Nature Watch
By Susan Benson,
CNHM Director of Education
Birds’ nests – can you imagine making a home for your young with a beak? Many might think of a nest as something made by the bird itself, such as the mud and grass nest of the robin, or the more complex woven northern oriole. For some, the nest is simply a spot on the soil, or a knot-hold left by a broken branch, a chamber in a tree, or a mud cavity. A bird’s nest helps hide the parent bird when incubating the eggs and shelters the young. We have evidence that using a nest is critical for warmth, provided by birds near volcanoes or hot water streams lay on heated soil near those places, or by the fact that so many nests are lined with materials that have insulation values. This entire nesting process is truly fascinating.
Why do birds build such elaborate nests? Perhaps, as real estate agents exclaim, is it location, location, location. To get off the forest floor, a bird must build a base that mimics the ground. They need to consider how to keep the eggs warmer, and sine the tops of the eggs are warmer than the bottoms, birds can create a layer of air-trapping insulation between the nest floor and eggs to keep the eggs evenly heated.
Some small birds find protection in the lower parts of nests of larger birds. For example, American kestrels and western kingbirds will often nest in the stick nests of golden eagles, and common grackles and house sparrows will nest in the nests of ospreys. They get protection from the hawk as well as leftover scraps of food.
The nesting habits of birds are varied. Gulls lay eggs on bare ground or rocks. Woodpeckers hew out a deep nest in a rotten limb. The kingfisher digs one out of a sandy bank, while the cuckoo takes possession of the nest of some other bird. The northern oriole constructs a hanging nest of elaborate workmanship. Using thin plant fibers, they loop one around the branch, hold down the irregular spiral, poke a new piece of material into it, pull it through, and loop it around the branch. They sometimes double the new end back, making a knot, by accident. When finished with the exterior weaving, they line the nest, and after ten thousand insertions of material and weeks of effort, they are ready to lay eggs.
The largest nests on record in North America have been built by the bald eagle. One in Vermillion, Ohio had been occupied by eagles for 35 years and was estimated to weigh about two tons when it crashed to the ground. What a nest!
The cup of the nest built by songbirds rests on a foundation nest of twigs interwoven with grasses, weed stems or rootlets, and is lined with finer grasses, mosses, strips of bark, dead leaves, pine needles, feathers, and animal hairs.
Some birds use mud or leaf mold to hold the nest together. Other birds use saliva to cement together the nest materials. Hummingbirds use spider webs to construct their tiny nest. Some birds will use all sorts of man-made products including Kleenex, barbed wire, and strips of plastic.
Saying someone is bird-brained seems like a compliment to me. The effort and innovation that birds have used to design such a wide variation of methods to protect their young suggests a high level of intelligence. Keep your eyes out for birds’ nests and the activities birds do this time of year to care for their young. Please continue to Email any observations to info@cablemuseum.org.
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 and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.
Thursday, May 28, 2009
Thursday, May 21, 2009
Warblers, Ovenbirds, Black Throated Warblers
Nature Watch
by Susan Benson,
CNHM Director of Education
"Teacher, Teacher, Teacher!" As a child, many of us may have exclaimed this to
our favorite elementary teachers. Today, it is instead the English translation of
the sound of the ovenbirds. This week we should be hearing this sound in the
forest as this six-inch high warbler returns from its 2,300 mile migration from
Nicaragua. Another sound that should be heard this week is the black-throated
green warbler, singing out to us, "zee-zee-zee-zoo-zee" Although found in two
slightly different habitats, these are both forest-dwelling birds that spend
their summers in northern Wisconsin, and are worth listening for, as we almost
never see them.
Ovenbirds migrate at night, flying 39 miles per hour to reach their northern,
summer home. The term "ovenbird" comes from the shape of their nests, built on
the ground with Pennsylvania sedge that resembles the shape of a Dutch oven.
When we hear the "t-cher" sound, it is the males often singing from near the
ground, and the call gets louder as they sing. Nearby male ovenbirds sing
together. One male begins singing, and the second starts immediately after. They
pause, and then sing one after the other again for up to forty repetitions. The
second joins in so quickly that they may sound as if only one bird is singing.
Ovenbirds hop across the forest floor of Wisconsin's mature forests, preferring
upland deciduous trees, or mixed conifer and deciduous forests. Ovenbirds forage
for insects off leaf litter on the forest floor.
