Signs of Spring 6: Caffeine and Coffee Trees

I have written about caffeine before. It is a wonderful chemical with many roles in nature including acting as an attractant for pollinators and as a protection against pests and pathogens. That it also helps us wake up in the morning is just one of those wonderful connections with nature!

Photo by A.C. Moraes, Wikimedia Commons

A recent paper published in the Proceedings of the National Academy of Science (September 20, 2016) describes the biochemical steps and controlling enzymes by which a diverse set of plants synthesize caffeine. The plants included coffee, tea, cocoa, citrus (specifically orange trees), and guarana (a climbing vine native to the Amazon Basin that makes fruit incredibly rich in caffeine (pictured to the left)) (Guarana, by the way is used in a variety of energy drinks including Monster, Full Throttle and Red Bull!). The authors of this paper found that there are subtle metabolic differences between some of these caffeine producing plants. Coffee and tea, for example utilize the same basic biochemical synthesis pathway to make their caffeine except for their final enzymatic step.  They also found that there are some very large differences in some pathways. Cocoa, orange and guarana, for example, not only start their synthesis processes with different substrates but also generate very different intermediate molecules on their way to making caffeine.

Their conclusions were that these plants, which are very distantly related to each other, evolved their caffeine synthesizing pathways independently of each other. This type of evolution is called “convergent evolution.” Its occurrence emphasizes the utility of caffeine as a plant secondary compound. This research also emphasized that MANY plants are potential sources of caffeine. This may be very significant considering what our next set of papers and reports are very clearly telling us.

Climate change has, unfortunately, become more of a political topic than a scientific one. The sad consequence of this is that the political acrimony associated with the debate clouds the reality of the scientific observations of global warming and prevents the taking of any real steps by which the on-going heating of our planet might be delayed or even reversed.

Photo by DirkvdM Wikimedia Commons

A report (“A Brewing Storm: The Climate Change Risk to Coffee”) published in September 2016 by the Climate Institute (an Australian non-profit organization) explored the impact of climate change models on the global distribution of coffee trees. They found that projected rises in global temperatures would reduce coffee producing land areas by 50% by 2050. Impact of climate change (which includes not only rising average temperatures but also changes in weather patterns and cycles of drought and excessive rainfall) were especially severe at low latitudes and low altitudes. The worldwide, tropical “bean belt” will need to move out of the afflicted tropical zones and up mountainsides in order to find suitable sites to grow coffee. It is estimated that there are 120 million people in these zones whose economic livelihoods depend on coffee.

Photo by F. Rebelo Wikimedia Commons

Coffee trees need very stable environments to grow and thrive. This has been one of the ongoing arguments in favor of planting coffee trees under a taller, cover forest. The micro-environment of these “shade coffee” sites are much more stable and predictable than open growth coffee plantations. This how wild coffee grows in its natural ranges in Ethiopia. This is also how most coffee was grown until the mid-Twentieth Century when sun-tolerant varieties of coffee were developed. These great, open, single crop plantations of sun-tolerant coffee produced higher bean yields but at the cost of increased demand for fertilizers and pesticides, increased soil erosion, and the catastrophic loss of forest habitats especially for birds.

The recent awareness of the multiple benefits of shade coffee have included not only an economic side (lower production costs), an ecological side (establishment of complex habitats for birds and other animals), but also an aesthetic side (shade grown coffee tastes better!). Climate change, though, is too much even for these coffee ecosystems!

Photo by Carvalho et al., Wikimedia Commons

Plant diseases are already ramping up on the edges of the global “bean belt.” In 2012 almost half of the coffee plantations in Central America were afflicted with the “coffee rust” fungus, Hemileia vastatrix. Coffee rust is a disease native to East Africa that has spread to all coffee producing countries around the world. It grows and disperses explosively in warm, wet environments (just the environmental conditions predicted by climate change models). Coffee rust has already reduced Guatemala’s coffee production by 85%!    The coffee borer beetle (Hypothenemus hampei) is also a currently significant pest that causes hundreds of millions of dollars of damage to coffee beans. This beetle is originally from Angola but spread early in the Twentieth Century to the rest of Africa and is now afflicting coffee trees in South and Central America and even Hawaii. The moister conditions of a world altered by climate change will allow this beetle to spread even more rapidly through a plantation and across broad geographic areas.

Coffee production is an important part of the economy of Tanzania. Temperatures, though, in Tanzania have been rising since the middle of the Twentieth Century and each degree of temperature rise has been correlated with a decline in coffee production. Coffee production in Tanzania has gone down by 50% since 1960 and is projected to be only a minimal part of the country’s agricultural output by 2060!

As I mentioned above, wild coffee (“coffea”) is a shrub native to Ethiopian cloud forests. There are a number of species of coffea found throughout Africa (including Madacascar and Cameroon), but the origin of our coffee trees are probably from the Ethiopian plants. Another consequence of climate change is that these coffea shrubs are very likely to become extinct before we get to the end of our current century. The loss of this genetic information could be devastating to the future of our cultivated coffee trees.

We can make caffeine in a factory, and we can cultivate some of the other types of plants to make caffeine rich infusions and beverages. I would prefer, though, a world in which we can still get a real cup of coffee.

 

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Signs of Spring 5: Harrison Hills Walk and Cavity Nesting Team (3.0)

Photo by D. Sillman

Last Thursday Deborah and I headed up to Harrison Hills Park in northern Allegheny County to take advantage of a few hours of sunny, spring weather before the next cold front (and set of snowstorms) blew in. We wanted to get at least one hike in during our Spring Break!

It was a beautiful morning: sunny, in the fifties (with a slight change of warming up close to sixty!). Only the wind made us think of the coming storms. There was an article in this week’s New York Times in which data on “first leaf” emergence from observers all over North America were compiled into an animated map. The wave of “first leaves” surged up the breadth of the country a full three weeks ahead of the thirty year average! It is an early spring this year, a VERY early spring!

We parked near the Environmental Learning Center and headed out across some open, grassy areas to find the first group of our nest boxes. The soil was wet and oozing underfoot and there was flowing surface water running from a number of seeps and springs. The water supported a thick growth of moss (in many places there was much more moss than grass). Small, black Pardosa spiders ran about on the soil and plant surfaces. We hoped that they were getting out of the way of our footfalls!

Photo by D. Sillman

Our boxes were in good shape and had weathered the winter very well. We were especially interested, though, in the direction that their access holes pointed. Last year, 9 of our 28 nesting boxes had house wren nests (no boxes from our 2015 study had had house wren nests). Six of the 9 house wren nesting boxes had been previously nested in by bluebirds (4 boxes) and chickadees (2 boxes). House wrens and bluebirds have many similar nesting characteristics: they tend to nest in two seasonal cohorts (early spring (May) and late summer (July/August), and they tend to select nesting sites no more than 50 to 100 feet from a wooded edge. Possibly our 2016 box relocation project moved a significant number of our boxes into nesting sites also preferred by house wrens.

