Monthly Field Guide

Cypripedium acaule

9,051 obs

Flowers bloom from late May through June, with the pink pouches at their most vibrant. The two distinctive pleated leaves emerge in early May and are easily spotted even before flowering begins.

Maianthemum canadense

8,794 obs

Heart-shaped leaves emerge early, followed by delicate white flower clusters in late May through early June. This is prime identification time when both leaves and flowers are present.

Lysimachia borealis

8,408 obs

Leaves emerge in early May, followed by the iconic seven-petaled white flowers from late May through June. This is prime time for identification when those perfect star-shaped blooms are unmistakable.

Trillium erectum

6,406 obs

Flowers bloom from late April through May, appearing just as tree leaves are emerging. The distinctive musky scent is strongest during peak bloom.

Houstonia caerulea

6,219 obs

Peak blooming time from April through June, when masses of pale blue flowers create stunning displays that can cover entire hillsides. This is when they're most easily spotted and identified.

Arisaema triphyllum

6,081 obs

The distinctive three-part leaves emerge in April-May, followed by the hooded flower structure in late spring. This is the best time for identification as the "pulpit" is most prominent and fresh-l...

Turdus migratorius

5,540 obs

Peak activity begins in March as robins return from southern wintering grounds, singing enthusiastically at dawn and beginning their famous nest-building with mud-lined cups. Look for them pulling ...

Dumetella carolinensis

3,865 obs

Catbirds return to New England in late April and May, immediately announcing their presence with territorial mewing calls. This is when you'll hear their most varied songs as males establish territ...

Branta canadensis

3,796 obs

Peak time for seeing families with fuzzy yellow goslings following their parents in single file. Adults are most vocal and territorial now, and you'll hear their honking calls frequently as they es...

Agelaius phoeniceus

3,777 obs

Males arrive first in March, setting up territories and singing constantly from prominent perches, their red patches blazing as they chase rivals and court the more secretive females who arrive later.

Icterus galbula

3,584 obs

Males arrive first in early May with their brilliant breeding plumage, singing loudly from treetops to establish territory. This is the best time to spot them as they're most vocal and visible whil...

Anas platyrhynchos

2,809 obs

Males display their brightest breeding plumage with vivid green heads and clean white collars, while pairs engage in courtship behaviors like head-bobbing and showing off their colorful wing patches.

Malacosoma americana

2,862 obs

Peak tent-building season when young caterpillars emerge and create their distinctive white silk shelters in tree forks, most visible in April and May.

Cicindela sexguttata

2,309 obs

Adults emerge in late spring and become active on warm, sunny days. This is peak season for spotting them as they're fresh, brightly colored, and actively hunting.

Photinus corruscus

2,276 obs

Still active in early spring, crawling on bark as trees begin to leaf out. This is when they're easiest to spot before summer insects become active.

Bombus impatiens

2,086 obs

Queens emerge from winter hibernation in early spring and can be seen searching for nesting sites, often appearing larger than workers you'll see later. They're among the first bees active, visitin...

Harmonia axyridis

1,772 obs

Adults emerge from winter hiding spots and begin laying bright yellow eggs in clusters on the undersides of leaves, particularly where aphids are abundant.

Bombus bimaculatus

1,660 obs

Queens emerge from winter hibernation and begin establishing new colonies. Look for large, solitary females visiting early flowers like crocuses and fruit tree blossoms.

Anaxyrus americanus

4,070 obs

Peak activity time! Males gather at ponds and pools in April-May, filling the night air with their long, musical trills. This is when you're most likely to see multiple toads together and witness t...

Notophthalmus viridescens

3,728 obs

Adults become active in warming waters and begin breeding. Look for them swimming in shallow areas of ponds and streams as ice melts.

Lithobates clamitans

2,921 obs

Males begin their territorial calling as waters warm, producing their distinctive banjo-like 'gunk' sounds. This is when you're most likely to hear them before you see them.

Plethodon cinereus

2,211 obs

Active under cover objects as temperatures warm, often found in pairs during their spring courtship season. This is an excellent time to find them under logs and rocks.

