What to look for in nature in Maine this May

When do the warblers arrive in Maine in May, and which other birds come back?

• Warblers that wintered in Florida

  Around the first of May, according to a Bangor Daily News birding column · Woodland edges, shrubby wetlands and any tall tree with new leaves, starting in the south

  Duchesne wrote that the warblers wintering in Florida begin to arrive around the first of May. He added that a few black-throated green warblers and northern parulas should be back by May Day, with the rest following within about a week, and that black-and-white warblers wintering closest to Maine come back first. The column dates from 2016, so treat its dates as a guide to what is usual, not a promise for 2027. Warblers are small, quick and high in the leaves, so listen first: the black-throated green has a buzzy, lisping song in conifers, and the parula’s rising trill ends in a sharp note.

• Hummingbirds and orioles

  Males lead the way; Audubon gives no Maine date, so follow Journey North’s maps for 2027 · Gardens, feeders and the edges of tall deciduous trees

  Audubon’s field guide notes that the male ruby-throated hummingbird moves north ahead of the female, and that these birds weigh no more than 0.1 to 0.2 ounce. Its feeder advice: skip red dye and clean them often. Baltimore orioles, which hang their pouch nests from drooping branches, also come to sugar water and fruit. Check Journey North’s sighting maps before hanging a feeder, since they track the first arrivals week by week.

• Barn swallows over the fields

  Maine Audubon says to listen from late April, so they are already settling in by May · Farm fields, barns, bridges and open water

  Maine Audubon’s backyard-bird feature describes a bouncy, high-pitched chatter over fields as the sign that barn swallows are back from a journey of more than 4,500 miles from Central and South America. The same article warns that falling insect numbers threaten these birds.

• Bobolinks in the hayfields

  Males come first, then the females; Audubon gives no dates · Open hayfields and damp meadows

  National Audubon reports that most bobolinks in the eastern United States now nest in hayfields, hide the nest on the ground in dense grass, and raise one brood a year. The young leave the nest 8 to 14 days after hatching, before they can fly, so a nest hidden in the grass is easy to trample. Audubon names the loss of nesting habitat as a likely cause of the species’ decline.

• Peregrine falcons on Acadia’s cliffs

  The nesting season runs through summer · Precipice Trail and the cliffs of Mount Desert Island

  The National Park Service says hikers usually cannot use the Precipice Trail in summer, a limit that protects peregrines during their annual nesting period. Visitors can still watch from the parking lot through the Peregrine Watch program, using spotting scopes. The Maine wildlife agency lists the peregrine as a State Endangered Species and credits recovery efforts for its return.

Where can you see puffins, loons and other water birds in Maine in May?

• Atlantic puffins

  Nesting through the summer; boat trips and festivals begin in late spring, and no source gives a firm return date for 2027 · Eastern Egg Rock, Petit Manan Island and Machias Seal Island

  Project Puffin began in 1973 to bring puffins back to former nesting islands off Maine, and National Audubon calls the effort a major success. A puffin lays usually one egg, in a burrow or rock crevice three to seven feet deep. Incubation takes 36 to 45 days, usually 39 to 42, and both parents share it. Maine’s wildlife agency says tens of thousands of people join puffin cruises each year. Festival programs include boat trips to the outer colonies, so go with an organized trip and stay on the boat or marked path rather than trying to reach a colony on your own.

• Eiders, terns and the other island nesters

  Late spring and early summer · About 500 Maine islands, mostly in the Midcoast and Downeast

  Maine’s wildlife agency says 13 seabird species nest on the state’s islands, and that about 500 islands hold nesting seabirds and common eiders. The agency has designated 21 roseate tern islands as Essential Habitat. Hens that lose their own broods become “aunts” that help guard others’. A bird that flushes from a nest is a bird you got too close to, so keep your distance from shore and your boat well back.

