NatureView

House Sparrow © Bill Gibbons 2011

Sparrows are everywhere here in the Bronx. Only the pigeons out number them. They are an invasive species, brought here from England in the nineteenth century; some say to help control insect populations, others so that immigrants from Europe could enjoy the presence of a familiar bird in their new home. Whatever the reason, the Sparrow has thrived and is now the most numerous songbird in the US. It has driven out some of the local species, notably the Bluebird, as it is an aggressive defender of its territory and because it stays put all winter long, so that when migratory birds return in the Spring the Sparrows are already well established.

Though its numbers are declining from the highs of the early twentieth century, it is doing much better here than in its original homeland. The English sparrows have been disappearing. Scientists aren’t sure why, but it may be because of a parasite has been undermining their health. Luckily American sparrows are not yet affected by it, but changing lifestyles among the human population have reduced its numbers here. In the days when horses were the main form of transportation, Sparrows enjoyed easy pickings among the oats spilled from their feed, or left undigested in their manure. Since the advent of the automobile, that food source is gone, making survival a little more difficult for these birds. Still, walk through the park and you will see plenty of them, picking over the ground or flocking in trees and shrubs.

Humpback Whale © Bill Gibbons 2011

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Lately we’ve been hearing more and more about the return of whales to New York Harbor. Right Whales, Humpback, Fin, Sei, Minke and Blue whales have all been spotted in the waters around the city. It’s a wonderful sign of the good effects of cleaner water.

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The humpback is said to be the most frequently spotted. It was common in the area in the nineteenth century. In Moby Dick, Herman Melville has this to say about it. “The humpback is often seen on the northern American coast. He has been frequently captured there, and towed into harbor. He has a great pack on him like a peddler; or you might call him the Elephant and Castle whale. At any rate, the popular name for him does not sufficiently distinguish him, since the sperm whale also has a hump though a smaller one. His oil is not very valuable. He has baleen. He is the most gamesome and light hearted of all the whales, making more gay foam and white water generally than any other of them”

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So it seems that in Melville’s day the humpbacks in the harbor would have been greeted by harpoons. Perhaps that’s why they made themselves scarce, or became scarce. The whaling ban is a good thing, but it’s hard not to admire the whalers of old. There’s a big difference between hunting from a row boat as they did in Melville’s time and shooting rocket propelled harpoons from a factory ship, and though the depredations of the early whalers harmed their prey, there is a nobility in their contests with the giants of the sea. It was much more of an equal contest in those days, one that the whale could win.

Daphnia swimming in a pond. © Bill Gibbons 2011

There are plenty of tiny creatures living in the city who pass their lives invisible to our eyes. Daphnia are one of them. I’ve found them in Van Cortland lake in the Bronx, but they can be found in just about any fresh water.

Daphnia is small, about a millimeter long and almost transparent. It is boneless, like all crustaceans, supported by a hard outer skin which it must shed or molt to grow. While it’s just visible to the naked eye as a fast moving dot, under the microscope its structure is revealed. Magnified, we see an elongated sphere, transparent and slightly yellowish. The outer shell, called a carapace, wraps around the body like a cape, a characteristic of its Order, the Cladocerans. Its head is covered by a helmet of the same material. The carapace is open towards the front, and we can see leaf-like legs waving rapidly. This rapid movement keeps water circulating around the gills attached to the legs and draws a current between the two halves of the shell that sucks plankton and bacteria towards the mouth. Continue reading →

A surprise visit by a hawk.

I see a number of hawks around the area, but still it was a surprise when I found this one perched outside my window a few months ago. It’s wonderful to see these noble birds so close to home. When they are wheeling overhead the pigeons try to keep a low profile.

Dytiscus sp.

This beetle is a ferocious predator ©Bill Gibbons

This Beetle, a ferocious predator and skillful diver, makes its home in ponds and still waters throughout the North East. Born from an egg in springtime, the larva is as deadly as the adult. Hollow, piercing jaws allow him to inject digestive fluid into his victim through the jaws, and suck out the liquified innards. Clinging to a stalk or stick the victorious larva will raise his prize above the surface of the water. The prey, perhaps a fairy shrimp, is pale and wriggling, but as the poison fills its body it darkens and grows still, shrinking and blackening as its vitals are sucked out. After a minute or two the larva will cast aside the black husk of its dinner

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