It must be a challenging life being a small, migratory bird. It is believed that
half of all adult ovenbirds die each year. Extensive studies have been made on
ovenbirds in the Chequamegon-Nicolet National Forest on the impacts of forest
fragmentation. In areas where the forests have decreased to very small sizes, egg
predation occurs more frequently. Studies are currently underway in Drummond and
Cable study plots to determine the impacts of exotic earthworms on ovenbirds and
other ground-nesting bird species. Although, not a species of special concern, it
is also believed that the populations are declining in the east as the forest
becomes more mature. With healthy populations in northern Wisconsin, ovenbirds
share a welcome sound to greet other forest dwellers such as ourselves until
early June.
The dark black bib and bright yellow face of the black-throated green warbler is
rarely seen, but the sound is often heard as they sing in coniferous forests. The
males begin their "zee-zee-zee-zoo-zee" in the middle of his territory to attract
females, and later in the breeding season to deter other males. This warbler sings
continuously throughout the breeding season - one individual was heard 466 times
in one hour. These warblers also glean insects from small branches; sometimes
hovering and picking their prey from branches in flight.
The black-throated green warbler is another bird that has challenges in its
summer and winter habitat. They migrate north in the spring from Mexico, where
populations are thought to be declining due to the loss of mature forests. This
species is also susceptible to nest parasitism by the brown-headed cowbird.
When taking a walk outdoors, be sure to be on the look-out for the sights and
sounds of our migratory warblers. Bring your binoculars and bird book, as
warblers are quick to move, and difficult sometimes to identify. Keep a tape or
DVD of bird songs in your vehicle to continue improving your bird song
identification skills. Maybe you'll be lucky enough to spot a "bouquet" or
"confusion" of warblers, which is simply a group of warblers, and is, simply
beautiful to see.
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 and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.
by Susan Benson,
CNHM Director of Education
"Teacher, Teacher, Teacher!" As a child, many of us may have exclaimed this to
our favorite elementary teachers. Today, it is instead the English translation of
the sound of the ovenbirds. This week we should be hearing this sound in the
forest as this six-inch high warbler returns from its 2,300 mile migration from
Nicaragua. Another sound that should be heard this week is the black-throated
green warbler, singing out to us, "zee-zee-zee-zoo-zee" Although found in two
slightly different habitats, these are both forest-dwelling birds that spend
their summers in northern Wisconsin, and are worth listening for, as we almost
never see them.
Ovenbirds migrate at night, flying 39 miles per hour to reach their northern,
summer home. The term "ovenbird" comes from the shape of their nests, built on
the ground with Pennsylvania sedge that resembles the shape of a Dutch oven.
When we hear the "t-cher" sound, it is the males often singing from near the
ground, and the call gets louder as they sing. Nearby male ovenbirds sing
together. One male begins singing, and the second starts immediately after. They
pause, and then sing one after the other again for up to forty repetitions. The
second joins in so quickly that they may sound as if only one bird is singing.
Ovenbirds hop across the forest floor of Wisconsin's mature forests, preferring
upland deciduous trees, or mixed conifer and deciduous forests. Ovenbirds forage
for insects off leaf litter on the forest floor.
It must be a challenging life being a small, migratory bird. It is believed that
half of all adult ovenbirds die each year. Extensive studies have been made on
ovenbirds in the Chequamegon-Nicolet National Forest on the impacts of forest
fragmentation. In areas where the forests have decreased to very small sizes, egg
predation occurs more frequently. Studies are currently underway in Drummond and
Cable study plots to determine the impacts of exotic earthworms on ovenbirds and
other ground-nesting bird species. Although, not a species of special concern, it
is also believed that the populations are declining in the east as the forest
becomes more mature. With healthy populations in northern Wisconsin, ovenbirds
share a welcome sound to greet other forest dwellers such as ourselves until
early June.
The dark black bib and bright yellow face of the black-throated green warbler is
rarely seen, but the sound is often heard as they sing in coniferous forests. The
males begin their "zee-zee-zee-zoo-zee" in the middle of his territory to attract
females, and later in the breeding season to deter other males. This warbler sings
continuously throughout the breeding season - one individual was heard 466 times
in one hour. These warblers also glean insects from small branches; sometimes
hovering and picking their prey from branches in flight.
The black-throated green warbler is another bird that has challenges in its
summer and winter habitat. They migrate north in the spring from Mexico, where
populations are thought to be declining due to the loss of mature forests. This
species is also susceptible to nest parasitism by the brown-headed cowbird.
When taking a walk outdoors, be sure to be on the look-out for the sights and
sounds of our migratory warblers. Bring your binoculars and bird book, as
warblers are quick to move, and difficult sometimes to identify. Keep a tape or
DVD of bird songs in your vehicle to continue improving your bird song
identification skills. Maybe you'll be lucky enough to spot a "bouquet" or
"confusion" of warblers, which is simply a group of warblers, and is, simply
beautiful to see.
