Monthly Field Guide

Impatiens capensis

4,267 obs

Plants continue flowering until the first hard frost, often still blooming in September and early October. Seed pods are most abundant and 'explosive' during this season, making it perfect for demo...

Pinus strobus

4,256 obs

Older needles (2-3 years old) turn yellow and drop, which is normal - don't worry, your white pine isn't dying! New cones begin forming and older cones mature to brown.

Phytolacca americana

4,006 obs

Berries ripen from red to dark purple, creating striking upright clusters that attract birds. Leaves may yellow before dropping, and stems become deeply colored.

Acer rubrum

3,778 obs

Often the first tree to turn color, displaying brilliant reds, oranges, and yellows. Fall color can vary dramatically even between trees in the same area.

Symphyotrichum novae-angliae

3,684 obs

Peak blooming occurs from August through October, creating spectacular purple displays. Seeds develop and disperse through November, creating fluffy white seed heads.

Eurybia divaricata

3,320 obs

Prime identification season when white daisy-like flowers bloom in flat-topped clusters from late August through October. Seeds develop into fluffy white dispersal heads that persist into late fall.

Bombus impatiens

12,020 obs

New queens and males emerge for mating flights, so you might see larger individuals again. Workers continue foraging on late-season flowers like asters and goldenrod until the first hard frosts.

Danaus plexippus

7,069 obs

The famous migration begins in late August and September, with monarchs clustering in large numbers and flying steadily southward. These fall butterflies are the super-generation that will make the...

Danaus plexippus

7,069 obs

The famous migration begins in late August and September, with monarchs clustering in large numbers and flying steadily southward. These fall butterflies are the super-generation that will make the...

Apis mellifera

5,184 obs

Numbers remain high as bees frantically gather nectar from late-season flowers like goldenrod and asters to stock up for winter. Workers may seem more focused and hurried in their movements.

Lophocampa caryae

4,228 obs

Mature caterpillars become most visible in early fall as they finish feeding and search for pupation sites. They may wander considerable distances from their host trees.

Halysidota tessellaris

3,056 obs

Mature caterpillars are most visible as they wander looking for places to pupate, often crossing paths and climbing down trees.

Ardea herodias

2,223 obs

Migration brings increased numbers to New England waters as northern birds pass through. Adults lose their breeding plumes but remain active hunters preparing for winter.

Meleagris gallopavo

2,088 obs

Large flocks gather to feed on acorns and nuts. This is when you're most likely to see impressive groups of 20+ birds moving through the woods together.

Larus smithsonianus

1,888 obs

Mixed flocks of adults and confusing brown juveniles gather at beaches and landfills. Adults start showing more wear in their plumage as they molt.

Nannopterum auritum

1,856 obs

Large flocks gather before migration, creating impressive roosting congregations on favorite perches. Best time to see multiple birds together.

Branta canadensis

1,831 obs

Migration season brings spectacular V-formations overhead with their iconic honking calls. Large flocks gather at staging areas like reservoirs and coastal marshes, though many year-round residents...

Anas platyrhynchos

1,816 obs

Large flocks gather as northern migrants join year-round residents, and males begin molting back into their handsome breeding colors with fresh, bright plumage emerging.

Laetiporus sulphureus

2,153 obs

Still actively fruiting into autumn, though specimens may be more weathered. Earlier summer specimens will have faded to pale colors and become tough and woody.

Amanita muscaria

1,887 obs

Peak season from September through October. Fresh specimens are most abundant and display the brightest colors before first frost.

Armillaria mellea

1,751 obs

Prime honey mushroom season from September through November when large flushes appear after autumn rains. This is when you'll see the most dramatic displays around infected trees.

Cortinarius iodes

1,643 obs

Peak season for finding Viscid Violet Corts. September through October offers the best chances, especially after autumn rains when many mycorrhizal fungi fruit prolifically.

Fomitopsis betulina

1,561 obs

Brackets continue growing and may develop stronger brown coloration. This is when many become most visible as leaves drop and expose the tree trunks.

Trametes versicolor

1,350 obs

Peak season for finding fresh, beautiful specimens as fall moisture returns. Many brackets from earlier in the year remain visible but become tougher.

Anaxyrus americanus

3,006 obs

Toads begin preparing for winter by eating heavily and seeking deeper shelter. Young toads that metamorphosed earlier in the year are now tiny versions of adults, often seen hopping across paths.

Lithobates clamitans

2,801 obs

Activity gradually decreases as temperatures drop, but you can still find them on warm days. They begin moving to deeper water for winter preparation.

Notophthalmus viridescens

2,553 obs

Adults prepare for winter by moving to deeper water. Young efts continue their land phase, often found under logs and rocks.

Plethodon cinereus

1,996 obs

Commonly encountered during leaf-turning season as they prepare for winter, often found clustered together under large logs or in rock crevices.

