In March, conditions will make the gradual and uneven transition from harsh winter to muddy spring at Fresh Pond. March brings the onset of new plant growth for the year and the final stretch of food scarcity for the reservation’s overwintering animals before the relative bounty of April and the summer months beyond. The shift from late winter to early spring brings with it the beginning of bird migration season. Some spring migratory bird activity can already be observed in March before the migratory torrent of April. As the ice leaves the reservoir, the environment around it begins to soften, and the pond’s natural communities begin to awake. There is much to observe at Fresh Pond throughout the month of March, whether it’s a merganser passing through or a red-winged blackbird settling in for the season.
EwA citizen scientists and interns survey the Lusitania meadow 📍 for arthropods every single week during the warm seasons. During the colder months, we explore the general biodiversity of the reservation in more detail. This gives us the opportunity to get to know the meadow and its surroundings intimately. Each week highlights different relationships between the plants and their visitors—fascinating stories unfold. This almanac is a wonderful means to share with our communities what we observe and record at Lusitania over the course of the year.
📅 Once a month, we open our nature documentation sessions to the public. Check us out on Eventbrite and come experience with us the magic of EwA’s study sites—oases in the middle of a very urban area.
While March heralds the arrival of spring, much of the month usually remains downright wintry. Conditions are less cold than in January or February, but they still tend to hover around freezing temperatures, with an average daily high of 7.4ºC (45.3ºC) and an average low of -0.5ºC (31.1ºF). March often sees at least one more deep freeze before spring, with the average monthly low-temperature mark at -9.6ºC. The fact that March is the wettest month of the year in Boston, with 110 mm of precipitation on average, can make the balmy days of late spring still seem very far away during this month. This precipitation is usually a mix of rain and snow, with March seeing 20 cm of snowfall on average.
March’s conditions aren’t just rough for us humans daydreaming of going on a hike without a jacket—they’re even rougher for our overwintering animals. The cold temperatures and likely snow cover that persist throughout part of the month mean that many food sources, like insects and plants, are either still inactive during March or just starting to leave their dormancy. Even though we mark the coming of spring this month with the spring equinox, for most animals, March means ramping up the resourcefulness one more notch to survive until things heat up.
Migrations and Mergansers
March is often considered a bad month for birding, with the discomforts of winter and muddy spring coinciding, and little migratory activity yet to observe. At Fresh Pond, though, you can note the beginning of spring’s huge migrations with some subtle changes to the Reservation’s resident birds.
One of Fresh Pond’s most distinctive groups of winter residents is the diving ducks, including the ring-necked ducks (Aythya collaris) we discussed in our December almanac. For much of the winter, they’re joined by the striking hooded merganser (Lophodytes cucullatus), with the males of the species sporting an instantly recognizable large black-and-white crest. By March, though, the hooded mergansers are largely gone, moving on to the wooded ponds and waterways on which they nest. The ring-necked ducks tend to remain on Fresh Pond in March, and they are usually joined by a less-showy but equally interesting relative, the common merganser (Mergus merganser).
Common mergansers, while not quite as distinctive as their hooded relatives, are still easily recognizable birds. They are best identified by their sharp, narrow, and serrated red beaks specialized for their diet, which consists mostly of fish. A merganser’s behavior is distinctive as well, sometimes dipping its head underwater before diving for potential prey. Mergansers are distinctive in their flight, flying low over the water, and organized in a straight line if flying in a group. Mergs may also swim with much more of their body underwater than other ducks, in a manner similar to cormorants.
While our resident mergansers do not undertake the same long-haul migrations that some birds do in the winter, they undertake shorter seasonal migrations to take advantage of available resources, and that’s why the type of mergansers you’ll most likely see at Fresh Pond changes from February to March. Both hooded and common mergansers are generally moving back northward in the spring, returning to waterways that underwent a deep freeze in the winter, but hooded mergansers tend to travel a little in advance of common mergansers. When the hooded mergansers leave their overwintering waters around Fresh Pond, the common mergansers take their place, before they depart for their breeding grounds as well. That makes March the best month to observe the beautiful common merganser at Fresh Pond. Mergansers are not often seen at the reservoir after the beginning of April, though, so make sure to see them while you can!
🔎 In Focus » Vilified Mergansers
Mergansers, like other fish-eaters, have often found themselves in conflict with fishermen, for good reason or not. Because they are such adept fish-eaters, mergansers, along with other birds like cormorants, tend to be blamed for poor catch if they become too abundant. There is not much evidence that mergansers have much effect on fisheries—the more likely culprits are overfishing and habitat degradation. Nevertheless, mergansers and cormorants are sometimes culled to appease fisheries.
