Nature Watch
By Susan Thurn,
Cable Natural History Museum
As I was walking down the road, the goldenrod stalks were waving in the wind. In late summer, the yellow colors of the goldenrod lights up the fields and roadsides. Now, its dead stems sometimes show life, with a round ball evident on some of the stems. This round ball is an insect gall, the home of a small fly spending the winter protected inside this plant. My body shivers in the cold, just thinking of what it might be like to be an insect inside that small ball, tucked inside a plant. What an interesting place to spend the winter!
A goldenrod gall is formed by a small fly, a fruit fly. The insect’s relationship with goldenrod began last spring when a female fly laid one egg in May to early June on the leaves of a goldenrod stem. After four days, the egg hatched and immediately the young larva chewed into the stem. The larva injected chemicals into the plants, causing cell division to increase and form the round gall. Its hard corky exterior protected the inner nutritious starches that provided food for the larva. As the gall grew, the fly larva created a central chamber that it lived in until the next spring. During the summer, the white larva fed on the inside of the gall, growing until early October. Since the adult flies have no mouthparts with which to chew, the larva then chewed a tunnel out to the surface of the gall, leaving a thin protective exterior over the outer opening.
During the winter, the mature larva went into a diapause, or dormancy. As winter approached, the water content in their bodies was converted from glycogen into glycerol, acting as antifreeze to keep ice crystals from forming in their bodies. Additionally, they had the plant gall to provide physical protection from predators.
In the spring, the fly larva will leave its dormant state and pupate inside the gall. Once it emerges as an adult fruit fly, it will crawl along the previously created tunnel, inflate a balloon-like body part between its eyes to create an opening in the thin covering, and escape its winter home. As an adult, the fly is smaller than a house fly, and lives about ten days. The cycle then begins again.
The goldenrod gall is not harmed by the insect’s presence. It seems like an ideal, and amazing, way for a small insect to survive and adapt to the harsher elements of our winter season. However, the small fly is still susceptible to dangers. Downy woodpeckers and chickadees are known to feed upon the insect larvae. Two species of parasitic wasps deposit their eggs through the growing gall tissue into the fly larvae, so that a small black wasp may emerge in spring instead of a fruit fly.
Wander the snowy fields in search of some goldenrod ball galls. Take a closer look at one of nature’s amazing delights. Enjoy nature in our own back yards.
For over 42 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 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.
Wednesday, January 26, 2011
Thursday, January 20, 2011
At the Feeder
By Susan Thurn,
Cable Natural History Museum
At the Feeder
Much activity has been at the bird feeders this past week, and one of my favorite views and sounds came from observing the mourning dove. Their gentle woo-oo-oo-oo sound made from their cooing perches that gives the bird its name can comfort us, and the rapid flight on whistling wings is pleasant when they burst into the air.
Mourning doves feed mostly on the ground, swallowing seeds to store them in their enlarged esophagus we call the crop. One mourning dove was found to have over 17,000 seeds in its crop. Once they are finished feeding, they fly to their safe perch for digestion of their meal. Wild seeds, grasses, herbs, cultivated grains, and the occasional berry make up the most of this dove’s diet, with a once in while meal of snails. The birds peck or push aside ground litter while searching for food.
Known as a lover of baths in the sun or rain by lying on the ground or on a tree limb, mourning doves stretch out a wing, holding it in place. Our bird baths and shallow pools of water are also bathing places, and the doves will bathe in dust as well. They will often gather at their drinking spots at dawn or dusk. The bird drinks through suction, not needing to lift their heads.
Adult mourning doves feed their nestlings "pigeon milk," milk secreted from their crop lining. This food is fed to the hatchlings for three days, more nutritious than cow or human milk because of its protein and fat. Except for during the breeding season, the doves roost communally in conifer or deciduous trees, spending more time in them on colder winter days. Take a walk outdoors, and look for their roosting areas, listen to their mournful morning call, and enjoy the beauty in our own back yard.
For over 42 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 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.
Cable Natural History Museum
At the Feeder
Much activity has been at the bird feeders this past week, and one of my favorite views and sounds came from observing the mourning dove. Their gentle woo-oo-oo-oo sound made from their cooing perches that gives the bird its name can comfort us, and the rapid flight on whistling wings is pleasant when they burst into the air.
Mourning doves feed mostly on the ground, swallowing seeds to store them in their enlarged esophagus we call the crop. One mourning dove was found to have over 17,000 seeds in its crop. Once they are finished feeding, they fly to their safe perch for digestion of their meal. Wild seeds, grasses, herbs, cultivated grains, and the occasional berry make up the most of this dove’s diet, with a once in while meal of snails. The birds peck or push aside ground litter while searching for food.