The problem is house wrens are one of the most common causes of nest failure in bluebirds, tree swallows and chickadees. House wrens destroy eggs, kill nestlings, and even kill adult birds so that they can then start their own nests in the usurped box. Also, male house wrens attempt to attract females by building numerous “dummy nests” (piles of sticks sometimes piled on top of the active nests of other birds!). These dummy nests are an important sign of house wren activity and can be used to thwart house wren nest invasion. Since these dummy nests contain no eggs, they can be removed from the nest boxes without violating the Migratory Bird Treaty’s protections of native bird species. Prompt removal of these stick piles may keep a male house wren occupied in re-building the displays rather than getting down to actual reproduction.

Photo by dfraulder, Wikimedia Commons

Also, the literature on “wren guards” (various nest box modifications that are designed to repel house wren nest box invaders) stresses that it is the visual cues of the nesting birds entering and leaving a nest box that are the critical stimulations that then trigger the house wrens to attack the active nest.  Possibly, turning all house wren utilized nest boxes to point their openings away from the surrounding woods (where the house wrens spend much of their time foraging for food and hiding in the covering vegetation) would make the visualization of the nesting birds entering and leaving the nest box less apparent and decrease the rate of house wren infestation. Re-orienting the boxes was one of the tasks that Deborah and I hoped to accomplish today.

We looped through the meadow near the purple martin houses and then hiked up into meadow on top of the nearby hill. I walked up to the “High Meadow” on a narrow path that cut through the woods while Deborah took the longer (but less likely to have ticks) route back down to the access road than ran from the Learning Center. I scared up a bird  from the dense vegetation along the path as I walked along. The sudden rise of the bird was noisy and very exciting!  I think it was a grouse but it moved so rapidly that I did not get a good look at it. I also picked up a black-legged tick (which Deborah found working its way up my pant leg when we stopped to do a tick-check up in the High Meadow). It is the time of year to be very watchful!

We finished the High Meadow and the nearby Bat House Meadow loop doing some small repairs on the seventeen boxes and their poles and turning each box so that it faced away from its surrounding trees. One box in the Bat House Meadow had a metal, predator guard on its pole. We remembered that that box was the one that had the black snake inside of it when Sharon (one of the Cavity Nesting Team) open up the box to check on a swallow nest. The snake had eaten the swallow nestlings and was napping inside of the box. Good adrenaline rush, I am sure! The guard should keep that from happening again.

Photo by D. Sillman

Five male bluebirds followed us around in the Bat House Meadow. They are the first bluebird arrivals (or, maybe, the hardy, overwintering individuals?) and are checking out and competing for optimal locations for their breeding territories. Plenty of boxes for everyone, boys! The females should arrive in a couple of weeks

We then drove to the park entrance and checked the two boxes set on a fence line just to the south of  Y-intersection of the two park roads. Both of these boxes had predator guards and both had old nest materials in them. Possibly some overwintering bluebirds had built some nests, or some late fall swallows had done some practice nest building. The dry grasses were not tightly woven together and there were few feathers and very little feces in either box. There was no evidence of any recent activity. We cleaned them out and packed away the debris.

Photo by D. Sillman

The road to the soccer fields was closed so we had a long walk from the upper parking lot down to the cluster of boxes set around the field edges. We turned each box to face away from the surrounding trees. The wet soil of the soccer fields were blooming with the tiny white flowers of Pennsylvania bitter cress (Cardamine pensylvanica), and in the even wetter areas along the flowing drainage ditches and streams, the mottled purple, tear-dropped shaped spathes of skunk cabbage (Symplocarpus foetidus) grew in dense clusters.

Photo by D. Sillman

One of our nest boxes was missing! “Box V” that had been set next to the pond just up from the soccer fields was gone. This had been an important tree swallow box in both 2015 and 2016. We will have to locate it or replace it before swallow breeding season starts in late May.

We hiked back up the hill to the parking area through the woods that bordered our two nest boxes that had no nesting activity either in 2015 or in 2016. We left the boxes in place, though, because these two meadows seem so perfect for bluebirds (or chickadees or nuthatches or swallows). There is something, though, about these two sites that birds don’t like. We will have to figure out what it is!

The shrubs and trees on the pond side of the uphill climb were covered with American bittersweet vines (Celastrus scandeus). A few of the vines still had some of their distinctive, orange, pea-sized berries on them. These berries are poisonous to people but are a very popular winter food for birds. January before last we were hiking on this path and were amazed by all of the overwintering robins that were there. They must have been living on these very abundant, bittersweet berries.

Bluebird season will start the third or fourth week of March! The boxes are ready, and the Cavity Nesting Team will be there to watch and report!

Happy Spring, everyone!

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Signs of Spring 4: Earthworms on the Sidewalk!

NASA, Wikimedia Commons

The full moon of March (which this year will occur on March 12) has many names. The Algonquin’s called it the “catching fish” moon, while the Omaha and the Cree called it the “little frog” or just the “frog” moon (we will have to wait a few weeks more, though, before the frog choruses begin to grace our evenings!). The Kiowa called it the “bud” moon, and several other tribes referred to it as the “crow” moon after the increased vocal activity of the flocks of crows as they sorted out their social and reproductive hierarchies after the long and stressful winter. A number of the northern tribes called the March full moon the “crust” moon after the icy snow crusts that form on the persisting snowpack due to the daytime thawing and nighttime re-freezing of the surface. They also called it the “sap” moon after the rising sap of the trees (especially the sugar maples!) which, interestingly, is caused by the same daytime warming and nighttime freezing cycles that cause the snow crusts.

The name most frequently applied to the full moon of March today, though, and attributed to Native American sources (although never in my readings to a specific tribe), is the “worm” moon.

Photo by H. Casselman, Wikimedia Commons

Walking out on last week’s warm, wet mornings, the “worm” moon appellation seems quite appropriate. On almost every sidewalk, driveway, or parking lot a significant number of “earthworms” of various species were wiggling along on the wet surfaces, moving in apparently random directions out from their former burrows in the surrounding grass. Why are so many worms emerging all at once? The emergence is probably a behavioral response to moisture and temperature variables that helps to disperse and expand the boundaries of an earthworm population (no, they are not drowning in the wet soil!). As earthworms reproduce and their clustered cocoons hatch the new worms tend to be clumped together, the spring dispersion helps to spread their numbers out across a soil habitat.

Photo by R. Bushby, Wikimedia Commons

The arrival of the migratory flocks of robins is coincident with this worm emergence event. Watching the foraging robins voraciously eating worms really gives you a good idea of how many earthworms are actually slithering along on or just hiding beneath the soil surface. Many bird species (including the grackles that just showed up under my bird feeder last week!) also opportunistically, and with less time and effort investment than the robins, catch and consume earthworms. European starlings, an alien invasive bird species, have even been known to follow the hunting robins at a distance and then, on seeing a robin grab a worm, dive at them noisily so that the worm is dropped when the startled robin flies away. The starlings, then, get a stolen, protein-rich, meal. This is only one of the ecologically disrupting things that starlings do, but that’s a topic for another essay.

