What to notice outside around Sudbury in July
37 things from the field guide you can notice around Sudbury in July.
Sky
- Why you can see the moon in the daytime skyThe moon spends almost as much time up in daylight as at night, and on the right days it sits plainly in the blue sky.
- Sundogs and sun halos: how ice crystals bend sunlightIce crystals high in the atmosphere can bend sunlight into a pale ring around the sun or bright patches on either side of it.
- Crepuscular rays: sunbeams fanning out near sunrise and sunsetWhen broken clouds and haze meet a low sun, bright and dark bands can fan across the sky near sunrise or sunset.
- How the sunset point moves along the horizon through the yearWhere the sun sets on your skyline slides north through spring and south through autumn, fastest near the equinoxes and nearly still at each solstice.
- The Big Dipper never sets from eastern MassachusettsFrom eastern Massachusetts the Big Dipper is circumpolar, circling Polaris once a day, though the tip of its handle skims the horizon at its lowest.
Weather
Birds
- Canada goose families merging into big flocks after the summer moltOnce the flightless summer molt ends in late July, Canada goose families in eastern Massachusetts pool into growing flocks that graze fields and use ponds.
- Barn swallows gathering on wires before fall migrationIn late August, barn swallow families line up on roadside wires as the last chicks fledge; most leave for Central and South America by mid-September.
- Why goldfinches nest in late summer, months after other songbirdsGoldfinches raise chicks after other songbirds are done, waiting for late summer, when seed fluff for nest lining and ripe seeds for chicks arrive at once.
- Crow or raven: how to tell them apart by the tailCrows and common ravens are both big black birds, and the tail settles it at a glance: a crow's opens like a fan, a raven's like a wedge.
Insects
- Cicada shells on tree trunks: what the empty brown husks areA brown husk on a tree trunk is the outgrown skin of a dog-day cicada nymph that climbed up after years underground and split open as a winged adult.
- How orb weaver spiders spin a new web after darkMany orb weavers eat their worn web and spin a whole new wheel in about an hour after dark, so the crisp web you find at breakfast is often brand new.
- How water striders stand on a pond's surface without sinkingWater striders stand on the surface film of eastern Massachusetts ponds on water-repellent, hairy legs, denting it into dimples without breaking through.
- Cricket chirps and temperature: why the chorus slows as nights coolCrickets are cold-blooded, so the tempo of their chirping tracks the evening air: brisk at dusk and slower as a late-summer night cools off.
- Moths at the porch light on warm summer nights around SudburyA single porch light on a warm, still night draws a small sample of the many moths already out in the dark around a Sudbury yard.
- Luna moths at the porch light, most likely in JuneAdult luna moths never feed and live only about a week, so one resting at a Sudbury porch light is a brief, lucky sight, most likely in June.
- Fall webworm tents on branch tips: the silk nests explainedThe gauzy silk bags wrapping whole branch ends on cherries and other hardwoods are fall webworm nests, with the caterpillars feeding safely inside.
- Tomato hornworms covered in white wasp cocoonsA green tomato hornworm studded with white capsules has been farmed from the inside by a tiny braconid wasp, and the capsules are its next generation.
- Hickory tussock caterpillars: look, but do not touchThe white caterpillar with black tufts crossing the trail is a hickory tussock seeking a spot for its cocoon, and its barbed hairs give many people a rash.
- Flying ant day: winged ants swarming after rain in late AugustOn a warm late-August day after rain, ant colonies send out winged queens and males for one mating flight; around Boston it is called the Labor Day ant.
- Milkweed tussock caterpillars eating milkweed leaves in gangsFlip a ragged milkweed leaf and you may find a gang of fuzzy black, orange and white milkweed tussock caterpillars eating it down to lace.
- Hummingbird moths: clearwing sphinx moths hovering at bee balmThat tiny hummingbird at the phlox may be a clearwing sphinx moth, hovering in daylight on blurred wings and sipping nectar through a long tongue.
- Bald-faced hornet nests: paper globes in the trees, seen from afarThe gray, teardrop-shaped paper globe in a tree has grown all summer and can hold 100 to 400 hornets; admire the chewed-wood architecture from a distance.
Plants
- Oak galls: the bumps and balls on oak leaves, and what makes themThe bumps and balls on eastern Massachusetts oak leaves are galls, tissue the tree grew around a tiny wasp or other insect, and most do the tree no harm.
- Ghost pipe: the white forest plant with no green, June to SeptemberGhost pipe rises in shaded Massachusetts woods from June through September, a waxy white plant with no chlorophyll that feeds through fungi on tree roots.
- Queen Anne's lace curling into bird's nests as it goes to seedAs its seeds ripen, each flat white Queen Anne's lace flower curls into a brown cup like a little bird's nest, and fields hold both stages side by side.
Mammals
- Fawns out exploring with their mothers in July and AugustMost Massachusetts fawns are born in May and June, and by July they are strong enough to run and are exploring yards and field edges with their mothers.
- Big brown bats hunting over yards at dusk in eastern MassachusettsThe most common bat in Massachusetts suburbs, the big brown bat, leaves its roost in the evening to hunt insects over yards, ponds and field edges.
- Beaver signs: chewed stumps and pale wood chips along pond edgesBeavers work mostly at night, so pointed stumps, pale wood chips and paired tooth grooves along a pond edge are often easier to find than the animal.
Fungi
- Why mushrooms pop up after rain in MassachusettsEach mushroom that appears after a Massachusetts rain is the short-lived fruiting body of a fungus whose threadlike main body stays hidden in soil or wood.
- Why lichen turns bright green after rainRain turns a lichen's gray outer layer see-through so the green algal partner shows, while lichens with cyanobacteria go dark green, brown or black.
- Slime mold on the mulch after rain: the yellow blob explainedA yellow blob that appears on mulch overnight is a slime mold: not a fungus but a giant single cell that creeps, eats, then dries into a brown spore mass.
- Black knot on cherry trees: the black lumps are a fungusHard black swellings on a roadside cherry's twigs are black knot, a native fungus, not fire damage or an insect gall, and it can keep growing for decades.
Amphibians
Landscape
- Why vernal pools dry up in summer, and why that mattersBy midsummer most Massachusetts vernal pools are shrinking toward a dry bed of dark leaves, and that regular drying is what keeps fish from settling in.
- Stone walls in the Sudbury woods and the farms they once edgedAlmost every stone wall in a Sudbury woodlot was a field or pasture edge, built of glacial stones farmers cleared between the Revolution and the Civil War.
- Kettle holes: ponds and hollows left by melting glacial iceSome round ponds and deep hollows in eastern Massachusetts mark where a block of ice, stranded and buried as the last glacier retreated, slowly melted.