Known as a lover of baths in the sun or rain by lying on the ground or on a tree limb, mourning doves stretch out a wing, holding it in place. Our bird baths and shallow pools of water are also bathing places, and the doves will bathe in dust as well. They will often gather at their drinking spots at dawn or dusk. The bird drinks through suction, not needing to lift their heads.
Adult mourning doves feed their nestlings "pigeon milk," milk secreted from their crop lining. This food is fed to the hatchlings for three days, more nutritious than cow or human milk because of its protein and fat. Except for during the breeding season, the doves roost communally in conifer or deciduous trees, spending more time in them on colder winter days. Take a walk outdoors, and look for their roosting areas, listen to their mournful morning call, and enjoy the beauty in our own back yard.
For over 42 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 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.
Wednesday, January 12, 2011
Where Do Birds Sleep
Nature Watch
By Susan Thurn,
Cable Natural History Museum
One of my favorite Christmas presents this year was the gift of a new mattress. I was pondering the other day, as I just woke up from a long winter night’s sleep, what is a night’s sleep like for a bird? How do they keep themselves warm? How do they survive such cold temperatures? Do they nest? Find other places to sleep? Whatever they do, a bird’s sleep could not compare to the comfort and warmth of my new memory foam bed!
Many people assume that birds use their nests during the winter, but a nest is a baby’s crib, something to be used during the spring rather than winter. However, some birds do use our human-made bird houses to sleep in for the night. Birds like woodpeckers, nuthatches, and other species curl up inside tree cavities for cover and heat. Many owls and other cavity-nesters find their favorite tree holes. Other birds crowd together in whatever nooks or crannies they find.
Our favorite, cheery goldfinches, sleep in thick evergreens, as do some sparrows, crossbills, snow buntings, and sometimes the chickadee. Songbirds such as blue jays and cardinals find dense thickets in which to sleep within. Crows and turkeys roost in trees. Crows sit close to the branches in their roost, feathers covering their feet, tucking their heads beneath their wings.
Some birds that prefer open fields will burrow into snow holes to escape the wind and cold. Ruffed grouse will dive down from the aspens in which they feed during the day to the deeper snow below, allowing the snow to insulate them from the colder night temperatures.
Some ducks sleep in icy water. Bobwhites sleep on the ground, heads facing outward to conserve body heat while protecting them from other dangers.
Wherever a bird sleeps, its first protection is from its feathers. Feathers repel water and insulate birds’ bodies from the cold. Using muscles, birds can raise or lower each feather, fluffing them to create warm air spaces. Burying their heads and feet also reduces heat loss.
Occasionally as I take a walk at dusk around the house I will pick up on the commotion as birds are settling in for the night. I keep my eyes open for the birds as they are getting ready for sleep. I wish for them sweet dreams and success throughout the night, and I appreciate my cozy warm home just that much more!
For over 42 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 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.
By Susan Thurn,
Cable Natural History Museum
One of my favorite Christmas presents this year was the gift of a new mattress. I was pondering the other day, as I just woke up from a long winter night’s sleep, what is a night’s sleep like for a bird? How do they keep themselves warm? How do they survive such cold temperatures? Do they nest? Find other places to sleep? Whatever they do, a bird’s sleep could not compare to the comfort and warmth of my new memory foam bed!
Many people assume that birds use their nests during the winter, but a nest is a baby’s crib, something to be used during the spring rather than winter. However, some birds do use our human-made bird houses to sleep in for the night. Birds like woodpeckers, nuthatches, and other species curl up inside tree cavities for cover and heat. Many owls and other cavity-nesters find their favorite tree holes. Other birds crowd together in whatever nooks or crannies they find.
Our favorite, cheery goldfinches, sleep in thick evergreens, as do some sparrows, crossbills, snow buntings, and sometimes the chickadee. Songbirds such as blue jays and cardinals find dense thickets in which to sleep within. Crows and turkeys roost in trees. Crows sit close to the branches in their roost, feathers covering their feet, tucking their heads beneath their wings.
Some birds that prefer open fields will burrow into snow holes to escape the wind and cold. Ruffed grouse will dive down from the aspens in which they feed during the day to the deeper snow below, allowing the snow to insulate them from the colder night temperatures.
Some ducks sleep in icy water. Bobwhites sleep on the ground, heads facing outward to conserve body heat while protecting them from other dangers.
