Saturday, August 15, 2009

GREAT EXPECTATIONS: August in the Piedmont

Birds.− In August, migrants such as chestnut-sided warblers, magnolia warblers and blackburnian warblers begin to pass through North Carolina as they head towards the neotropics for the winter. These warblers will be duller colored than they were in the spring, having lost their vibrant breeding plumage and molted into drabber winter attire.

This month, we will consider the topic of “mobbing.” Mobbing is an anti-predator strategy used most commonly by birds, but also by mammals. This behavior usually involves a group of birds (e.g., crows) dive-bombing, squawking at, defecating on or simply flying about a predator (e.g., hawk). Mobs are often assembled when birds use a specialized “mobbing call.” This mobbing call attracts conspecifics (i.e., birds of the same species) and may also serve to further disorient a potential predator. Mobbing is a strategy particularly preferred by gulls, terns and crows. These birds tend to mob a predator when it is close to the nest, and they may use different calls and mobbing responses for different predator species. In North Carolina, mobbing behavior has been observed in gulls, crows, mockingbirds, eastern kingbirds and barn swallows.

Butterflies.− Expect to see a continued rise in swallowtail sightings after the mid-summer lull, as well as a pulse in the migrant cloudless sulphurs and little yellows. Also, be on the lookout for the 2nd and 3rd broods of the tawny and hackberry emperors, respectively.

Reptiles & Amphibians.− Keep an eye out for snakes and turtles, especially baby box turtles, which begin to hatch this month. Fence lizards and skinks are also out in abundance. Listen for large choruses of green tree frogs and bullfrogs, as well as occasional calls from eastern narrow-mouthed toads and eastern spadefoots.

Other Insects.− Expect a pulse in grasshopper and cicadas activity this month. You may also see green lacewings flying around in the evenings. Lacewings are fascinating insects that are important predators in many agricultural systems. They consume aphids and other soft-bodied insects. Predators of lacewings include bats and spiders. Interestingly, lacewings are sensitive to the frequencies emitted by bats when hunting and will try to evade them. Lacewings also will not struggle in a spider web, but attempt to free themselves by chewing the strands of the web.

In Bloom this Month.− Be on the lookout for some striking August flowers:

In Bloom:
SMALL-FRUIT AGRIMONY – Agrimonia microcarpa
AMERICAN BEAUTY-BERRY -Callicarpa americana
TRUMPET-CREEPER – Campsis radicans
TICK-TREFOIL – Desmodium nudiflorum
DEVIL'S-GRANDMOTHER - Elephantopus tomentosus
JOE-PYE-WEED – Eutrochium (syn.Eupatorium) dubium
SNEEZEWEED – Helenium autumnale
SCARLET ROSE-MALLOW – Hibiscus coccineus
ST. ANDREW’S CROSS - Hypericum hypericoides
CARDINAL-FLOWER – Lobelia cardinalis
GREAT BLUE LOBELIA – Lobelia siphilitica
CORAL HONEYSUCKLE(S) - Lonicera sempervirens
BLACK-EYED-SUSAN - Rudbeckia fulgida
GREEN-HEAD CONEFLOWER – Rudbeckia laciniata
ROSINWEED – Silphium sp.
AXILLARY GOLDENROD - Solidago caesia
IRONWEED – Vernonia sp.

Sunday, August 9, 2009

REVISITED: Historic Occoneechee Speedway Trail (Hillsborough, NC)

Overview: The Historic Occoneechee Speedway Trail (HOST), a 44-acre preserve and historical site, includes three miles of trails that take visitors around the original speedway (open from 1948-68), or alternately, along the banks of the Eno River. This trail is set to join the statewide Mountains to the Sea Trail.
Directions: Travel south on I-85. Take exit 165 and turn right onto NC 86. Continue straight through the first stop light (intersection of NC 86 and US 70) for 0.5 miles. The entrance to the park will be on the right hand side, across from the Vietri glass store.
August 2009 Observations:

Bark of cherry-bark oak (Quercus pagodifolia)

Leaves of cherry-bark oak (Quercus pagodifolia)

Mating large milkweed bugs (Oncopeltus fasciatus) on common milkweed (Asclepias syriaca) seedpod.
Mating large milkweed bugs (Oncopeltus fasciatus) on common milkweed (Asclepias syriaca)

Unidentified caterpillars on a walnut tree (Juglans nigra)

Hackberry emperor (Asterocampa celtis)