Resources & Research : Animal & Plant of the Month

Art Elser

Animal of the Month
Swainson Hawk

The Swainson's hawk, Buteo swainsoni , is a large raptor about the size of the red-tailed hawk. It is 21 inches long and has a wing span of 52 inches. These hawks are warm-weather visitors to PCC, with the first migrants appearing in early spring and leaving in mid fall.

Perhaps I should have capitalized migrants because these amazing creatures make round trips to Argentina on their annual migrations, over 6,000 miles. The pampas of Argentina are similar to the plains of North America, so these hawks feel at home here. They migrate in flocks of hundreds, sometimes thousands, using thermals to gain altitude, followed by long glides.

Swainson's and red-tailed hawks compete for food and nest sites here at PCC. This April, while near lone tree, we watched pairs of both species vying for the existing nest in that tree. Perhaps the competition was too much for both pairs since neither seems to have claimed the nest.

During breeding season the Swainson's diet consists of mice, voles, ground squirrels, rabbits, birds, and reptiles. During the rest of the year, this hawk feeds on insects like grasshoppers, locusts, and beetles, thus one of its common names is grasshopper hawk. Its normal diet of insects leads to its long migration away from our winter to a place where insects are plentiful.

Because Swainson's hawks often hunt from low perches or from the ground, look for them low, on fence posts or gates. They will, however soar like red-tails, so don't exclude looking up for them. The dark trailing edge of the wings of a Swainson's easily distinguish it from the red-tail. The Swainson's wings are also more pointed than the red-tail's. And when perched, the rusty-colored bib identifies the hawk is a Swainson's.

Plant of the Month

Prarie Primrose, spring 2008 JPMoyer

Plant of the month, July 2008
Prairie Evening Primrose
Oenothera albicaulis
Evening Primrose Family
Onagraceae

Look for:

•  A beautiful flower that blooms in the late afternoon and evening, usually withering to a pink color in the bright sun the next day

•  A flower that can grow to 18 inches in height with an erect velvety stem

•  Flowers in loose clusters, with four white heart- shaped petals, four sepals, four to eight stamens

•  A tube called the hypanthium, easily mistaken as part of the stem

•  Leaves that are alternate, deeply incised, woolly and grey green in color

•  A plant that grows on disturbed prairie soils and on barren slopes near anthills

Ecological and Human Use:

•  The oil from the plant contains a highly concentrated source of natural unsaturated fatty acids

•  The oil is given by contemporary naturopaths and other alternative practitioners to relieve discomfort of symptoms associated with PMS, eczema, sunburn, fibrocystic breast disease, arthritis, and diabetes (no FDA approval)

•  Native Americans used this plant in soups and sauces