As many of you know, I studied earthworms very intensively in my Ph.D. research and in a variety of studies here at Penn State back in the 1980’s and early 1990’s.  A “worm” moon, then, should have some special meaning to me, and, I admit, it does. It is not at all clear to me, however, how Native Americans could have had any ecological or historical connection to these earthworms! Almost all of the organisms we call “earthworms” are, like the European starling and the gypsy moth and Colt’s foot and so many other species of plants and animals around us, organisms that were introduced to North America by European settlers as they spread across the forests and plains of the continent. Earthworms are a group of alien, invasive species!

Photo by S. Shepherd, Wikimedia Commons

Earthworms do many important things in their soil habitats. They improve the stability of a soil’s structure and its drainage properties, and they accelerate rates of leaf litter decomposition and nutrient cycling. Aristotle called them “the intestines of the Earth,” and Charles Darwin spent many years of his life intensively observing and describing their activities and their extremely positive influences upon soil fertility. My own research described the immense benefits that robust populations of earthworms could have on leaf litter decomposition in established forests ecosystems and on re-forested strip mines, and in the cycling and rehabilitation of sewage sludge.

A few years ago, though, an article in the Science section of the New York Times described some of the more negative consequences of the extremely active shredding and burying of leaf litter in worm rich soil ecosystems. Earthworm activity leads to the loss of leaf litter habitats for a wide variety of other invertebrates. It also leads to the loss of the protective, soil covering leaf litter “blanket” and changes the nature of the soil community’s nutrient and energy webs. Earthworm activity also changes the way that organic materials are distributed through the soil profile. The soils of what seem to be undisturbed ecosystems are, in fact, irrevocably changed from their original conformations by the actions of the introduced earthworms.

So, how could Native Americans describe the mass emergence of earthworms in the spring and relate it to the March moon if these earthworm species didn’t arrive in North America until possibly the Seventeenth or even the Eighteenth Centuries? I don’t think that they could or did, and careful examination of lists of specific tribal moon names backs up this idea. No specific tribal designation for the March moon includes the “worm” moon.  Fish, frogs, buds, crusts, crows and more are listed, but no worms. My feeling is that the “worm” moon is, like the worms themselves, an imported thing brought by the settlers from their European homes that quickly became incorporated into the structure and perceived history and ecology of their new environment.

Did the increased abundance of the earthworms lead to increases in American robins and other earthworm eating birds? Did earthworm activity change forest soil properties to favor different tree species? Did the cleared land plowed into farm fields become more productive because of the swelling numbers of earthworms? Did the earthworms cause the extinction of some litter dwelling beetles and other insects? Did the activities of these extremely active earthworms drive native annelid species into their very restricted present day distributions?

What interesting ideas! Something to look at in my retirement!

Happy worm moon, everybody!

 

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Signs of Spring 3: Tree Buds and other Emergences

Photo by D. Sillman

The branches of the silver maple at the bottom of my field are covered with flowers (photo to the left). Last week’s warm weather stimulated the opening of the flower buds a good two weeks before “normal.”  If the early spring holds on, the leaf buds will be opening soon, too. This tree is always the first one to flower up on our hill. It is definitely an important sign of spring!

There are also four, large red maples close to my house (photo below). They typically flower a week or two after the silver maple. A cold, lingering winter (like the one in 2015) can push this flowering to early April, but usually by mid-March the little, red flowers open up first on the tree nearest the street (I think that it’s warmer there) and then on the trees clustered more toward the middle of my field. When the red maples bloom the honey bees begin to swarm and local beekeepers start to see red maple pollen in the honey in their hives

Tree buds are structures that encase and protect the forming flowers and leaves. The outer part of the bud is made of tough scales that form overlapping, shingle-like structures around the delicate leaf or flower growth tip. These bud scales keep out destructive insects and also insulate the inner tissues. These scales are, really, very tiny, very tough, highly modified leaves. Buds are classified as to whether they encase flowers (“floral” buds), or leaves (“vegetative” or, simply, “leaf” buds), or both floral and leaf embryonic tissues (“mixed” buds), and by their position on a branch (“terminal” buds are found at the end of a twig and “lateral” buds are found along the sides).

Photo by D. Sillman

On silver and red maple trees most buds are either floral or vegetative. The floral buds are larger and spherical and the leaf buds are smaller and more oblong. The floral buds are also typically clustered together in bunches on the twig. Over the winter I have watched squirrels nipping off the lateral buds on the red maple branches (they must be a welcome dietary supplement to balance out all of the sunflowers seeds they had been eating from my bird feeders!). Most of the branches, though, were too thin for them to get out to the terminal buds, so I expect to see both flowers and leaves concentrated at the ends of tree branches this spring and summer.

As I said, the floral buds on the silver maple just opened and soon, if this warm weather holds, the red maple buds will open revealing the delicate clusters of red and yellow flowers. The tiny pollen grains from these flowers will then be spread mostly by the wind (although honey bees, as I mentioned before, will be visiting some of these flowers). By chance some of the wind-blown pollen will encounter ova in the ovaries of other flowers and accomplish the fertilization phase of the reproductive life cycle. The pollen is produced in prodigious amounts by these trees, and you can easily understand why. The probability of a given pollen grain, randomly dispersed through the atmosphere by the wind finding an appropriate ovum is infinitesimally small!  To insure that fertilization occurs at all, the trees must fill the air with pollen. Human interactions with this pollen mass can generate allergic reactions in sensitized individuals. Hardwood tree pollen, in general, is a major spring allergy trigger. Dripping noses and red eyes, unfortunately, come with the season.

Photo by Dcrjsr, Wikimedia Commons

Once an ovum is fertilized it will develop into the maple tree’s distinctive winged seeds (their “samara”). These “maple keys” will, by early May or so, form great, fluttering clouds as they drop from the trees and become scattered by the wind across lawns and woodlots. A large red maple tree can produce over a million of these seeds each year! Some of these seeds will germinate immediately while others may lay dormant in the soil until the following year. Many of these seeds will be eaten by birds and squirrels. These seeds and their seedlings are topics for a summer essay (and (great news!) summer is not that far away!)

Out in my front yard bird feeders at night there have been some regular visitors throughout the winter. The deer, of course, come in numbers to clean out any corn that hasn’t been eaten by the crows or jays or gray squirrels. They also like to use their noses to tip up the sunflower feeders to get a big mouthful of those (very expensive!) seeds! A possum has been a regular all winter. He digs around in the spilled seed beneath the feeders and always seem confused and frozen in place if I turn the yard light on.