Lithobates palustris

1,883 obs

Recently metamorphosed juveniles disperse from water while adults prepare for hibernation. Both may be found moving through moist woodland areas as they seek winter shelter.

Pseudacris crucifer

1,753 obs

Preparing for winter by seeking shelter under logs, bark, and leaf litter. Calling may resume briefly during warm spells but much less intense than spring.

Sciurus carolinensis

3,304 obs

Hyperactive gathering mode as they collect and bury nuts for winter storage. You'll see them constantly on the move, cheeks bulging with acorns. Their memory for cache locations is remarkable durin...

Odocoileus virginianus

2,220 obs

Breeding season brings dramatic behavior changes — bucks become bold and aggressive, their necks swell with muscle, and they make scrapes in the ground that smell musky. Coats begin turning gray-br...

Tamias striatus

1,946 obs

Frantic preparation mode as they stuff cheek pouches with acorns, nuts, and seeds. Their fur becomes thicker and more vibrant, and they may appear noticeably plumper as they build fat reserves.

Sylvilagus floridanus

1,522 obs

Developing thicker, grayer winter coats and feeding heavily to build fat reserves. Often seen gathering near reliable food sources like gardens and bird feeding areas.

Tamiasciurus hudsonicus

956 obs

Frenzied cone harvesting activity with constant chattering. Middens grow rapidly as they prepare for winter storage.

Procyon lotor

715 obs

Raccoons bulk up dramatically for winter, sometimes doubling their weight. Their fur becomes noticeably thicker and more luxurious. Increased activity around food sources like fruit trees and garba...

Araneus diadematus

1,603 obs

Mating season brings males wandering in search of females. Females create egg sacs and their webs may appear more tattered as they focus energy on reproduction.

Leiobunum vittatum

1,315 obs

Most abundant and noticeable as they seek mates and lay eggs, often gathering in groups in tree holes, wood piles, or other sheltered spots to stay warm.

Argiope aurantia

1,267 obs

Females are at their absolute largest and most noticeable as they prepare to lay eggs, while males can often be found on the edges of female webs during mating season.

Pisaurina mira

936 obs

Spiderlings disperse from nursery webs and adults continue hunting until first frost. Late fall is when you might spot the last generation of young spiders establishing territories.

Argiope trifasciata

883 obs

Peak season when mature females create their largest, most visible webs from early September through October as they prepare for mating and egg-laying.

Neoscona crucifera

761 obs

Peak season for observation! Mature females reach full size and often become active during daylight hours. This is when you'll see the most impressive webs and largest, most colorful spiders.

Thamnophis sirtalis

2,656 obs

Still active but increasingly focused on feeding heavily before winter, making them bolder about hunting in open areas. Young snakes born in late summer are now pencil-thin miniatures of adults, pe...

Chrysemys picta

1,706 obs

Turtles remain active on warm days but begin preparing for winter, spending more time feeding and less time basking as temperatures cool.

Chelydra serpentina

1,332 obs

Still active but beginning to slow down as temperatures drop. They start moving toward deeper water areas where they'll spend the winter.

Nerodia sipedon

688 obs

Increase basking behavior to build up energy reserves before winter. Young snakes born in late summer are now more visible as they hunt actively before their first winter.

Lampropeltis triangulum

474 obs

Breeding season occurs in late summer/early fall, making them slightly more visible as they search for mates. They begin seeking winter shelter in October as temperatures drop.

Storeria dekayi

292 obs

Continues feeding heavily before winter, often concentrated around compost piles and leaf litter where earthworms are abundant. Still active on warm October afternoons.

Littorina littorea

846 obs

Still active but beginning to cluster more tightly in crevices. Shell colors often appear most vibrant after summer algae growth.

Arion subfuscus

605 obs

Very active as they feed heavily before winter, often seen on fallen leaves and around decomposing organic matter. This is prime slug-spotting season in New England.

Crepidula fornicata

503 obs

Still active but preparing for winter. Good time to find shells as autumn storms may wash specimens ashore.

Limax maximus

408 obs

Peak activity period as they feed heavily before winter, often found near compost piles and fallen leaves. This is when you're most likely to witness their spectacular aerial mating displays.

Cepaea nemoralis

365 obs

Snails are busy feeding before winter, often seen on fallen leaves and in compost areas. Empty shells become more noticeable as vegetation dies back.

Mytilus edulis

362 obs

Mussels continue growing rapidly, adding new shell material before winter. Storm activity increases, washing more empty shells onto beaches for easy collecting and identification.

Carcinus maenas

1,157 obs

Still very active but beginning to move to deeper waters. Great time for observation as they're often foraging heavily before winter.

Pagurus longicarpus

540 obs

Still active but beginning to move to slightly deeper waters. Shell competition intensifies as crabs prepare for winter dormancy.

Hemigrapsus sanguineus

487 obs

Still very active but beginning to move to slightly deeper water. Great time to spot them as they're often fattening up before winter.

