Wednesday, February 23, 2011

Pine grosbeak

Nature Watch

By Susan Thurn,
Cable Natural History Museum

This past week my parents have had a special visitor at their bird feeders. It began for them as a flash of slightly different colors – a rusty head and rump, gray underneath, with two white wing bars. Out came their bird field guide to identify their guests as pine grosbeaks, and in this case my parents have been hosting first-year males.

Pine grosbeaks spend most of their time in the boreal forests of Canada, but their wintering areas are determined by food availability. When food decreases, they move to find the food, creating what we call winter irruptions. These irruptions are not common and are irregular for pine grosbeaks.

Pine grosbeaks flock together in winter, and they often frequent a fruit or berry tree until all of it is consumed. They eat through the fruits by biting it with their sharp pointed beak, discarding the pulp, and crushing the seed. Most of their diet is made up of plants, including buds, seeds, and seeds or fruit of spruce, pine, maple, apple, mountain ash, juniper and grass and weed seeds. They are also awkward flycatchers, catching insects, or even spiders. A breeding pine grosbeak develops pouches in the floor of its mouth for carrying insect and plant food to its young. They also eat snow or drink water every day.

Not as much information is available about pine grosbeaks. Even their populations are not well-known because it is difficult to gather data on this species. The boreal forests of Canada are believed to host most of the entire breeding population of pine grosbeaks and some other boreal bird species. Pine grosbeak irruptions are usually in intervals of five to twenty-five years. How lucky any of us are to have this bird species visit our 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, “In a New Light” photographic exhibit focused on the St. Croix National Scenic Riverway. Find it in Cable at 13470 County Highway M. Also discover us on the web at www.cablemuseum.org, on Facebook, or at our blogspot, http://cablemuseumnaturewatch.blogspot.com/ to learn more about our exhibits and programs.

Thursday, February 17, 2011

Coyotes

Nature Watch

By Susan Thurn,
Cable Natural History Museum

Its tracks lead down the driveway and off into the woods past our house. The tracks are in a straight line, showing an animal with purpose and a plan. At night, the eerie sound surrounds our house as it filters through the night air. Sometimes the sound is as if from a short distance, and other nights the sound comes closely from across the field. The tracks and night songs are evidence that a coyote family is one of our many neighbors.

Howls, yips, yelps and barks make up the high-pitched, varied calls of a coyote. Heard mostly at dusk or night, the calls are filled with short notes or long rising and falling notes. When a coyote is calling its pack together it howls with one high note, but when together as a pack, they yip and yelp more in continued communication.

What is on the coyote menu? Coyotes do well in so many different environments because they are not too choosy about their diet. They predate on small mammals such as voles, squirrels, rabbits, and mice. They will eat fish, snakes, insects or other invertebrates. They will eat ground-nesting birds, and grouse as well. They also scavenge on dead animals. During late summer and winter, they feed on fruits, berries and other plants.

When I play with our dog Tucker, I often “stalk” him from across the yard. When coyotes hunt a mouse or vole, they will stalk slowly through the grass, using their sense of smell to locate the prey, then leaping upon it. Coyotes can pounce up to thirteen feet and run up to a speed of up to 35 miles per hour. A single animal will chase down rabbits, while a hunting pack or pair will team up to pursue larger prey as big as deer. Pack hunting is more common in the winter, and a pack of adults, yearlings, and young will pursue a deer to exhaustion or drive it toward a member of the pack hiding in the brush.

Coyotes are social animals, playing often. They advertise their location with their sounds and smells. Enjoying home ranges up to ten square miles in size, they are a common animal that surrounds us in the north woods. They are known to us through folklore as being very mischievous animals. They are also an enjoyed part of popular culture, as I remember, having grown up with the spectacular, “100-lives” Wile E. Coyote. Most of all, today, I continually enjoy the sounds of their calls at night. They are aptly named, as their scientific name, Canis latrans, means “barking dog.” They are truly a neighbor to appreciate!

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, “In a New Light” photographic exhibit focused on the St. Croix National Scenic Riverway. Find it in Cable at 13470 County Highway M. Also discover us on the web at www.cablemuseum.org, on Facebook, or at our blogspot, cablemuseumnaturewatch.blogspot.com, to learn more about our exhibits and programs.

