Lloyd Center Leps Provide Clues on Climate Change

Between stifling heat, biting insects, and a long stretch until fall foliage emerged, the woods and other interior landscapes were an afterthought through most of summer.  Late July to early August featured migratory movements of various species that provided subtle reminders of seasonal change, but kept our eyes on the shoreline.  The north to south shorebird shift sent a diverse assemblage of shorebirds to intertidal zones, and the Green Darner migration clouds of dragonflies over beaches.

Perhaps it was the July wave of Monarch butterflies that passed through our butterfly garden around the Center’s main facility that diverted attention back to the interior habitats. Unlike during our last Lep (Lepidoptera) update two years ago when a major drought had taken hold, the right water balance was in place for a good summer growing season this year, allowing flowering plants to grow many feet tall, and lush stands of milkweed (the food plant of the monarch caterpillar) to take hold on the property.      

In addition to the Monarchs, other familiar species found at the Center that take advantage of its wide diversity of microhabitats, and/or which visited our butterfly gardens only in migration, included Spicebush Swallowtail, the eastern race of the Tiger Swallowtail, American Lady, Red Admiral, and Cloudless Sulfur, all of which were seen nectaring. Like the monarchs, the admiral and sulfur are commonly along the shorelines as they migrate, with the admiral the far more abundant of these two species. In the Lloyd Woods across the road, a “Question Mark” (named for its wing pattern and from the Angel Wing family) was spotted at rest on a tree, also likely as a stopping point in migration.

In addition to these more conspicuous species, there were other smaller butterflies that are fast fliers and easier to miss, some of which are also indicative of northward range shifts due to climate change. These include the “Zabulon Skipper” and “Red-banded Hairstreak”, which according to former Research Director and staff Lepidopterist Mark Mello, were mostly southern species a decade ago, but have become more common northward. The “Sachem” skipper is also more common in the south but spreads north some years, such as this season. The “Little Glassywing” is another inconspicuous skipper recognizable by a unique spotting pattern on the wing, and inhabits moist areas.

In a season that has been slower for the Monarchs, these species depict a diverse Lep community that provide clues to both healthy habitat conditions locally, and on a larger scale, slowly warming planet that has many taxonomic groups heading north. Stop by our gardens next season when the bushes will again be buzzing with activity, including butterflies that utilize this food source that has been established here.