Monday, April 21, 2014

April’s origin

April has had a bad time of it. Songs bemoan its showers, a poet calls it the “cruelest month,” its length has been cut, and its first day is for fools. Even the origin of its name is uncertain.

In the early Alban calendar, April was the longest month, with 36 days. Various Roman emperors fiddled with its size until Julius Caesar chose the 30 days that stuck. Because April is the time when trees and flowers come to life, many scholars believe its name came from the Latin, aperire, which means “to open.”

Others have pooh-poohed this idea, pointing out that no other month has been named for a condition of nature. Instead, they say, the likely source is a goddess.

These scholars, steeped in dusty mythology of ancient Greece and Rome, maintain that the Romans dedicated this month to Venus, the goddess of love, because April is the month when nature begins its myriad methods of reproduction. The Greek for Venus was Aphrodite, and, the scholars say, that is the root of the name – from Aphrodite to Aphrilis to Aprilis to our April.

Aperire seems so much simpler and more reasonable.

Friday, April 11, 2014

Scilla season

Late March and early April is the season for scilla, a pretty wildflower import that is hardy enough to survive freezing nights and conservative enough not to make a weed of itself.

Scilla siberica is a native of the woodlands of Eurasia. A century or so ago, planting its tiny bulbs was all the rage and today, many old homesteads have sections of lawn that, in early April, turn blue with thousands of small flowers that have spread from those old plantings. If the weather remains cool, the blossoms can last for weeks, providing not only beauty for the eye but nourishment for bees.

Scilla, also known by the rather unattractive name of squill, used to be more common, but some modern owners of antique houses spread weed killers on their lawns, wiping out the old colonies.

They did to scilla what scilla might do to them if they ate it. The word is from the Latin, “to harm,” reflecting the fact that most species are somewhat poisonous – which is actually a boon to gardeners.

It explains why, when so many other flowers are gobbled by the hungry deer, scilla blooms brightly and plentifully – as long as lawns remain poison-free.

Tuesday, April 08, 2014

'Ducks' without feathers

A Wood Frog sounds like a duck
You’re walking along a wooded road or a forest path in early spring and off to one side, you hear ducks quacking. Dozens of them, chattering away.

You look, but there are no ducks in sight, though there is water.

But if you look closely, you’ll see small, brownish frogs. Those are your quackers: You are hearing the chorus of spring mating calls of the Wood Frog.

These hardy amphibians crawl out of the earth as soon as the snow melts and the ground thaws. They head for the nearest water, usually a vernal pool surrounded by woods. There they mate and their eggs are deposited underwater.

Vernal pools provide ideal mating grounds for these frogs and Spring Peepers. These ephemeral waters have the advantage of being around in the spring, but are usually gone by late summer. Consequently, they can’t support fish, which would eat the frog eggs and tadpoles. And they last long enough to allow eggs to become frogs.

Scientists say many amphibians seem to be in decline. The good news about Wood Frogs is that their populations appear to be in good shape, even increasing, especially as the former farmlands of our region return to forest, allowing for more vernal pools.

This trend could continue, as long as wise land-use officials see the life-giving value of vernal pools and protect woodlands in which they appear.

Monday, March 31, 2014

Peeper keeper

Peep. Peep. Peep.

Choruses of spring peepers have risen from the woods. But how did those inch-long amphibians deal with the vagaries of New England weather that can swing temperatures from the 70s to the 20s in April?

To peepers, a sudden freeze or even a spring snowstorm is no sweat. Cold air triggers the frog's liver to create glucose. Blood brings this antifreeze to the vital organs like the brain and heart, keeping them from freezing. But the rest of its body — more than 60% of it — can freeze for weeks without harming the frog.

So on a walk in a wood on a cold spring day, you may find a small, frozen frog. If you put it in your warm hand, the iced peeper will simply melt and hop away, no doubt with a song in its heart.

Wednesday, March 26, 2014

Sour Swamps

As winter thaws out of the ground and opens the waters of our swamps, a characteristic sour scent appears. It tickles our noses with a strong smell that is far from perfume, but still has a strange attraction. 

We are probably smelling a soup of scents.  

Anaerobic bacteria, the kind that thrive in water and soil with little or no oxygen, give off hydrogen sulfide and phosphine gases as they feed on the products of decomposing leaves, grasses and other vegetation from the previous seasons’ plants. Those gases combine with others offered by freshly thawed, but decaying vegetation. Add to the mix the malodorous Skunk Cabbage, and you have a special blend of wetland aromas that can be found only in early spring. 

This pungent and pleasant scent signals renewal in these hotbeds of life. Swamps are where the new season really begins, a nursery full of not only stinky bacteria, but countless aquatic and land insects, small fish, amphibians, reptiles, mollusks, as well as wildflowers, that serve as food for other wildlife emerging from dens or arriving by wing. 