Wednesday, February 9, 2011

Not only found in the hall of the Library of Congress

Nature Watch

By Susan Thurn,
Cable Natural History Museum

How does a cooper’s hawk end up in the main hall of the Library of Congress? Is the bird stopping in for a library card? Reading a book is indeed one of the best things, after all! This is also an amazing library, with 32 million books and materials in 470 languages! Could it instead be chasing a meal indoors? The Cooper’s hawk is indeed one of the birds that can be enjoyed not just in one of the most amazing libraries in the world, but also in the north woods.

The Cooper’s hawk is a smaller hawk, quite colorful with red eyes, a dark gray back, and rusty bars on its breast. This hawk is very similar to the sharp-shinned hawk, making it very difficult to tell between the two species. When in flight, Cooper’s have stiff wingbeats with short glides. In hunting, they are quite skilled.

A very skilled flyer, Cooper’s hawks move through tree canopies in woodland habitats. They are often in high speed pursuit of medium sized birds. Some of their preferred dinners include the starling, mourning dove, pigeons, robins, grouse, flickers, and jays. They will also eat chipmunks, squirrels, mice, and even bats, although the western Cooper’s hawk more commonly eats mammals. They also rob nests for eggs. They can eat up to 12% of their own weight in one day. For a 200 pound person we would have to eat 24 pounds of food each day!

Cooper’s are also sometimes unwanted guests at our bird feeders, searching for an easy menu of birds rather than bird seed. When they capture their prey, the hawks use their feet and kill it with repeated squeezing. They also have been observed drowning their prey underwater until it stops moving.

Our north woods Cooper’s hawks prefer dense evergreen or deciduous forests. They spend our winters as migrants in Central America – Ahh, a summer in the northwoods followed by a winter in the warmth of the south. However, this lifestyle may not always be an easy one. A study of over 300 Cooper’s hawks showed that nearly 25% of them had evidence of healed bones, a result of swift flight through a rather challenging forest habitat. Perhaps getting a library card would seem easier! Actually, Cooper’s hawks have become much more common in urban areas, as cities provide them with plenty of pigeons and mourning dove prey.

Visitors to the Library of Congress were lucky to have a lovely view of one spectacular bird. The Cooper’s hawk is indeed a gem, and one we are lucky to share our homes with as well!

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 new traveling exhibit in February, "In a New Light" photography exhibit, 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, February 3, 2011

White-breasted Nuthatches

Nature Watch

By Susan Thurn,
Cable Natural History Museum

“Yank, Yank, Yank,” came the sound from the trees near the bird feeder. Looking out, the small bird with clean black, gray, and white markings, became visible, headed down the tree face-first. The white-breasted nuthatch is a favorite for many of us who enjoy them around our homes.

The nuthatch name comes from their feeding habit that includes jamming nuts or seeds into the tree’s bark. They then pound at them with their sharp bill to get the seed inside. Seeds are as much as 70% of the white-breasted nuthatches winter diet, which they cache, or store, under loose bark or in tree crevices. They hide the food with a piece of moss, bark, lichen or snow. During the warm months, the white-breasted nuthatch will eat beetles, stink bugs, gall flies, scale insects, caterpillars, or ants. They have been observed feeding on the ground, and of course, enjoy feeding stations for sunflower seeds, nuts, or suet. When we see the birds making frequent, regular trips to the feeder and returning more quickly than it seems it would have taken them to eat the seeds, the nuthatches are most likely storing those seeds away for another day!

White-breasted nuthatches have some extremely interesting behaviors. As cavity nesters, they will often smear insects around the nest entrance to deter their main competitor for the same cavities, squirrels. When they leave the nest hole, they will also wipe the entrance with fur or vegetation, presumably to make it difficult for predators to smell their presence.

During the winter, white-breasted nuthatches travel with mixed flocks of other birds such as chickadees, titmice, red-breasted nuthatches, and downy woodpeckers. Scientists believe that chickadee calls carry information about predators, offering protection and a means to find food easier.

If we are to go looking for a white-breasted nuthatch, they are most commonly found in mature, deciduous forests, while the relative red-breasted nuthatch prefers the coniferous forest more. Explore and enjoy the wonder of this nature in your 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.