Living on the Lake: Fascinating facts about common birds

Did you know that robin hopping across your lawn is a dedicated parent and mate? Or that turkey vultures use vomit as a way to scare away predators when they come too close? Or that great horned owls have their young as early as February and a baby loon can swim the day it is born, but can't fly until it is at least 11 weeks old?

Robins, turkey vultures, great horned owls and loons are relatively common birds in the Northwoods of Wisconsin and yet when we see them throughout the summer months, most of us don't really know much about their habits and reproduction.

Of these four, only the great horned owl makes its home here year round while the others fly to warmer climes during Wisconsin's cold winters. However, all four species reproduce in the Badger State and their habits and rituals provide fascinating observation.

Take, for instance, the turkey vulture. These massive birds can frequently be seen riding the thermals above valleys and lakes in Wisconsin during the summer months. For many years it was thought that vultures were raptors, in the same category as eagles and hawks. But in 1996 a Department of Natural Resource study was done on these birds and DNA samples were taken. The samples proved that these birds are more closely related to storks than eagles.

Vultures are relatively silent birds, only emitting grunts and hissing on occasion. This is because they have no "syrinx" or voice box. Another fascinating aspect about these birds is that they mate for life. When it comes time to reproduce, they don't build a nest but instead lay their eggs on the ground hidden in cover, or on rocky outcrops and even hollow logs. They lay between one to three eggs, with two eggs the norm.

Both the mother and father vulture incubate the eggs and take care of the young. They have a unique defense strategy if something threatens their chicks. They either play dead, or worse, vomit on the perpetrator. This is extremely foul-smelling stuff, and is especially potent if it gets in the eyes of a predator.

Turkey vultures are considered the garbage cans of the areas they inhabit because they can be seen many times eating carrion. They can smell rotting flesh many miles away, and they are one of the few birds that have a very developed sense of smell. And while carrion is their favorite dining choice, they will also eat pumpkins, grass, leaves and seeds.

Robins are also seed eaters. However, it is more common to see them back-stretched against a worm they are pulling out of the ground. Their diets include cherries, strawberries and the berries of the hawthorn, dogwood and sumac. These birds are members of the thrush family, which are known for their melodious songs and chirps. Robins can have up to three broods of chicks in one year, but only about 25 percent of the babies make it to their first November. Robins can live up to about 15 years of age but usually don't make it past age six.

"Robin's egg blue" is a familiar term to many, and robins lay between three to five eggs in a brood. Robins stay together to raise their young, but only the female incubates the eggs. The incubation period lasts about 14 days. The dad robin will help feed the chicks though, and he is especially good at defending them if they are threatened. Robins love the dive bomb method of warding off predators. In the summer, female robins sleep on their nests while male robins gather, forming large roosts. After the nesting season is over males and females will roost together. Robins migrate to Florida, down through the Gulf Coast, into central Mexico and the Pacific coast during the winter months.

Loons also migrate. Their range is from the northern tier states of the U.S. into Alaska. Perhaps there is no bird more beloved than this speckled wonder with its piercing red eyes. Seeing them swimming and diving on Northwoods lakes is a sight welcomed by many and their calls and yodels have fascinated man from the beginning.

Loons don't necessarily mate for life. Male loons return to a territory first after migrating from either the Atlantic or Pacific coasts. These birds prefer cold northern lakes that provide a good food source and islands and sheltered bays for raising their young. Once a male selects a territory, he then waits for a female. If she is receptive to the location, the birds will mate.

Both the male and female will build a nest, usually a crude affair, made from mud and weeds along a quiet shore. Incubation of the eggs and the rearing of young chicks is also a family affair, with the male helping the female. Baby loons can swim only minutes after they hatch, but they can't fly until they are about three months old. Loons usually lay two eggs and it takes 27 to 30 days before the chicks are ready to emerge from their shells.

Loons have a varied diet and besides fish also enjoy snails, crayfish, frogs, salamanders and aquatic insects. They are a very vocal bird and their various calls have been categorized into four verbalizations which include the yodel, the tremolo, the hoot and the wail. Each of these sounds represents a certain behavior. For instance, the soft and almost inaudible hoot is usually vocalized between a pair and means contentment while a yodeling loon is likely being threatened by a predator.

Young loons migrate with their parents after their birth year but do not fly back looking for a territory until their second or third year of life when they are mature enough to mate. These are territorial birds and sometimes males will defend their lake to the death.

Great horned owls are also territorial, especially during the mating season and when they are raising their young. This big bird with the deep yellow eyes and upright feather tufts on its head is found over a large range from Arctic regions to the Straits of Magellan.

Great horned owls start courting in January and many times by February are raising young. A female owl will lay between one to five eggs and both the male and female will incubate the eggs as well as feed the young. It takes about four weeks for owl eggs to hatch and the little owlets are ready to fly out on their own when they are about eight weeks old.

These birds primarily hunt at night and are expert rodent killers but aren't above killing chickens for a meal. They can eat a mouse whole and then, when they are through digesting this meal, they eject a pellet. Many times these small, mummified pieces can be found underneath the trees owls roost or nest in. While their hoots can be heard for miles, they are stealthy fliers and silently ply the night air for their prey.

Birds are such a welcome part of the landscape and watching them is a pastime that has many followers. But knowing their habits and lifestyle makes that hobby even more interesting. So the next time you see a robin hopping across your lawn or hear an owl hoot off in the distance, realize these creatures lead fascinating lives, especially during the warm months of a Wisconsin summer.

Mary Ann Doyle is the associate editor of the Star Journal.