Spring is a wonderful time of year, with leaves and blooms emerging, birds singing, and amphibian reproduction in full swing. But breeding occurs over a prolonged period since different species have distinct tolerances and adaptations for seasonal progression in temperature and related habitat changes. So for example as I write this on May 2, the bluebirds on our farm near Galax, VA, are already sitting on eggs, but we just heard the first of the season willow flycatchers which will soon be breeding here.
The arrival of ruby throated hummingbirds is a joyous occasion since they are so active and come readily to feeders. We have coral honeysuckle vines and red buckeyes in bloom to offer them some natural food.
One of my favorite ways to assess seasonal changes is to bike down a rail trail to the New River. The view of a red bud tree in bloom next to one of the old 1931 bridges shows one attractive spring scene. A fire pink flower along the trail was being visited by a spicebush swallowtail butterfly, eager to obtain nectar to fuel its activities. This species is interesting since the underside of the wings is brightly marked with orange spots and a blue wash; this is believed to mimic the coloration of the toxic pipevine swallowtail and thus confer protection against bird predators.
Amphibians are of course very active in spring time. In late April bullfrogs are just beginning to be active and the males start calling to defend their territories. This male is distinctive due to its very large eardrum behind the eye and a bright yellow throat. The booming call of the male attracts females to lay floating egg masses in his territory. Bullfrogs are a dominant predator along the pond bank but remain close to water, unlike toads which migrate to water only to breed. Bullfrogs also differ from toads in that their tadpoles can co-exist with fish, which toads generally do not. I have been careful to keep some of my wetlands fish free for this reason, that numbers of aquatic invertebrates and amphibians cannot live with fish predators.
One predominant sound of spring in our front yard is the song of Baltimore and orchard orioles which nest in a large maple tree. The showy orange male Baltimore is strutting and singing his stuff while the dull yellowish female was just beginning to weave a nest on April 26. They choose the very end of tiny branches, presumably to discourage snakes and squirrels from reaching the nest. But it is remarkable that any nests escape predation and my wife constantly hounds me to remove the numerous black rat snakes from our property to increase the chances that the young will survive.
Tree swallows are very active in setting up nests in our boxes and are constantly squabbling over ownership of a box. The backs of the males have a structural color that refracts light, either green or blue depending on the angle, which contrasts nicely with pink dogwoods in the background. There is intense rivalry with bluebirds over nest box cavities and the swallows often win the first round. But the bluebirds will nest up to three times whereas our tree swallows normally only nest once.
If you are lucky you may hear a “chink” sound and see a bird high in a tree which is the spectacular rose breasted grosbeak. The female is a dull brown pattern but the male has a striking patch of red on its breast. These do not nest at our lower elevation but we enjoy watching them pass by on their way to the higher ridges.
In Florida we would hardly pay attention to a bald eagle since they are relatively common. But here in Virginia they are uncommon and I noticed one while biking across the New River. This was a “dirty bird” with a mottled head and a whitish tail, showing that it is about four years old and nearing maturity. There are a small number of nests in western VA and young birds also migrate north from FL. It would be wonderful if this eagle would settle down and raise a family!
So treasure these golden days of spring; each of us is only permitted a limited number of these marvelous spring experiences so savor them well.