Category Archives: Natural History

Sky Islands

2019 Trip to Southwest United States, Arizona, Arizona Photos, Bio-Diversity, Birds, desert, Natural History

There are many sky islands in Arizona.  Madera Canyon was one of them. Madera Canyon is located on a sky island. We went there after the debacle of Tucson’s Festival of Books. Sky islands are  incredible mountain ranges that rose up abruptly out of the desert lowlands without  foothills.  The mountains seemed to be  emerging out of the earth as if by magic.

Later I learned more about this phenomenon.  I learned that such mountains usually had an elevation of between 6,000 and 8,000 feet. I also learned that these mountains which looked like islands in a sea of grass or sea of desert scrub actually had an abundance of wild life.  These islands include most of Arizona’s biotic communities. They are among the most bio-diverse ecosystems on the planet. They are often the meeting place between desert and forest and everything in between. It is precisely that diversity that attracts wild life, especially birds. That is why these sky islands contain well over half the bird species in all of North America.  Not just Arizona. They also contain 29 bat species, more than 3,000 species of plants, and 104 species of mammals.

 

Sky Islands are havens of biodiversity. That is really their most important feature.  When you move into these “islands” in the desert there is an astounding range of biodiversity.  As Gary Paul Nabhan said, “In fact the “sky islands” of southeastern Arizona and adjacent Sonora are now recognized by the national Union for the Conservation of Nature as one of the great centers of plant diversity north of the tropics.”

The reason for that diversity is of course the great variety of topography in the state. That produces a wonderful variety of life, both flora and fauna. As Nabhan said, “When we compare our desert with others, the contrast is striking. Overall, the Sonoran Desert has the greatest diversity of plant growth forms–architectural strategies for dealing with heat and drought–of any desert in the world.”

The Sonoran Desert is certainly not the bleak and barren place that many expect–and sky islands are the apexes of diversity.

What makes Madera Canyon so special is the creek at the bottom. It traverses  4 life zones and many habitats between the desert floor and the mountain tops.  It has become world famous for its diverse flora and fauna. According to the Friends of Madera Canyon, “the variety of climates within 10 miles is similar to that found in driving from Arizona to Canada!”

Southwestern Arizona and this canyon are spectacular places for people who love wildlife and wild plants. This area is ranked the third best birding area in the US!  It contains some 400 birds species and especially 14 of Arizona’s 15 hummingbird species. That is more hummingbirds than any where else in the United States. But today we saw none at all.

It was interesting that the more we gained in altitude the more deciduous trees appeared and the less cactuses.   I have learned that usually in Arizona the higher the altitude the higher the precipitation so the more diverse the vegetation. Trees need the added the moisture on the higher elevations. Of course, if the mountain is too high, as in the San Francisco Peaks then there are no trees at all. Just snow. Trees, like all life is finicky.  Like Goldilocks, things have to be just right.

The landscape of southern Arizona seems dry—it is dry.  But it does get rain. In fact this region gets about 11 inches (280 mm) of rain per years. This is enough rain to allow a surprising amount of vegetation to flourish. Even wild flowers abound.  That seems impossible. It looks so dry and nearly barren. But the land is not barren—far from it.

On the day we were there an enthusiastic birder showed me a photograph of an Elegant Trogon (Trogon elegans) one of the rarest birds in the United States. A couple of years ago my brother-in-law Harv and I went in search of it but did not find. He has seen it a few times. Me never. Darn! The birder showed me a photograph he had taken of it. I was really jealous.  Later I went in search of it. I found another birder who had found it and he told me exactly where to go, but I missed it. I am an incompetent fledgling birder.    We spent some time sitting on a bench with camera and binoculars in hand. We saw a lot of birds of different species, but surprisingly no hummingbirds. Usually in the past we saw a large variety of hummingbirds here. I was puzzled by their absence.

House Finches are interesting birds because they were released in the eastern part of North America by people who brought them from Europe in the 1940s and now they have spread over most of North America including Arizona and Manitoba.

 

Acorn Woodpeckers often drill small holes in trees in the autumn to insert their acorns. Often their “granary trees” are used over and over again and contain thousands of acorns. Aren’t birds weird?

Mexican jays have co-operative breeding where the young from previous years help the parents to raise the new young.  Nature is not just competition, sometimes it involves cooperation.

 

The oldest plant in the Sonoran Desert–maybe the world

2019 Trip to Southwest United States, desert, Natural History, Plants

 

 

Creosote Bush (Larrea tridentata.)

 You would have to be a much better photographer than I am, to make this inconspicuous plant look interesting. But it is interesting. Very interesting. It is probably the most interesting plant in the Sonoran Desert. They are very common. Ubiquitous I would say.

