By Susan Thurn,
CNHM Director of Education
This week’s Museum Junior Naturalists went out in search of ladybugs. Ladybird beetles, to be precise. This adventure was part of a citizen science project for the Lost Ladybug Project, a search for native ladybugs organized by the Cornell University Department of Entomology. Twenty-six children ages 5-12 donned their insect nets in a field and forest edge along the Namekagon River. We swept above the flowers and plants with hopes of finding ladybugs. We placed a sheet underneath tree branches and gently knocked the branches to observe what fell out of the trees. After a thorough search, we successfully caught ONE ladybug, which promptly flew away. I had thought that an adventurous group of children would be the perfect eyes to spot a ladybug. Now I wonder if they even really knew what they were looking for. Do they, like I did as a child, play regularly with ladybugs?
How could it be that we could only find one ladybug? Three ladybug species, the two-spot, the nine-spot, and the transverse ladybugs were once common but now appear to be rare. Three other species, the parenthesis, spotted pink, and convergent ladybugs, are more common natives. Scientists believe these native ladybugs are disappearing, and the Lost Ladybug Project is using citizen-based science to help find them. Scientists are looking for information on which ladybugs are still present and how many individuals can be found.
While many of the natives seem to be disappearing, ladybugs from other places have greatly increased their numbers and range. Many of us are familiar with the multicolored Asian ladybug, introduced from Japan for biological control of insects. This ladybug has a big appetite, and has adapted to eat the same foods our native ladybugs eat, even eating native and its own ladybug larvae. This is the same ladybug we see in our homes as they winter in huge masses. The checkerspot and seven-spotted ladybug are also ladybugs that were introduced into North America in the late 50’s and 60’s, and their populations continue to spread.
What are the current results of the Lost Ladybug studies? According to the ladybugs being reported, the numbers of introduced ladybugs far exceeds that of the natives. Over half of the findings are introduced ladybug species. Scientists are discovering which habitat niches in which the native ladybugs are the most successful. They are finding that the Asian ladybug is spreading its range into places that wasn’t previously inhabited. Pathogens are being found in native ladybug populations which could be contributing to their decline. Research is showing that native ladybugs that have less food grow into smaller, shrinking adults. Finally, evidence is appearing that the native nine-spot is inter-breeding with the introduced seven-spot ladybug.
Why should we care about ladybugs? They are beautiful. I remember as a child of seven, loving them, catching them again and again and enjoying their tickles across my skin. I learned from a ladybug about how animals use their bright coloring as a warning to predators to remind them of the awful repellents they release when attacked. They are very important because they assist with eating other plant-feeding insects, keeping those populations low. The fewer the ladybugs, the more fragile ecosystems can become during a pest insect population explosion. Keep your eyes open for a ladybug in your own yard. Share your ladybug stories at the Museum’s Nature Watch blog at www.cablemuseumnaturewatch.blogspot.com. Explore and wonder from 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 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, July 27, 2010
Monday, July 19, 2010
Night Sky
By Susan Thurn,
CNHM Director of Education
The “dog days” of summer are here! We refer to them as the hottest days of the year. These dog days are based on an ancient Greek belief that Sirius, also called the Dog Star, was responsible for the heat. Skywatchers of long ago actually thought that the heat from Sirius and the sun combined to produce hotter weather. Ancient Egyptians used the star as a “watchdog,” as Sirius appeared in the night sky right before the Nile River’s flooding season. There are several interesting events to watch for in the next week in the night sky as we enter this year’s dog days.
Right after sunset, be sure to check out the low western horizon to see the planets lined up, from left to right, Saturn, Mars, and Venus. Venus is so bright it is the second brightest object in the sky (next to the moon,) so look there first. Mars and Saturn are next to it, but they might be fainter. Each night, they seem to be getting closer and closer together, which is a line of sight effect, but still a fun race to watch in the night sky. A glimpse of Mercury can also be made down very low in the skyline, but a pair of binoculars might help to view it.
There are exciting stars and constellations to look for in our night sky. Look south in the night sky for a bright orange star called Antares that helps to identify the hook-shaped Scorpius, while just to the left, the brightest stars of Sagittarius form a teapot. The steam above the teapot’s spout is the Milky Way. Look in the eastern sky for the summer triangle. The brightest star shining in that direction is Vega. Deneb is the star on the lower left corner of the triangle and Altair is on its lower right.