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 and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.
Thursday, May 14, 2009
Jumping Spiders
Nature Watch
May 14, 2009
By Susan Benson,
CNHM Director of Education
We all know the song “head, shoulders knees and toes, knees and toes.” Well, I sing a different version of this song about insects – “Head, thorax, abdomen, abdomen.” First graders in many of the area schools get to sing and learn about insects when I visit their classrooms in the spring as part of the Museum’s MuseumMobile program. Previously we had studied spiders, so first graders in this region are equipped to identify the differences between arachnids and insects. This week in Drummond, we went outdoors to catch insects or spiders in the school forest. One of the highlights of our explorations included the very “cool” jumping spiders. Jumping spiders are truly amazing spiders for many reasons.
A jumping spider’s family name is Salticidae, whose roots come from the Latin word saltare, to jump or dance. Jumping spiders are daytime hunters. Thought to have the best eyesight of most invertebrates, they are well designed to hunt their prey. Using their keen sight, they run toward their prey, slow down, and then stalk as they get closer. A silk dragline is attached to the ground before they jump so they can move to a safe place afterwards. When jumping, they have a hydraulic-like system – by altering the pressure of their body fluids, they can jump without needing muscular legs. With this technique they can jump from 20-80 times the length of their body. In comparison, I would have to be able to jump 433 feet!
When they are not hunting, jumping spiders maintain woven homes for resting and hibernating that are located under stones, bark, or in leaves. Having no local shopping centers to find their food, they must search anywhere and still be able to return to their home. In lab tests, jumping spiders were presented with prey and artificial branches arranged so that the predator had to walk around the obstacles to get to the prey. The spiders were able to scan the “maze”, move in a pathway around the obstacles, rescan the maze, and find the prey. This experiment showed some evidence of memory or intelligence in a small creature with what we would say is a very tiny brain. Without creating a mental map, how else could the spiders have set out a path away from their prey and still had a successful hunt?
Animals of any shape or size can continue to amaze us. Next time you are out for a walk, step slowly through your lawn, or through a meadow to observe the jumping spiders near your home. Or perhaps while sitting on the ground in the sun, you’ll see one approach, jumping lively or maybe looking at you “curiously” with its keen eyesight. Jumping spiders are just one of the animal species with mind-boggling abilities.
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 and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.
May 14, 2009
By Susan Benson,
CNHM Director of Education
We all know the song “head, shoulders knees and toes, knees and toes.” Well, I sing a different version of this song about insects – “Head, thorax, abdomen, abdomen.” First graders in many of the area schools get to sing and learn about insects when I visit their classrooms in the spring as part of the Museum’s MuseumMobile program. Previously we had studied spiders, so first graders in this region are equipped to identify the differences between arachnids and insects. This week in Drummond, we went outdoors to catch insects or spiders in the school forest. One of the highlights of our explorations included the very “cool” jumping spiders. Jumping spiders are truly amazing spiders for many reasons.
A jumping spider’s family name is Salticidae, whose roots come from the Latin word saltare, to jump or dance. Jumping spiders are daytime hunters. Thought to have the best eyesight of most invertebrates, they are well designed to hunt their prey. Using their keen sight, they run toward their prey, slow down, and then stalk as they get closer. A silk dragline is attached to the ground before they jump so they can move to a safe place afterwards. When jumping, they have a hydraulic-like system – by altering the pressure of their body fluids, they can jump without needing muscular legs. With this technique they can jump from 20-80 times the length of their body. In comparison, I would have to be able to jump 433 feet!
When they are not hunting, jumping spiders maintain woven homes for resting and hibernating that are located under stones, bark, or in leaves. Having no local shopping centers to find their food, they must search anywhere and still be able to return to their home. In lab tests, jumping spiders were presented with prey and artificial branches arranged so that the predator had to walk around the obstacles to get to the prey. The spiders were able to scan the “maze”, move in a pathway around the obstacles, rescan the maze, and find the prey. This experiment showed some evidence of memory or intelligence in a small creature with what we would say is a very tiny brain. Without creating a mental map, how else could the spiders have set out a path away from their prey and still had a successful hunt?
Animals of any shape or size can continue to amaze us. Next time you are out for a walk, step slowly through your lawn, or through a meadow to observe the jumping spiders near your home. Or perhaps while sitting on the ground in the sun, you’ll see one approach, jumping lively or maybe looking at you “curiously” with its keen eyesight. Jumping spiders are just one of the animal species with mind-boggling abilities.
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 and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.