Since January, I have been smelling skunks when I take Izzy out for her morning walk. I haven’t seen a skunk in quite a while, though. They must be coming in very late at night. Two nights ago I saw someone whom I hadn’t seen for months: a raccoon! They are regulars in the summer, but either this raccoon got very hungry hanging out in his hollow tree or the warm night made him think that spring was upon us. Raccoons don’t hibernate, but they do power down in cold weather and sleep in their tree or ground dens slowly metabolizing their stored fat reserves. This one had found some leftover corn which he continued to confidently eat even after I opened the porch door, shone my flashlight on him and said “hello.”

Photo by N. Townsend, Flickr

There have been more bird songs in the mornings and through the afternoons. Cardinals are singing their territories, and titmice are whistling for mates. Mourning doves begin calling well before dawn, and chickadees are joining in. White throated sparrows are still singing as are the Carolina wrens (they have been going on all winter).

Pileated woodpeckers have been pounding away on the spindly black locust tree out in the back of my yard. I also heard one down on Roaring Run last weekend banging away on one of the tall sycamores on the hill side of the trail. So many other bird species benefit from these tree holes! As someone said, if you want bluebirds (and tree swallows, and nuthatches and chickadees) leave some old trees for woodpeckers to work on!

I haven’t seen any snakes yet this year or chipmunks for that matter. Both of these animals are true hibernators and this transient warm spell probably won’t overcome their evolutionary perspective on our variable, late winter weather. Soon, though, very soon!

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Signs of Spring 2: Hardwood Forests

Photo by D. Sillman

We had a mid-February Saturday afternoon that was 63 degrees and full of sunshine. The skies were a deep “Colorado” blue, and the air smelled fresh and alive. Deborah and I went for a walk down on Roaring Run to stretch out our winter legs and look for some signs of spring.

The Roaring Run trail follows the old Main Line Canal route along the northern bank of the Kiskiminetas River. The canal was built in the 1830’s and almost immediately became obsolete because of improvements in railroad technology. The canal was filled in and covered with railroad tracks which were themselves replaced in recent decades by a really excellent hiking and biking trail. On one side of the trail a short slope drops off steeply to the river while the other side a long hillside rises up to a tall, bordering ridge. The hill up to the ridge top is forested with a mix of fast growing tree species that have filled in after repeated clear cuttings. The original trees were cut in the “timber phase” of Pennsylvania forest use and then two or maybe even three regrowth stages were cut in the Pennsylvania “charcoaling phase.” Red maple, yellow birch, yellow poplar, white ash, black cherry and red oak (with a few sycamores and catalpas thrown in) dominate the forest.

Photo by D. Sillman

The first thing I noticed as we started down the trail was an abundance of downed trees and branches.  Tree trunks were sawed and stacked alongside the trail at the ends of leading trails of fresh sawdust that indicated where they had fallen across the trail path. This has been, overall, a mild winter but there have been enough windstorms to severely thin out the trees. Many of the downed trees were poplars, but many of limb piles were red maple branches. Poplars have soft trunk wood and are easily broken by wind. That’s why you only see old, large yellow poplars in sheltered stands of trees or in deep, protected hollows. Red maples (possibly the most abundant tree of the eastern hardwood forest!) have relatively brittle limbs and branches. I pick up fallen branches under my red maples all year round.

The consequence of this thinning, though won’t be seen for another couple of months. With all of the trees still in their leafless winter aspects, the sunlight poured down to the leaf covered forest floor. You could feel the warming of the litter and soil and the stimulation of seed germination and root growth. All this sunlight will start the growth of the early spring wildflowers and other understory plants (these hillsides are covered with blankets of white flowered trillium in April!). Then the tree canopy leaves will unfurl, and the forest floor vegetation will settle into a shady, cool, moist, low energy dynamic for the duration of the summer and early fall.

Photo by D. Sillman

In the canopy spaces made by the fallen trees, though, the sunlight will continue to warm and energize the forest floor. A race among seedlings of maples, poplars, ashes and cherries that have been subsisting in the shadows of the over story trees begins and the fastest seedling to grow, or the one luckiest enough not to be browsed by deer, will quickly take over the open spot in the canopy. The wind pruning lets the forest reestablish itself. It is an opportunity to start a youthful patch of trees that will live well on into the next century.

Just as Deborah strode on ahead on her walk (she walks faster than I do!), a sudden gust of wind broke a medium top branch from one of the sycamores on the river side of the trail. The branch snapped with a loud “bang” and clattered down through the canopy carrying other, smaller limbs with it. The branches landed in a pile right on the river’s edge. They will be carried away when the river swells up with our spring rains. I am glad that it didn’t fall on my head!

Photo by D. Sillman

I didn’t see any birds on my walk. Deborah did see, though, an old oriole’s nest hanging from a limb of a tall poplar tree. The distinctive basket-shaped nest would be hard to spot when the tree was in summer leaf, but today its stood out clearly against bright blue sky and black, bare branches.

Deborah also saw a small bat (a little brown bat?) flying around the bridge that crosses the Roaring Run stream. It is possible that the past two warm days woke up the bat from its hibernation and that he/she will return to his/her cave when night falls. It is more likely, though, that the bat woke up because of the irritation of the white nose fungus and in a half-awake state had burned through its winter fat stores and was now out of its cave and desperately seeking food. We did see some stoneflies out today, but not enough to feed a hungry bat.

A stone wall alongside the trail in between the two-mile trail marker and the bridge is part of an old lock from the Main Line Canal.  In the summer, this is a good place to look for snakes (I have seen garter snakes, black snakes and even copperheads around here in warmer months). Today the early leaves of Dutchman’s Breeches were visible in the crevices between the rocks. A few years ago a troop of Boy Scouts “cleaned up” this part of the trail and did a great deal of damage to the wildflowers that had been growing in the rock wall.  Thinking that were removing “weeds” the scouts pulled up Dutchman’s Breeches and Indian Corn and who knows how many violets and other spring flowers. Sometimes the urge to make things neat and tidy should be resisted!

Near the start of the trail an informational sign talked about the on-going program to control the exotic invasive plant, Japanese knotweed. The sign talked about a two pronged herbicide application that effectively killed the knotweed. There was a picture of a riverbank choked in knotweed and discussion of the benefit to native plants to have this dense, shading invasive removed. Looking up from the sign, though, all I could see was a forest of knotweed. I don’t think that the chemical offensive was at all effective.

Many people were on the trail today and lots of them had their dogs with them. We met a three month old pit bull and several, more mature terriers, beagles and hard to identify mutts (my favorites!). They seemed to enjoy the warmth and sunshine, too.

I will have to have a long talk with Mazie about her “six more weeks of winter” prediction from House Cat Day. Looks like she (and Phil the Groundhog, too) missed this year’s early spring.

