My vocabulary has been stretched lately to describe the day's rain in my calendar daybook: Wintry showers (few of them), thick rain, warm rain, misty rain, day-long drizzle, downpours, deluge. But the record rains did nothing to slow the start of spring, and if my vocabulary has been stretched trying to describe rain, it is totally overwhelmed by all the colors of green about me. The pale, soft new leaves of next month's wildflowers are just emerging. In contrast, the mosses, lichens and liverworts are lush and brilliant, their colors ranging from the darkest greens through grey and blue-greens to brilliant chartreuse, sometimes all on and beneath a single tree. The mosses may be soft, but their colors are strong and assertive. The contrast of textures and tones is enhanced by the low angle of the sunlight and the misty air. In mid January I found the first grouse flowers (
Synthyris reniformis), spring queen, snow queen. Now I see them everywhere in the woods. Every aspect of these harbingers of spring is beautiful, the delicate buds and small lavender flowers, the glossy broad leaves, the way the plants grow in the soft moss. They grow easily in our yard in undisturbed moist shady areas where moss thrives.
Last week I found the first frog eggs of the year, a large mass near the surface by the edge of the pond, eggs of a red-legged frog. I have only heard Hyla call once, last Friday. I know people in town have been hearing them regularly, but it is my experience that they do not start calling until the temperatures are warmed into the fifties, which does not happen so early here in the hills.
Today I cleaned the barn to the serenades of a song sparrow. He has been singing for several weeks. Early in the morning we had several of our regular visitors on the pond. First mallards, then later, a male wood duck arrived. Our pond is very small, and this is perhaps why we rarely see several species, or many individuals on it at the same time. Two weeks ago, however, I was astonished to see 23 Canada geese on the pond. Geese rarely visit us, and never more than one or two. After swimming about for a while, completely undisturbed by my endeavors with the manure cart, or by the dogs playing ball and chasing after the horses in the arena, the geese sauntered into the pasture and proceeded to "graze and poop" for hours. Now five geese eat as much as a sheep, so I was seeing the equivalent of four and three fifths sheep freeloading out there. I am very stingy with my pastures in the winter (none for horses, only the well drained hill for sheep), and I was becoming downright grumpy about those geese. Luckily for my temper, they left in the afternoon and have not returned. More popular, indeed beloved, are the two and sometimes four varied thrushes that scratch in the duff and compost in the wild garden on the east side of the house.
It is so wonderful to find signs of spring everywhere, but also a little disturbing. This winter has been very mild. It seems that winters are always mild these days. Frogs are laying eggs and birds establishing territories, days or even weeks earlier than they did twenty or thirty years ago. Plants have far shorter dormant periods or none at all. One very noticeable characteristic of our new milder winters is that even if day-time temperatures are only average or even below average, the night time temperatures remain quite high. Frosts are uncommon now, and less severe. It seems to me that spring growth can begin earlier because plants can cope with chilly dark and soaking weather if the daily average temperatures are in the forties. When we think of global warming, we think of dry, torrid summers. Warm winter nights are perhaps even more characteristic of the changes we are living with.