Dryophytes versicolor

2,147 obs

Breeding season brings them down from the trees to pools and ponds where males call loudly from vegetation near the water. This is the best time to spot them as they're most active and vocal from A...

Lithobates catesbeianus

1,759 obs

Adults emerge from winter hiding spots in mud and begin moving to breeding areas. Males start their territorial calling as water temperatures warm, though peak breeding comes later.

Sylvilagus floridanus

2,989 obs

Most active season as breeding begins and fresh green vegetation emerges. Look for adults with noticeably worn fur from winter, and by late spring, watch for tiny young rabbits barely larger than h...

Tamias striatus

2,712 obs

Chipmunks emerge from winter dormancy in March or April, looking noticeably thinner after months of living off stored fat. This is mating season, so you might hear more chittering calls and see inc...

Sciurus carolinensis

2,580 obs

Highly active as they emerge from winter shelters, often seen frantically searching for cached nuts and beginning to build leaf nests (dreys) in tree forks. This is peak mating season, so expect to...

Odocoileus virginianus

2,369 obs

Does give birth to spotted fawns in late spring, and you might glimpse these adorable babies following close to mom. Coats are developing their rich reddish-brown summer color, and bucks are growin...

Castor canadensis

1,091 obs

Most active as ice melts and they repair winter damage to dams and lodges. Fresh wood chips and newly chewed stumps appear as they take advantage of rising sap in trees.

Procyon lotor

1,000 obs

Mothers emerge with new kits (babies) that are incredibly curious and playful. This is prime time for observing family groups as they forage together, with young ones learning to use their dexterou...

Thamnophis sirtalis

4,388 obs

Emerges from winter dens in March or April, often gathering in groups to mate before dispersing. This is when you're most likely to see multiple snakes together, basking sluggishly in sunny spots a...

Chrysemys picta

4,292 obs

Painted turtles emerge from winter hibernation and begin active basking on warm days, making this an excellent time to spot them as they're hungry and seeking sun to warm up.

Chelydra serpentina

1,880 obs

Active as waters warm, often seen basking on logs or swimming near the surface. Mating occurs in spring, and you might spot pairs together in shallow water.

Nerodia sipedon

1,748 obs

Emerge from winter hiding spots in April and May, often seen basking in sunny spots near water to warm up. This is when they're most sluggish and easiest to observe closely.

Lampropeltis triangulum

861 obs

Emerges from winter hiding spots in late April or May, often found basking on warm rocks or pavement during cool mornings. This is prime time for spotting them as they're more active after months o...

Malaclemys terrapin

430 obs

Terrapins emerge from winter dormancy and begin basking on sunny days, often seen on logs or floating debris in marsh channels as they warm up from months of inactivity.

Cerioporus squamosus

1,659 obs

Peak fruiting time when fresh, tender brackets emerge after warm spring rains. Look for the brightest colors and strongest cucumber-like scent.

Ganoderma tsugae

694 obs

Existing shelves from previous years remain visible and new growth may begin appearing as temperatures warm. Look for fresh white growing edges on established brackets.

Fomitopsis mounceae

608 obs

Existing brackets become more noticeable as snow melts away. Fresh growth zones may begin forming on established specimens as temperatures warm.

Flavoparmelia caperata

587 obs

Becomes more vibrant green with spring rains, making identification easier. This is an excellent time to spot the contrast between wet and dry coloration as weather alternates.

Gymnosporangium juniperi-virginianae

515 obs

Orange gelatinous masses swell and become prominent on cedar branches after spring rains, releasing spores that drift to nearby apple trees. This is the most dramatic and visible stage.

Trametes versicolor

504 obs

Fresh, colorful brackets begin emerging on logs as temperatures warm and spring rains provide moisture. Look for the most vibrant color bands during this season.

Dermacentor variabilis

1,321 obs

Peak activity begins in April and May when adults emerge to seek blood meals and mates. This is when you're most likely to find them questing on grass tips and low vegetation.