 

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Signs of Spring 1: Good News and Bad News

Photo by D. Sillman

 

I have been looking everywhere for signs of spring! Although this has not been a terribly hard winter (here in Western Pennsylvania, anyway), everyone is justifiably sick of the cold temperatures and the gray skies. Also, most of us desperately miss the color green and the morning choruses of the waking birds and the evening trilling of the peepers and tree frogs! We are ready for spring to arrive!

My cat Mazie (pictured above) has decided that we will have more winter this year, though. She fled from the front yard to the porch and ran all the way to the basement when we did our fifth annual House Cat Day experiment!

The three of the first four “Signs of Spring” I have seen are not terribly welcome ones. I guess we have to take what we can get! I’ll start with the “nice” one and then get all dark and gloomy.

Honeybee in bird feeder

Photo by D. Sillman

The bees are awake and “afoot!” On a warm afternoon last week a squadron of honeybees converged on my bird feeders in search of anything sweet and edible! I think that the powdery residue of the shelled corn that I have been putting out for the jays, crows, and squirrels drew the bees in (and hopefully gave them something that they could take back to their hive). The photo on the left shows one of the honey bees checking out the sunflower seeds! It is not energetically beneficial for the bees to go out foraging before there are any flowers, but it was nice to see them after all of these bee-less winter months!

Photo by D. Sillman

A second sign of spring was inside my home: over the past few weeks the distinctive aroma of brown marmorated stink bugs has been rising in unexpected places throughout my house. When we were sitting in the living room in the evening, when I was riding my exercise bicycle in the afternoon, when we were getting ready to feed our dog her dinner, all of a sudden our olfactory senses were overwhelmed by the pungent scent of a stink bug (or three, or four). The bugs were stuck away and hiding in all sorts of nooks and crannies (up in fluorescent light fixtures, under dressers, behind books on shelves, in the labyrinth of all of the cans in pantry, in a pair shoes) and were being roused from their winter torpor, I think, by the warmer temperatures and growing day lengths.

What we are seeing is probably the tip of the hibernating horde of stink bugs! A few will come out to check out the weather conditions and then either wander off to die (or get caught in one of my stink bug bottles) or tuck themselves back into one of their hidden hibernaculae.

The ability of these stink bugs to overwinter is remarkable. There is some mortality among the hibernating bugs, but a significant percentage of even the outside hibernators make it through to spring and to their opportunity to mate. Colder temperatures, though, reduce this percentage of survival. Several models of climate change and global warming have included increased survival of stink bugs at higher and higher latitudes with, then, significantly larger spring and summer populations of this potentially destructive pest. When you factor in their ability to find their way into our houses and spend the winter months hibernating in tiny crevices and hideouts all around us the survival rate goes up to near 100% and the northern, “freeze” boundary disappears altogether.

Photo by Dori Wikimedia Commons

My third sign of spring came from a colleague at Penn State. I got an email from Rob Bridges a few weeks ago in which he described watching some crows feeding on a road killed rabbit out in from of his house (Rob and I have many interesting conversations like this!). As he watched, though, the crows were suddenly sent flying by the arrival of a turkey vulture who then proceed to dine on the pressed rabbit.

This surprised me because turkey vultures that live around here in the summer are expected to spend their winters in Florida or Texas. Our cold winter temperatures would not only put a great deal of stress on the vultures but also prevent the generation of the thermal updrafts that they require to sustain their long, daily flights in which they search for food. Turkey vultures also primarily use their sense of smell to find carcasses on which to feed. Cold temperatures will inhibit both the generation and the distribution of these scent lines!

Turkey vultures are also quite gregarious.  They night roost in large, communal groups and usually forage or day roost in smaller groups (called “wakes”). A turkey vulture is seldom seen without companions! Where are the other members of his wake hiding out?

Hinckley, Ohio (a small town just south of Cleveland) celebrates the spring return of their turkey vultures with a “Return of the Buzzard” day on March 15. For the past fifty-seven years they have been greeting the returning flocks of turkey vultures as an important sign of spring. It makes more sense than Groundhog Day, that’s for sure (although it less aesthetically pleasing than Housecat Day!). But, Lower Burrell, PA has an eight week jump on Hinckley! The vultures are back!

Photo by D. Sillman

Finally, a very unwanted Sign of Spring came in on our dog, Izzy: black legged ticks!

I have removed three ticks over the past few days from Izzy. They were adult, female “black legged ticks” (also called “deer ticks,” but most properly called  Ixodes scapularis). These adult forms had been very abundant back in the Fall and some, apparently, have successfully overwintered and are still seeking the blood meal they need to make their eggs.

Pennsylvania is experiencing an ongoing population explosion of black-legged ticks. The reason for this increase is not precisely known. Possibly the increased populations of rodents (especially white-footed mice) particularly in our suburban ecosystems may be providing the ticks with an abundance of small hosts on which to feed. Black-legged ticks, then, in their larval and nymphal life stages are very likely to find a white-footed mouse from which they can take a blood meal. These mice are also significant reservoirs for the bacterium that causes Lyme disease, so the ticks that feed on them have a very high probability of assimilating and then passing on these bacteria.

The true “spring” blacklegged ticks are the eight-legged nymphs that have been overwintering since last summer. These are the “medium sized” deer ticks and very significantly they may be carrying the bacterium that causes Lyme disease. These ticks will feed on a wide range of mammals (from white-footed mice to dogs to cats to deer to humans). Both dogs and humans are susceptible to Lyme and both are experiencing out of control epidemics of the disease!

So, bees, stink bugs, vultures and ticks! Quite a quartet of Spring! I hope to see some crocuses, red maple flowers and flocks of robins and bluebirds soon, too!

 

 

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Signs of Winter 11: Oaks and Acorns

Photo by Jamaine Wikimedia Commons

Oak trees use their acorns to “fly” or “stride” (or hop or run) from one habitat to another. I now have a yard and field with twelve young oak trees (a mix of white, northern red, and scarlet oaks) growing in the places where eight of my forty year old spruces once stood (but which were, alas, knocked down in a June 2006 microburst event). The acorns that started these trees were undoubtedly dropped from the branches of the spruces when some careless blue jay or crow tried to talk with their beaks full. The oak seedlings were quite inconspicuous under the dense branches of the spruces but have now grown into solid looking pole trees that are twenty to twenty-five feet tall.

In 1996 my daughter had a fourth grade science project in which she had to identify the trees of her yard and neighborhood. She and I wandered about on our two acres and up and down our street and identified fifteen or twenty different tree species. We saw, though, no oaks at all! Most of the trees we identified were intentionally planted and placed as the surrounding houses were built in the 1950’s and 1960’s, and a few were orchard relics of an even older, farm-related past. Great swaths of lawn was the dominant habitat type all around us, and there were very few “wild” trees to be seen anywhere.