It isa shrub or  bush. But, it is a perennial bush that has some amazing properties. It can live for up to 2 years without rain. Today it did not have its tiny yellow flowers. They have already turned into tiny fruit.  These plants are believed to be among the oldest living plants. Some are as old as 11,000 years old! That is older than the Old Testament was written. That is older than the pyramids. Archaeologists believe Egypt’s large pyramids are the work of the Old Kingdom society that rose to prominence in the Nile Valley after 3000 B.C. Historical analysis tells us that the Egyptians built the Giza Pyramids in a span of 85 years between 2589 and 2504 BC. Is it possible that a creosote bush is twice as old as that? At least one such plant was carbon dated to be more than 11,000 years old.

Creosote is the probably the most drought resistant perennial plant in North America. It must be to survive in a desert for that long.  And we humans think we are smart? As humans we naturally value what we do. Does anything we do compare with this? This was an old friend worth cherishing. I tried to show I appreciated it.

Is Arizona the “Sweet Spot” of Nature?

2019 Trip to Southwest United States, Arizona, Natural History

This is the Colorado River before it reaches the Grand Canyon in Northern Arizona

 

Sean, our extremely young and extravagantly enthusiastic “banker,” at least for today, asked us if we realized that Arizona was nature’s sweet spot. By that he meant that the rest of North America suffered recurring natural disasters. But not Arizona. The west coast has frequent tsunamis. The east coast has hurricanes.  The mid-west has tornados. The north of course has bone-chilling cold and blizzards. Arizona escapes all these calamities. Hence it is in the sweet spot. He admitted they have infrequent dust storms and heat stroke victims, but nothing serious. That may be true but the future effects of climate change may make these events more frequent and more serious.

Of course, even more importantly, he ignored the fact that Arizona is DRY. It is so dry here that it is really unlivable. Phoenix gets 40% of its water from the Colorado River, which is being depleted. It no longer reaches the Pacific Ocean as historically it did. It is dry long before it reaches the coast. Too many straws are slurping that water. The States and Indigenous groups and municipal governments  draw from the Colorado River  pursuant to an anachronistic formula set out by a complex agreement made with all those organizations. In fact the federal regulator has given notice that unless the parties are able to successfully renegotiate that agreement by agreeing to reductions, it will impose a new formula upon them. The deadline for renegotiation just passed and a near agreement was reached. It is likely that a temporary solution will be reached, but it also appears further painful reductions will have to be renegotiated again within a year because of the historic 19 year drought in this area.

The rest of the water is obtained by drawing from aquifers that are also being depleted and  recycling captured water.

The real problem is that there is not enough water for all the people and livestock in this region. And the population and livestock numbers keep rising. This region, I suspect is in for a much bigger problems than the occasional blizzard.  It may not be the “sweet spot” for long.

Hummingbirds: How Smart are they?

2019 Trip to Southwest United States, Birds, Hummingbirds, Natural History

 

 

After our adventures on the highways we did make it safely to our rented home in San Tan Valley Arizona. Our first Arizona friends to visit us were the hummingbirds. They arrived the first day we were here and went directly to the same spot we had our feeder last year before we had time to set it up.  How smart is that? I don’t think anyone has fed them here for 9 months!

As we were reading in the backyard, we saw an intense aerial display that could match any of the dogfights in either of our World Wars. Two Anna’s Hummingbirds conducted this military exercise. They flew after each other for so long that mostly they had no time to dine on the nectar we provided. That is not very smart! I did get a couple of photos of one of them in one of the few moments when he stopped to drink, including the image above.

Humans have a strong tendency to think they are better and smarter than everything else. Many of us believe that God made this world for humans to rule. The world is subordinate to us. Sometimes however, humans should learn a little humility.

I have watched a few astonishing nature shows on television about hummingbirds. One of them was about  Andy Hurley and his research partner Sue Healy who study hummingbirds. In particular, they study rufous humming birds, astonishing little birds with brains the size of a grain of rice. Yet even these birds are smart–very smart. Their hearts can beat at more than a 1,000 beats per minute! Their wings beat at more than 70 times per second! All of that requires the expenditure of an enormous amount of energy. How do they get that energy? Well they need to be smart to find it.