Phidippus audax

959 obs

Adults emerge from winter shelters and begin active hunting as temperatures warm. This is when you'll see the most dramatic courtship displays, with males waving their front legs and showing off co...

Dolomedes tenebrosus

701 obs

Adults emerge from winter hiding spots under bark and begin active hunting. This is when you're most likely to spot them moving between trees.

Eriophyes cerasicrumena

673 obs

Mites become active as cherry leaves emerge, beginning to form new galls that appear as small bumps on fresh foliage.

Pisaurina mira

596 obs

Adults become active as temperatures warm, beginning their hunting season on emerging vegetation. Mating activity starts in late spring with males searching for females.

Leucauge venusta

542 obs

Adults begin appearing in late spring as temperatures warm, with females starting to construct their first webs of the season in sheltered spots.

Littorina littorea

615 obs

Most active as warming waters trigger feeding and reproduction. Look for them grazing on algae films covering the rocks, leaving tiny scrape marks.

Cepaea nemoralis

486 obs

Active snails emerge from winter hiding spots as temperatures warm, leaving silvery slime trails on sidewalks and garden paths after spring rains. This is peak time for finding both live snails and...

Arion subfuscus

416 obs

Most active as temperatures warm and moisture increases - look for them emerging from winter hiding spots under logs and stones, often leaving fresh slime trails on damp mornings.

Crepidula fornicata

347 obs

Best time to find fresh, undamaged shells as winter storms subside. Living snails become more active as water temperatures rise.

Testudinalia testudinalis

252 obs

Most active during spring tides when they can move around and feed on newly growing algae. Look for them during low tide explorations in April and May when winter storms have cleared.

Mytilus edulis

246 obs

This is peak spawning season when mussels release eggs and sperm into the water. You might notice the water looking slightly cloudy near large mussel beds during reproduction.

Flavoparmelia caperata

587 obs

Becomes more vibrant green with spring rains, making identification easier. This is an excellent time to spot the contrast between wet and dry coloration as weather alternates.

Umbilicaria mammulata

479 obs

Spring rains make the lichen more pliable and darker in color, making it easier to feel the characteristic leathery texture and observe the single attachment point.

Lobaria pulmonaria

324 obs

Becomes more vibrant as spring rains wet the surface, showing off its bright green color transformation. This is an excellent time to observe the dramatic wet-to-dry color changes.

Cladonia cristatella

306 obs

The red caps are often most vibrant in spring as moisture returns, and the gray-green stalks appear fresh and sturdy. This is an excellent time to spot new growth emerging from established colonies.

Dibaeis baeomyces

277 obs

The pink fruiting bodies are often most vibrant in late spring, standing out beautifully against fresh green mosses. This is an excellent time to spot new colonies as they become active with warmin...

Cladonia rangiferina

256 obs

Becomes more vibrant and noticeable as snow melts, revealing extensive gray carpets that may have been hidden all winter. Spring rains make the lichen slightly more pliable and greenish-tinted.

Carcinus maenas

598 obs

Crabs become more active as waters warm, emerging from deeper winter refuges. This is prime time to spot them in tide pools and under rocks during low tide.

Oniscus asellus

478 obs

Active as temperatures warm, emerging from winter hiding spots under deep leaf litter and logs. Look for them during warm, humid days when they're most active.

Porcellio scaber

378 obs

Active and easy to spot as they emerge from winter hiding spots under logs and stones. Look for them in garden mulch and compost areas.

Armadillidium vulgare

353 obs

Most active as temperatures warm and they emerge from winter hiding spots under deep leaf litter and logs. This is when you'll see them most often during the day.

Philoscia muscorum

328 obs

Active and easiest to spot as they emerge from winter hiding spots under logs and stones. This is when you're most likely to see them scurrying around during the day.

Semibalanus balanoides

289 obs

Look for newly settled young barnacles as tiny white dots on rocks, and watch for increased feeding activity as water temperatures warm and plankton blooms provide abundant food.