Twenty-one years later, though, the wild oaks abound on the edges of my property thanks to careless birds and also to my personal abhorrence of weed-whackers and any need for tidiness and control in my landscaping!

Photo by D. Mullen Flickr

Let’s think about oak tree flowers and acorn production (and I am going to focus on white oaks as my example oak species): white oaks flower in the spring right about the same time as they leaf out. Here, in Western Pennsylvania, that is mid-April or so. A given tree will have both yellow, staminate flowers arrayed in dense catkins and red, pistillate flowers that are usually singular or in pairs. The staminate flowers mature a week to ten days before the pistillate flowers (a good protection against self-pollination) and in the three days of pollen dissemination winds can carry the tiny pollen grains great distances. If a pistllate flower gets pollinated it will begin to form it acorn. If it does not get pollinated, it will senesce and drop off the tree. It is possible, then, to get a good idea of the success of a year’s pollination efforts by simply observing the abscission or persistence of the white oak’s pistillate flowers during this critical time period of the spring!

Weather conditions, though, greatly influence the timing and success of pollination. Wet weather slows down pollen release, and dry winds and freezing temperatures can greatly inhibit flower development. Ideal acorn development occurs, according to Sharp and Sprague (from their 1967 paper in Ecology), when the weather is warm for the ten days before flowering and then cool for the two or three weeks after flowering.

Thinking about the extremely variable weather of the month of April, these perfect conditions are not likely to occur very frequently! Interestingly, variability in the production of acorns may be an extremely important feature of an oak tree’s overall reproductive strategy!

Photo by Dcjsr Wikimedia Commons

A mature white oak (a tree between 50 and 200 years old) can produce up to 10,000 acorns a year! That same tree, though, may produce no acorns at all in any particular year, and somewhere in between zero and ten thousand in most of the intervening years. Acorn production (also called “mast production”), then, is quite unpredictable from year to year. On average, a good acorn year (also called a “mast year”) occurs only every four to ten years. These mast years, though, are only partially correlated with the weather and with some of those flower survival and pollen formation factors mentioned above. There seems to be some other, more innate biological process going on in the oak tree that helps to regulate the overall potential for the tree to make acorns.

Which gets me to the reason I am writing this post! Back in November, my good friend from California, Larry, sent me an article from the Wall Street Journal. The Journal is not a paper I regularly read, and it is definitely not a paper in which I would expect to find a very interesting article about oak tree reproduction! However, the November 6, 2016 issue had an article entitled “Boom or Bust Breeding Cycle that Helps the Mighty Oak Survive” (by J. C. McGinty) that beautifully described the evolutionary logic employed by oaks that necessitates great yearly fluctuations in acorn production.

D. Sillman

The idea is very straightforward: acorns (especially white oak acorns) are highly desirable food for many species of birds and mammals (in fact, more than 180 species of birds and mammals eat white oak acorns (everything from crows to turkeys to blue jays, and deer to raccoons to a variety of mice!). In non-mast years almost all of the white oak acorns produced are consumed before they can germinate. The only way that an oak tree can slip a few acorns through this consumption filter is to occasionally overwhelm the system with acorns. It is only in mast years, then, that substantial numbers of acorns survive to form oak seedlings!

Last Fall in Pennsylvania we had, according to Marc Abrams (a Penn State professor of forest ecology and physiology) a “super mast year!” Abrams reported a greater mass of acorns on the red oaks around State College than he had ever seen in his thirty years of observations. Deborah and I had noticed this, too, on our local hiking trails here in Western Pennsylvania. In places with abundant oak trees it was actually difficult to walk because of all of the rolling acorns underfoot! I had to go back in my hiking notes to 2006 (ten years ago! A typical mast-year cycle!) to find references to such acorn abundances.

Photo by D. Sillman

So, there will be a lot of winter food for white tailed deer and wild turkey this year! The Journal article also makes reference to another, less welcome species that is expected to benefit from the acorn abundance: the white footed mouse. White footed mice are one of the key biological reservoirs for the bacterium that causes Lyme disease. The mice pick up the bacterium from black legged tick bites and then pass it along to more ticks that subsequebtly feed on their blood. It is expected that with a booming population of white footed mice in our woods and fields, a higher percentage of black legged ticks will be exposed to the Lyme bacterium and thus potentially carry the disease to even more humans. Pennsylvania already leads the nation in the number of Lyme disease cases per year. This new, acorn powered mouse system, though, might drive our old infection numbers into even more astronomical levels!

So, oaks go boom and bust with their acorns and by feeding so many mammals and birds get the benefit of seed transport and dispersion! A couple of my young oaks actually made some acorns this past year! I wonder where they will end up?

 

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Signs of Winter 10: Delicious Microbial Ecosystems

Photo by J. Hamilton

I have to admit something: I love bread. I think that I could give up almost any other food more easily than bread. The very thought of not having bread (for breakfast, lunch and/or dinner) makes the meals feel incomplete and inadequate.

I have kept up with the growing nutritional literature that clearly shows that calories from carbohydrates (all those sugars!) are more likely to contribute to fat deposition (insulin is the mediator of this reaction!). Much of the blame for our obesity epidemic seems to be attributable to excessive carbohydrate ingestion. I do try to limit my sugar consumption from soft drinks (I avoid them), candy and cookies (I try to be disciplined) and prepared foods (is corn syrup in everything?), but bread, really good bread, and especially homemade bread, is something that I will not give up easily.

Both of my kids agree with me (only Deborah has any restraint on bread consumption in our immediate family!). Marian and Joe gave me a bread maker for Christmas, in fact, and I have been working my way through my bread cookbook making Challah, honey bread, Vienna bread, Swiss egg bread, whole wheat bread, and more several times a week. What an amazing invention! I wish that they would come up with a comparable “beer machine” so that I could as easily add homemade ale to my regular diet.

No, come to think of it, it is probably better that beer making is as time consuming and laborious (all of that washing and sanitizing!) as it is.

As part of our new, family bread making tradition, Marian bought three packages of sourdough starter from a company based in San Francisco and gave Joe and I each one for Christmas (and kept one for herself). We decided to each start our sourdough cultures at the same time in our respective corners of America (Seattle, Albuquerque, and Apollo, PA) and then compare the breads that we eventually make.

Photo by M. Hamilton

We all began our starters (which we will call our “sponges” from now on) within a few days of each other. Joe (in Seattle) and I (in Apollo) had an immediate problem with temperature. The mixture of water, bread flour and the provided packet of dried yeast and bacteria spores had to be incubated at 85 degrees! There was nowhere in Joe’s apartment or in our house that was 85 degrees this time of year! The packet instructions, though, suggested that you turn on your oven light and put the sponge container into the closed oven. Joe tried it and I followed suit, and it works!! We’ll figure out how to replace a worn out oven light later (I hope that it is not too expensive!)! All of our sponges, though, were happily bubbling away and giving off whiffs of alcohol and sour yeast. The sourdough, microbial ecosystem was established.