A very scary story connected to this same type of warming trend is reported in the journal Nature, 12 January, 2006, in a research article by J. Alan Pounds
et al. and in a review article by Andy Blaustein and Andy Dobson, "A Message From the Frogs." Seventeen years ago the golden toad of Costa Rica disappeared mysteriously from its pristine range in Costa Rica's Monteverde cloud forest park. Perhaps less publicized is the disappearance during the last two decades of sixty-seven percent of the one hundred ten species of Harlequin frogs, gaily colored members of the toad family living in the mountainous American tropics. Pounds and his fellow researchers believe they have found the cause, a fungal disease chytridiomycosis, specifically caused by the pathogen,
Batrachochytrium dendrobatitis. With global warming, the middle altitudes of the tropical mountain forests, where the greatest number of these amphibian species live, have become significantly cloudier, causing nighttimes to be warmer and days to be cooler, averaging close to the optimal temperatures for the spread of this Batrachochytrium. The fungus ceases to grow at 28 degrees Celsius and dies at 30 degrees, but without hot sunshine, basking in a warm place, which would kill the fungus, is impossible. The nights are not cold enough to destroy the fungus either. Blaustein and Dobson link this important piece of research with broader aspects of global warming. Scientists have warned that warming, coupled with our ever more tightly linked global economy, will increase the rates of disease transmission everywhere. Blaustein and Dobson point out that Batrachochytrium is not native to the Americas but was imported along with Xenopus, clawed frogs from Africa, for laboratory use since the 1950s.Though the frogs did not escape, their pathogen did, becoming widespread in the 1970's. And so a new disease, against which amphibians had evolved no defenses, arrived in the American tropics just as the climate became highly suitable for this fungus to undergo a population explosion. The disaster is not unique to exotic pathogens. In the far north, nematode parasites of musk oxen are threatening the health and even the existence of the herds because they now complete their full life cycle in one year not two, effectively doubling the population of these parasites. The same can be said for the mountain pine beetle in our western states which also now completes its life cycle in one year not two. Profound and prolonged cold weather can knock black pine beetle populations, but with our milder winters, this now seems unlikely. Wherever we look we see that global warming is a very bad thing. Why can't the government see it? Why can't each of us, in both our personal and our political action, commit to fighting this threat to the natural world we love? Soon it will be too late.
It's been fun to call our joyful tree frog Hyla, though scientific, a sort of affectionate nickname. But UO herp guy, Tom Titus, has let it drop that in the scientific community this fellow is now to be called
Pseudacris regilla.
Speaking of Tom Titus, if you haven't seen his website lately, just visit to enjoy the exceptional photos of amphibians, reptiles, their parts and their researchers. We need Tom back for a herp review! Click on "Field Trip Gallery":
http://biology.uoregon.edu/reference/herpetology/
And more from Tom on "Connections":
The lungless salamander family Plethodontidae contains well over 200 species, all of which exhibit a complete evolutionary loss of lungs. They transfer all of their oxygen and carbon dioxide through the skin and lining of the mouth. Many species, including all of those found in western North America, have direct development, meaning the larval stage occurs inside the egg rather than in the water. Eggs are laid in moist cavities in logs or talus, and the hatchling salamanders are miniature versions of the adults.
A nine species branch of the genus Plethodon is restricted to the Western United States. Of these species, Dunn's Salamander (
Plethodon dunni) and the Western Redbacked Salamander (
Plethodon vehiculum) are my favorites. They are beautiful and common, especially in the Coast Range. Dunn's and Western Redbacked Salamanders are also the closest evolutionary relatives on the Plethodon tree. New species most commonly evolve when populations of the ancestral species become geographically separated. Thus, the daughter species are typically separated geographically. But these sister salamander species co-occur across much of their range, especially in Oregon. To my knowledge the reason(s) for this are not understood.
The Western Redbacked salamander has a sharply delineated back stripe of red, yellow, green, or no stripe at all. Dunn's Salamander nearly always has a green back stripe, but the edge is usually not sharp and the stripe is suffused with black pigment. In some individuals the black pigment is so prominent that little or no green back stripe can be seen.
Although the habitats of Dunn's and Western Redbacked Salamanders overlap, they differ somewhat. Dunn's Salamanders can most often be found under objects in wetter habitats along well-shaded springs and seeps. Western Redbacked Salamanders occur in these habitats as well, but are more commonly encountered in woody debris or talus on the forest floor. Recent experiments have shown that Western Redbacked Salamanders survive dehydration better than Dunn's salamanders.
- Tom Titus
Since I like words: Tom emailed me that these "closest living relatives in the lungless salamander family are broadly sympatric over western Oregon." Tom went on to explain to me, "Sympatric means they co-occur. That is, their ranges overlap. It's interesting," Tom continued, "that these two species, Dunn's Salamander and the Western Redback Salamander are sympatric, as most of the time populations diverge into new species when they are separated from one another by a geographic boundary of some sort. The divergence of populations into separate species within the same geographic region is a rare event." - Editor