Reflections in Nature

Diary entry for March 7, 2014: “Ted Brown, who lives in Farmer’s Valley, told me that he saw a large flock of robins this morning.”

After checking past diaries, I noted that March 2, 1999, was the earliest date I found on seeing my first robin of spring. By now, I’m sure we’ve all seen robins.

The early returning robins often find nasty weather, causing us to wonder why they didn’t wait a few weeks before making the trip north.

Quite a few years ago I heard the following story: The robins already had returned when a late deep-cold freeze, with temperatures never rising above zero, hit our area. A woman heard something hit her window and when checking outside she found a robin laying in the snow. The woman took the bird, which was more dead than alive, into the house, where she tried to keep it warm and also give it food. Then, she got the idea to call the airport to see if any flights were going to Florida and found that one was scheduled. Much to her surprise, the airline personnel agreed to her request to take the robin to Florida, where it would be released. This story goes to show how far people will go to help wildlife that are in trouble.

During a drought one year, I received a call from a man who said he noticed the robins were having a hard time finding worms in his yard. Of course, the robins’ favorite meal of earthworms is not readily available during a drought because the worms would be deep in the soil, seeking moisture.

The caller stated he had put a variety of seeds in the bird feeder; however, the robins did not feed on them. I told him that the only time robins might visit feeders is in early spring when a late storm hits and everything is covered with ice and snow; however, once the weather clears, the robins no longer will visit feeders.

Why do robins rush north only to fight late spring snow and ice storms? Well, the answer is simple. The male robins need to come back early so they can set up their home territories.

In about 10 to 14 days, the females will follow, with the juvenile birds (both males and females) returning last.

The male robin will return to the same territory that he had the previous year. If the female survives, she also will return to the same area. Females and juveniles are not as precise as adult males; however, there are many documented cases in which a female mated with the same male and built her nest in either the same tree or niche on a porch for consecutive years.

One study showed that 55 percent of a group of robins returned to the same community; 20 percent returned within 10 miles; and 10 percent settled 100 miles from where they were hatched.

If a robin does change its territory, it does so in a southern movement. For instance, a robin hatched in the east would not migrate to the west but rather would stay south of where it was hatched.

I’m often asked, “Do robins nest when they go south for the winter?” No. As a matter of fact, while in their wintering grounds, which is the southern United States, robins do not show territorial aggressiveness.

Male robins only select territories in their northern breeding grounds and, even then, they’ll only defend the territory until the end of the breeding season.

By the middle of August in our area, robins will have stopped chirping in the mornings, an indication that the breeding season is over.

The average size of a robin’s territory is about 1/2-acre. Of course, this all depends on their population and food supply. The first male robin to arrive north usually tries to stake out a large territory and, as more and more robins stream north, the size of territory shrinks.

There also are communal feeding grounds (football fields, cemeteries, golf courses, etc.) set up that are open to all robins. Although territories could overlap, with two sets of robins looking for food in the same area, it is unlikely to find two sets of robins nesting in the same area.

A male will defend the center of its territory more aggressively than the outer edges. The bird defending the territory most often will win the conflict, especially if the fight takes place near the center of his territory.

If a male robin is dispossessed from his territory, which rarely but sometimes happens, the female will not leave with him but accepts the winner. Therefore, it is assumed that a female is attracted more to the territory than to the male.

Well, the robins have returned and spring has sprung. The most interesting time to observe wildlife is when they are raising their families. So pull on your boots, go outside and enjoy nature.

Bower retired after 34 years as a wildlife conservation officer for the state Game Commission. He has published several books about his experiences. Questions and comments may be sent to him at 153 Redington Ave., Troy PA 16947.

Reflections in Nature

Throughout the months of February and March, with temperatures hovering in the single digits, our backyard cardinal has been singing. Every morning when I go outside to fetch wood for the stove, I am greeted with the cardinal’s cheerful calling. To me, it is the promise of spring coming soon.

The pair of cardinals along with many blue jays visiting our backyard feeder have added a splash of color to the overcast days of winter.

The northern cardinal was one of the many species originally described by Linnaeus in his 18th century work. It initially was included in the genus Loxia, which now contains only crossbills.

In 1838, the bird was placed in the genus Cardinalis and given the scientific name Cardinalis virginianus, which means “Virginia cardinal.”

In 1918, the scientific name was changed to Richmondena cardinalis to honor Charles Wallace Richmond, an American ornithologist. In 1983, the scientific name was changed again to Cardinalis cardinalis, with the common name changed to Northern Cardinal to avoid confusion with the seven other species also termed cardinals.

The cardinal now belongs to the finch family, and the scientific name Cardinalis caddinalis is Latin, pertaining to a door hinge, that upon which something turns or depends. The common name of cardinal comes from the cardinals – important dignitaries of the Roman Catholic Church – who wear scarlet robes; hence, the red color of the bird is known as cardinal red.

The cardinal is one of the most admired of all North American birds, not only for its brilliant coloring but also its songs. They sing frequently, especially in late winter into the breeding season. Both sexes sing, with the female being the only bird that can sing the male’s songs.

The male will sing and his mate will repeat whatever song he sang. They have a repertoire of 28 songs. During the summer months, their sweet whistles are one of the first sounds heard in the morning.

The male that I have heard calling every morning is beginning to set up his territory. Earlier in the winter, he appeared, at times, to be driving the female away; however, this behavior has changed. I recently watched as the male fed the female a sunflower seed, a sure sign of spring.

The cardinal’s originally are bird’s of the south; however, in recent decades, they have expanded their common range north through the United States and even into Canada. The population growth can be due to an increase in winter bird feeding and the bird’s ability to adapt to parks and suburban human habitats.