So what all was going on here? Why did we have to “feed” the fermenting brew every day for a week or more? Why was the texture and consistency of the sponge changing so much? What the heck was in that little dry pack of starter?

To answer these questions in reverse: the packet contained up to seven species of wild yeast and up to five species of lactobacilli bacteria (the classic sourdough microbial array!). These yeasts and bacteria have been identified as the “sourdough agents” responsible for the distinctive San Francisco sourdough bread! The yeasts (which are, of course, unicellular fungi that are able to live in both aerobic and anaerobic environments) first break down starches in the flour to mixtures of simple sugars and disaccharides (like sucrose and maltose) and then start to work on the simple sugars and the sucrose making lots of carbon dioxide in the process (all that bubbling!). The bacteria then start working in particular on the maltose (yeast are apparently “maltose intolerant”) and break it down to lactic acid and acetic acid (significantly dropping the pH of the system!) and the process make more carbon dioxide. There are hints of other organic acids in the scent coming off the sponge (not always pleasant odors!), but these scents change and mellow as the days go by (less butyric acid and more acetic acid, I am sure!).

There is an intense battle for space and food resources between the starter yeast and bacteria species and the yeasts and bacteria that were just riding along in the flour (or had just dropped into the system from the surrounding air!). Different locations will make different microbial contributions to the sponge (hence the Hamilton experiment across the country!). The starches of the flour are being rapidly broken down (which explains the sudden liquefaction of the sponge), and this food source needs to be replenished daily (hence the daily “feeding” of the sponge with fresh flour and water). The liquid portion of the sponge, by the way, is called “hooch” (that seems appropriate based on its smell).

Photo by M. Hamilton

The yeasts and the bacteria populations swing wildly up and down, but, eventually, reach an equilibrium and form a relatively stable community. All of this takes an active week or so of feeding and fussing (all at 85 degrees F!), and, then, finally, the sponge is ready to use in bread!

When making bread the added sourdough sponge yeast and bacteria will break down some of the starches in the bread flour and produce the carbon dioxide that acts as the leavening agent to make the bread rise! The sponge will also contribute many of the acids and other exotic flavors from its complex microbial community to give the sourdough its unique flavor. Often regular bread yeast is added to the mix just to make sure that sufficient carbon dioxide of produced to make the brad light and fluffy. Too much added yeast, though, can breakdown the flavors of the sourdough sponge.

I have made two loaves of sourdough bread so far. The complex sourdough flavors were only faintly detectable in the first loaf but much more robust in the second. The texture of both loaves, though, was incredible!

Lactobacilli bacteria like the ones in sourdough are also the major microbial agent in making yogurt! A particular species (Lactobacillus bulgarius (also called “Lactobacillus acidophilis”)) mixed with Streptococcus thermophiles break down the lactose (a disaccharide) in milk generating lactic acid in the process. These acids then denature the milk proteins causing curdling (thickening) of the milk (thus forming yogurt!). The breakdown of the lactose makes the food easier to digest and the acidic environment prevents other bacteria from growing in the yogurt (thus preserving it!). Another great use of bacteria!

I am going to have a slice of bread and some yogurt for breakfast! Go microbial ecology!

 

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Signs of Winter 9: More Birds!

Photo by D. Sillman

Photo by D. Sillman

We are coming up on a very exciting, four-day weekend! (Come to think of it: what four-day weekend is not exciting?) From Friday, February 17 to Monday, February 20, birders and bird enthusiasts from over 130 countries will be participating in the Great Backyard Bird Count (GBBC). The count is sponsored by the Cornell Laboratory of Ornithology, the National Audubon Society and Bird Studies Canada and is intended to be a “citizen scientist” assessment of bird populations from all over the world. Last year 162,052 check lists were submitted by participating counters, 5689 species were identified, and a total of 18,637,974 birds were counted. Pennsylvania had 8705 checklists submitted (second only to California among the U.S. states!), and several regular readers of this blog finished high on the list rankings of both Allegheny and Armstrong Counties! Check out the web site (http://gbbc.birdcount.org/) to see more!

Photo by D. Sillman

Photo by D. Sillman

This world wide count of birds began in 1998, and it has grown in scope and in participation with each passing year. Participants are asked to spend fifteen minutes either stationary at some observation point or walking through a habitat counting and identifying the birds they see. On-line checklists developed by eBird facilitate the reporting of these observations, and the compilation of the data from the observers seems to be nearly instantaneous!

The 2016 GBBC generated some interesting observations:

  1. Three Mexican and Central American thrushes (relatives of our very familiar American robin), the white-throated thrush, the rufous-backed robin, and the clay-colored thrush, were counted along with several other Central American bird species up in the continental United States. The speculation is that these birds are moving northward in response to the warming trend generated by climate change.
  2. Common redpolls (a northern finch species) were seen in regions far to the south both in 2015 and in 2016. The areas of their occurrence, though, were quite different. In 2015, the redpolls were primarily seen in the northeastern states of the U.S., while in 2016 they were seen in the northwestern states of the U.S. The reason for this shift from eastern to more western sites is not clear.
  3. Snowy owls continue to range southward all across the continental U.S. Increased summer prey in their arctic summer ranges (due to warmer temperatures?) apparently has caused a population explosion in this extreme northern species. In the winter, when prey is scarce, many snowy owls (especially young individuals?) have to make long southerly migrations in order to find food and avoid intense, intra-specific competition.
  4. The redwing (a European relative of the American robin) was seen in Nova Scotia and British Columbia. The British Columbian bird was thought to have been pushed over to Canada from Siberia by strong, El Nino powered winds! Another reflection in the GBBC of the impact of climate fluctuations on bird populations!
Photo by D, Daniels Wikimedia Commons

Photo by D, Daniels Wikimedia Commons

Also, the pine siskins which were seen abundantly in 2015 checklists throughout the northern U.S. were only rarely seen in 2016. Possibly the reduced intensity of the 2016 winter allowed these very northern birds to remain in their preferred northern, coniferous habitats.

So what is accomplished by this Great Backyard Bird Count? Tracking the pine siskins is interesting. Tracking the southward eruption of the snowy owls is exciting (check out the website!), and just knowing how many birds are out in our wide ranging habitats is important. But, maybe most important is getting all of these people outside all at once to look at birds! That is the payoff that is priceless!

Photo by D. Sillman

Photo by D. Sillman

The species that I counted for my 2016 Great Backyard Bird Count lists were as common as could be and included all of the top ten “most frequently listed” species from the study. I saw dark-eyed juncos (reported on 63, 110 checklists), northern cardinals (on 62,323 lists), mourning doves (on 49,630 lists), downy woodpeckers (on 47,393 lists), blue jays (on 45,383 lists), American goldfinches (on 43,204 lists), house finches (on 41,667 lists), tufted titmice (on38,130 lists), black-capped chickadees (on 37,923 lists) and the American crow (on 37,277 lists). My birding experience does not range into wild, exotic discoveries. I was very happy to see my cardinals, juncos, blue jays, titmice, chickadees, and crows!

