By Susan Benson,
CNHM Director of Education
A small flash of blue flutters by on a bright sunny day. This is the spring azure butterfly, which although cannot have the title as first butterfly we see, it is the first butterfly to emerge from its over-wintering chrysalis. I have been observing them for a few weeks now, although late April is usually the earliest we see the adults. When I see my first blooming violet, I know to begin looking for these tiny, one-inch blues. Where can we best find a spring azure butterfly? Woodland edges, bogs, swamps, overgrown fields, and pine barrens are some of their preferred habitats.
The small spring azure caterpillars are light green with a darker-looking green stripe along their back. They feed on the leaves and flowers of dogwood, cherry, and blueberries. They have an amazing symbiotic relationship with ants, producing honeydew, a sweet substance that attracts ants. The ants feed on the honeydew and protect the caterpillars from predation until they form their chrysalis.
This butterfly has only one brood per summer, making our observations of them that much more special. The females only live for about four days, mating on the first day and laying their eggs on day two. The adults seldom eat nectar or other foods with such a short life cycle.
Looking in a dictionary, we can find definitions of the word azure such as: of or having a light, purplish shade of blue, like that of a clear and unclouded sky. Certainly this butterfly species is aptly named, and thoroughly enjoyed!
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 new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.
Monday, May 24, 2010
Monday, May 17, 2010
Warbler Migration
By Susan Benson,
CNHM Director of Education
May is the best time for seeing some of the most beautiful birds, the warblers. These small birds are on their way back from Central and South America, nearing the completion of their thousand mile or more journey to their northern breeding grounds. These mostly insectivorous insects are nocturnal migrants, flying almost non-stop trips, or stopping for several days along the route to refuel their bodies for the next flight. Warblers fly in flock or waves, bringing a bright spot of color to our lives. Many male warblers also sing their beautiful songs, making them even more noticeable. On a good day after a warbler wave has arrived, a birder can see or hear over a dozen species of warblers. Here are some special warblers to keep an eye or ear out for:
Yellow-rumped Warbler: Named after its most distinctive yellow patch above its tail, this is a commonly seen warbler in spring. The brighter males forage higher in the trees than most other warblers. They are also the warbler that is most likely seen darting out from a tree to catch an insect. Their preferred habitat includes mature coniferous and mixed coniferous-deciduous woodlands. Their song is a variable trill.
Black-and-white Warbler: With its distinctive black and white plumage, it forages for insects while creeping along the trunks and branches of trees like a nuthatch. It is one of the earliest migrating warblers and prefers mature or second-growth deciduous or mixed forests. Its sweet sound is a “wheezy, wheezy, wheezy, wheezy”
Black-throated Green Warbler: As its name suggests, the male has a black throat, and is also noticeable with its yellow face. This bird is often heard rather than seen, as it prefers conifer trees, and usually is hiding deep within one. Its "zee zee zee zoo zee" song is very distinctive, and as this bird chooses to stop for its breeding season in northern Wisconsin, we continue to hear it throughout May into very early June.
These are just three of maybe fifteen easier seen or heard warblers in the north woods. Look for warblers near you by finding their preferred habitats. Forest edges and near waterways are also good places to look or listen for warblers. It is also worthwhile to listen to a bird songs CD to learn more about warbler song identification. Grab your binoculars and your field guide to enjoy the color and song show!
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 new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.
CNHM Director of Education
May is the best time for seeing some of the most beautiful birds, the warblers. These small birds are on their way back from Central and South America, nearing the completion of their thousand mile or more journey to their northern breeding grounds. These mostly insectivorous insects are nocturnal migrants, flying almost non-stop trips, or stopping for several days along the route to refuel their bodies for the next flight. Warblers fly in flock or waves, bringing a bright spot of color to our lives. Many male warblers also sing their beautiful songs, making them even more noticeable. On a good day after a warbler wave has arrived, a birder can see or hear over a dozen species of warblers. Here are some special warblers to keep an eye or ear out for:
Yellow-rumped Warbler: Named after its most distinctive yellow patch above its tail, this is a commonly seen warbler in spring. The brighter males forage higher in the trees than most other warblers. They are also the warbler that is most likely seen darting out from a tree to catch an insect. Their preferred habitat includes mature coniferous and mixed coniferous-deciduous woodlands. Their song is a variable trill.
