Lodge Nature Trail, 9 miles east of Cable on Garmisch Road.
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.
May 21, 2008
By Susan Benson,
CNHM Director of Education
Locals like to call the time between when the snow melts and when the trees leaf out “mud season,” and with good reason. We may have had a short mud season this spring, but get out into the woods to discover a flowering spring treat: ephemerals.
Spring ephemerals are short-lived wildflowers that take advantage of a narrow window of opportunity when the sun rises higher in the sky and stays out longer, but before trees completely leaf out and block sunlight from reaching the forest floor. These opportunistic flowers will sprout, flower, wither and die back all in the space of about a week.
Often the first wildflower noticed by casual walkers is the trillium, a plant belonging to the lily family that has a large, often white, three-petaled flower above three broad bracts that look like leaves. These white flowers slowly turn into a shade of purple in the middle of spring.
Another ephemeral is hepatica, named from its leaves, which, like the human liver have three lobes. As part of the doctrine of signatures, it was once believed that plants were created for the use of human beings and as such, each plant displayed a signature of the purpose for which it was created - hepatica was thought an effective treatment for liver disorders. In marshy areas, look for skunk cabbage, a strong-smelling plant that Henry David Thoreau once called the “hermit of the bog.” Other spring wildflowers include spring anemone, spring beauty, wild geranium, marsh marigold, and bloodroot.
Being among the very first plants to grow and on the drab forest floor, spring ephemerals’ flowers stand out and attract pollinators like bees. Ants also play a role in the life cycle of these plants; after flowering, the spring ephemerals typically produce a small black seed with an energy-rich sac attached to it. Seeking food, ants gather the sacs and carry them to underground nests, leaving behind the seeds underground in their “garbage pile”, and essentially planting the seeds.
Watch for the flowers of spring ephemerals on woodland spring hikes, but avoid picking the flowers or digging up the plants, which are often rare or fragile and play an important role in the woodland ecosystem. If you are looking for some great places to hike and find spring ephemerals, try out the Forest Lodge Nature Trail, 9 miles east of Cable on Garmisch Road.
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 13, 2008
Spring Birds
Nature Watch
May 13, 2008
By Susan Benson,
CNHM Director of Education
If you have bird feeders at home, this past week you might have found the songbirds “eating you out of house and home.” My parents are feeding at least a pound of bird seed a day. There are many species of birds at my parents’ bird feeders, and almost daily my mother lists off to me the birds she’s seen. Here’s a list of returned migrants and year-round resident birds list from one day this past week: song sparrows, white-throated sparrows, white-crowned sparrow, chipping sparrow, downy woodpecker, hairy woodpecker, mourning dove, purple grackles, slate-colored junco, Eastern towhee, chickadees, blue jays, American goldfinch, American robin, ruby-throated hummingbird (yes-they’re back!), red-bellied woodpecker, purple finches, cardinal, red-winged blackbird, evening grosbeaks, rose-breasted grosbeaks, Baltimore oriole, brown-headed cowbird, and red-breasted nuthatch. Species seen in their yard include a catbird, house wren, flicker and yellow-bellied sapsucker. Other species visiting include chipmunk, red and gray squirrel, cottontail rabbit and white-tailed deer. The striking blend of colors is a continued pleasure to the eye.
The particular species that caused me excitement while feeder watching this week included the rose-breasted grosbeak, evening grosbeak, and Baltimore oriole. Go outdoors and listen for the rich, warbling song of a rose-breasted grosbeak, sounding a bit like a robin that has taken singing lessons. These birds prefer to nest in deciduous woodlands, especially at the edges. They eat seeds, fruits, buds and insects. The nest, an open cup of sticks, twigs, grasses, decayed leaves, or weed stems, is lined with fine twigs, roots or hairs that they place in trees or shrubs. The nest of this grosbeak is so thinly constructed that the eggs can sometimes be seen from below through the nest. The male spends about 1/3 of its day participating in the incubation of the eggs. When you hear the male, it probably means it is near or actually on the nest.