Lepomis macrochirus

272 obs

Spawning season brings bluegills into shallow water where males create circular nests in sandy or gravelly areas, becoming more aggressive and showing intensified coloration. This is when they're m...

Micropterus nigricans

237 obs

Males become territorial and build circular nests in shallow water during spawning season (May-June), turning darker and more aggressive. This is when they're most likely to be seen in the shallows.

Lepomis gibbosus

207 obs

Males develop brighter colors and create circular nests in sandy or gravelly shallow areas, aggressively defending their territory with flared gills and spread fins.

Salvelinus fontinalis

159 obs

Most active as ice melts and water temperatures rise, making this an excellent time for spotting them in shallow areas. Colors become more vibrant as they recover from winter.

Perca flavescens

150 obs

Spawning season brings perch into shallow, weedy areas where they're most easily observed. Look for schools of adults in 3-10 feet of water near vegetation.

Alosa pseudoharengus

124 obs

Peak spawning migration from April through June, when massive schools run upstream to freshwater spawning areas. This is when they're most visible and easiest to observe in large numbers.

Scutigera coleoptrata

263 obs

House centipedes become more active as temperatures warm, often appearing more frequently as they hunt for emerging insects and begin their breeding season indoors.

Rudiloria trimaculata

189 obs

Active as soil warms up, often found under logs and in leaf litter as they emerge from winter hiding spots. Good time to search as vegetation is still sparse.

Lithobius forficatus

114 obs

Most active as temperatures warm up, often seen hunting at night or discovered when turning over garden stones and logs. This is when they emerge from deeper winter hiding spots.

Oxidus gracilis

77 obs

Active as soil warms and moisture increases from snowmelt and spring rains. Often found under lifting mulch and emerging leaf litter where they've been feeding on decomposing organic matter.

Apheloria virginiensis

73 obs

Adults become active as soil warms, often found under logs and in leaf litter as they begin feeding on decomposing plant matter.

Pseudopolydesmus serratus

56 obs

Active as soil warms and becomes workable, often found under logs and stones as snow melts. This is when they're easiest to spot as they emerge from deeper winter hideouts.

Cyanea fulva

218 obs

Young jellies may start appearing in late spring as water temperatures warm, though they're still developing their full complement of tentacles and mouth-parts.

Aurelia aurita

66 obs

Moon jellies begin appearing in warmer coastal waters as temperatures rise, often first spotted in protected bays and harbors where the water warms earliest.

Metridium senile

53 obs

Most active as waters begin to warm, with tentacles fully extended for feeding on increasing plankton. This is when they're easiest to spot and photograph.

Aulactinia stella

32 obs

Most active as warmer water returns, with tentacles frequently extended for feeding. Good time to observe feeding behavior as they capture small crustaceans and fish.

Diadumene lineata

14 obs

Most active as water temperatures begin to warm, with tentacles fully extended during high tides for feeding. This is when they're easiest to spot and photograph.

Cyanea capillata

10 obs

Large adults begin appearing in New England waters as they follow cold currents southward. This is when you might see the biggest specimens of the year.

Strongylocentrotus droebachiensis

101 obs

More active as waters begin to warm, often seen moving across rocky surfaces during low tides. This is prime time for finding them in accessible tide pools.

Echinarachnius parma

50 obs

Beach-washed specimens become more common as winter storms subside and the first warm weather brings beachcombers out. Living sand dollars begin moving into shallower waters.

Asterias rubens

49 obs

Most active as waters warm up, often found in shallow tide pools during low tides. This is prime time for tide pooling and spotting them.

Asterias forbesi

34 obs

Most active as waters warm up, moving into shallower areas and beginning their peak feeding season on shellfish beds.

Ophiopholis aculeata

15 obs

Brittle stars become more active as water temperatures rise, making them easier to spot during spring low tides when they venture out from winter hiding spots.

Henricia sanguinolenta

13 obs

Active in deeper waters as temperatures begin to warm. Best spotted during exceptionally low spring tides that expose normally submerged rocky areas.