April is a month of changes. Plants and animals begin to wake up. We become optimistic. And as we move into late spring and the temperature swings level out, we see and hear more as more plants burst forth with pollen and seeds, insects pollinate and spread seeds, and animals mate and migrate.
An early wildflower
The skunk cabbage is an early bloomer but hard to find in Rock Creek Park. It has the rare ability to generate heat even when it is covered with snow and leaves. It melts the snow and the flower stalk emerges. The hot air dissipates, filled with “eau de skunk,” and this attracts insects that like the smell of carrion – flies, carrion beetles, small bees. They pollinate the flower.
In February I start to scan the maples and elms that line our streets. I am watching for the first tiny blooms, a sure sign of spring. Their flowers are to be pollinated by the wind, as it is too early for bees.
The maple above shows the bunches of reddish seeds that result by the end of March. This tree bloomed in late February, and now, only five weeks later, it is already covered with bunches of reddish seeds. Soon they will grow into the winged seeds we see all over our lawns. The elm trees are already a vibrant green with their seeds.
This is a way these trees get an early start on the growing season. Following them over the next months are our other native trees, with the oaks (remember all that pollen) the last ones to bloom. For a tree to bloom and leaf, its roots must start sending sap and nutrients into the trunk and branches, but we do not know what triggers this. Why are maples and elms so early? We don’t know.
Bloodroot is one of the early ephemeral wildflowers. They are called “ephemerals” because they have a short life and a short blooming season. Their aim is to get pollinated, make seeds and disappear before the trees leaf and shade them too much.
In this photo, you will notice that the petals are bright white and wide open to display the stamens and pistil. The flower is presenting a striking invitation to insect pollinators – flies, ants, small native bees. If the sun goes in, the flowers close up.
Bloodroot and other spring wildflowers get their seeds dispersed with the help of ants. Each bloodroot seed has a little packet of nutrients attached at one end. Ants collect the seed, take it back to their nest, and feed the packet to their babies. The seed eventually germinates there, some distance from the original plant, starting a new clump.
Mating and migrating
Our resident songbirds will start to nest in April – cardinals, robins, song sparrows, jays. They are singing territorially as I write this (in the first week in April), though I have not seen any nest building.
In Rock Creek Park however, red-shouldered hawks and our resident barred owls are sitting on eggs or feeding chicks. The big birds start mating in January.
Migrants start to arrive in mid- to late April. A hummingbird that is a frequent backyard visitor always arrives around April 15th.
The big wave usually comes the first and second weeks in May. In theory we can see up to 25 species of warbler in Rock Creek but we almost never get that many.
May is also the time for songbird migrants – orioles, rose-breasted grosbeaks, scarlet tanagers, cuckoos, vireos, sparrows, thrushes. Some will stay, like the Baltimore orioles which nest here, but most make only a brief stop. They drop out of the sky around 7 a.m., eat and rest that day, and often leave the same evening.
The night song
Frogs and toads feel the mating urge in late March. The first species we will hear in Forest Hills are American toads. They have crowded into goldfish ponds, puddles and the creek in Broad Branch Branch Daylighted Stream Park. They sing for a mate, a long musical trill of almost 30 seconds. When a female accepts him she will lay 4,000 to 8,000 eggs. They will hatch into tadpoles, which grow seven to eight weeks to become adults in July.
Spring peepers (tree frogs) follow the toads. On a warm day you can open your backdoor and hear them all over Forest Hills. Their call is a piercing whistle repeated at one-second intervals (sometimes said to be like sleigh bells). A female lays up to 1,000 eggs.
So many eggs and tadpoles tell us that infant mortality is high. Birds, fish, raccoons, foxes and many pond creatures count on them for spring meals.
My neighbor tells me that there are almost no baby toads left in her yard or goldfish pond, because two red-shouldered hawks have spent the last weeks eating them. The hawks sit in a tree (or perch on the bird feeder below) and wait, then drop down and pick up a small toad, an inch or so long, for lunch.
If you really want to see and hear frogs, go to the Broad Branch Stream at Linnean Avenue and Broad Branch Road on a warm damp night after dark. Four or five species will be calling and you will be amazed at the cacophany.
As things heat up
As the month progresses, we will see more butterflies. The dragonflies will appear along Rock Creek and in the Broad Branch Stream. Honeybees emerge and start working when the temperature goes over 50 degrees. Right now, I am seeing big carpenter bees cruising low and looking for mates. Garden perennials green up.
I keep careful tabs on my backyard. On a warm sunny day, when the yard warms in the afternoon, I love to sit out there quietly for an hour or so, watching and waiting for action. Occasionally I look up into the sky to see if there is a hawk riding the thermals. I don’t expect any earth-shaking discoveries, but it’s intriguing to see what goes on day by day in this micro-habitat.
Photos generously provided by the Audubon Naturalist Society (skunk cabbage and bloodroot), Dick Rowe (birds), Marlene Berlin (toad) and Ellen Sieminski Gawlak (red-shouldered hawks).