Signs of Spring

Red bud blooming at 1931 RR bridge on the New River Trail.  Photo by Bill Dunson

Ruby  throated hummiingbird at Galax farm.  Photo by Bill Dunson

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. 

Fire pink with swallowtail (possibly spicebush swallowtail) along the  New River Trail.  Photo by Bill Dunson

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.  

Bullfrog in spring pond.  Photo by Bill Dunson

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.

Baltimore oriole male at Galax farm.  Photo by Bill Dunson

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.

Rose breasted grosbeak male along the New River Trail.  Photo by Bill Dunson

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.

Bald eagle at Fries Juunction New River.  Photo by Bill Dunson

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.

Bill Dunson
Galax, VA and Englewood, FL

Spring Peeper (Hyla crucifer)

Most of us recognize the high shrills of our spring peeper as a significant harbinger of spring. These are our first frog breeders, sometimes beginning as early as late February, but most commonly mid-March. For this important event in the ongoing life of peepers, the tiny frogs migrate to vernal pools, and pond and stream edges in meadows and woodlands, where the competition for mates commences. The males sing two types of songs…one is their ‘announcement or advertisement call’ and the other an ‘aggression call’. Both songs are issued from the approximately 12” diameter territory of each male, with the first call meant to attract females and the second to warn off other males.  

Peepers are tree frogs, and when the mating season comes to an end, they return to the woodlands and edge habitats for a mostly solitary existence; eventually hibernating under leaves on the ground through the cold months and withstanding freezing temperatures by producing glucose as an anti-freeze. Their diet consists of small invertebrates.

Six years ago I took it upon myself to do a bit of field research into ‘that noisy bunch of frogs’. Below the north slope of our land lies a cow pasture through which Bridle Creek flows. In the lowest lying land, the meadow becomes a marsh in which our local clan of peepers congregates every spring. Their cacophonous peeping becomes nearly deafening at the height of their frenzy.  This marshy area is temporary, so the business at hand must be accomplished before sunny summer days dry it out. It takes 1 ½ to 2 months for the tadpoles to develop into frogs, after a week of gestation. That gives them a window of less the 3 months…which is exactly right for this spot.  

When I approached the meadow wetland, the closer I got to the breeders, the less they sang. This was during the early morning hours, but well after first light. From what I have learned, it might be easier to observe them at night, with a flashlight; but with a bit of patience, I was fully rewarded. Once I positioned myself in the middle of the marsh, I squatted and remained motionless. After 10 or 15 minutes they forgot I was there, and got back to work.  Surrounding me were dozens of mating pairs along with hopeful males trilling in concert. I returned to this exhibition for several days in a row, watching, listening, and photographing the spectacle.   

The first two pictures were taken in the meadow, the third in my yard at night…near a small artificial pond.