'Rush hour!'

More than 260 species of birds have been recorded on Pahranagat National Wildlife Refuge, most of them migrating on the Pacific Flyway. The wealth of natural resources on the refuge makes it a valuable rest station for a large number of migrating birds. Credit: USFWS

It’s a busy time at the Pahranagat National Wildlife Refuge, as waves of birds arrive

By Dan Balduini
November 30, 2017

Traffic is picking up along the Pacific Flyway and the Pahranagat National Wildlife Refuge is a major rest stop for thousands of waterfowl on that route.

Pahranagat’s lakes and marshes are a critical stopover site for hundreds of species of migratory birds, and refuge staff is already seeing some early arrivals.

Refuge manager Rob Vinson says refuge staff completed habitat projects and the welcome mat is out for the waves of ducks, geese, coots, grebes, herons, cranes, and other birds expected fly in.

“We already have several species of waterfowl on the refuge and we expect to see others arrive in sequence,” said Vinson. “As the weeks and months progress, we will see different species of waterfowl showing up in southern Nevada.” 

Vinson, a wildlife biologist and waterfowl management expert with the U.S. Fish and Wildlife Service, says ducks migrate along weather fronts as seasons change—spurred on by the decreasingor increasing periods of daylight each day. Different species rely on different migration cues and strategies, so the various avian species tend to arrive at different times of the year.

Cinnamon teal and northern pintail are some of the earliest fall arrivals at Pahranagat. These birds use photoperiods as cues to migrate and usually arrive from the end of August through September. Most of the cinnamon teal are gone by mid-October, while pintails stay longer and can normally be seen throughout the winter.

A cinnamon teal preens during a stopover on the refuge during its migration along the Pacific Flyway. Credit: USFWS

Green-winged teal migrate on photoperiods and also use weather fronts to help them move south.

They start showing up in mid-September and can typically be seen on the refuge throughout the winter. Most of the diving ducks that use the refuge (such as redheads, canvasbacks, and ring-necked) also migrate on weather fronts, as colder conditions in their northern breeding territories cause them to push southward. Ordinarily, these birds arrive at the Pahranagat refuge by mid-October.

Tundra swans and Canada geese ordinarily start arriving in November. Since these birds are adapted to colder climates, they tend to move southward just ahead of ice-ups when food resources become difficult to obtain. The swans are also some of the first waterfowl to move back north to their nesting areas in the artic at the beginning of their breeding season.

Sandhill cranes normally fly in at the end of September, but visitors would be very lucky to see them. The cranes only stay on the refuge long enough to rest and refuel before moving on to their wintering grounds in the southern United States and northern Mexico. The cranes also pass through the refuge in March and may stay several days as they replenish body fats that have been burned on their journey back to nesting ground in northern Nevada, Oregon, Idaho and western Utah.

A green-winged teal arrives at the refuge. Credit: USFWS

More than 260 species of birds have been recorded on the refuge, most of them migratory. While it is impossible to foresee exactly which species will be there on any given day, the wealth of natural resources on the refuge makes it a valuable spot for a large number of birds. In addition to waterfowl, many other birds are commonly seen on the refuge, including bald eagles, mourning doves, sandpipers, ibis, egrets, and herons.

Refuge staff is able to predict species’ migratory patterns fairly accurately using data collected through banding efforts, which involve fitting individual birds with metal tarsal bands.

When birds are recovered, the band information helps biologists understand breeding and wintering distribution, behavior, migratory routes, survival, and reproduction. 

Refuge staff has banded thousands of waterfowl as they pass through the refuge. The data is reported to the National Bird Banding Laboratory when the bands are recovered, either through recapture during operations, or by the hunters who have harvested them, or from birds found after death. The information provided to the laboratory was used to develop the flyway system that has been in use since 1950.