The first day of spring is March 21, but March can be a fickle month with weather bringing everything from icy winds or snow to downright balmy days.

Depending on the weather patterns, it’s often hard to know if spring has arrived, especially if a late winter storm system descends upon the mid-Atlantic. Regardless of whether March comes in like a lion and out like a lamb (or vice versa), you can always be assured that winter is on its way out when you see (or hear) some of my favorite harbingers.

Osprey (Pandion haliaetus) are a spring icon. These birds occur in nearly every corner of the globe, but nowhere as abundantly as on the Chesapeake Bay. Two feet long with wingspans of 4–5 feet, these brown and white birds of prey are easily recognized when in flight, as their long narrow wings look like an outstretched M.

Their abundance around the Chesapeake is due to the availability of food; they feed exclusively on live fish. Curved, sharp talons and rough-soled feet are designed to hold onto slippery fish. Ospreys hunt by soaring over water, periodically hovering on beating wings as they scan for fish. Upon sight of its prey, An osprey makes a spectacular dive. Folding its wings tightly, it descends swiftly and plunges feet first into the water, often submerging itself completely.The musical trill of the American toad illustrates how beauty also exists in the “ear” of its beholder. (Isaac Chellman / U.S. Geological Survey)

The Chesapeake Bay also provides ospreys with great nesting areas near water such as duck blinds, navigation markers, or man-made nesting platforms. Offshore structures offer eggs and chicks protection from predators, like raccoons.

Another sign of spring sign can be heard from small pools forming in forests and fields. Known as vernal pools, these small pools fill with water from melting snow, rain or underground sources.

Not directly connected to flowing streams and rivers, these pools do not contain fish. Because of the absence of these predators, amphibians like salamanders, frogs and toads use vernal pools to congregate and breed. Vernal pools explode with activity and the sound of frogs and toads calling for mates.

Wood frogs (Rana sylvatica) are one of the earliest visitors to vernal pools. You can recognize them by their call, a hoarse clacking sound, reminiscent of a quack. The wood frog is an explosive breeder usually laying a large mass of eggs in a few days and leaving soon after.

The spring peeper (Hyla crucifer), a tree frog, follows the wood frog by a week or two. Its unmistakable mating call, the peep, and large geographic range makes the spring peeper one of the most familiar frogs in North America. Its mating call can sometimes be heard up to a half a mile away.

Another familiar spring visitor is the American toad (Bufo americanus). Its habitat ranges from mountains to backyards, where there are moist places, insects to eat and shallow waters to breed. Despite their warty appearance, their mating call is a pleasant musical trill.

Many beautiful wildflowers begin to appear in March. One of the oddest is the Jack-in-the-pulpit (Arisaema triphyllum). Found in woods, bogs, and swamps, the Jack-in-the-pulpit is easily identified by its striped purple and green hood (the pulpit) enveloping a club-shaped spadix (the Jack) of male and female flowers. The spathe on this plant is elegant, vase-shaped and tapering to a delicate point.

Another early bloomer found in forests, thickets and clearings (including yards) is the tiny spring beauty (Claytonia virginica). With five white, white with pink stripes, or pink petals, spring beauty are among the earliest flowers in the pring the landscape. But because of its flower size (0.5–0.75 inches), it is easily missed.

Totally opposite from the spring beauty, are the very showy Virginia bluebells (Mertensia virginica). Despite its name, this flower is found throughout the Chesapeake Bay watershed in moist floodplains. Clusters of large trumpet-shaped flowers start out as pink and turn more blue as the season progresses. The acidity of the soil also influences their color, from white to pink to blue. The higher the acidity in soil, the bluer the flower.

Yellow perch (Perca flavescens) make their spawning run from late February to mid-March and offer some of the earliest opportunities for sport fishermen to break out their rods and tackle. Their delicate meat and early arrival makes these fish a favorite.

Striking in appearance, yellow perch are easily recognized by golden yellow and dark vertical bands. Populations of yellow perch are most prevalent in Upper Chesapeake Bay tributaries. These fish spend most of the year in brackish water and migrate to freshwater to spawn. Yellow perch never leave the river system where they hatched, they merely move between brackish and freshwater.

Before setting out, remember to check with your state’s natural resource agency for fishing regulations and licenses.