Double-crested Cormorant (Nannopterum auritum)

The Double-crested Cormorant (Nannopterum auritum) is a substantial member of the Phalacrocoracidae family, known for its dries wings in classic spread-wing pose. Along Oklahoma's Central Flyway, this species is a year-round resident, frequenting the lakes, rivers, and reservoirs that characterize much of northwestern Oklahoma's diverse landscape. The Salt Plains National Wildlife Refuge near Jet, Oklahoma, serves as one of the premier locations for observing this species in the Central Flyway corridor.

Quick Facts

Feature	Details
Scientific Name	Nannopterum auritum
Family	Phalacrocoracidae (Cormorants)
Size	20-30 inches (51-76 cm) in length, weighing approximately 1.5-5 pounds (0.7-2.3 kg)
Habitat	Lakes, rivers, and reservoirs
Diet	Fish
Seasons in Oklahoma	Year-round
Conservation Status	Least Concern

Identification Guide

When identifying the Double-crested Cormorant in the field, look for the dries wings in classic spread-wing pose. This species measures approximately 20-30 inches (51-76 cm) in length, weighing approximately 1.5-5 pounds (0.7-2.3 kg). In the lakes, rivers, and reservoirs habitats typical of northwestern Oklahoma, careful observation will reveal the distinctive features that separate this species from similar birds in the area.

Physical Description

The Double-crested Cormorant presents dries wings in classic spread-wing pose, making it a rewarding find for Central Flyway birders. This species belongs to the cormorants group and shares the lakes, rivers, and reservoirs with several related species, though careful observation reveals the unique characteristics that make the Double-crested Cormorant unmistakable.

The Double-crested Cormorant feeds primarily on fish, and observing feeding behavior can be an excellent identification tool. Watch for this species foraging in lakes, rivers, and reservoirs throughout the Salt Plains region and surrounding areas of the Central Flyway.

Tips for Field Identification

Males and females may differ in appearance, so familiarizing yourself with both plumages will improve your identification success rate during visits to the Central Flyway.

Key field marks to look for include:

Size and shape: 20-30 inches (51-76 cm) in length, weighing approximately 1.5-5 pounds (0.7-2.3 kg), with a build typical of cormorants
Distinctive features: Dries wings in classic spread-wing pose
Behavior: Watch for feeding activity in lakes, rivers, and reservoirs
Voice: Listen for this species' characteristic calls, which are often the first indication of its presence in dense habitat

Habitat and Range Along the Central Flyway

The Central Flyway stretches from the Arctic tundra of Canada through the Great Plains of the United States to the Gulf of Mexico and beyond into Central and South America. Oklahoma sits at a critical juncture in this migratory corridor, and the Double-crested Cormorant takes full advantage of the state's lakes, rivers, and reservoirs during its year-round residence.

In northwestern Oklahoma, the Double-crested Cormorant primarily inhabits lakes, rivers, and reservoirs. The unique geography of the Salt Plains region, where the Great Salt Plains create a mosaic of salt flats, shallow wetlands, grasslands, and wooded riparian corridors, provides exceptional habitat diversity that supports the Double-crested Cormorant alongside hundreds of other bird species.

The Double-crested Cormorant's range along the Central Flyway extends through the heart of the Great Plains, with Oklahoma representing a core part of its permanent range.

Seasonal Presence in Oklahoma

As a year-round resident of the Central Flyway region, the Double-crested Cormorant can be observed in all seasons across northwestern Oklahoma. Their consistent presence makes them one of the more reliable species to encounter during any birding trip to the Salt Plains area. Seasonal behavioral changes, from breeding displays to winter flocking, add variety to observations throughout the year.

Migration Patterns

While the Double-crested Cormorant is a year-round resident in Oklahoma, local movements do occur in response to weather conditions and food availability. During particularly harsh winters, some individuals may shift southward within the state, while the arrival of spring can trigger short-distance movements to optimal breeding territories within the Central Flyway region.