• Common loons on their nests

  Nest-sitting is under way in May on lakes that opened in April · Quiet coves and the shores of islands in lakes and ponds

  The wildlife agency’s loon brochure lists three signals that mean you are too close: a loon splashing upright across the water in what it calls the penguin dance, a quavering tremolo call, and a loon lying flat on the shoreline with its head down on a nest. Paddlers, who slip easily into shallow water, often startle nesting loons without knowing it. Use binoculars, back away at the first sign, and keep fishing lines out of coves where loons are nesting. Boat wakes can flood a shoreline nest.

When is Maine’s spring turkey season in 2027, and what are the birds doing?

• Gobbling, strutting and nesting

  Breeding in April and May, then egg laying and incubation · Field edges, forest openings and wooded hillsides in every county

  IFW says dominant toms do most of the breeding and draw hens with strutting and gobbling. A hen then scrapes a shallow nest on the ground, lays an egg a day for up to 10 to 12 days and sits for 26 to 28 days. Poults leave the nest the day they hatch and feed on insects near field edges for their first weeks. They begin roosting in trees at five to six weeks. The agency estimates a spring population of about 70,000 turkeys, a figure that leaves out the year’s hatch, and says snow depth is the main thing limiting where they live.

• The 2027 spring season

  Monday, May 3, through Saturday, June 5, 2027, with a youth day on April 30 · Wildlife Management Districts across the state

  IFW’s published 2026–27 schedule opens the spring season for archery equipment or shotgun on May 3, 2027, and closes it on June 5. In Wildlife Management Districts 7 and 9 through 29 a hunter may take two bearded turkeys, and in districts 1 through 6 and 8 the limit is one. Youth days fall on April 30. Rules can change in a new lawbook, so confirm them on the agency’s hunting pages before heading out.

What are Maine’s moose, bears and bats doing in May?

• Moose calving

  Cows give birth in May, per the Maine wildlife agency · Spruce-fir lowlands, wet thickets and the edges of ponds, especially in the North Woods

  IFW says cows give birth in May, usually to one or two calves, and that a calf remains at its mother’s side for roughly twelve months, until she drives it off shortly before the next calf arrives. Newborns are vulnerable to predators such as bears. A cow with a calf will defend it, so a moose beside a road or trail in late May deserves a wide, calm detour. Winter ticks are part of this story too: the agency says fully fed female ticks drop off moose in late spring and lay up to 4,000 eggs in the leaf litter, and that winter ticks are the leading cause of death for moose under a year old.

• Black bears out and hungry

  Cubs left the den in mid-April; breeding runs May through August · Lowlands, wetlands, field edges and anywhere there is easy food

  IFW says bears feed on early grasses, clover and hardwood buds in spring, often in wet lowlands, and calls this a time of food stress because little natural food is available. It estimates about 25,000 bears in Maine, a number that has been fairly steady since 2008. The agency’s advice is to bring feeders in during the active season, April 1 to November 1, and to rake up spilled seed and store the rest indoors. Most conflicts, the agency says, can be prevented by removing food around homes.

• Bats returning to their summer roosts

  Hibernation lasts until April or early May; pups are born in May, June or July · Attics, barns, tree cavities and the air above ponds at dusk

  Maine has eight bat species, five of which hibernate here and three of which migrate south. White-nose syndrome has emptied caves that once held hundreds of bats, and IFW and the U.S. Fish and Wildlife Service installed a gate at the largest hibernation site. Most Maine bats have one pup a year, and pups cannot fly for about a month. The agency warns that disturbing a colony in spring can make mothers abandon or drop their young, and its recommended exclusion-free period, when bats should not be shut out of a building, runs from May 15 to August 15. If bats use your attic, count them in early June and again in late July to see whether the number rises as the pups learn to fly.

What is blooming and which insects are out in Maine in May?

• Trailing arbutus, the Mayflower

  In flower from mid-April for roughly a month, so still blooming in early May · Sandy, acidic soil under pines and oaks, and along rocky trails

  A Coastal Mountains Land Trust writer noted in mid-April that trailing arbutus would be flowering for the next month or so. The plant is a low, creeping evergreen with small pink or white flowers. Look low and kneel, because it is easy to step on. If you find a bloom in your town, record the date in the field journal, since the timing of early bloom shows whether a spring runs early or late.