Black-and-white Warbler: With its distinctive black and white plumage, it forages for insects while creeping along the trunks and branches of trees like a nuthatch. It is one of the earliest migrating warblers and prefers mature or second-growth deciduous or mixed forests. Its sweet sound is a “wheezy, wheezy, wheezy, wheezy”
Black-throated Green Warbler: As its name suggests, the male has a black throat, and is also noticeable with its yellow face. This bird is often heard rather than seen, as it prefers conifer trees, and usually is hiding deep within one. Its "zee zee zee zoo zee" song is very distinctive, and as this bird chooses to stop for its breeding season in northern Wisconsin, we continue to hear it throughout May into very early June.
These are just three of maybe fifteen easier seen or heard warblers in the north woods. Look for warblers near you by finding their preferred habitats. Forest edges and near waterways are also good places to look or listen for warblers. It is also worthwhile to listen to a bird songs CD to learn more about warbler song identification. Grab your binoculars and your field guide to enjoy the color and song show!
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 new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.
Tuesday, May 11, 2010
Black Bears in Spring
By Susan Benson,
CNHM Director of Education
With snow falling on the ground it was difficult to write about a spring phenological observation. This morning when I awoke to several inches of snow on the ground, I discovered a thief that had been by the house during the night. My fiance has a 1974 Classic Plymouth Duster, a very nice looking car. Having just taken it out of winter storage, he had covered it with a rather pricey car cover. This morning the car cover was gone, completely out of sight. Upon much inspection, we discovered the culprit – a black bear. It would have been unbelievable had I not seen the bear tracks with my very own eyes. Or have seen the tooth or claw marks in the car cover. What could that black bear have wanted with a car cover? Good protection from the snow, the very thing we were protecting the car from? Food? My theory is that this made in China car cover perhaps was made using “waterproof” fish oil, and the bear caught the scent and was hoping for a fish meal. I guess we’ll never know what was in this bear’s mind, but it made for a very comical morning. What do bears eat in the spring, anyway?
When black bears emerge from their dens in mid-March, they recover near the den as their metabolism revs up again. During this time their fur looks healthy, but soon they shed their winter coat. When their digestive system is ready to go, black bears will begin foraging to replace lost calories from the long winter without food. Bears, especially the males, will travel long distances in the spring to find food. Males home range can be fifteen to twenty-seven square miles, while females usually maintain a five-square mile area. If food is scarce, bears will wander farther from their territory looking for food, and may extend their feeding hours into the daylight. In mid-May, the breeding season begins, and the males will start roaming greater distances.
If a sow gives birth during January or February, her cubs will stay with her 18-24 months. She communicates with her cubs using her voice that includes “woof” and whimpering sounds.
Black bears locate their food by relying on their amazing sense of smell. A black bear can smell a candy bar from two miles away. They feed mostly from evening twilight until sunrise. In early spring when plants are still dormant, bears will rely on small mammals or carrion for their food. They will also rip open rotten logs or anthills to feed on the insects, both eggs and larvae that are found inside. As plants begin to sprout, black bears will switch to up to 40 different types of plants. They will also eat last year’s berry crop, tubers, acorns, nuts, mice, squirrels, or beetles. Bears molars are flattened for grinding and chewing plant food instead of slicing through meat.
Missing car covers, tracks in the snow, or disappearing bird feeders are not the only signs to look for of bears. Their scat filled with digested plants or seeds is very noticeable. Even as I write this, I continue to ponder and smile at our morning visitor, wondering just what it wanted with the car cover. Please send your own black bear stories to info@cablemuseum.org, or post a comment on the Museum’s Nature Watch blog, cablemuseumnaturewatch.blogspot.com.
For over 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 new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs.
