Cedar Waxwing

Cedar Waxwing

As I resume posts after an absence, I chose Inge’s picture of a Cedar Waxwing. Not an uncommon bird in Virginia and seen here any month of the year, but a sighting always draws a long look. They look cocksure in their dandy uniform.

More often seen in a small flock than alone, they can strip berries from ornamental bushes or native trees like dogwoods in a few minutes. Why Cedar? Probably because they like the fruit of cedars. But in the warm months they also catch insects for a richer source of protein for breeding.

Virginia Nature Journal for April

Algernon Swinburne

Smells arouse old memories, good and bad. The coconut bouquet of prickly gorse bushes evokes memories of ranks of jasmine blossom on the chalky downs of the Isle of Wight where I was born and Algy Swinburne grew up. Oh, to be in England, now that April’s there (Robert Browning). But here in Tidewater Virginia, the scent of pine resin at this season conveys no particular emotion for me, nor can it trigger flashbacks.

Crabapple tree blooming in April
Crabapple tree blooming in April

I read that memory is less aroused by sound than by smell which owes its potency to a handshake between our olfactory bulbs and the hippocampus. But when I hear the lazy phrases of a blackbird, my mind is transported to a remembered English garden where one sang every afternoon announcing its territory from a perch in apple blossom. But here, where brown thrashers, wood thrushes and mocking birds are better musicians, the chorus of woodland songsters never evokes the same emotion, perhaps because some neural networks close after childhood.

And yet less emotion does not mean less care for the birds that choose to make a home in our yard. In a landscape where native plants of Virginia are retreating before the advance of so many inedible aliens, they need us when food supplies reach a nadir. The bird feeder was not full for very long and never empty during the winter. Long before our neighborhood birds started looking for nesting sites I made a batch of boxes for them, one for every acre. They are luxury condos made of durable white cedar with green shingle roofs and a critter-guard against snakes, raccoons and squirrels.

WelcomeEggs_smallThe boxes were designed for bluebirds, which are surely in the top ten for popularity. Cavity nesters depend on these artificial homes because cautious park officers and yard owners fell dead trees which might have offered them a home. Apart from untold numbers of nest-boxes in gardens, there are 230 boxes around public trails and golf courses in James City and York counties that are monitored weekly by local naturalists. It is exciting to find a clutch of 4 or 5 bluebird eggs (sky blue, of course), and experts assure us that a brief inspection does not affect breeding success.

The program has reversed the steady decline in their population, and now there are more bluebirds in the area than at any time in living memory. Over 700 of them fledged from these boxes alone last year. The Virginia Bluebird Society collects breeding data from across the state, and at summer’s end we will know what impact the hard winter had on their population.

Chickadee nesting in bluebird box
Chickadee nesting in bluebird box

There were bluebirds in our yard until the deep freeze started in February, but we saw few afterwards. There are reports of birds found dead in nest-boxes where they were roosting. Drinking water was frozen for several weeks, and there were few berries or other natural foods at the end of winter. Perhaps the hard weather explains why a chickadee took up residence in one of our bluebird boxes, a tufted titmouse in another, and Carolina wren is building a nest in a third. One box is vacant where a pair of bluebirds raised two broods last year.

Bluebird laying recordBluebirds are nesting elsewhere, but they started late this year, although no later than in the past two years. Our records for 2012-15 suggest their breeding schedule is flexible, so that hungry fledglings are not hatched before insects are abundant again. In the warm spring of 2012, the first eggs were laid three weeks early.

The great horned owls breeding on Jamestown Island don’t have to be respecters of temperature and weather because their prey is ever present. They were sitting on eggs in January, and their owlets were almost ready to fly when the bluebirds were starting to gather straw and down to line their nests.

Red-shouldered hawk on nest
Red-shouldered hawk on nest

Besides the vagaries of weather, bluebirds face the daily challenge of evading predators. They have little to fear from nocturnal species like owls, but a pair of red-shouldered hawks has taken up residence in our woodlot, and I guess they have chicks sitting on the untidy matt of sticks in the fork of a loblolly pine. Their breeding schedule coincides with the re-appearance of frogs and reptiles and when baby rodents set foot out of the nest and naïve baby birds flutter out of theirs. We hear the hawks screaming kee-rah all day long to scare birds out of cover or before taking a dive at them on the bird feeder. I feel no special sympathy for an English sparrow in yellow talons, but there would be a rush of emotion if I noticed a splash of blue on prey feathers.