Some years ago I was giving a talk at a conference about Deborah’s and my Virtual Nature Trail and the actual, physical nature trail on our campus that was the inspiration for it. At the end of my presentation I was asked a question, “what is special, or unique about this nature trail?” I sensed an undertone to the question of “why would anyone want to go see this trail?” Usually you come up with answers to questions like this much later, but somehow I found the answer right away: There is nothing particularly unique or “special” about this trail, and this is what made it so important. It is the beauty in the ordinary, as Bill Bryson once put it “the low level ecstasy” of the common species and common terrain that make this site so wonderful. Sitting back and seeing what is around you in nature always elevates and inspires you!

And, to me, this is what makes the Great Backyard Bird Count and the sight of all of those ordinary birds that every day gobble down my sunflower seeds, corn, peanuts and thistle, so amazing.

Photo by D. Sillman

Photo by D. Sillman

Another very interesting idea about birds and bird species was described late last year in a paper published in the journal PLOS ONE (November 23, 2016). Ornithologists at the American Museum of Natural History looked at the morphological and genetic characteristics of a sampling of bird species and determined that conventional methods of defining avian species were greatly underestimating the total number of species! Instead of the currently accepted 9000 or so species of birds, this group proposes that there are, in fact, 18,000 bird species. They came to this conclusion by utilizing an evolutionary species concept rather than the currently applied biological (or ecological) species concept. The evolutionary concept of a species describes distinct lineages of gene flow rather than the ecological occurrence of an interbreeding (or potentially interbreeding) population. One of the co-authors on this paper referred to the biological concept of a species (a traditional definition in most biological educations!) as “an outdated point of view.”

I am happy to be outdated on this subject as long as we can keep talking about birds!

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Signs of Winter 8: House Cat Day #5!

Taz and Friend Photo by D. Sillman

Taz and Friend
Photo by D. Sillman

Four years ago I wrote about Groundhog Day and suggested that we change this early February day-of-prediction to focus not on an animal that is sound asleep in his grass-lined burrow dreaming of gardens to ravage, but rather on an animal with whom we could more naturally base an ecologically or culturally significant day of hope for the coming spring.

I went through the cases for using a number of different species for our new holiday. Robins, for example, are the classical spring arrival species. Also, many robin flocks spend the winter locally in close by refuges. In fact, a flock of robins just dropped into my yard two weeks ago (January 5). They explored the leaf piles while snow accumulated on their heads and backs! Then they departed and I have not seen them since. With their sudden appearances and departures, robins might not be a reliable enough species on which to base our new holiday.

Photo by P. Vivero, Wikimedia Commons

Photo by P. Vivero, Wikimedia Commons

I also suggested bumblebees as an excellent indicator species in recognition of the early emergence of the hibernating queens and their remarkable ability to generate body heat and survive (usually) that initial cold flight of early spring. If we force the queen bumblebees out on early February flights, though, they probably would all freeze to death. Not a very happy thought for a day of celebration!

I also thought about scarlet tanagers as a species representing the long distance migrators that return to our northern habitats after a winter respite in South America. The scarlet tanagers, though, will not be around until April (much too late to get any publicity about the coming spring).

Taking all of this into consideration, I settled on what was, to me anyway, the most logical and most reliable and most available indicator species among us. That species, of course, is the house cat (Felis catus). Our cat, Mazie, is pictured below.

Photo by D. Sillman

Photo by D. Sillman

Cats are the most popular house pet in the United States (the Humane Society estimates that there 74 to 86 million house cats in the U.S. (as compared to “only” 70 to 78 million dogs)). As I wrote in my November 24, 2016 blog (“Our Other Best Friend”) cats have a complex relationship with humans and may be the only animal species that has chosen us as a co-evolutionary partner rather than vice-versa (hence the hypothesis that cats are not really domesticated at all but are wild animals exploiting our habitats and resources!). The resemblance of domesticated cats to their closely related wild species, the focus of many cats on places rather than people, and their perceived aloofness and self-absorption are factors that cause people to have intense feelings (both positive and negative) about cats.

A cat’s inherent love of sunshine and warmth, though, make them a perfect biological agent to help us predict the nearness of the coming warm seasons! And, since they are living in our houses year round, they are available for predictive experimentation!

Photo by D. Sillman

Photo by D. Sillman

Four years ago on February 2, 2013 I took Mazie out into the snow-covered front yard (I tried to take both of my cats, but Taz sensed that something was up and disappeared into one of her magical hiding places somewhere in the house). I put Mazie down in the yard (on a nice dry towel!), and left the front porch door open. If Mazie ran for the porch, then we would have six more weeks of winter. If she stayed on her towel or started walking around in the yard thus avoiding a dash back into the house, then spring was just around the corner.

I was amazed how fast she ran back into the house! But, that year the weather suddenly turned warm by late February. March temperatures set record breaking highs (I even remember a day when it nearly got up to ninety degrees!).  Maybe our predictive model was not articulated correctly.

In 2014 and 2015 I followed the same experimental procedure, and Mazie, as I reported on this blog, responded with equal speed and agility and got back into the house almost before Deborah could take the lens cap off of her camera. In both of these years winter hung on grimly well into March. Mazie’s predictions, then, fit the observed phenomenon.

In 2016, though, Mazie’s response to the front yard was entirely different. She stepped off her towel and explored the front flowerbed, jumped at some little Pardosa spiders that were running around in the grass and seemed to enjoy herself very much. The early onset of spring that this behavior predicted came about! We had a mild, pleasant March and April and eased our way into a warm early summer.  Mazie had delivered in three out four years! She should get a job with The Weather Channel!

We’ll find out on Thursday, February 2 if Mazie’s weather predictive abilities continue to prevail!! She will return to the front yard for our fifth experimental trial. Deborah will have her camera all ready to record the action! I am sure that Mazie will do her best for us all!

Photo by M. Hamilton

Photo by M. Hamilton

By the way, my daughter who lives in Albuquerque also plans to put her cats (Mora and Bella) out on House Cat Day (Mora and and the much missed Binx are pictured to the left). The predictive model is slightly altered down there in warm, sunny New Mexico, though. When her cats go outside into the southwestern sunshine they typically do not come back into the house until it is time for dinner. In early February, the New Mexico spring has already started! In order to make House Cat Day a worldwide event, we may need to adjust the timing model in order to compensate for variations in latitude.

Send on your own experiences and observations!

Happy Winter, everyone! (But, it’s almost time to start thinking about Spring!)

(House Cat Day 2017 is once again dedicated to Taz and Binx. They will be greatly missed forever!)

 

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