Forster's Tern (Sterna forsteri)

The Forster's Tern (Sterna forsteri) is a moderately-sized member of the Laridae family, known for its orange bill with black tip. Along Oklahoma's Central Flyway, this species is a spring, summer, fall visitor, frequenting the marshes and lakes 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	Sterna forsteri
Family	Laridae (Gulls and Terns)
Size	9-14 inches (23-36 cm) in length, weighing approximately 3-10 ounces (85-280 grams)
Habitat	Marshes and lakes
Diet	Fish and insects
Seasons in Oklahoma	Spring, Summer, Fall
Conservation Status	Least Concern

Identification Guide

When identifying the Forster's Tern in the field, look for the orange bill with black tip. This species measures approximately 9-14 inches (23-36 cm) in length, weighing approximately 3-10 ounces (85-280 grams). In the marshes and lakes 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 Forster's Tern presents orange bill with black tip, making it a rewarding find for Central Flyway birders. This species belongs to the gulls and terns group and shares the marshes and lakes with several related species, though careful observation reveals the unique characteristics that make the Forster's Tern unmistakable.

The Forster's Tern feeds primarily on fish and insects, and observing feeding behavior can be an excellent identification tool. Watch for this species foraging in marshes and lakes 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: 9-14 inches (23-36 cm) in length, weighing approximately 3-10 ounces (85-280 grams), with a build typical of gulls and terns
Distinctive features: Orange bill with black tip
Behavior: Watch for feeding activity in marshes and lakes
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 Forster's Tern takes full advantage of the state's marshes and lakes during its seasonal visits.

In northwestern Oklahoma, the Forster's Tern primarily inhabits marshes and lakes. 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 Forster's Tern alongside hundreds of other bird species.

The Forster's Tern's range along the Central Flyway extends through the heart of the Great Plains, with Oklahoma representing important breeding territory.

Seasonal Presence in Oklahoma

Spring is an excellent time to observe Forster's Terns in the Central Flyway as they move northward through Oklahoma. The Salt Plains area becomes particularly active from mid-March through May, with Forster's Terns frequenting marshes and lakes throughout the region. Early morning hours along the shores of Salt Plains Lake and the surrounding refuge lands offer prime viewing opportunities during this season.

During the summer months, Forster's Terns can be found breeding and raising young in the marshes and lakes of northwestern Oklahoma. The long daylight hours from June through August provide extended observation windows. The Byron Fish Hatchery area north of Jet on SH 38 and the surrounding woodlands are particularly productive spots during this season.

Fall migration brings Forster's Terns through the Central Flyway in significant numbers from September through November. The Salt Plains National Wildlife Refuge becomes a critical stopover point as these birds refuel for their continued journey. Birders stationed along SH 64 between Cherokee and Jet often report sightings during this peak migration period.

Migration Patterns

The Forster's Tern's migration through the Central Flyway follows patterns that have been refined over thousands of generations. In Oklahoma, the timing of arrivals and departures varies somewhat from year to year depending on weather patterns, but generally follows predictable seasonal rhythms. The Salt Plains National Wildlife Refuge, established in 1930, has provided a consistent and protected stopover point for migrating Forster's Terns throughout its history.

Diet and Feeding Behavior

The Forster's Tern sustains itself on fish and insects, a diet well-suited to the resources available in marshes and lakes 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 Forster's Tern's feeding behavior is well-adapted to the marshes and lakes 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 Forster's Tern'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 Forster's Tern 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 Forster's Tern in the Central Flyway include:

Habitat loss and fragmentation: Conversion of marshes and lakes 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 Forster's Tern 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 Forster's Tern along Oklahoma's Central Flyway, these locations offer the best opportunities:

1. Washita National Wildlife Refuge

This area provides suitable marshes and lakes habitat for the Forster's Tern and is worth exploring during spring, summer, fall 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. Canton Lake

Canton Lake offers diverse aquatic and grassland habitats that support the Forster's Tern during its time in the Central Flyway. The lake's varied shoreline and surrounding uplands provide multiple viewing angles and habitat types for birders to explore.

3. Optima National Wildlife Refuge

Birding Tips for Observing the Forster's Tern

Best time of day: Early morning hours typically offer the most active viewing, especially during spring migration
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 Forster's Tern in the Central Flyway

Related Species

Other gulls and terns 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.