Oniscus asellus

453 obs

Still quite active as they prepare for winter, often found in large groups under the same log or stone. They're gathering in the dampest, most protected spots they can find.

Cancer borealis

407 obs

Crabs begin moving to deeper waters as temperatures drop. Larger specimens may still be found in protected tide pools and under rocks during extreme low tides.

Semibalanus balanoides

398 obs

Adults continue feeding to build energy reserves for winter, and you may notice some barnacles beginning to look more weathered from summer wave action.

Flavoparmelia caperata

643 obs

Remains visible and identifiable as leaves drop, often becoming more prominent on tree trunks. Color shifts between yellow-green and bright green with autumn rains.

Umbilicaria mammulata

356 obs

Cool, moist fall conditions bring out the best coloration and flexibility, making it an ideal time for identification and photography as the lichen darkens and becomes more prominent against the rock.

Cladonia rangiferina

322 obs

Takes on a subtle warmth in color as autumn light filters through, and increased moisture from fall rains makes it more supple to the touch.

Lobaria pulmonaria

291 obs

Remains visible but may be partially obscured by falling leaves. The cooler, damper weather brings out richer colors and makes the texture more pliable to touch.

Xanthoria parietina

201 obs

Colors may appear slightly muted but the lichen remains easily identifiable. Good time to observe differences between sunny and shaded colonies.

Dibaeis baeomyces

193 obs

Often produces a fresh flush of bright pink fruiting bodies in the cooler, moister conditions. The contrast against fallen leaves makes identification easier.

Lepomis macrochirus

268 obs

Bluegills feed heavily to prepare for winter, often gathering in deeper areas but still accessible in shallow bays on warm afternoons. Their colors may become slightly more muted as water temperatu...

Micropterus nigricans

180 obs

Fish actively feed to build reserves for winter, often moving to deeper water but still approachable near structure. Colors may appear more muted as water temperatures drop.

Brevoortia tyrannus

175 obs

Schools begin their southern migration, often hugging the coastline closely. This is when beach-walkers are most likely to encounter schools in shallow water.

Fundulus heteroclitus

155 obs

Fish begin forming larger schools and may move to slightly deeper waters. Their colors become more subdued as breeding activity decreases.

Morone saxatilis

125 obs

Fall migration south begins with fish feeding heavily to build energy reserves. Colors may appear slightly darker.

Salvelinus fontinalis

118 obs

Spawning season brings the most spectacular colors - reds become deeper, whites more brilliant. Males develop hooked jaws and become more territorial.

Scutigera coleoptrata

293 obs

Remain active indoors as outdoor temperatures drop, often becoming more noticeable as they move to warmer areas of the house and continue hunting for overwintering insects.

Narceus americanus

226 obs

Oxidus gracilis

170 obs

Very active as they feed on newly fallen leaves and prepare for winter. This is often the best time to spot them as they're out processing the abundant organic matter.

Rudiloria trimaculata

124 obs

Still active as they prepare for winter, often concentrating under logs and in deep leaf litter. The fresh fallen leaves provide both food and shelter.

Lithobius forficatus

69 obs

Still quite active but beginning to seek deeper shelter for winter. Often found when cleaning up garden beds or moving firewood.

Pseudopolydesmus serratus

52 obs

Very active as they feed on freshly fallen leaves. Often found in deeper leaf litter as they prepare for winter dormancy.

Strongylocentrotus droebachiensis

150 obs

Still active but beginning to slow down as waters cool. Good season for tide pooling discoveries as summer crowds thin out.

Asterias rubens

143 obs

Still active but may move to slightly deeper waters as temperatures drop. Good time to find them on dock pilings and breakwaters.

Asterias forbesi

117 obs

Still active and visible, often moving to slightly deeper waters as temperatures begin to cool.

Echinarachnius parma

57 obs

Storm activity increases the number of shells washing ashore. This is often the best season for collecting well-preserved white specimens as autumn storms churn up the sea floor.

Henricia sanguinolenta

30 obs

Still active but beginning to move to slightly deeper waters. Late fall diving may reveal them on exposed rocky ledges.

Arbacia punctulata

17 obs

Still active but beginning to seek deeper water and more sheltered spots as storms increase.

Chrysaora chesapeakei

51 obs

Numbers begin to decline as water temperatures cool, though some individuals may persist into early fall in protected bays.

Metridium senile

47 obs

Still active and feeding heavily before winter, though tentacles may contract more frequently as water temperatures drop and storms increase.

Physalia physalis

47 obs

Occasional sightings may continue into early fall during warm years, but they become increasingly rare as water temperatures drop.

Diadumene lineata

41 obs

Still active but may be less extended as water temperatures drop. Stripes remain visible even when contracted.

Astrangia poculata

39 obs

Still active but beginning to slow down as temperatures drop. Colonies remain clearly visible and identifiable on hard surfaces.

Cyanea versicolor

28 obs

Continue to be present in early fall, though numbers typically start declining as water temperatures drop toward winter.