The large, stocky finch with a bright yellow back, rump and underparts, is the evening grosbeak. Their song, a series of short, musical whistles, appears not to be used in the functions of mate attraction and territory defense. Evening grosbeaks nest in coniferous forests, built mostly by the female and constructed loosely from sticks, moss, lichen and rootlets. The inside can be lined with grasses, roots, lichens, hair and plant fibers. Evening grosbeaks feed on a wide variety of natural foods such as seeds (especially maples,) small fruits, insects and other invertebrates. Some years you may see flocks at feeders, while in other years they stay further north and are not seen in their winter range. Results from the Christmas Bird Count show that the evening grosbeak is an irruptive species across much of North America. Long-term research shows that these birds exhibit a biennial pattern of irruption; plentiful years followed by years when low numbers are reported.
I squealed with delight this week at the arrival of the brilliant orange and black Baltimore oriole. This bird received its name from the fact that the male's colors resemble those on the coat-of-arms of Lord Baltimore, after whom the city of Baltimore, Maryland is named. Young male Baltimore orioles do not have adult plumage until the fall of their second year. In spite of this, some first-year males with female-like plumage succeed in attracting a mate. The orioles appetite consist of caterpillars, fruits, spiders, and nectar. Their gourd-shaped nest is hung from the thin branches or a fork in a tall tree, and is woven from hair and plant fibers. In our backyards, they can be enticed to visit feeders with oranges, nectars, grape jelly, or peanut butter. Most feeders are orange, as orioles probably recognize the color orange from afar, matching their own plumage; if they spot the bright orange color of an oriole feeder, they usually drop down to investigate.
While watching the orioles feed on oranges and grape jelly this past weekend, I started wondering: like many humans, can birds have a food allergy to jelly containing high fructose corn syrup? I looked to our regional bird expert, Laura Erickson’s birding blog, where participants recommended feeding only small amounts of natural grape jelly, real grapes, or grapes mashed in with jelly. One birder shared the following from Kent Mahaffey, manager of the San Diego Wild Animal Park: “Natural nectars contain 12% to 30% sugars, while jams and jellies are more than half sugar…We do our best for them when we stick as closely as possible to their natural diets.” Could it be that we need to shop at the nearest health food store for our birds as well?
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.
May 13, 2008
By Susan Benson,
CNHM Director of Education
If you have bird feeders at home, this past week you might have found the songbirds “eating you out of house and home.” My parents are feeding at least a pound of bird seed a day. There are many species of birds at my parents’ bird feeders, and almost daily my mother lists off to me the birds she’s seen. Here’s a list of returned migrants and year-round resident birds list from one day this past week: song sparrows, white-throated sparrows, white-crowned sparrow, chipping sparrow, downy woodpecker, hairy woodpecker, mourning dove, purple grackles, slate-colored junco, Eastern towhee, chickadees, blue jays, American goldfinch, American robin, ruby-throated hummingbird (yes-they’re back!), red-bellied woodpecker, purple finches, cardinal, red-winged blackbird, evening grosbeaks, rose-breasted grosbeaks, Baltimore oriole, brown-headed cowbird, and red-breasted nuthatch. Species seen in their yard include a catbird, house wren, flicker and yellow-bellied sapsucker. Other species visiting include chipmunk, red and gray squirrel, cottontail rabbit and white-tailed deer. The striking blend of colors is a continued pleasure to the eye.
The particular species that caused me excitement while feeder watching this week included the rose-breasted grosbeak, evening grosbeak, and Baltimore oriole. Go outdoors and listen for the rich, warbling song of a rose-breasted grosbeak, sounding a bit like a robin that has taken singing lessons. These birds prefer to nest in deciduous woodlands, especially at the edges. They eat seeds, fruits, buds and insects. The nest, an open cup of sticks, twigs, grasses, decayed leaves, or weed stems, is lined with fine twigs, roots or hairs that they place in trees or shrubs. The nest of this grosbeak is so thinly constructed that the eggs can sometimes be seen from below through the nest. The male spends about 1/3 of its day participating in the incubation of the eggs. When you hear the male, it probably means it is near or actually on the nest.
