A killdeer. (Photo by Mary Holland)
March is one of the most anticipated months for naturalists, for it never fails to bring back the signs of life that announce spring has arrived after months of snow and wintry weather. For several centuries the British parted ways with the Gregorian calendar and declared March 25 the first day of the New Year. This makes enormous sense to most natural historians, for March is the month of awakenings, when the earth begins to thaw and life begins to stir after months of relative inactivity. Many hibernating mammals and amphibians resume their normal metabolism, mating seasons begin, a few flying insects appear, migrant birds start returning from their southern wintering grounds, sap begins to flow in shrubs and trees, and the heat-generating skunk cabbage even blossoms. March is synonymous with rebirth, a new beginning for all living things. Following are just a few of the many annual harbingers that are announcing (or perhaps already have) spring’s arrival in Harvard.
Wood frogs
The wood frog, one of the earliest frogs to emerge from hibernation, digs itself up through the forest floor and migrates to a nearby temporary pool where the males’ duck-like courtship calls can be heard reverberating through woodlands in the early spring. This process begins in March and calling usually peaks in April. Soon after the frogs arrive at the pool, mating takes place; often there is still ice on part of the pool. Within four to six days an individual female wood frog finishes laying her 2,000 to 3,000 eggs. The frogs then return to the woods from which they came, leaving behind clumps of their eggs that are often attached to branches just under the surface of the water.
Spotted salamanders
On the first rainy spring night that is 40 to 50 degrees Fahrenheit, nocturnal spotted salamanders leave their subterranean environs and make their annual mass migration to the nearest temporary woodland pond or vernal pool. Pairs form and do a courtship “dance” in the water, after which the male deposits a packet of sperm called a spermatophore on the bottom of the pond. The female picks up the spermatophore with her cloaca, or genital opening, and fertilization takes place. She then lays up to 200 eggs in one to ten solid gelatinous masses before leaving the pond and resuming her life underground.
Red-winged blackbirds
You know that spring is really on its way when the male red-winged blackbird’s familiar “konk-la-ree” song bursts forth over marshes and open wetlands in late February. His red and yellow epaulets, or shoulder feathers, are erected and prominently displayed as he hunches forward in song, claiming his territory and advertising for a mate. Red-wing calls build during March, and by early April, when most females appear, marshes and wetlands are alive with singing males.
Ruffed grouse
The male ruffed grouse is well known for his mating “call,” which he actually creates with his wings while standing on a fallen log, stonewall or other raised surface. Although drumming occurs year-round, it is most frequently heard this time of year, right after snow-melt, when it is used to attract females and ward off other males. The drums are a series of progressively faster thumps created by air rushing to fill the vacuum the male creates under his wings when he rapidly flaps them in front of his body.
Striped skunks
Striped skunks wake periodically throughout the winter, particularly during mild spells, but for the most part are in a deep sleep, emerging in February or March to breed. At this time the males are out and about, searching for mates, and their tracks, as well as an occasional scent, are noticeable. Skunks are polygamous, and although their breeding season lasts from mid-February through mid-April, the majority of mating takes place during the third week of March.
Killdeer
Our most widespread and familiar American plover, the killdeer, is one of the earliest ground nesters to return to Harvard. Its call, “kill-deer, kill-deer, kill-deer,” is heard over open fields and pastures as it once again takes up residence here.
Fishers
For fishers, especially female fishers, March and April are extremely busy months, for they are giving birth as well as mating. After a 10- or 11-month delay in embryo implantation (it’s present in their body, but isn’t implanted in the uterus for many months), the young are born, often in a nest located in a cavity in a large, hollow tree. On average, two or three young are born in March or April.
Roughly 10 days after the birth of her young, the mother leaves the den to mate. The breeding season for fishers peaks in March and there is a surge in male fisher activity at this time. These forest-dwelling members of the weasel family commonly scent mark their territory by rolling on small saplings, breaking branches, and leaving their scat or urine beneath them, and in so doing pack down the snow around the saplings.
Mourning cloak butterflies
Because they overwinter as adults, protectively hidden under the loose bark of a tree, and have no metamorphosis to undergo in the spring, mourning cloaks are one of the first butterflies to be observed in the new year. They emerge from hibernation on the first warm days of March and can be observed drinking sap from injured tree branches, especially oaks, where they walk down the trunk of the tree to the sap and drink head downward. They also feed on rotting fruit and occasionally on flower nectar.
Naturalist and writer Mary Holland lived in Harvard for many years before moving to Vermont.
She can be contacted at mholland@vermontel.net.
