Thursday, September 22, 2011

The rare "Buckeye" Flutters at NBNC



The Common Buckeye is a striking butterfly with bold eye spots that can be flaunted in an attempt to guise as an owl and intimidate potential predators. Just looking at the picture of this gorgeous insect, it isn't hard to believe that it would be exciting to see one at the North Branch Nature Center, but what makes this sighting special is that the Common Buckeye is amongst the rarest butterflies in Vermont.

The mostly tropical genus of Buckeyes are fairly common in the south, where they can be found year-round in some places. The Common Buckeye regularly wanders north in summers, colonizing new areas as it expands northwards, occasionally even penetrating into southern portions of New England, but is extremely rare as far north as Vermont. Colonization in New England is only temporary as this species cannot survive our harsh winters. In fact, no sightings were known in Vermont before 2004 and in the recently completed Vermont Butterfly Survey, it was one of the ten least frequently encountered butterfly species.

While it came as a surprise to find a Buckeye at the Nature Center, it wasn't totally unexpected. 2011 has been an unprecedented year for "southerners" in Vermont, with butterfly species such as Giant Swallowtails (extremely rare and only seen in southern Vermont), Harvesters, and also plenty of Common Buckeyes being reported from numerous locations around Vermont. In fact, on August 24, Bryan Pfeiffer found two Common Buckeyes near Wrightsville Reservoir, just down the road from NBNC.

As climate change progresses and our planet slowly warms, perhaps sightings like this will become more common. After all, while a warming planet will be detrimental to many species, for others, it will create new opportunities. As the graceful Buckeye suns itself on the trails at NBNC, it is somewhat bittersweet that we enjoy its vivid pattern as it flashes its "owl eyes" towards our gaze. While there are many ugly signs of our rapidly changing climate, some come with bright colors and wings.

Friday, September 16, 2011

Caterpillars of NBNC (part 2)

As we dig deep into our drawers, searching for sweatshirts forgotten months ago, it is hard not to wonder what caterpillars do to prepare as winter draws nearer. Some species of caterpillars are still active even into October. Here, we look at some more caterpillars found around the Nature Center and how they've adapted to make it through the long, cold winters:


Its a sure sign that fall is around the corner when you see a Wooly Bear walking across the lawn. Wooly Bears, the larval name for the Isabella Tiger Moth, overwinter as caterpillars and pupate after emerging the next spring.


You can barely turn a corner around NBNC without bumping into a Hickory Tussock Moth caterpillar. They will stick together in groups when they first hatch in the mid-summer, but tend to separate as they grow, and by September can be fairly spread out. As winter comes, they will crawl into the leaf litter, spin a cocoon, and endure the cold months as a pupa.


These gentle giants start showing up in the fields of NBNC in late summer. The Gallium Sphinx Moth caterpillar feeds on bedstraw (aka Gallium). Caterpillars pupate and overwinter in loose cocoons in shallow underground burrows.


This caterpillar in the genus Panthea was found near the NBNC building this summer. Although we're not sure exactly what species it is, all in the genus feed exclusively on the needles of conifers and overwinter as pupae.


Many caterpillars, such as this Banded Tussock Moth, have tufts of hair protruding from various places. In fact, a "tussock" typically refers to a tuft of grass on a hummock, describing the hairy tufts. The Banded Tussock Moth incorporates many of its hairs into the cocoon where it overwinters.

Tuesday, September 6, 2011

Caterpillars of NBNC (part 1)

Amongst the many creatures worth watching this fall, the caterpillars that creep and crawl around our fields and forests can be every bit as interesting as the moths and butterflies they become. Stunningly patterned and with fascinating behaviors, we've marveled at the variety of caterpillars we observe at NBNC every year. Here are a few that spent their larval-lives at the Center:


Monarch caterpillars feed on milkweed. The migratory Monarch butterfly makes a 2,000+ mile journey from Vermont to Mexico each fall. Join NBNC for Monarch tagging on Wednesday afternoons as we attempt to track their journey. More info about this program


Black Swallowtail caterpillar near the NBNC building at the edge of the field. Their host plants include those in the carrot family, such as Queen-Anne's-Lace, parsely, and dill.


White-marked Tussock Moth. Caterpillars feed on a wide range of hardwoods and contain hairs(setae) that can cause skin irritation if handled.


Milkweed Tussock Moth. To no surprise, caterpillars feed on milkweed. They can be gregarious, forming large groups.


Paddle Caterpillar (Funerary Dagger Moth). A striking caterpillar whose long, paddle-shaped setae give it the resemblance of a viking ship. The caterpillar is described as "scarce" in Caterpillars of Eastern North America, but this individual was found right in the front lawn of NBNC!