CNHM Director of Education
With snow falling on the ground it was difficult to write about a spring phenological observation. This morning when I awoke to several inches of snow on the ground, I discovered a thief that had been by the house during the night. My fiance has a 1974 Classic Plymouth Duster, a very nice looking car. Having just taken it out of winter storage, he had covered it with a rather pricey car cover. This morning the car cover was gone, completely out of sight. Upon much inspection, we discovered the culprit – a black bear. It would have been unbelievable had I not seen the bear tracks with my very own eyes. Or have seen the tooth or claw marks in the car cover. What could that black bear have wanted with a car cover? Good protection from the snow, the very thing we were protecting the car from? Food? My theory is that this made in China car cover perhaps was made using “waterproof” fish oil, and the bear caught the scent and was hoping for a fish meal. I guess we’ll never know what was in this bear’s mind, but it made for a very comical morning. What do bears eat in the spring, anyway?
When black bears emerge from their dens in mid-March, they recover near the den as their metabolism revs up again. During this time their fur looks healthy, but soon they shed their winter coat. When their digestive system is ready to go, black bears will begin foraging to replace lost calories from the long winter without food. Bears, especially the males, will travel long distances in the spring to find food. Males home range can be fifteen to twenty-seven square miles, while females usually maintain a five-square mile area. If food is scarce, bears will wander farther from their territory looking for food, and may extend their feeding hours into the daylight. In mid-May, the breeding season begins, and the males will start roaming greater distances.
If a sow gives birth during January or February, her cubs will stay with her 18-24 months. She communicates with her cubs using her voice that includes “woof” and whimpering sounds.
Black bears locate their food by relying on their amazing sense of smell. A black bear can smell a candy bar from two miles away. They feed mostly from evening twilight until sunrise. In early spring when plants are still dormant, bears will rely on small mammals or carrion for their food. They will also rip open rotten logs or anthills to feed on the insects, both eggs and larvae that are found inside. As plants begin to sprout, black bears will switch to up to 40 different types of plants. They will also eat last year’s berry crop, tubers, acorns, nuts, mice, squirrels, or beetles. Bears molars are flattened for grinding and chewing plant food instead of slicing through meat.
Missing car covers, tracks in the snow, or disappearing bird feeders are not the only signs to look for of bears. Their scat filled with digested plants or seeds is very noticeable. Even as I write this, I continue to ponder and smile at our morning visitor, wondering just what it wanted with the car cover. Please send your own black bear stories to info@cablemuseum.org, or post a comment on the Museum’s Nature Watch blog, cablemuseumnaturewatch.blogspot.com.
For over 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 new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs.
Monday, May 3, 2010
Green Darner
By Susan Benson,
CNHM Director of Education
This past week I was bitten by a dragonfly. It was April 27, to be exact. I hope no one gets too alarmed by this statement. Dragonflies are not exactly one of the animal world in which we fear. This event, however, goes down in my phenology journal. I have always had a close relationship with insects, as I have been an avid fan since I was in second grade. I could share the most inane details about certain insects that would bore people in minutes. Dragonflies land on me, or near me, regularly when I am near water. I have always thought we were big buddies. As my fiancé and I were walking down to the Namekagon river, he asked me if dragonflies bit, and I promptly answered, “they could, but they never would.” I was in the midst of rescuing a damaged, but beautiful specimen. Just as I was ready to put it down, it bit me, again and again! For a moment, I felt great sympathy for mosquitoes.
This dragonfly was a green darner, easily identified by their green thorax and bright blue abdomen. They also have an obvious bull’s eye pattern on top of their face. Green darners are the first dragonfly to be seen in early spring, and their second “flight” begins in early August through October. In the fall, northern juveniles migrate south, flocking together in the thousands. They fly south to the southern states, and their offspring fly north in the spring. They arrive in our region, lay eggs, and those eggs become the juveniles that leave us this fall. Local birders believe that the green darner migration occurs at the same time the American kestrel migration happens down the North Shore, and it is believed that the kestrels feed on the green darners as a migratory fuel source. It is possible that we have a non-migratory population as well. These residents overwinter as nymphs and hatch in the spring.
