Field notes

Rule one: never eat anything you have identified from a photo or an app. Rule two: always take a spore print, which costs nothing and settles more questions than any book. Rule three: learn the deadly few first. Destroying angels and other Amanitas grow in Maine woods every fall and cause most serious poisonings in North America.

Rule four: photograph, do not pick, and never collect inside Acadia National Park. A forest floor without its mushrooms has nothing for slugs, beetles and red squirrels. Rule five: come back next week. The same log can fruit different species every few days through October.

Lowbush blueberries ripen from late July to early September. The big Downeast barrens are privately owned and harvested commercially, so stay out unless a sign or the grower says you are welcome. Many farms run pick-your-own days, and they are worth the drive.

Inside Acadia, picking a small amount of berries for eating on the spot is allowed, but check current park rules before you go. Leave plenty for the bears, foxes, cedar waxwings and the next hikers, and never trample the low shrubs to reach a better patch.

Harbor seals haul out on Maine's ledges to rest, digest and, in May and June, to nurse their pups. Every time they are flushed into the sea they burn energy, and pups can be separated from their mothers. Seals are protected under the federal Marine Mammal Protection Act, and NOAA asks people to stay at least 50 yards away.

The signs are simple. If a seal lifts its head and looks at you, stop. If it starts moving toward the water, back away slowly. A pup alone on a beach is usually waiting for its mother. Keep people and dogs well back and call the regional marine mammal stranding network rather than touching it.

Pink lady's slippers depend on a soil fungus to feed their seedlings, which can take ten years or more to flower for the first time. Dug-up plants almost always die within a couple of seasons, because the fungus does not come with them.

The flower itself is a trap. Bumblebees push inside the pouch looking for nectar that is not there and can only escape past the pollen. Look for them in late May and June under pines and oaks in acidic soil, and enjoy them where they grow.

Bobolinks nest on the ground in tall grass and need about 65 days from the first egg to young that can fly. In Maine that usually means mid-July. Fields cut earlier lose nearly all their nests, and the species has declined sharply across New England as hay is cut earlier and more often.

The farmers we work with on the Blue Hill Peninsula delay their first cut, or leave strips uncut, and the birds have come back. Late mowing also lets wildflowers set seed, which is why those fields are so good for monarchs and bumblebees by August.

Big waves come in sets, and every so often one is much larger than the rest. Never stand on low ledges, at the edge of Thunder Hole or on a breakwater during a storm swell. The safe spots are high, set back from the edge, with dry rock and plenty of room behind you.

Check the National Weather Service marine forecast and the tide chart. The most dangerous mix is a long-period swell arriving at high tide. If in doubt, watch from the car or a café window in Bar Harbor, and bring binoculars for the eiders riding the troughs.