The last night sky treats to watch for include the July 26 full moon, and the southern Delta Aquarids meteor shower peak that will occur July 28-29, producing 20 meteors per hour at their best. The best viewing of this meteor shower is in the east, after midnight, in the constellation Aquarius. Jupiter also begins rising in the east between 11:00 p.m. and midnight, and for those who are early risers, the brightest object in the southeast before dawn, is Jupiter.
Turn out the night lights in your home, and get outdoors with a telescope, binoculars, and a chair or blanket. Explore and wonder from 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 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
The “dog days” of summer are here! We refer to them as the hottest days of the year. These dog days are based on an ancient Greek belief that Sirius, also called the Dog Star, was responsible for the heat. Skywatchers of long ago actually thought that the heat from Sirius and the sun combined to produce hotter weather. Ancient Egyptians used the star as a “watchdog,” as Sirius appeared in the night sky right before the Nile River’s flooding season. There are several interesting events to watch for in the next week in the night sky as we enter this year’s dog days.
Right after sunset, be sure to check out the low western horizon to see the planets lined up, from left to right, Saturn, Mars, and Venus. Venus is so bright it is the second brightest object in the sky (next to the moon,) so look there first. Mars and Saturn are next to it, but they might be fainter. Each night, they seem to be getting closer and closer together, which is a line of sight effect, but still a fun race to watch in the night sky. A glimpse of Mercury can also be made down very low in the skyline, but a pair of binoculars might help to view it.
There are exciting stars and constellations to look for in our night sky. Look south in the night sky for a bright orange star called Antares that helps to identify the hook-shaped Scorpius, while just to the left, the brightest stars of Sagittarius form a teapot. The steam above the teapot’s spout is the Milky Way. Look in the eastern sky for the summer triangle. The brightest star shining in that direction is Vega. Deneb is the star on the lower left corner of the triangle and Altair is on its lower right.
The last night sky treats to watch for include the July 26 full moon, and the southern Delta Aquarids meteor shower peak that will occur July 28-29, producing 20 meteors per hour at their best. The best viewing of this meteor shower is in the east, after midnight, in the constellation Aquarius. Jupiter also begins rising in the east between 11:00 p.m. and midnight, and for those who are early risers, the brightest object in the southeast before dawn, is Jupiter.
Turn out the night lights in your home, and get outdoors with a telescope, binoculars, and a chair or blanket. Explore and wonder from 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 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, July 13, 2010
Woodland Butterflies
Woodland Delights
Susan Thurn,
CNHM Director of Education
My mother is a passionate gardener, and she knows all of her plant friends by name. Others have birds at their feeder, or squirrels, chipmunks, or bears that they know and call by name. A Museum member called to report her repeated observation of Compton’s tortoiseshell butterflies this week. The following day, I was out scouting Mount Telemark for a hike up the big hill, and saw a variety of woodland butterflies as well. In northern Wisconsin, we have several woodland butterflies that are worth getting to know by name. Please let me introduce you to the Compton tortoiseshell, northern pearly-eye, common wood nymph, and little wood-satyr, all woodland delights.
The Compton tortoiseshell butterfly is more common in our northern counties. It belongs in a group of butterflies called true brush-foots because they appear to have only four legs. Their front forelegs are reduced in size, usually hairy and resembling brushes. Adults emerge in July, in deciduous woodlands, trails, openings, and woodland edges. From above, this butterfly looks mostly a rusty orange and black butterfly, with single white marks near the edge of each wing. The wings have sharper angles with a small tail on the hind or lower wing. From below, the butterfly could be mistaken for tree bark, as they have a camouflaged coloring with a silvery mark in the middle of the hind wing. Last year, Compton’s tortoiseshell butterflies were seen in higher numbers, as the species does have periodic fluctuations in its populations, being abundant for years and then disappearing for other years. Its common name is from a famous English naturalist, Philip Gosse, who studied the butterfly while living in the town of Compton in Quebec in the nineteenth century. These butterflies overwinter as an adult, mating in the spring for a July emergence.
The northern pearly-eye butterfly is a common woodland species rarely found in openings. It is also commonly seen in woodlands, woodland edges, or while we are hiking down a woodland trail. This species is best identified by its brown coloring with lighter areas on the fore or front wing, and two obvious dark spots through both wings. Other spots trail down the hind wing. From below, the spots are circled with a yellow, brown, and white ring. The hind wing spots have a small white dot in the center. This species may be more difficult to identify with its fast, erratic flight that sometime ends further away against a sunlit tree.