Green darner eggs are laid inside stems of aquatic plants. The female uses her sharp, egg-laying ovipositor to pierce the plants. It is during this egg-laying time that females must beware or they may become dinner to a fish. The hatching darner nymphs, which to me look almost “alien,” live in the water and feed primarily on fish eggs, tadpoles and aquatic insects. Adults eat fly midges, mosquitoes, caddisflies, butterflies and moths, and other flying insects. In general, this species prefers fishless habitats that have still waters such as permanent or temporary ponds, marshes, or slow streams with emergent vegetation.
Green darners are nicknamed because their abdomen looks like a darning needle. They are also called mosquito hawks. With their outstanding flight abilities and almost 360-degree sight, they can fly fifty miles per hour and kill prey larger than themselves. They can also reach altitudes of nearly 18,000 feet. Scientists track their movements through tiny locating beacons which allow us to know so much about these species.
I could impress everyone with my knowledge that dragonflies belong to the order Odonata. A translation of this word is “toothed ones,” due to the awesome lower lip, which used to capture and hold their prey while their mandibles do the eating. Indeed, I now know all about their mouth parts, and have the two millimeter “owie” to prove it, along with a whole new dose of respect and admiration for these insects.
For over 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 new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.
CNHM Director of Education
This past week I was bitten by a dragonfly. It was April 27, to be exact. I hope no one gets too alarmed by this statement. Dragonflies are not exactly one of the animal world in which we fear. This event, however, goes down in my phenology journal. I have always had a close relationship with insects, as I have been an avid fan since I was in second grade. I could share the most inane details about certain insects that would bore people in minutes. Dragonflies land on me, or near me, regularly when I am near water. I have always thought we were big buddies. As my fiancé and I were walking down to the Namekagon river, he asked me if dragonflies bit, and I promptly answered, “they could, but they never would.” I was in the midst of rescuing a damaged, but beautiful specimen. Just as I was ready to put it down, it bit me, again and again! For a moment, I felt great sympathy for mosquitoes.
This dragonfly was a green darner, easily identified by their green thorax and bright blue abdomen. They also have an obvious bull’s eye pattern on top of their face. Green darners are the first dragonfly to be seen in early spring, and their second “flight” begins in early August through October. In the fall, northern juveniles migrate south, flocking together in the thousands. They fly south to the southern states, and their offspring fly north in the spring. They arrive in our region, lay eggs, and those eggs become the juveniles that leave us this fall. Local birders believe that the green darner migration occurs at the same time the American kestrel migration happens down the North Shore, and it is believed that the kestrels feed on the green darners as a migratory fuel source. It is possible that we have a non-migratory population as well. These residents overwinter as nymphs and hatch in the spring.
Green darner eggs are laid inside stems of aquatic plants. The female uses her sharp, egg-laying ovipositor to pierce the plants. It is during this egg-laying time that females must beware or they may become dinner to a fish. The hatching darner nymphs, which to me look almost “alien,” live in the water and feed primarily on fish eggs, tadpoles and aquatic insects. Adults eat fly midges, mosquitoes, caddisflies, butterflies and moths, and other flying insects. In general, this species prefers fishless habitats that have still waters such as permanent or temporary ponds, marshes, or slow streams with emergent vegetation.
Green darners are nicknamed because their abdomen looks like a darning needle. They are also called mosquito hawks. With their outstanding flight abilities and almost 360-degree sight, they can fly fifty miles per hour and kill prey larger than themselves. They can also reach altitudes of nearly 18,000 feet. Scientists track their movements through tiny locating beacons which allow us to know so much about these species.
I could impress everyone with my knowledge that dragonflies belong to the order Odonata. A translation of this word is “toothed ones,” due to the awesome lower lip, which used to capture and hold their prey while their mandibles do the eating. Indeed, I now know all about their mouth parts, and have the two millimeter “owie” to prove it, along with a whole new dose of respect and admiration for these insects.
For over 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 new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.
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