And so, though it arises from death, this sour scent is really a sign of life.

Sunday, March 23, 2014

Size and color vs. cold and hot

Do birds of the same species look alike throughout their ranges?

You might think that a species, by definition, would look the same wherever it was, but in fact most non-migratory birds differ within their ranges. 

Hairy Woodpeckers are bigger
in the northern part of their
range than they are in
the southern part.
Birds of a wide-range species that live in the cold end of the range tend to be bigger than birds that live in the warm end. A Hairy Woodpecker from Central America is noticeably smaller than a Hairy Woodpecker from Canada. 

Larger birds tend to be able to conserve heat better than smaller ones. Over many generations smaller birds born in cold regions have been more likely to die from mid-winter cold, leaving the larger siblings to carry on the species.

The process of size variation doesn’t take all that long, either. The House Finches, introduced into North America in the mid-1800s, have already developed smaller versions in the southern United States than are found in northern states and Canada.

The tendency of a species in cold climates to be larger than its fellow members in warm climates applies not only to birds, but all warm-blooded animals. In fact, it is a scientific principle is called Bergmann’s Rule, named for 19th Century German biologist Carl Bergmann, who developed it.

A similar principle is called Allen’s Rule, which says that cold-region birds have shorter wings, beaks and legs than those in the warm regions – all techniques, again to conserve heat.

Gloger’s Rule is not about size, but color. In 1833, Wilhelm Gloger, a German naturalist, postulated that, due to the intensity of the sun, warm-blooded members of the same species living in warmer climates tend to be darker than those in colder climates. It works for humans and other animals including birds. Birds of a single species that ranges from cold to hot will have deeper feather colors in the south than in the north.

Friday, March 21, 2014

Murmurations of starlings

Starlings are weed birds, right?

Well, certainly they are not natives, they are not colorful, and they are usually not much noticed.

But starlings perform one of the most amazing shows in nature.

It’s called a “murmuration.”

Rather than spend a lot of words explaining this astonishing phenomenon, I recommend this video.

Keep in mind that while, in our own murmurations, we may not have as many birds as are depicted in the video, smaller shows like this can be seen wherever there are starlings gathered before and after breeding season.  And that’s pretty much anywhere in North America during most of the year.

Wednesday, March 19, 2014

Ranges big and small

The dwelling ranges of birds can vary from tiny to global.

The 50 small Galapagos Islands about 600 miles off the coast of Ecuador are home to two-dozen species of birds found nowhere else on Earth.

In the United States, the Everglades Kite is found only in certain parts of southwestern Florida. The summer range of the Kirtland’s Warbler is limited to young Jack Pine forests of Michigan, found in an area only about 60 by 100 miles at the top of the Lower Peninsula. This warbler winters in the Bahamas.

The Osprey can be found
on every continent.
Both birds are classified as endangered species, which is not surprising, given the limited ranges in which they live.

Some species span the globe.

Many like the Herring Gull are circumpolar, a term that means a bird can be found around the world on one side of the equator or the other. A few species, such as the Osprey and Short-eared Owl, can be found on every continent.

Among migrating species, the summer and winter ranges can be astonishingly far apart. The American Golden-Plover spends its summer on the north shores of Alaska and Canada and its winters in Argentina and Paraguay.

Monday, March 17, 2014

What is the 'range' of a bird?

What does “range” mean when talking about a species of bird?

The range of a bird species is the territory in which one would expect to find it living at one time of the year or another. Ranges vary from small areas of less than the size of Rhode Island to nearly the entire world.

Several factors determine a species’ range, chief among them the climate and the kind of soil. Climate and soil affect the kind of vegetation that grows, and vegetation is the source of food, nesting sites and materials, and protection for most birds. Few birds can survive in the desert, where vegetation is spare, but some have adapted to it. Other birds require the sea, or at least lakes or rivers, for their survival.

Various factors also limit range. Oceans are the most obvious; few birds are capable of crossing an ocean under normal conditions. Temperature limits range; few birds can survive an Arctic or Antarctic winter, for instance. High mountains define some range boundaries -- many species are found either east or west of the Rockies.

The Red Knot can be seen in 
Connecticut, but Connecticut is not 
part of the Red Knot's range.
Many birds migrate and their territory includes a “summer” or “breeding” range and a winter range. Often the summer and winter ranges overlap so that a species might live year round in some states or provinces while in other regions, the birds appear only in summer or winter. In the case of such species as the Tundra Swan and the Snow Goose, summer and winter ranges are widely separated.

Although during migration these birds fly over a lot of land and may stop for a bite to eat on the way to and from ranges, the territory in between the winter and summer grounds is not considered part of its range.  For example, the Red Knot has a winter range at the southern tip of South America and a summer range in the northern Arctic. While it can be seen on Connecticut shores in March, Connecticut is just a brief stopover on its long way north and not part of its range.