Diet and Feeding Behavior

The Double-crested Cormorant sustains itself on fish, a diet well-suited to the resources available in lakes, rivers, and reservoirs throughout the Central Flyway. In the Salt Plains region of northwestern Oklahoma, this species has adapted its foraging strategies to take advantage of the unique combination of habitats available.

The Double-crested Cormorant's feeding behavior is well-adapted to the lakes, rivers, and reservoirs of the Central Flyway region. In northwestern Oklahoma, this species has found abundant food resources in the diverse habitats surrounding Salt Plains Lake and the associated refuge lands.

Seasonal changes in food availability influence the Double-crested Cormorant's diet throughout the year. During spring and summer, increased insect populations often supplement the diet, while fall and winter may see a greater reliance on seeds, berries, or other seasonal food sources available in the region.

Conservation Status

The Double-crested Cormorant is currently classified as Least Concern by the International Union for Conservation of Nature (IUCN), indicating a stable and healthy population across its range. In the Central Flyway, this species benefits from the protected habitats at Salt Plains National Wildlife Refuge and other conservation lands throughout northwestern Oklahoma. However, ongoing habitat management and monitoring remain important to ensure this species continues to thrive in the region.

Threats and Challenges

The primary threats facing the Double-crested Cormorant in the Central Flyway include:

Habitat loss and fragmentation: Conversion of lakes, rivers, and reservoirs to agricultural or developed land reduces available habitat
Climate change: Shifting weather patterns may alter the timing of migration and availability of food resources
Human disturbance: Recreational activities near sensitive habitats can disrupt feeding and nesting behaviors
Pesticide exposure: Agricultural chemicals can reduce insect prey populations and cause direct toxicity

Conservation Efforts in Oklahoma

Oklahoma's network of wildlife refuges, state parks, and conservation areas provides essential protected habitat for the Double-crested Cormorant and many other Central Flyway species. Key conservation initiatives include:

Ongoing habitat management at Salt Plains National Wildlife Refuge (580-626-4794)
Water level management to maintain optimal wetland conditions
Grassland restoration programs throughout northwestern Oklahoma
Citizen science programs including Christmas Bird Counts and breeding bird surveys
Educational programs at Great Salt Plains State Park (580-626-4731)

Best Viewing Locations

For birders hoping to observe the Double-crested Cormorant along Oklahoma's Central Flyway, these locations offer the best opportunities:

1. Alva and Northwestern Oklahoma State University area

This area provides suitable lakes, rivers, and reservoirs habitat for the Double-crested Cormorant and is worth exploring during year-round when this species is present in the Central Flyway region. Check local conditions before visiting and respect all posted regulations to help protect wildlife habitat.

2. Glass Mountains

3. Salt Plains National Wildlife Refuge

The flagship birding destination of northwestern Oklahoma, Salt Plains NWR encompasses over 32,000 acres of salt flats, wetlands, and grasslands. The refuge, located along SH 64 and SH 38 north of Jet, Oklahoma, is home to 312 documented bird species and provides excellent habitat for the Double-crested Cormorant. Contact the refuge at 580-626-4794 for current conditions and viewing recommendations.

Birding Tips for Observing the Double-crested Cormorant

Best time of day: Early morning hours typically offer the most active viewing, especially during winter months
Equipment: A quality pair of binoculars (8x42 or 10x42) is essential, and a spotting scope can be helpful for detailed observation
Patience: Allow time for the bird to exhibit natural behaviors
Respect wildlife: Maintain appropriate distances and avoid disturbing nesting or roosting birds
Record your sightings: Report observations to eBird to contribute to scientific knowledge of the Double-crested Cormorant in the Central Flyway

Related Species

Other cormorants you may encounter while birding in the Central Flyway:

This guide is part of the CherPub Central Flyway Bird Guide series, covering all 312+ bird species documented at Salt Plains National Wildlife Refuge and throughout Oklahoma's Central Flyway corridor. For more information about birding in northwestern Oklahoma, visit Salt Plains NWR or contact the refuge at 580-626-4794.