Wildlife Watch by Marian Harman – May 2023


Where Have All the Fireflies Gone?

Do you remember running around on the lawn at dusk, catching fireflies in a jar, looking at them with wonder, and then releasing them? Are these nostalgic summer childhood memories a thing of the past? Will our children and grandchildren have a chance to make these same memories?

There are about 170 species of these beautiful beetles in the United States, and most are threatened or endangered. Massachusetts has about 20 species. They are declining at a rapid pace due to the presence of pesticides and herbicides in their preferred habitats, close mowing of lawns, and the presence of outside lighting.

Most fireflies prefer edge environments where fields or lawns meet forest. Females are usually flightless, and perch on grasses or shrubbery. Males fly over sending their pulses of light in a pattern unique to each species. When the female sees the right flash pattern, she answers it with the same pattern so that the male can see her. Outdoor lighting can disrupt this communication. Close mowing of lawns can leave nowhere for females to cling.

After mating, females crawl down the stem of the grass and lays eggs in the soil the bottom of the grass stem. After 3-4 weeks, larva hatch and crawl up the grass stem to start feeding on small invertebrates all summer. In late fall, larva overwinter underground,  emerging the next spring or summer as fireflies. Every stage of firefly development is vulnerable to frequent mowing and to the use of pesticides and herbicides.

Some years ago, we conducted a somewhat controlled experiment at our old farmhouse in Westford. For the fifty years we lived there, we never used herbicides, pesticides, or fertilizer on our lawn or gardens. We reduced the size of our lawn so that we mowed only the small front lawn and a back yard only large enough for playing badminton. The rest of our property was a horse pasture that was mowed only once a year. One year we participated in Project Firefly Watch, a program run by the Museum of Science. We tried to count our fireflies weekly. We watched for about an hour each week, and counted the number of individuals we saw as best we could. We counted different flash patterns, and different colors of the flash, which indicated how many species we were seeing. We noted time of the evening, and habitat type. What I remember best about that project was that our results showed that our mowed lawn supported very few individual fireflies—some nights none at all. But our horse pasture, right next to the lawn, supported hundreds of individuals of several different species. The only difference between the two patches of grass was that one was mowed, and the other was not. This was very convincing, so we started to mow the back lawn less frequently, with the result that we were able to coax more fireflies to our back yard.

American Native Plants.org, encourages interested homeowners to :1. Cut your lawn at a higher setting, preferably 2.5-3” high. This will help attract fireflies, and protect your grass roots from heat and drought. 2. Cut lawns less frequently. In a drought situation, do you really need to mow every week? This program is known as Low-mow Spring and Summer. 3. Install a water feature, if no body of water is nearby. 4. Turn off outside lighting. Mass Audubon continues to run the Firefly Watch program, whereby citizen scientists can send in data on fireflies in their area. Check out the information on this program on massaudubon.org/firefly watch. You can bring back the beauty and awe of watching fireflies for your children and grandchildren.

Many thanks to flora and fauna reporters for the month of May. Please send reports by the end of June to be included in the next month’s report. Reports can be sent to mariancharman@gmail.com.


May Reports

Lisa Groves and Joel Tedford at Cider Mill Pond area. A rescue tale: A garter snake was eating a large frog in the water of the “indian grinding stone”. “We left it alone, and went away. But that night we thought about it and worried that the snake might not be able to get out. We went back the next day, and there it was still in the water, and still hanging on to the frog. We got the snake out. It dropped the frog, but seemed not to be able to close its mouth, as it was so cold. We put it under leaves and sticks to rest. It was gone the next day, the dead frog still there.

Maureen George, Porter Rd. May 2, northern flicker at feeder, two bluebirds investigated the nest box, but tree swallows chased them away, and are using the box.ß I have had twenty-five species at the feeder over the years.

Rosemarie Koester, Providence Rd. May 2, first hummingbird arrived.

Gerry DiBello, Court Rd. May 3, Baltimore oriole arrived. M

Marian/Bill Harman, Old Colony Drive. May 5, 50’s, sunny, lovely. A walk on the beaver dam trail: Common bumble bees (Bombus impatiens) visiting the low-bush blueberry flowers. Seen or heard: goldfinch, titmouse, chickadee, red-winged blackbird, pine warbler, song sparrow, barred owl, red-bellied woodpecker, cardinal, downy woodpecker, grackles, swamp sparrow, American redstart, white-breasted nuthatch, yellow warbler, Carolina wren, tree swallow. May 7, 70’s, lovely. A walk on the trail between Crisafulli School and Westford Academy: first catbird heard, first starflower blooming, first wood anemones blooming. In Graniteville by Stony Brook, first oriole heard. At home, 6 p.m. first oriole heard singing a clear whistle, just a day before my mother’s birthday (she loved orioles, and we always said they returned on her birthday). Toads heard singing in the evening. May 10, 78 degrees! Sunny, lots of pollen. A walk on the beaver dam trail: some mosquitos out, starflower, blueberry, bluets blooming. A flicker few up from the ground right in front of me. A 230 year old pine (Bill measured circumference and estimated age) is just off the trail. Heard our first great-crested flycatcher. A swamp sparrow on the trail, just a few feet from me, very unwary. I waited and after a few minutes it hopped into the woods. Heard or saw: grackles, red-winged blackbirds, jays, song sparrows, swamp sparrows, goldfinches, cardinal, first catbird heard here, yellow warbler, pair of Canada geese in Keyes Pond. A different oriole heard.