Wherever a bird sleeps, its first protection is from its feathers. Feathers repel water and insulate birds’ bodies from the cold. Using muscles, birds can raise or lower each feather, fluffing them to create warm air spaces. Burying their heads and feet also reduces heat loss.
Occasionally as I take a walk at dusk around the house I will pick up on the commotion as birds are settling in for the night. I keep my eyes open for the birds as they are getting ready for sleep. I wish for them sweet dreams and success throughout the night, and I appreciate my cozy warm home just that much more!
For over 42 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 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.
Thursday, January 6, 2011
Blue Jay
Nature Watch
By Susan Thurn,
Cable Natural History Museum
“Jay! Jay!” is a familiar sound around our bird feeders. These blue jays are identified by their perky crests with blue, black and white plumage. Seeing them in large groups around our feeders is not uncommon. Find out the following information about these intelligent birds worth getting to know better.
To understand a blue jay's mood, just look at its crest. If it is up, this suggests a stressed or aggressive bird.
Blue jays are primarily vegetarians, eating mostly nuts, fruit, grain and seeds from trees and shrubs. They especially like acorns. They also eat small invertebrates such as beetles, caterpillars or grasshoppers. Having a reputation for raiding nests for eggs or young birds, studies have actually shown that this behavior is less common. Jays hold their food in their feet while pecking at it.
Blue jays store food in caches during the fall so that they may eat the food later in winter. They can carry food in their throat and upper esophagus, an area called a “gular pouch.” This “storage method” can allow jays to store one acorn in their bill, one in their mouth, and up to three acorns in their pouch. Six blue jays fitted with radio transmitters each cached up to 5,000 acorns in one autumn! It is no surprise this bird has the reputation as being a re-forester of the oak tree.
Blue jays have been observed "anting," rubbing their wings with ants. They even lose their balance as they are doing this. Why do they do this anting behavior? Scientists believe the substance from the ants can repel parasites, or perhaps help clean the feathers.
Some blue jays migrate, while others stay put all year-round. Migrating flocks of up to 250 birds have been observed flying over hawk-watching spots. The groups have included adults and young birds, but there seems to be no age difference between migrating jays and those that remain as residential birds. Some jays migrate one year but not the next. Scientists believe that the amount of jays that migrate is less than 20 percent. This migration continues to be quite a mystery.
The striking blue color with the snow as a backdrop makes a delightful winter sight. Our resident blue jays are fun to have around, and their sounds a joyful greeting to our ears. Be sure to get outside this week to enjoy what winter brings!
For over 42 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 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.
By Susan Thurn,
Cable Natural History Museum
“Jay! Jay!” is a familiar sound around our bird feeders. These blue jays are identified by their perky crests with blue, black and white plumage. Seeing them in large groups around our feeders is not uncommon. Find out the following information about these intelligent birds worth getting to know better.
To understand a blue jay's mood, just look at its crest. If it is up, this suggests a stressed or aggressive bird.
Blue jays are primarily vegetarians, eating mostly nuts, fruit, grain and seeds from trees and shrubs. They especially like acorns. They also eat small invertebrates such as beetles, caterpillars or grasshoppers. Having a reputation for raiding nests for eggs or young birds, studies have actually shown that this behavior is less common. Jays hold their food in their feet while pecking at it.
Blue jays store food in caches during the fall so that they may eat the food later in winter. They can carry food in their throat and upper esophagus, an area called a “gular pouch.” This “storage method” can allow jays to store one acorn in their bill, one in their mouth, and up to three acorns in their pouch. Six blue jays fitted with radio transmitters each cached up to 5,000 acorns in one autumn! It is no surprise this bird has the reputation as being a re-forester of the oak tree.
Blue jays have been observed "anting," rubbing their wings with ants. They even lose their balance as they are doing this. Why do they do this anting behavior? Scientists believe the substance from the ants can repel parasites, or perhaps help clean the feathers.
Some blue jays migrate, while others stay put all year-round. Migrating flocks of up to 250 birds have been observed flying over hawk-watching spots. The groups have included adults and young birds, but there seems to be no age difference between migrating jays and those that remain as residential birds. Some jays migrate one year but not the next. Scientists believe that the amount of jays that migrate is less than 20 percent. This migration continues to be quite a mystery.
The striking blue color with the snow as a backdrop makes a delightful winter sight. Our resident blue jays are fun to have around, and their sounds a joyful greeting to our ears. Be sure to get outside this week to enjoy what winter brings!
For over 42 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 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.
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