• Red trillium and the long wait to bloom

  A few weeks, ending when the canopy closes · Rich hardwood woods and shaded slopes

  The Heritage Trust says a red trillium takes an average of 15 years to grow big enough to flower and can live 30 years. That is a good reason to leave one where it grows. Wild strawberry blooms nearby, and the trust notes it will bear red fruit by June.

• Browntail moth caterpillars

  Out of their webs and feeding since mid-April; treatment works best before late May · Coastal Maine and up to 60 miles inland, most heavily in the Midcoast and the capital region

  The Maine Forest Service says browntail caterpillars leave their winter webs and begin feeding in mid-April. Their hairs, which come from caterpillars, cocoons and shed skins, cause a rash, and the agency advises avoiding heavily infested areas from April to August. The agency also says to avoid leaf blowers and lawnmowers on dry days in infested areas and to do yardwork on wet days instead.

• Black flies near running water

  Seasonal timing varies with the stream and the weather · Wherever there is fast or slow running water, including the North Woods

  UMaine Extension’s fact sheet explains that black flies need running water to breed, unlike mosquitoes, which prefer standing water, and that only the females bite. Because their breeding is sensitive to pollution, the flies serve as a sign of clean water.

What is May weather like in Maine, and what hazards should you watch for?

How fast do the days lengthen in Maine in May?

When is the last spring freeze in Maine?

What can you see in Maine’s night sky in May 2027?

• Eta Aquariid meteors, at new moon

  Peak night May 6 into the morning of May 7; the mornings of May 5 to 7 are all good · Radiating from Aquarius, low in the east-southeast in the last hours before dawn

  These meteors are dust from Halley’s comet. Sea and Sky calls 2027 an above-average year with up to 60 meteors an hour at best and roughly half that from the north, and notes that the new moon leaves the sky dark all night. In Maine expect fewer than those figures, because the radiant in Aquarius is still low in the east when the sky begins to brighten this far north. Go out in the last two hours before dawn, find a dark horizon to the east and southeast and give your eyes 20 minutes.

• The Flower Moon, a seasonal Blue Moon

  Full on Thursday, May 20, at 6:59 a.m. EDT; best evening to watch it rise is Wednesday, May 19 · Rising in the east-southeast after sunset

  The full Moon arrives after sunrise on the 20th, so the evening of the 19th is the best view of a nearly full Moon rising. The Naval Observatory table has moonrise at 7:48 p.m. in Portland and 7:46 p.m. in Bangor that evening, so start looking toward the east-southeast soon after sunset. Sea and Sky also lists May 20 as a Blue Moon, by the old almanac habit of naming the third full Moon in a season that holds four. Nothing qualifies under the newer calendar-month rule this year.

• Mercury at its best evening showing of the year

  Greatest eastern elongation on May 28, with the best evenings from about May 12 to June 5 · Low in the west-northwest, 45 to 90 minutes after sunset

  Sea and Sky marks May 28 as the night Mercury stands highest above the western horizon after sunset, with 22.9 degrees between it and the Sun. By our own figures for the central United States, Mercury lingers roughly 90 minutes after sunset in mid-May and a bit longer at the start of June, which makes this Maine’s best evening try of 2027. Treat the minutes as approximate, since they shift with latitude. You need a clear, low horizon over the water or a field.

• The Moon beside Jupiter, then Mars

  Evenings of May 12 and 13 · Jupiter high in the south-southwest after dark; Mars farther east

  Our own calculation puts the closest approach of the first-quarter Moon to Jupiter at 5:52 p.m. EDT on May 12, in daylight, so the best view is after dark that evening, with the Moon just next to the planet. On the 13th the Moon moves on to within about 3 degrees of Mars. Jupiter stays up late all month, and the same calculation has it setting some seven hours after sunset on May 1.

What can Maine families do outdoors in May 2027?

Safety notes for May in Maine