The common wood nymph may be the most common butterfly in Wisconsin in a woodland habitat. Its lack of color makes it less conspicuous, but still worth looking for. This species is usually seen from below, so its underside has two large eyespots with a yellow ring on its fore wing. It is most often found in open fields near woodlands. This is the most common satyr butterfly that can be seen, and the best time to catch a flash of this butterfly is in July.
The less common little wood-satyr is often mistaken for a northern pearly-eye, but the little wood is much smaller, and found flying within only a few feet of the ground. They also fly more slowly, looking almost lazy in its flight. From above, it has two obvious eyespots on the fore wing and on the hind wing, ringed with white. When seen from below, it has two eyespots on the fore wing, while the hind wing has two eyespots and several smaller eyespots. There are also two darker lines across both wings. This species is also found earlier in the season, more in June than July.
My passion in nature is for butterflies. I try to know all their names, and take great joy in learning more about them through observation. These four butterfly species are all so amazingly camouflaged that I find it difficult sometimes to identify them. I use little things to help me remember them: Compton’s – orange and black with white; pearly-eyed – two main spots, trailing spots, with white dots in the center; common wood nymph – obvious large eyespots on the forewing with yellow rings; little wood satyr – smaller with two spots on top (forewing) and two on bottom, and lazy flight near the ground. May you all get to know these butterflies, and enjoy these woodland delights!
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.
Susan Thurn,
CNHM Director of Education
My mother is a passionate gardener, and she knows all of her plant friends by name. Others have birds at their feeder, or squirrels, chipmunks, or bears that they know and call by name. A Museum member called to report her repeated observation of Compton’s tortoiseshell butterflies this week. The following day, I was out scouting Mount Telemark for a hike up the big hill, and saw a variety of woodland butterflies as well. In northern Wisconsin, we have several woodland butterflies that are worth getting to know by name. Please let me introduce you to the Compton tortoiseshell, northern pearly-eye, common wood nymph, and little wood-satyr, all woodland delights.
The Compton tortoiseshell butterfly is more common in our northern counties. It belongs in a group of butterflies called true brush-foots because they appear to have only four legs. Their front forelegs are reduced in size, usually hairy and resembling brushes. Adults emerge in July, in deciduous woodlands, trails, openings, and woodland edges. From above, this butterfly looks mostly a rusty orange and black butterfly, with single white marks near the edge of each wing. The wings have sharper angles with a small tail on the hind or lower wing. From below, the butterfly could be mistaken for tree bark, as they have a camouflaged coloring with a silvery mark in the middle of the hind wing. Last year, Compton’s tortoiseshell butterflies were seen in higher numbers, as the species does have periodic fluctuations in its populations, being abundant for years and then disappearing for other years. Its common name is from a famous English naturalist, Philip Gosse, who studied the butterfly while living in the town of Compton in Quebec in the nineteenth century. These butterflies overwinter as an adult, mating in the spring for a July emergence.
The northern pearly-eye butterfly is a common woodland species rarely found in openings. It is also commonly seen in woodlands, woodland edges, or while we are hiking down a woodland trail. This species is best identified by its brown coloring with lighter areas on the fore or front wing, and two obvious dark spots through both wings. Other spots trail down the hind wing. From below, the spots are circled with a yellow, brown, and white ring. The hind wing spots have a small white dot in the center. This species may be more difficult to identify with its fast, erratic flight that sometime ends further away against a sunlit tree.
The common wood nymph may be the most common butterfly in Wisconsin in a woodland habitat. Its lack of color makes it less conspicuous, but still worth looking for. This species is usually seen from below, so its underside has two large eyespots with a yellow ring on its fore wing. It is most often found in open fields near woodlands. This is the most common satyr butterfly that can be seen, and the best time to catch a flash of this butterfly is in July.
The less common little wood-satyr is often mistaken for a northern pearly-eye, but the little wood is much smaller, and found flying within only a few feet of the ground. They also fly more slowly, looking almost lazy in its flight. From above, it has two obvious eyespots on the fore wing and on the hind wing, ringed with white. When seen from below, it has two eyespots on the fore wing, while the hind wing has two eyespots and several smaller eyespots. There are also two darker lines across both wings. This species is also found earlier in the season, more in June than July.
My passion in nature is for butterflies. I try to know all their names, and take great joy in learning more about them through observation. These four butterfly species are all so amazingly camouflaged that I find it difficult sometimes to identify them. I use little things to help me remember them: Compton’s – orange and black with white; pearly-eyed – two main spots, trailing spots, with white dots in the center; common wood nymph – obvious large eyespots on the forewing with yellow rings; little wood satyr – smaller with two spots on top (forewing) and two on bottom, and lazy flight near the ground. May you all get to know these butterflies, and enjoy these woodland delights!
