Monday, July 24, 2017

A Change of Feathers: The Molt

By Anna Autilio
Lead Environmental Educator

Feathers are one of the defining characteristics of birds. They produce the brilliant red of the Northern Cardinal, and the shocking blue of an Indigo Bunting. Though one purpose of feathers is to be flashy and attractive, especially to a potential mate, feathers have a host of other functions. From helping a bird keep warm, to protecting it from UV rays, to masking the sounds of flight, to the act of flying itself, feathers allow birds to survive in nearly every ecosystem on Earth. And yet, they are not permanent fixtures on a bird’s body.

Northfield, the Broad-winged Hawk, growing in some new tail feathers.
Contrast the 2 white-striped on the right with the duller brown on the left.
The process of losing and replacing feathers is called the molt, and it is a uniquely bird event. Though snakes shed their skin, dogs their fur, and insects their exoskeletons, a bird’s molt is timed, ordered, and an astounding physiological process.

The function of the molt is to replace last year’s feathers that have been damaged by wear and exposure, to ensure the thermoregulatory and aerodynamic properties remain reliable. In North America, most birds go through a molt of all of their flight and body feathers each summer, a process that can take weeks or months. Most wouldn’t want to drop all of their feathers at once, then spend a week grounded while regrowing them all! Instead, the pattern of molting in each species is unique, but ordered. Some, like the hawks, lose their innermost primary flight feather first, and proceed outward. Some start in the middle and proceed in both directions, like the falcons. Some owls molt synchronously, losing all the feathers on their tails in the space of a few days, but it does not appear to impede their mobility.

Molting body feathers: the reddish bars on Northfield's flanks are replacing
the brown, tear-drop splotches.
Our ambassador Broad-winged Hawk, Northfield, is an excellent molting educator, and this summer is helping visitors visualize the molt in action. As a second-year bird, Northfield came to VINS in June 2016, still with a coat of down. By late August he had grown in the full set of feathers that was his “juvenal plumage”, characterized by mottled brown on his back and wings, a brownish tail with multiple thin stripes, and most noticeable of all, heart-shaped brown splotches on his flanks and legs. This summer, Northfield is undergoing what ornithologists call the “prebasic molt” into his adult or “basic plumage”. His brown mottling is becoming darker and more reddish as new body feathers grow in. His tail feathers are being replaced by wide, starkly black-and-white stripes, and sadly, his "heart-pants" are giving way to russet horizontal bars on his chest.

Broad-winged Hawks are long-distance migratory birds, and so Northfield's wild counterparts often have trouble fitting the entire molt in before September, when they must soar down the Appalachians to Central America. As such, some Broad-wings suspend the molt mid-summer, and finish it on their wintering grounds. 

Molting birds can be hard for the casual observer to identify--a strange mix of two radically different birds in one—but understanding molting patterns can help scientists learn much about a particular bird’s age and lifestyle. Within each feather is the story of when and where it was grown.

What should you do if you find a molted feather? Enjoy looking at it, then leave it be. 

Wednesday, July 12, 2017

Book Review: The Snake and the Salamander

by Sara Evangelos
VINS Docent
with Nicole Meyer, Environmental Educator

The Snake and the Salamander: Reptiles and Amphibians from Maine to Virginia
Alvin Breisch
Illustrations by Matt Patterson
Johns Hopkins University Press 2017
Let’s face it: Reptiles and amphibians aren’t at the top of most people’s favorite animals list. Often, says author Alvin Breisch, they’re “treated as second-class citizens.” But Breisch’s new book The Snake and the Salamander could go a long way toward changing that. With engaging, enlightening text, Breisch connects us to the world of “herps”—snakes, turtles, salamanders, lizards, and frogs.

The Snake and the Salamander is part art book, part natural history, part plea for conservation, and is written for readers of any age. Each animal’s page lists common and scientific names, size, and status as endangered or threatened. But if you’re looking for a field guide, this isn’t it. Instead of offering a structured, dry list of facts, Breisch creates a portrait of each animal, exploring aspects of behavior or biology that he considers important. Why is the eastern ratsnake such a good climber? Can a softshell turtle really run 15 miles an hour? Is the American bullfrog an invasive species? How did the eastern fence lizard move to Staten Island? Did you know that the northern leopard frog is the state amphibian of Vermont?

Breisch offers 83 portraits of reptile and amphibian species found in 13 states in the Northeast, from Maine to Virginia. Organized by habitat into nine sections, the book shows us herps in their environments, from Dry Pine Woodlands to Bogs to Wicked Big Puddles—the name for seasonal wetlands, like the vernal pool at VINS. Breisch explains how species have been affected by deforestation and recovery in New England. And he defines scientific concepts in relation to specific animals: How do salamanders and skinks differ? What’s a rattlesnake’s rattle made of? How exactly does a constrictor kill its prey?

Breisch draws on science, history, and popular culture, and offers snippets of his own encounters with herps. He adds plenty of information on biology, genetics, breeding, behavior, and diet. We learn terms like ovoviviparous, fossorial, allopatric, diploids and triploids. Through a portrait of the carpenter frog, we learn about the variety of frog calls and what they communicate. And we discover that the smooth greensnake isn’t even green at all, but a mix of yellow and blue pigments.

Each animal portrait offers insights ranging from the practical—Why is it so hard to tell exactly where those spring peeper calls are coming from?—to the scientific—What’s an obligate species?—to the entertaining—Why doesn’t Linus like queensnakes? We learn that the timber rattlesnake had such a toxic, terrifying reputation that it was chosen to adorn the “Don’t tread on me!” flag during the Revolutionary War. We also learn about the snake’s behavior, breeding, coloration, and history with Native Americans and European settlers.

Matt Patterson’s original color illustrations partner beautifully with the informative text. While photos in a field guide capture one individual—that you might expect to see in the wild, but probably won’t—Patterson’s illustrations are composites, based on many photographs. They show habitat, size, coloration, and reproduction: an eastern box turtle next to a strawberry plant; a red cornsnake swallowing a mouse; a group of adult and young broad-headed skinks; a northern dusky salamander with eggs; male and female painted turtles.

The Snake and the Salamander is full of engaging, fascinating facts presented in the context of habitat, science, and history. You won’t learn everything there is to know about these often misunderstood animals. And you won’t see maps of exactly where to find each species. But getting to know hellbenders and mudpuppies is a great start. And that’s one major benefit of this book: it inspires people to fall in love with reptiles and amphibians, to learn about how and where they live—and to protect them.

Environmentalists know that when people get excited about a single species—say, a Siberian tiger or California condor or blue whale—they want to save that animal’s habitat. During the past 30 years, as we’ve learned more about reptiles and amphibians, their reputation has improved. But there’s a long way to go. By making herps come alive, The Snake and the Salamander encourages us to protect these extraordinary animals.

About the Author and Illustrator
Alvin R. Breisch, a collaborator with the Roosevelt Wild Life Station, was amphibian and reptile specialist and director of the Amphibian and Reptile Atlas Project for the New York State Department of Environmental Conservation until he retired in 2009. He coauthored The Amphibians and Reptiles of New York State: Identification, Natural History, and Conservation. Matt Patterson illustrated Freshwater Fish of the Northeast, which won the 2010 National Outdoor Book Award in the category of Design and Artistic Merit.