The large, stocky finch with a bright yellow back, rump and underparts, is the evening grosbeak. Their song, a series of short, musical whistles, appears not to be used in the functions of mate attraction and territory defense. Evening grosbeaks nest in coniferous forests, built mostly by the female and constructed loosely from sticks, moss, lichen and rootlets. The inside can be lined with grasses, roots, lichens, hair and plant fibers. Evening grosbeaks feed on a wide variety of natural foods such as seeds (especially maples,) small fruits, insects and other invertebrates. Some years you may see flocks at feeders, while in other years they stay further north and are not seen in their winter range. Results from the Christmas Bird Count show that the evening grosbeak is an irruptive species across much of North America. Long-term research shows that these birds exhibit a biennial pattern of irruption; plentiful years followed by years when low numbers are reported.
I squealed with delight this week at the arrival of the brilliant orange and black Baltimore oriole. This bird received its name from the fact that the male's colors resemble those on the coat-of-arms of Lord Baltimore, after whom the city of Baltimore, Maryland is named. Young male Baltimore orioles do not have adult plumage until the fall of their second year. In spite of this, some first-year males with female-like plumage succeed in attracting a mate. The orioles appetite consist of caterpillars, fruits, spiders, and nectar. Their gourd-shaped nest is hung from the thin branches or a fork in a tall tree, and is woven from hair and plant fibers. In our backyards, they can be enticed to visit feeders with oranges, nectars, grape jelly, or peanut butter. Most feeders are orange, as orioles probably recognize the color orange from afar, matching their own plumage; if they spot the bright orange color of an oriole feeder, they usually drop down to investigate.
While watching the orioles feed on oranges and grape jelly this past weekend, I started wondering: like many humans, can birds have a food allergy to jelly containing high fructose corn syrup? I looked to our regional bird expert, Laura Erickson’s birding blog, where participants recommended feeding only small amounts of natural grape jelly, real grapes, or grapes mashed in with jelly. One birder shared the following from Kent Mahaffey, manager of the San Diego Wild Animal Park: “Natural nectars contain 12% to 30% sugars, while jams and jellies are more than half sugar…We do our best for them when we stick as closely as possible to their natural diets.” Could it be that we need to shop at the nearest health food store for our birds as well?
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.
Sunday, May 11, 2008
Migratory Birds
Nature Watch
May 11, 2008
By Susan Benson,CNHM Director of Education
Wood thrush or American redstarts; they might be just one bird species, but they both share two habitats. How amazing that the same individual bird that returns to our yard each spring spent the winter further south. Many neotropical migratory birds breed in North America and spend our “winter” in Central or South America.
Over the years, land in North and South America has changed dramatically due to human land uses. Current human population pressures in Central and South America force people to clear forested land for homes, fuel, and agriculture. In these tropical habitats, bird migrants compete with resident birds for smaller habitat areas. These migratory birds might also be hunted for food or removed as pests of agriculture.
In the U.S. there is more forest cover now than at the turn of the century, but the forests are fragmented into smaller parcels, affecting habitat quality for wildlife that depends on interior forest conditions. Even small roads, running through a forest, fragment it and affect forest interior ground nesters. Nest predators such as brown-headed cowbirds, blue jays, raccoons, and feral cats gain access to songbird nests in these smaller forested areas. Wood thrushes and American redstarts are two birds that although present in the northwoods, can be affected by fragmented forests.
Wood thrushes forage for food on the ground, picking up insects and the occasional berry. Female wood thrushes build their nests in deciduous forests as low as six feet off the ground in tree branches.
