canal boat Blue heron in the river.
The Delaware River Watershed provides water to over 17 million people and supports a world-class trout fishery and bald eagles.

Birds & Butterfilies

butterfly and hummingbird picture

As part of the Atlantic Flyway, the corridor hosts large numbers of waterfowl and waterbirds in the wooded riverside habitats. According to wildlife biologists, the highest concentration of eagle wintering areas in New York is found in this watershed.


There are many species of butterflies right here in the Delaware River valley, but the Monarch is one of the most popular and well-recognized. Each summer the monarchs arrive from Mexico after wintering there during our coldest months.

There are over 150 different species of butterflies recorded in New York State.

Seasons and Limits


The Monarch ButterflyRevitalizing the Monarch Butterfliy

Fostering the Flyway by the Byway

Monarch butterflies are in trouble. In the last 20 years, their population has dwindled from more than a billion to just 150 million, a nearly 82% decline that has been observed with alarm along the Delaware River which serves as a flyway for the annual migration of Northeastern Monarchs from their summer breeding grounds to their wintering roosts in central Mexico.

Download the Monarch Butterfly brochure (PDF) >>

Learn more about Monarchs >>



How to Identify Birds


Pay attention to the following:Seasons and Limits

body shape
proportions of the head, legs, wings
tail shape
length of the bill

Field Markings

Pay particular attention to the field marks of the head and the field marks of the wing.

Approximately 200 species of birds have been identified within the corridor, including the bald eagle, which winters and nests in the Delaware watershed.

Field Marks of the Head
When identifying an unknown bird, the following field marks of the head are particularly important:
Eyebrow stripe (or superciliary line, above the eye)
Eyeline (line through the eye)
Crown stripe (stripe in the midline of the head)
Eyering (ring of color around eye)
Throat patch
Color of the lore (area between base of beak and eye)
Whisker mark (also called mustache or malar stripe)
Color of upper and lower beak
Presence or absence of crest
Beak shape and size are also important identifying characteristics.

Field Marks of the Wings
Note the presence or absence of the following:
Wing patches


Vertical or Horizontal Posture
A Flycatcher or American Robin perch with their breast held forward in an eractedor vertical position. While Vireos, Shrikes and Warblers perch in a horizontal position with their tails pointed out at an angle.


After you have determined the shape and posture of the bird. Use the surrounding elements to detemine the size of the bird. A sparrow may carry itself the same way as a crow and have a similar shape but it is much smaller in size. These kind of deduction help in determining the type of bird you are watching. Poor light and thick brush can alter ones ability to immediately recognize the bird. Don't be discourage.

owl perched in a tree

Flight Pattern

Most birds fly in straight line with consistant rythum from their flapping wings. Do pay attention to the character of their flight patterns.

Flapping verses Glidding
Eagles and Hawks are a superb example of gliders. Their pattern is typically to make several wing flaps follwed by graceful glides as they watch for their prey below. There are many designated Eagle Observation areas along the Upper Delaware Scenic Byway.

Up and Down Flight Pattern
Finches exhibit a roller-coaster-like flight pattern, high peaks with dramtiac falls. As opposed to woodpeckers that exhibit a flight pattern with moderate rises and falls.


The diverse landscape of the Upper Delaware River valley provides habitat for a variety of birds that breed here or migrate through: more than 260 species have been identified in the recreation area. River and stream corridors are hosts to species ranging from Louisiana waterthrush to bald eagles.

pictures of 2 birds

Bottomland forest along the river support cirulean warblers. Hemlock dominated ravines offer breeding habitat for blackburnian and black-throated green warblers, acadian flycatchers, and hermit thrush.

Agricultural fields provide open space that is frequented by wild turkey while the surrounding trees offer hunting perches for raptors scanning fields for small prey. Grasslands provide breeding habitat for bobolink and grasshopper sparrow while wetlands are inhabited by waterfowl, shorebirds, and herons.

Deciduous forests, perhaps the largest landscape component, provide habitat for birds ranging from the scarlet tanager to the ruffed grouse. During the fall and spring months many birds migrate along the river valley. More than 30 species of warblers have been recorded during spring migration. In the fall the Kittatinny Ridge provides an important migratory corridor for raptors.

The Delaware River valley offers important wintering habitat for a large population of bald eagles attracted to the open water for foraging. Golden eagles are less frequently sighted but are recorded nearly every winter. Bald eagles are frequently seen along the river during the summer months and in 2002 the first recorded successful nest in the recreation area fledged two young.

Some references from the Cornell Lab of Ornithology.

Upper Delaware Scenic Byway - Sections color chart Southern Gateway Section of the Upper Delaware Scenic Byway Lower Section of the Upper Delaware Scenic BywaysMid Section of the Upper Delaware Scenic BywayUpper Section of the Upper Delaware Scenic Byway Northern Gateway of the Upper Delaware Scenic Byway