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UPCOMING OPPORTUNITY:
Join us for another
Winter Hummingbird Expedition to Costa Rica
in November/December 2005 or February 2006

HUMMINGBIRD MORNINGS
On 20 August 2005
we'll be at McDowell Nature Preserve
just southwest of Charlotte NC
(Click on the logo at left for details about booking
"Hummingbird Mornings" for your own facility in 2006 or beyond)

DOG DAYS OF AUGUST

No matter where we've been for the past few weeks--from western Kentucky to northern Virginia to Hilton Pond Center in South Carolina's Piedmont--it has been hot. And humid. And very uncomfortable, especially as we set up and sweated through our "Hummingbird Mornings" presentations at various outdoor venues. We don't perspire nervously when we lead workshops and bird banding demonstrations, but lately we've had major tributaries of saltwater flowing downward from every square inch of skin. Ah, yes, we MUST be in the middle of the "Dog Days of August."

All text, illustrations & photos © Hilton Pond Center

The term "dog days" has its origin in pre-recorded times and describes the hottest, most sultry days of summer--not because it was an uncomfortable time just for dogs but because it coincided with the 20 days preceding and 20 days following the conjunction of Sirius with the Sun (about 3 July through 11 August). Sirius, the Dog Star, was so-named because it was the most prominent star in a constellation ancient start-gazers thought looked liked a big dog (above), hence the name Canis Major. Sirius, the brightest star at night, is high in the sky during daylight hours--and thus, the ancients thought, must add its own heat to the already scorching days of summer.

It's interesting how our human bodies--which operate quite efficiently at an internal temperature 98.6 degrees Fahrenheit--begin to feel discomfort when ambient conditions are more than about ten degrees above or below 70 degrees, and especially when the relatively humidity gets to 50% or so. When the temps drop to 60, many folks begin to shiver and grab a coat, while much above 80 we start shedding layers and searching for shade in which to stand.

Despite outside temperatures in the middle to upper 90s this week across the eastern U.S., it was business as usual at Hilton Pond Center, and when we wandered out in the heat we came across all sorts of evidence that nature doesn't shut down and take a siesta when the mercury approaches the century mark. Among other activity, Ruby-throated Hummingbirds were buzzing around the feeders as usual, and a new generation of fledgling Northern Cardinals obviously have taken a liking to our sunflower seed offerings.

When we went out for an afternoon stroll, we found that a variety of insects seemed especially impervious to the heat--including those omnipresent, ever-noisy Dog-day Cicadas (above right), whose droning call is synonymous with summer. Interestingly, at this time of year we catch an occasional cicada in our mist nets, and from a distance it's sometimes hard to tell the big bug isn't actually a hummingbird snared in the mesh.

We discovered one active Dog Days animal quite by accident when we bent down to remove from the trail a still-leafy limb of Northern Red Oak, snapped off by recent thunderstorms. As we glanced at one of the smaller twigs, we noticed a REALLY tiny, quarter-inch weevil-like insect (above). Some weevils have highly elongated snouts, but the one we found appeared to be one of the Broad-nosed Weevils. Based on size, shape, and habitat, we suspect ours was an Asiatic Oak Weevil, Cyrtepistomus castaneus, introduced from Japan. Occasionally weevils can be serious pests--Southerners still lament the impact of the Boll Weevil on cotton crops--but those at Hilton Pond Center likely have minimal impact on plant hosts unless there's a weevil population explosion. (We'd appreciate your thoughts on our ID of this particular weevil, highly magnified above by a 1X-5X Canon macro lens.)

Also along the trail we spotted a neon-green blob (below), crawling across the lichen-encrusted branch of a Shagbark Hickory tree. Upon closer inspection, we found it to be a caterpillar we'd never seen at the Center--or anywhere else, for that matter--and wondered what it could be. Fortunately, we'd just received a copy of David Wagner's newly published Caterpillars of Eastern North America (Princeton Univ. Press, 2005), so we hurried back to the old farmhouse that doubles as our office and started thumbing through the comprehensive 500-page field guide. It's a terrific book for identification purposes, with half-page photos of each caterpillar PLUS spread-wing photos of the adult moth or butterfly that produced it. And, to top it off, the book includes detailed and nicely composed word descriptions of each caterpillar, its range, and host plants.

It only took a few minutes of page-turning to determine the bright green caterpillar we found was from a Great Purple Hairstreak, Atlides halesus, a butterfly we hadn't ever observed around Hilton Pond. As we read Wagner's account of the larva we quickly understood what it was doing on that hickory branch. It seems that caterpillars of the Great Purple Hairstreak dine exclusively on new leaves and young flowers of Eastern Mistletoe--which happens to grow at the tops of large oaks and hickories just outside our office. The probable reason we'd never seen one before is that these mistletoe-eating larvae--and maybe the aduts--are typically up in the canopy. We imagine that, like us, this particular caterpillar was out for a stroll one afternoon, just looking for more mistletoe as we searched out subjects for our weekly photo essay.

While we were in the office identifying the caterpillar the mailwoman came and knocked on the door with a parcel requiring a signature. We were pleased to receive a package but got even more enthused when she handed over a slightly bulky envelope with the return address of "Bird Banding Laboratory, Laurel MD." We knew from experience this envelope contained special news that someone, somewhere had recaptured or found a banded bird from Hilton Pond Center. Sure enough, when we ripped open the envelope, out fell a folded piece of paper that was indeed a "Report to Bander"--a computer printout detailing the results of what we banders refer to as a "foreign encounter."

It seems that on 29 July 2005, Travis Lynn of Conneaut Lake PA--not far up I-79 from our Pittsburgh birthplace--came across a dead Chipping Sparrow with a shiny aluminum band on its leg. (The Chipping Sparrow in the photo above is in winter plumage.) Travis read the band number and reported it to the BBL's toll-free number at (800) 327-BAND, from which he learned we had banded this bird as an adult of unknown sex 15 months previously on 16 April 2004. We suspect this little "chippie" spent the winter of 2003-2004 at or near Hilton Pond and maybe even returned for the most recent winter season. In any case, that this sparrow was at Conneaut Lake in late July 2005 indicates it likely bred in northwestern Pennsylvania; as the crow flies, that's a one-way straight-line trip of about 460 miles--not bad for a bird that barely weighs half an ounce.

We regret our little Chipping Sparrow flew all that way north only to meet its demise, but we're especially grateful Travis Lynn reported his finding to the Bird Banding Laboratory and helped provide interesting information about the life history of Chipping Sparrows that winter in the Carolina Piedmont. We're also glad that--despite the heat--every living thing at Hilton Pond Center does NOT shut down and hide each August, leaving us nothing to photograph or write about during these sweaty but stimulating "Dog Days of Summer."

All text, illustrations & photos © Hilton Pond Center