May 11, a walk on Emmet land from Nashoba Brook parking lot: heard: oriole, northern waterthrush (this brings back memories of Dick Emmet who loved this bird), great-crested flycatcher, titmouse, cardinal, chickadees, grey tree frogs heard. Blooming: starflower, Canada mayflower, wood anemone, violets, wild oats, sarsaparilla. May 15, 65-70, sunny. Same oriole heard with pattern of “I am happy, are you?” Wood thrush heard, and “chick-burr”—a scarlet tanager! May 17, windy and cold, 50’s. Sunny, with high tree pollen count. A walk on the beaver dam trail: a few pink ladies’ slippers blooming, a few wild oats plants, none blooming. One little polygala bravely blooming. There used to be so many…Two patches of rattlesnake plantain. The woods has many more witch hazels now in the blown-down area, there are also more red maples, birch, blueberry bushes, some oaks and baby pines. Birds: pine warbler, redstart (seen and heard), red-tailed hawk swooped low over the brook. Nesting grackles and red-wings chased it off. Painted turtles basking on logs in the brook. Also heard, Carolina wren, veery, a virtuoso cardinal, catbird, downy woodpecker, titmice, blue jays, chickadee, song sparrow, goldfinch. Butterflies seen (not many!): tiger swallowtail, spring azure, mourning cloak. May 18, 60-70’s, sunny. A walk to the meadow: scarlet tanager heard, not seen. He kept moving ahead of me. Also catbird, goldfinch, brown creeper, cardinal, titmouse. Blooming: violets, bluets, wild geranium, cinquefoil, buttercups. Joe-pye-weed plants are coming up. Ferns seen: NY fern, interrupted, cinnamon, sensitive, hay-scented. May 20, 60’s, cloudy, humid. Rose-breasted grosbeak singing here! Our resident oriole singing, hairy woodpecker. May 23, 70’s beautiful. A walk on the beaver dam trail: Lots of birds singing—18 species seen or heard: one scarlet tanager, 2 song sparrows, 2 warbling vireos, 2 gray catbirds, 2 pine warblers, robin, 1 Eastern wood-pewee, 1 cardinal, many red-winged blackbirds and grackles, 2 yellow warblers, 2 great-crested flycatchers, 2 veerys, 2 common yellowthroats, 1 Baltimore oriole, mourning dove, Carolina wren, barn swallows. Blooming: blueberries, Canada mayflower, sarsaparilla, starflower, witch hazel has its nuts, cinnamon fern fertile fronds. May 25, a new oriole in the yard. Sounds like “Come and get me-You!”  A pair of house finches on the thistle seed. May 28, 80’s, hot and humid. A veery, singing in the woods, heard from the deck.

Annual Trust Bird Walk at Nashoba Pond, led by Lenny Palmer. Lovely, sunny, 70’s. May 12, Thirty-one species! Birds seen/heard: grey catbird, red-bellied woodpecker, yellow warbler, four warbling vireos, great blue heron, mourning dove, tree swallows, grackles, red-winged blackbirds, American crow, turkey vulture, Carolina wren, northern cardinal, ovenbird, American robin, four Baltimore orioles, white-throated sparrow, common yellowthroat, tufted titmouse, song sparrow, northern parula, goldfinches, house finch, pine warbler, chipping sparrow, eastern phoebe, hermit thrush, indigo bunting, veery, brown creeper, rose-breasted grosbeak, eastern towhee. Blooming: cuckoo flower, marsh marigold,  pink ladies’ slippers, starflower, Canada mayflower, high-bush blueberry, violets. At home: a pair of orioles. May 29, 60-70 degrees, lovely. On beaver dam trail, a scarlet tanager is singing his heart out. I couldn’t see him. How can a red bird in a green tree hide so well?

Diane Duane, Howard Rd., May 23. Some cedar waxwings in a tree in her yard.  May 30th – Baltimore oriole in white oak tree.

Tara Nolan, Old Colony Drive, May 23. Large raccoon near our feeders.

Rosemarie Koester, Providence Rd. May 27. May wildlife report:  Cardinals, goldfinch, house finch, blue jays, grackles, red-winged blackbirds (mostly males), downy and red-bellied woodpeckers, hummingbirds come often, chickadees, tufted titmouse, robins (two little beaks in a nest in yew in front), owl (sounded like the cough of a dog), turkeys, mostly male showing off their tails, a few chipmunks, gray squirrels, bunny nest under the shed, a garter snake in the driveway. I gently encouraged it away from the garage door. Occasional bee, a few frogs (usually have more). Lots of poison ivy around the area. Saw and removed garlic mustard and put it in a bag. Mayapple spreading. I pulled it using gloves, as roots are toxic. Lilac bushes were great, more than normal. Forsythia never bloomed, azaleas not blooming except  a few at the bottom (caused by drought and cold snaps.


Marian Harman is a member of the Westford Conservation Trust. The Trust is a non-profit conservation organization whose mission is the preservation of Westford’s open spaces and trails. New members and volunteers are always welcomed. Check out the Trust’s website at westfordconservationtrust.org, and visit us on Facebook.