Tag Archives: butterflies

The Myth-Busting Mourning Cloak

Posted on April 2, 2013 by Kristin S.

Mourning cloak copyright Frank ModelEvery year I wait eagerly to see my first butterfly of spring. Most likely, it will be a mourning cloak (Nymphalis antiopa), a large butterfly with velvety brown wings and yellowish white wing edges. This beautiful “harbinger of spring” emerges on the first warm days, often before all the snow has melted.

How does the mourning cloak appear so early in the season? Hold onto your hats because this gorgeous insect contradicts everything we tend to believe about butterflies:

Myth 1: Butterflies die or head south for the winter.
Mourning cloak adults hibernate through the New England winter. Relying on “antifreeze” chemicals in their blood, mourning cloaks spend the winter in a sheltered place, such as in rock crevices, under bark, or in a woodpile. They emerge on warm days, sometimes as early as February, and treat us to visions of spring with their graceful flight. Other overwintering butterflies in New England to watch for include eastern commas, question marks, and compton tortoiseshells.

Myth 2: Adult butterflies only live for a few days.
Due to their overwintering strategy, mourning cloaks can have a lifespan of over 10 months. One of our longest-lived butterflies, mourning cloaks have been seen in flight in Massachusetts during every month of the year.

Myth 3: Butterflies nectar on flowers.
There are no blooming flowers in early spring when mourning cloaks emerge, so how do they feed? Mostly on tree sap, particularly from oaks. Mourning cloaks will also feed—brace yourself—on animal droppings and decaying things. Occasionally, if I have been hiking hard, a mourning cloak will land on my hand or head, attracted by the minerals in human sweat.

So, on the first warm day head toward a sun-dappled opening in the woods, preferably with storm-damaged trees and broken branches dripping sap, and wait for this resilient insect to make its appearance. Like you, it has managed to survive another New England winter.

To learn more about the mourning cloak and other butterflies of Massachusetts, check out Mass Audubon’s Butterfly Atlas.

Photo © Frank Model

Big News for the Giant Swallowtail

Posted on August 22, 2012 by Hillary T.

To say Mass Audubon has been all aflutter over the recent spate of giant swallowtail sightings is putting it mildly. Why are we getting so excited about a butterfly? Well, the giant swallowtail (Papilio cresphontes) was generally considered a rare butterfly in the state, usually spending most of its time to the south and west of Massachusetts.

In fact, according to Butterflies of Massachusetts, between the years 2000 and 2008, there were no giant swallowtails spotted in the Commonwealth. Then a few sightings were reported in 2009 and 2010 and even more in 2011. But this year, there have been many reports from all over the state including Ipswich River (Topsfield), Arcadia (Easthampton and Northampton), Drumlin Farm (Lincoln), Wellfleet Bay (South Wellfleet), and Broad Meadow Brook (Worcester).

Sharon Stichter, editor of the Butterflies of Massachusetts website, confirms that giant swallowtails have been reported in 2012 from just about all areas of Massachusetts. “Last year, we had the first-ever large influx of this southerly species at Sheffield at the beginning of the summer season. Then the offspring (the second brood) radiated out over the state, laying eggs on host plants,” she said.

How could a butterfly that was once rare in Massachusetts be seen in so many places? The short answer: Climate is an important factor in the shifting ranges of many species worldwide, and there is evidence that this is true for Massachusetts, too.

Stichter notes that the unusually mild 2011-2012 winter allowed for many of their chrysalids to survive, resulting in this year’s even larger summer flight. However, she adds, a cold winter could knock the species back to further south, at least temporarily.

It’s not just the giant swallowtail that’s relocating. According to a new study just published by Harvard Forest scientists and the Massachusetts Butterfly Club (including Stichter), there is evidence of “strong shifts in butterfly populations due to climate warming in the state.” The report goes on to say that some species that were once common are showing sharp declines, and southern species, like the giant swallowtail, are showing some of the biggest increases.

Identifying a Giant Swallowtail

While you may find a giant swallowtail around its host plants, which include northern prickly ash and hop tree, you’re most likely to see one feeding from common nectar-producing species such as milkweeds, bee balm, and thistles, among others.

Just don’t let its cousin, the more commonly seen eastern tiger swallowtail, confuse you. Here’s how to tell them apart:

Eastern tiger swallowtail

  • A tiger swallowtail’s open wings are mostly yellow with thin brown vertical stripes and a brown border across bottom.
  • When on a plant, a tiger swallowtail will settle its wings for a few seconds at a time.

 

 

Giant swallowtail

  • A giant swallowtail’s open wings are mostly deep brown with a yellow stripe running across to top and lower wings.
  • A giant swallowtail typically flutters constantly while nectaring.
  • The giant swallowtail has X-like yellow markings near the end of the upper surface of the wing tips and a yellow spot on the tails.

Have you seen a giant swallowtail in Massachusetts? If so, tell us when and where in the comments.