Sunday, March 25, 2012

First Butterflies!

Click to enlarge this picture, and then look at the flower petals. One of them has antennae! It's a resting cabbage white butterfly, also called a small white, Pieris rapae.  
 I saw a pair of cabbage white butterflies flying among spring flowers on the first day of spring this week. They are the first butterflies I've seen this year.

Cabbage whites are common in Europe, Asia, and northern Africa. They were introduced to North America in the mid 1800s, and have flourished here to become one of our most common butterflies. Their little green caterpillars are big agricultural pests on crops like broccoli, mustard, kale, horseradish, cauliflower, lettuce, and cabbage. The caterpillars cause so much damage that they have their own name -- imported cabbageworms. They also feed on invasive weeds like garlic mustard, so they thrive in disturbed urban habitats like where I live in Brooklyn Heights in New York City.

The cabbage white butterfly has a wingspan of about two inches. The close-up shot below shows a butterfly so pale that its diagnostic wing markings can barely be seen; it has one black dot in the center of each forewing, identifying it as a male, and black wing tips. Females have two dots on the forewing. Individuals that emerge early in the season are lightly marked like this one. Later in the season, individuals will have darker markings.

The sighting reminded me of this poem by the Russian writer, Iasyr Shivaza. These butterflies will not live until autumn.

White Butterfly

The sun is shining on a white butterfly,
You are so happy.
You are playing with a golden ray.
Riding the spring wind. 
Now you are up in the sky,
Reaching towards the white clouds. 
Now you are in the garden,
Sniffing the fresh flowers.
In selecting the flowers, I see,
Your ambition is high. 
The whole garden is yours, 
Alight wherever you like. 
You are playing with a red flower,
Which is like the sun. 
The chrysanthemums are waiting for you,
And the snow-white peonies...
You are like spring, seeking only
The flowers in full bloom. 
But you could never, oh butterfly, 
Alight upon a golden leaf. 

Sunday, March 18, 2012

Flower Flies

It is technically still winter, but warm temperatures and blossoming flowers say it's spring in Brooklyn. And flower flies are back!
Flies are not all creatures of garbage and decay. Flower flies visit flowers to eat pollen or drink nectar. There are about 6000 kinds worldwide and many of them are beautiful. They are also called hover flies, for their helicopter-like flight, and syrphid flies or syrphids for their scientific family, Syrphidae.

Black-and-yellow colored flower flies are often mistaken for wasps or bees. That's all according to plan! They are Batesian mimics; although they are harmless, they resemble more dangerous insects. Predators are likely to leave them alone and look for easier prey.

A wing count tells us that they are flies, with just two wings; if they were bees or wasps they would have four. Look closely at newly opened flowers and you will probably find flower flies.

Sunday, March 11, 2012

A Pigeon Couple

Courting pigeons, technically called rock pigeons, formerly called rock doves, Columba livia. 

We usually can't tell the gender of pigeons just by looking at them. They are monomorphic; males and females look the same. And their reproductive organs are internal and concealed so we need to see the birds perform gender specific behaviors, like the birds in these pictures.

The bird on the right above is a male. He was courting the female on the left in Cadman Plaza Park in Brooklyn this morning with a courtship display called tail-dragging.  He spread his tail and puffed out his chest and neck feathers. He strutted around dragging his spread tail on the ground.
When the female moved away he  rushed to follow her. He was animated and persistent.
They did this for about ten minutes, until she flew away. He followed.

On the way home I heard northern cardinals and white-throated sparrows singing. Spring!

Sunday, March 4, 2012

Muscovy Ducks

I remember first seeing one of these bumpy red-faced ducks by the Cooper River in Camden, New Jersey, when I was a child. At first I thought it was bleeding, then I thought it must be a mutant. Years later I discovered that's how it's supposed to look! It is one of the most striking looking birds you are likely to encounter in a city park.

The Muscovy duck is low-slung and long, with a wide flat tail. 

If you try to look up the Muscovy duck in a field guide, though, you probably won't find it. (And just when you are thinking that you have found the best field marks ever: a giant brightly patterned duck with red facial skin and a fleshy bump over the bill.) The ones we see in city parks are feral domestic ones, escaped from the barnyard and established in the wild. Most field guides don't include them because they are considered domestic birds. 

Wild Muscovy ducks are native to Mexico, Central, and South America. Wild ones are black with glossy greenish backs and large white patches on their wings; they are rarely seen north of Texas in the United States. Domestication produced the all black, all white, and seemingly endless forms of piebald black-and-white that we see in parks. 
Click on any of the photos to enlarge them.