Thursday, May 7, 2009
Watch for in Early May
Nature Watch
May 7, 2009
By Susan Benson,
CNHM Director of Education
Although April showers didn’t shower much in our region, May flowers appear to still be on their way. For some, May brings the first fish caught, the last frost, the first lawn mowing, and the first swim in a nearby lake or river. Regardless of our interests, spring continues to bring exciting natural events for us to observe. Look high and low for any of the following birds or plants of the north woods.
The first hummingbird is often spotted in the first or second week of May. Northern orioles typically return about the same time, but usually in the second week. Rose-breasted grosbeaks can be seen at the feeders again. Other birds to watch for in the first two weeks of May are the catbirds, wood thrushes, scarlet tanagers, indigo buntings, and wood pewees. Warbler migration also begins early in the month.
There are other bird behaviors to watch for this month. For birds, courtship in May sometimes begins aggressively because of the need to defend territory. Some courtship rituals include singing. Most song is emitted by the male, and is delivered from prominent perches, although some species sing during flight. This song is a way of defending territory against other males and to tell a female of the presence of the male. Some studies suggest that birds sing when aroused by an intrusion of another bird species into their territory, showing aggressive competition between species.
Birds that do not sing in courtship have other means of attracting attention, producing percussive and rhythmic sounds. Woodpeckers drum with the bill on dead limbs and nighthawks dive toward their mate producing a booming sound. Ruffed grouse drum their wings while perched on logs. Many birds preen each other and rub their beaks together as a form of courtship. Others use gifts of food. Birds like the common tern, blue jay, cedar waxwing and others will offer their partners food.
Male birds with the showiest plumage and courtship displays do not help raise their young. They may attract and mate with many females but take no part in nest building, hatching eggs, or rearing the chicks. The females have dull plumage, often mottled brown, so they are camouflaged when sitting on the nest.
In the plant world, many trees are currently flowering. Watch for the red bloom of the maples, or the yellow-green birch and aspen catkins, looking more like a worm than a flower. Hepatica is currently blooming. Marsh marigolds should begin blooming soon. Other plants to begin searching for are the trilliums, violets, and columbine.
The Museum staff is enjoying hearing from readers about their phenological observations, and is adding this information to their database. If you have an observation to share, please email the Museum at info@cablemuseum.org. Enjoy the spring outdoors with a bicycle ride or walk, and be sure to bring a pair of binoculars along!
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.
May 7, 2009
By Susan Benson,
CNHM Director of Education
Although April showers didn’t shower much in our region, May flowers appear to still be on their way. For some, May brings the first fish caught, the last frost, the first lawn mowing, and the first swim in a nearby lake or river. Regardless of our interests, spring continues to bring exciting natural events for us to observe. Look high and low for any of the following birds or plants of the north woods.
The first hummingbird is often spotted in the first or second week of May. Northern orioles typically return about the same time, but usually in the second week. Rose-breasted grosbeaks can be seen at the feeders again. Other birds to watch for in the first two weeks of May are the catbirds, wood thrushes, scarlet tanagers, indigo buntings, and wood pewees. Warbler migration also begins early in the month.
There are other bird behaviors to watch for this month. For birds, courtship in May sometimes begins aggressively because of the need to defend territory. Some courtship rituals include singing. Most song is emitted by the male, and is delivered from prominent perches, although some species sing during flight. This song is a way of defending territory against other males and to tell a female of the presence of the male. Some studies suggest that birds sing when aroused by an intrusion of another bird species into their territory, showing aggressive competition between species.
Birds that do not sing in courtship have other means of attracting attention, producing percussive and rhythmic sounds. Woodpeckers drum with the bill on dead limbs and nighthawks dive toward their mate producing a booming sound. Ruffed grouse drum their wings while perched on logs. Many birds preen each other and rub their beaks together as a form of courtship. Others use gifts of food. Birds like the common tern, blue jay, cedar waxwing and others will offer their partners food.
Male birds with the showiest plumage and courtship displays do not help raise their young. They may attract and mate with many females but take no part in nest building, hatching eggs, or rearing the chicks. The females have dull plumage, often mottled brown, so they are camouflaged when sitting on the nest.
In the plant world, many trees are currently flowering. Watch for the red bloom of the maples, or the yellow-green birch and aspen catkins, looking more like a worm than a flower. Hepatica is currently blooming. Marsh marigolds should begin blooming soon. Other plants to begin searching for are the trilliums, violets, and columbine.
The Museum staff is enjoying hearing from readers about their phenological observations, and is adding this information to their database. If you have an observation to share, please email the Museum at info@cablemuseum.org. Enjoy the spring outdoors with a bicycle ride or walk, and be sure to bring a pair of binoculars along!
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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