Although it is a very common species of Eastern forests, the wood thrush is of high conservation concern because of steady, long-term population declines throughout its range for many reasons. According to the Cornell Lab of Ornithology's Bird Population Studies, this species has declined 43% since 1966. Declines in wood thrush populations have been linked to acid rain and forest fragmentation. This species seems dependent on large tracts of mature forest in some parts of its range, but is tolerant of disturbance in other areas. In a study done by Hoover (1995,) he found a 12% nesting success in a 22 acre forest while there was a 72% success rate in a 300 acre forest. In winter, wood thrushes are vulnerable to deforestation in the lowlands of Central America. The brown-headed cowbird frequently parasitizes wood thrush nests. In some parts of the Midwest all of the Wood Thrush nests contain at least one cowbird egg, and some may contain up to eight.
American redstarts hover while gleaning foliage, flushing out the hiding insects. They move rapidly while foraging, flashing their wings and tail to flush insect prey. They prefer second growth deciduous forests that contain abundant shrubs. Nest sites are located at the crotch of a branch from the main trunk of a tree. Nests are placed from 3-45 feet above the ground. They winter in the southern United States, Mexico, Central and South America. Declines have been seen in some areas, but the species is still widespread and abundant. Cowbird parasitism has been reported at 20% for this species.
While birding around the house this spring, enjoy these bird species. Listen for the flute-like sounds of the wood thrush or the varied musical see notes of the redstart.
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.
May 11, 2008
By Susan Benson,CNHM Director of Education
Wood thrush or American redstarts; they might be just one bird species, but they both share two habitats. How amazing that the same individual bird that returns to our yard each spring spent the winter further south. Many neotropical migratory birds breed in North America and spend our “winter” in Central or South America.
Over the years, land in North and South America has changed dramatically due to human land uses. Current human population pressures in Central and South America force people to clear forested land for homes, fuel, and agriculture. In these tropical habitats, bird migrants compete with resident birds for smaller habitat areas. These migratory birds might also be hunted for food or removed as pests of agriculture.
In the U.S. there is more forest cover now than at the turn of the century, but the forests are fragmented into smaller parcels, affecting habitat quality for wildlife that depends on interior forest conditions. Even small roads, running through a forest, fragment it and affect forest interior ground nesters. Nest predators such as brown-headed cowbirds, blue jays, raccoons, and feral cats gain access to songbird nests in these smaller forested areas. Wood thrushes and American redstarts are two birds that although present in the northwoods, can be affected by fragmented forests.
Wood thrushes forage for food on the ground, picking up insects and the occasional berry. Female wood thrushes build their nests in deciduous forests as low as six feet off the ground in tree branches.
Although it is a very common species of Eastern forests, the wood thrush is of high conservation concern because of steady, long-term population declines throughout its range for many reasons. According to the Cornell Lab of Ornithology's Bird Population Studies, this species has declined 43% since 1966. Declines in wood thrush populations have been linked to acid rain and forest fragmentation. This species seems dependent on large tracts of mature forest in some parts of its range, but is tolerant of disturbance in other areas. In a study done by Hoover (1995,) he found a 12% nesting success in a 22 acre forest while there was a 72% success rate in a 300 acre forest. In winter, wood thrushes are vulnerable to deforestation in the lowlands of Central America. The brown-headed cowbird frequently parasitizes wood thrush nests. In some parts of the Midwest all of the Wood Thrush nests contain at least one cowbird egg, and some may contain up to eight.
American redstarts hover while gleaning foliage, flushing out the hiding insects. They move rapidly while foraging, flashing their wings and tail to flush insect prey. They prefer second growth deciduous forests that contain abundant shrubs. Nest sites are located at the crotch of a branch from the main trunk of a tree. Nests are placed from 3-45 feet above the ground. They winter in the southern United States, Mexico, Central and South America. Declines have been seen in some areas, but the species is still widespread and abundant. Cowbird parasitism has been reported at 20% for this species.
While birding around the house this spring, enjoy these bird species. Listen for the flute-like sounds of the wood thrush or the varied musical see notes of the redstart.
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.
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