Another early sign of migration season you can observe at Fresh Pond in March is the return of the red-winged blackbirds (Agelaius phoeniceus). The marshy center of Lusitania Meadow is home to nesting red-winged blackbirds throughout the summer, and they return to Fresh Pond in waves, with breeding males arriving first. You might even be able to observe some early males at the meadow in late February, but some are likely en route to other breeding areas, and their territorial displays won’t reach full swing until march. Males establish their territory in a variety of ways, the most frequently observed of which is perching on top of a reed, displaying their distinctive red epaulets, and making a trilling song that should be very recognizable to frequent wetland visitors. Males also exhibit a territorial song-flight, flying slowly between perches in their territory and occasionally singing. To males facing off at the limits of their territory will face each other, silent, with epaulets and bills clearly visible.
A couple of calls of the red-winged blackbird, with on the right below the distinctive territorial ‘conk-la-ree‘ trill of the male red-winged blackbird–a classic sound of wetlands across the continent.
Male territories vary greatly in size, from as large as ¼ acre to much smaller when conditions create heightened competition. Female blackbirds, when they return, choose a good nesting territory rather than choosing a mate. This means that male blackbirds with larger territories tend to have multiple mates. Blackbirds, both males and females tend to return within 30 miles of their birthplace to breed each spring, and the majority return to an even closer radius than that. While the exact territory will change in shape from year to year, males return to the same territory year after year until their death. Red-winged blackbirds do not exhibit specific pair-bonding, but their loyalty to a specific breeding site (a behavior known as philopatry) sometimes results in the same pair incidentally breeding for years.
Seeds: Late Winter Foods
While the vernal equinox on March 20th brings the early days of spring, foraging animals still need to rely mostly on food sources from the previous year until plant growth truly kicks into gear in April and May. By March, the winter food supply for granivorous (seed-eating) birds is running low. This means that some less-conspicuous or less-desirable food sources, like plants that yield many very small seeds, become more important in the diets of these birds, whose most common Fresh Pond residents include song sparrows (Melospiza melodia) and American goldfinches (Spinus tristis). Lusitania meadow is full of these types of plants, and March brings with it an excellent opportunity to observe this foraging behavior.
Lusitania meadow remains full of these dried seed heads, remainders of the past summer’s flowers, through March. Perhaps the most conspicuous and plentiful of these are the goldenrods (genus Solidago) and the false sunflowers (Heliopsis helianthoides), both of which belong to the aster family (asteraceae), which contains most of the goldfinch’s favored plants. Goldenrods produce a very large number of seeds, but these seeds are tiny and relatively difficult to forage, so they are usually among the last to have their seeds eaten. Other seed-bearing plants you might observe goldfinches and sparrows feeding on in March at the meadow include mullein (genus Verbascum), common evening-primrose (Oenothera biennis), curly dock (Rumex crispus), and Queen Anne’s lace (Daucus carota). Some birds that stash seeds, such as chickadees, also stash seeds in the dried flower heads of Queen Anne’s lace, so keep your eyes peeled!
While Goldfinches are year-round seedeaters, the diet of song-sparrows shifts to include many more insects during the warmer months of the year when that food source is available. The territorial calls of birds beginning to nest, like red-winged blackbirds, juncos, and chickadees, inform us that those warmer days are just around the corner.
Of course, there is so much more to enjoy in March at Lusitania! Go check for yourself and enjoy your visit. 📅–Join an EwA walk next month. Share your findings with us (you can comment below)! We will be back next month with a new slice of life in the meadow.
EwA Useful Links
🦆–Birds of Lake, Pond, and Marsh: Water and Wetland Birds of Eastern North America (1999) by John Andrew Eastman.
🌿–The Book of Field and Roadside: Open-country Weeds, Trees, and Wildflowers of Eastern North America (2003) by John Andrew Eastman.
by Mike McGlathery | Updated Feb, 26th 2023
First published on March, 4th 2020. Editing & layout by Claire O’Neill. Banner picture © Claire O’Neill All the in-text species photos in this article are visual records that the EwA team collects at our various study sites, including at Fresh Pond. Click on any picture and you will land on the record and its owner. Photos are licensed under Attribution-NonCommercial (CC BY-NC). See EwA’s biodiversity occurrence records specific to this place in the EwA at Fresh Pond iNaturalist project.
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