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, July 6, 2010
Eggs in a Basket
Susan Thurn,
CNHM Director of Education
The Eastern phoebe is nesting in the same nest again in my house eaves. Not just for the second year, but for the second time this year. Many bird species have more than one brood in a season. Birds may lay more than one brood per year as a survival strategy. A bird is driven to pass on its genetic material through reproduction, and more young can mean more of them reach adulthood. Many songbirds have enough time to raise more than one family with a short period of time between egg-laying and fledge time. Their young can still have time enough to fatten up for their southern migration, or to prepare for our northern winters. It used to be thought that most birds nested for life. However, some birds do not nest for life, and some birds do not even keep the same mate for a second brood. How many eggs does a bird “put in a basket,” anyway?
Eastern phoebes are very loyal to their nesting locations, using them not only for their typical two broods per season, but also using them for many years. The phoebe makes repairs to the nest, apparently following the 3-R’s – reduce, reuse, recycle, by using the nest again. Most research suggests that phoebes keep the same mate through the season. Other birds in our region that can have two broods per season with the same mate include chipping, field, and song sparrows, juncos, towhees, catbirds, and robins.
Birds that often have two broods per season and sometimes choose different mates for the second brood include brown thrashers, bluebirds, and house wrens. The story gets even more interesting, however. Bluebird studies have shown that generally, northern birds have fewer broods than southern birds, but still have about the same number of young each season. In our neck of the woods (or fields, as that is the habitat bluebirds prefer,) bluebirds have two broods. Further south, where the food supply of insects is greater because of a longer warm season, bluebirds have three broods. Broods in the north lay more eggs than bluebirds in the south, and so end up with about the same number of young.
Would it be better to have more babies at once, or spread them out over one season? Would there be an advantage to having more nests, but fewer mouths to feed? Do northern birds sacrifice time to raise and train fledglings? Perhaps only a parent could know. Actually, it appears that there is a trade-off because although southern birds might have a “basket” full of more eggs, they have higher hatching failures.
It is fascinating to continue discovering about the natural history and science of birds. It was a Museum member who brought this question about birds and their second broods to my attention. It is often this spark of curiosity that will lead us to our own discoveries, perhaps to a bird in our own neighborhood that is in the midst of its second brood.
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
The Eastern phoebe is nesting in the same nest again in my house eaves. Not just for the second year, but for the second time this year. Many bird species have more than one brood in a season. Birds may lay more than one brood per year as a survival strategy. A bird is driven to pass on its genetic material through reproduction, and more young can mean more of them reach adulthood. Many songbirds have enough time to raise more than one family with a short period of time between egg-laying and fledge time. Their young can still have time enough to fatten up for their southern migration, or to prepare for our northern winters. It used to be thought that most birds nested for life. However, some birds do not nest for life, and some birds do not even keep the same mate for a second brood. How many eggs does a bird “put in a basket,” anyway?
Eastern phoebes are very loyal to their nesting locations, using them not only for their typical two broods per season, but also using them for many years. The phoebe makes repairs to the nest, apparently following the 3-R’s – reduce, reuse, recycle, by using the nest again. Most research suggests that phoebes keep the same mate through the season. Other birds in our region that can have two broods per season with the same mate include chipping, field, and song sparrows, juncos, towhees, catbirds, and robins.
Birds that often have two broods per season and sometimes choose different mates for the second brood include brown thrashers, bluebirds, and house wrens. The story gets even more interesting, however. Bluebird studies have shown that generally, northern birds have fewer broods than southern birds, but still have about the same number of young each season. In our neck of the woods (or fields, as that is the habitat bluebirds prefer,) bluebirds have two broods. Further south, where the food supply of insects is greater because of a longer warm season, bluebirds have three broods. Broods in the north lay more eggs than bluebirds in the south, and so end up with about the same number of young.
Would it be better to have more babies at once, or spread them out over one season? Would there be an advantage to having more nests, but fewer mouths to feed? Do northern birds sacrifice time to raise and train fledglings? Perhaps only a parent could know. Actually, it appears that there is a trade-off because although southern birds might have a “basket” full of more eggs, they have higher hatching failures.
It is fascinating to continue discovering about the natural history and science of birds. It was a Museum member who brought this question about birds and their second broods to my attention. It is often this spark of curiosity that will lead us to our own discoveries, perhaps to a bird in our own neighborhood that is in the midst of its second brood.
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.
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