Chris Michelson

Bird Watch

Though most days are still quite warm, fall migration is well under way for a number of species and will soon start for many others.

Hummingbirds have been moving through the Casper area since the first week of July. In the past two weeks there have been reports of four species of hummingbird in the Casper area.

Broad-tailed hummingbird is a local nester and is by far the most common species in the area. This species can be found most commonly on Casper Mountain and in the foothills at the base of the mountain. It is also spotted along the North Platte River and other riparian locations.

Rufous hummingbird has been moving through the area since early July. The bright copper colored male is easy to identify while the female and juvenile birds are more difficult. One hint in locating this species is that unlike the broad-tailed hummingbird, this species does not make a wing noise that can be heard.

A few calliope hummingbirds have been reported in the last few days. This species is rather smaller than the others in this area.

The hummingbird highlight for this season was the report of a male black-chinned hummingbird at the Garden Creek Audubon Center. This species is more commonly found in southwestern Wyoming. There is some evidence that this species is expanding in range so perhaps in the future it will be seen here more often.

Shore birds continue to move through central Wyoming. Greater yellowlegs and lesser yellowlegs have been noted in some numbers. The first birds to arrive have been breeding plummaged adults, while recently there have been a few juvenile birds which is the normal pattern for shore bird migration. Other species reported recently include the solitary sandpiper, Baird's sandpiper, spotted sandpiper and marbled godwit. Wilson's phalarope are being reported in good numbers on many small ponds. American avocet, black-necked stilt and willet are all still present.

Some species of birds that come to Wyoming to breed are starting to move back to the south. Swallows of all species have decreased in numbers during the past couple of weeks. Swallows are among the first species to depart since they migrate quite a distance. Some flycatcher species have also started to head south. All of the insect eating birds tend to be rather early migrants. Many grassland species have started to disperse from the breeding areas. They have not yet started to migrate but they are moving to new areas. Such species as lark bunting and horned lark fall in this category.

In the next couple of weeks one can expect to see a number of other species in the riparian habitat along the North Platte River. By mid August, one can expect the first Wilson's warbler and Townsend's warbler to appear and several vireo and sparrow species. There will be many young birds which will be more difficult to identify. Juvenile sparrows are small brown-streaked birds that can be quite a challenge. Depending on weather conditions, other species of warbler can also start to be encountered. Remember that the fall migration occurs over a longer period of time with some birds remaining for longer periods if food and weather are good, while the urge to mate keeps the spring migration to a rather short window.

Chris Michelson is a veteran bird watcher and board member of the Murie Audubon Society.