Next Post: Cuisine for Carnivores


Citizen Science

Thomas Jefferson
Thomas Jefferson in Williamsburg, Virginia

At one time all scientists were amateurs. Most were gentlemen with private incomes like Charles Darwin or clergymen like the Rev. Gilbert White whose church stipend enabled him to spend spare time rambling in the Hampshire countryside. There was a rich crop of these men too among the founding fathers of America: Benjamin Franklin discovered electrical activity in thunderstorms by flying a kite, and Thomas Jefferson created an almanac by recording the weather for nearly fifty years. Today we call them citizen scientists, and after science became a paid profession they continue to flourish where many eyes are needed for collecting “big data.”

One of those sciences is astronomy, which was so memorably presented on BBC TV by Patrick Moore (1923-2012), and for which other amateurs are credited with discovering new exoplanets. Another is ornithology because birders supply tons of data to the Cornell Lab of Ornithology, the Audubon Society, and the British Trust for Ornithology. And the third—ever since Jefferson—is meteorology.

Years of recording temperatures and rainfall at Monticello helped him to plan the dates for planting crops in his garden. The data were also useful in the patriotic cause of proving the superiority of the Virginia climate compared to Paris where he lived at one time (there was no contest with London weather). In those times climate was thought to be fixed at a given place, just as the continents were believed to be immovable and species immutable.

Mark Twain wrote, Climate is what we expect, weather is what we get. But today the opposite is true because we no longer know what the future climate holds, and we have a firm expectation that weather will always be capricious. More than ever, climate scientists and weathermen/women depend on data from volunteers for modeling the atmosphere for days or even decades ahead.

Jefferson would have drooled at the equipment that is now available to backyard meteorologists. A starter weather station includes a thermometer, barometer, anemometer, hygrometer, and wind vane, but some really sophisticated equipment is affordable. The data can be uploaded to networks like Weather Underground which has more than 32,000 active stations worldwide. All data points are valuable because weather is local, and they contribute to a growing understanding of climate change.

rain gauge
Rain gauge for citizen scientists

You can join a network for the cost of a customized rain/ hail/ snow gauge ($30). This isn’t glamorous science like measuring glacier retreat, Arctic sea ice, or even sea levels and temperature, but data from your own backyard will be pooled with thousands of other observations for professional analysis.

Naturalists contribute data from monitoring wildlife and flora, which is called phenology. We are warned that if a warming trend continues the return dates of birds and butterflies that winter in warmer climes will be earlier, and they will breed further north. Hummingbirds arrived in Williamsburg today (April 12), but future generations may see them in March or even staying the year round.

Budburst is a phenology project for volunteers to record when trees and plants flower. A pollination by beesYoshino cherry tree in our yard bloomed the very same days this year as last, but we can’t assume the same in the future because this species is highly sensitive to temperature. Researchers in Seattle predict that cherry blossom will reach its peak 5-13 days earlier in Washington DC by 2050 than today (estimates vary depending on carbon emissions). If so, the National Cherry Blossom Festival and Parade will have to move forward to March.

It’s hard to say whether natural signs or physical measurements are the more reliable guides to the climate, but temperature and rainfall have the longest records.  The first frost dates in fall have been recorded in Williamsburg for over a century. Lately they have been getting later, and the growing season of frost-free days between spring and fall is correspondingly longer. The number of days when temperatures fell below freezing have declined by 20 days over the same period (notwithstanding the recent cold winter), which harmonizes with old stories when people drove across the frozen York River and skated on ponds.

first freeze
Date of first frost in Williamsburg, VA

It seems a contradiction then that average temperatures here in the hottest month of the year (July) are unchanged since records began in 1895 (78°F/ 25.5°C). Summer temperatures in Monticello (100 miles west) have also remained the same as when Jefferson recorded them, and it’s much the same story for rainfall. This leads people to wonder if the climate is really changing.

Jefferson as weatherman
Average annual temperatures in Virginia

But note the huge variances in the data. Our rainfall in July, which averaged 5 inches over the past 120 years, has a range of between 1 and 13 inches. You need data over a long period to prove a consistent trend in average temperature and rainfall with this statistical noise. But there have been more exceptionally hot days in summer here as elsewhere, and this may be the warning signal. We are so accustomed to paying attention to averages and medians (50 percentiles) that we can overlook the significance of outliers. I was reminded after an old cabin was taken down recently in the Allegheny Mountains when I was shown where the builder had scrawled in the joint between logs: June 6th 1878 frost killed beans.

Allegheny Mountains cabin
Frost killed beans 1878

Farmers and gardeners have always dreaded late freezes and heat waves, but if the climate becomes more dominated by freak weather we too will have something to groan about, and much more than scant snow on the piste or scorching sun on the barbecue. Amateur scientists today stand in a long tradition, but they are a different bunch to the gentlemen of yore who were led by private curiosity into the field. Today’s efforts by legions of volunteers are often propelled by a hope that through understanding nature we can better preserve it.

Next Post: Fertility Preservation

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