Although cardinals don’t migrate, the young birds, after leaving the nest, will wander in all directions for each to set up its own territory. The northern cardinal is so well loved that it has been named the official bird of no fewer than seven states.

The male northern cardinal perhaps is responsible for getting more people to open up a field guide than any other bird. They’re a perfect combination of familiarity, conspicuousness, style and a shade of red that is hard to resist watching. Even the lightly brown colored females sport a sharp crest and warm red accents.

Pairs mate for life and remain together year-round. Mated pairs sometimes sing together before nesting.

During courtship, cardinals could participate in a bonding behavior in which the male collects food and brings it to the female, feeding her beak-to-beak. If the mating is successful, this mate-feeding could continue throughout the period of incubation.

Males sometimes bring nesting materials to the females, who do most of the nest building. The female uses her beak to crush the twigs until they are pliable, then turns in the nest to bend the twigs around her body. Then with her feet, she pushes the twigs into a cup shape.

The cup will have four layers: coarse twigs (bits of trash) covered with a leafy mat; lined with grapevine bark and, finally, grasses, stems, rootlets and pine needles. A nest typically takes three to nine days to build.

Three or four eggs are laid, with incubation taking 12 to 13 days. The female generally incubates the eggs. On rare occasions the male will incubate for brief periods of time.

The young fledge 10 to 11 days after hatching.

Both the male and female indulge in “anting,” meaning they pick up and crush ants to rub on their plumage. After anting, the cardinal’s plumage appears to be wet. The reason for anting is not totally understood.

Although at this writing, snow still is covering the ground and the temperatures are below freezing, nature already is gearing up for spring’s arrival.

Bower retired after 34 years as a wildlife conservation officer for the state Game Commission. He has published several books about his experiences. Questions and comments may be sent to him at 153 Redington Ave., Troy PA 16947.

Reflections in Nature

On a day when the temperature dropped below zero, I noticed that the leaves on a rhododendron bush in our front yard were curled up tight, appearing as green pencils hanging from the bush. After noticing this, I began to check and found that the colder the temperature becomes, the tighter the leathery leaves curl.

This process is called thermotropism, which comes from two Greek words: thermo, meaning measuring temperatures, and tropism, meaning a turning.

Just as the sunflowers in the summer turn their heads toward the sun for warmth, the rhododendron’s leaves curl because of the cold. The leathery leaf becomes slightly brittle and a bluish-green color.

The old mountain people reckoned there was no need for a clock if they had a crowing rooster, and only plumb fools would squander money on store-bought thermometers when they could look at a leaf on a rhododendron bush.

The leaf curls to its own temperature and not to the ambient air temperature. Of course, if the air is cold, the leaves are cold; however, a snow covering will help keep the leaves warm and less curl will be evident.

The curled leaf always will expose the waxy surface of the top of the leaf, while the softer underside receives the protection. The colder the temperature becomes, the tighter the curl of the leaves, and as the temperature warms, the leaves uncurl. The process is the rhododendron’s way of survival during the winter’s harsh weather.

I asked my forester friend, Jim Lacek, who lives in Towanda, if all green plants photosynthesize during the winter months.

Here is his answer: “I reviewed many books in my library and could not find any direct answer to your question. However, I can state that all plants with green surfaces do photosynthesize whenever there is enough sunlight, air and water to enable the process to occur. Even during the so-called dormant period caused by drought, cold and flooding, plants (with linear leaves); trees (pine, spruce, fir, yew); herbaceous plants (moss and fern); broad leaf plants (laurel, rhododendron and boxwood); and hardwood trees (with young green bark such as boxwood maple and striped maple) do have photosynthetic periods during the so called dormant or winter months.”

To paraphrase from Alex Shigo’s book, “A New Tree Biology,” the cell locked within the wood requires a constant supply of food and water and other essential elements. The cells also must have ways to exhaust waste and gasses. The movement is powered by energy trapped in the process called photosynthesis.

Even when the tree is not growing (dormant) or when the leaves in summer are trapping energy, the living cells still require the constant supply of food, water and energy.

Evergreen trees initially were found in cold climates in the northern hemisphere. Trees in more southern areas enjoyed an extended growing season, with plenty of sunshine for photosynthesis; however, evergreens in the north had a much shorter growing period of warmth.

These trees and bushes had to find ways to continue collecting sunlight all year long in order to survive. They used the chlorophyll found in their leaves (the reason for their green color) in order to absorb and convert sunshine into food, allowing the evergreen plants to remain green all year long, which was necessary to survive.

This also is the reason why leaves (needles) found on conifers, such as spruce and pines, actually are tightly rolled leaves. Although the rhododendron leaves are broader, they are leathery and do curl up during extreme cold weather.

During the winter months, an evergreen tree could be seen with brown needle tips either on one side of the plant, only one or two branches or on the whole tree. The injury, which is found on the outer portion of the branches, is most severe on the side of the tree facing the wind. It is called winter desiccation, a common type of winter injury to spruce and pine trees that occurs during the winter months when the photosynthetic process is slowed.

The evergreen tree continues to lose water at a higher rate (through its needles) than a deciduous tree which has lost its leaves. A warm, sunny or windy day increases the amount of water loss from the needles.

If the soil is frozen or soil moisture is low due to dry conditions, the tree’s roots are unable to pick up enough water to meet its needs; therefore, the needles dry out and die. However, they could hold their green color until spring when warmer temperatures arrive, delaying the browning of the needles.

The closer we look at nature, the more we are amazed.

Bower retired after 34 years as a wildlife conservation officer for the state Game Commission. He has published several books about his experiences. Questions and comments may be sent to him at 153 Redington Ave., Troy PA 16947.