         Hurley and Healy found that in the lab birds like this do surprising things, but not nearly as surprising as the things that the birds do in their environment. That is where their intelligence really shines. They set up a number of fake flowers for the real birds. Each a different colour. They created a pattern of cardboard disks on top of sticks or poles stuck into the ground to resemble flowers. These were artificial flowers filled with a sucrose solution that resembles nectar.  The birds were actually offered slightly better food than they would get in the wild, in order to keep them interested. “Being smart birds they recognized a good thing when they saw it.” They kept coming back for the nectar of the gods. “Not only do they see it; they remember it,” Hurley said.

Because male rufous hummingbirds are so territorial, the same bird comes back to the cafeteria over and over again. As Hurley said, “A Male rufous hummingbirds has hundreds if not thousands of flowers in its territory. As a result, he has to remember where good food is, and where he has just visited.” That takes serious smarts! As Healy said, “they seem to know where a flower is after one visit. One visit! And we are still asking ourselves how do they do it?” Remember that is one visit among hundreds or even thousands of flowers! That also takes serious smarts. No doubt this is far beyond my capacity. But that is not all. They are even smarter than that!

As David Suzuki, who presented the show, said, “Its not just bird brain power, its biology. Hummingbirds have such a high metabolism they cannot afford to waste precious energy looking for food.”

People need a meal every 3 or 4 or 5 hours. “Hummingbirds are thinking I need a meal every 10 minutes! They have to make decisions that are really important, and if they don’t do it well they die. ” If we miss MacDonald’s we can always go to Wendy’s down the street. It doesn’t much matter to us. We have the time to make mistakes and correct them. Hummingbirds don’t have the luxury of much time. They cannot make a lot of mistakes.

Hummingbirds have another big problem–that is biodiversity. Normally that is a good thing for all of us, but for hummingbirds in the wild that can be a serious obstacle. In the wild, unlike the nectar Café the scientists could create, flowers replenish their nectar at different rates. In the experiment the scientists mimicked this diversity. The question then became can the hummingbird figure out which fake flowers are empty and which are filled with sucrose solution? The scientists were shocked at how well these tiny birds with their tiny brains did in the wild.

For half the flowers, after a bird visited, the scientists waited 10 minutes before replenishing. The other half of the flowers were refilled after 20 minutes. So a bird came in, visited 3 or 4 flowers, then went away and came back 10 or 15 minutes later, and then the bird must decide which flowers have not yet given up nectar and which ones will have it already. That is no an easy test. I would not want to take this examination, particularly if my life depended on it. Hummingbirds have no choice. They take such tests every day, over and over again. As a result the scientists  saw a hummingbird that had already sipped from 2 flowers. Then when it returned it headed straight for a new one. After a day of doing this, the hummingbird had a remarkable ability to separate out the 10 minute and 20 minute flowers. The bird must treat them differently.

Scientists call this episodic memory. I am glad I heard this expression. That is because I know I will forget it. That’s because I have so little of it. “They have to remember not just the what, and the where, but the when.” As Suzuki said, “this is a cognitive skill once thought to belong only to humans.” How wrong can we get?  How stupid are we? At least in comparison to these little birds with their minute brains.

Hurley described this well, when he said, “I would need a clipboard and pencil and 8 different stop watches for hours and hours and hours. Yet the birds are able to do this, seemingly without effort. They are smarter than me.” They are astonishing creatures and we have underestimated them–forever. As Healy said, “These birds have extraordinarily small brains and yet they do things that we find phenomenal.”

Naturally, that brings up an important question, ‘when it comes to brains does size matter?’  Humans are a good example of species where the size of brains does matter. Humans have very large brains for the size of their bodies and humans have an astounding capacity thanks to their brains. Well some of us at least.

The question was, ‘can a hummingbird outsmart a human?’  It seems unlikely. Andy Hurley is still amazed by hummingbirds after studying them for more than 25 years. Hurley said, “I’ve been humbled by these birds.” That was a lesson he wanted to pass on to his students. Humility is good.

Hurley did an experiment that required his students–smart University students–to forage like a hummingbird at the University of Lethbridge. He set up a memory test with candy instead of nectar. This one was to test the students. He had 8 paper cups.  4 of the paper cups were visited by students earlier. He asked the students to go to the cups that they had not yet visited to determine if they had candy hidden underneath them or not. One would think humans could do this easily. After all, humans have huge brains, and university students are thought to be the best of the best. The Students did pretty good. They got it right 75% of the time. This was the same as hummingbirds!

This made Professor Hurley say to his students, “You have brains that are 7,000 times larger than hummingbirds. My question is what are you doing with all those neurons? Why are you not scoring better than an animal that has a tiny, tiny brain?” The students chuckled. They chuckled at themselves that is.

Why are hummingbirds so smart? According to Professor Hurley, “the answer is that there is intense natural selection of hummingbirds to get this right because if they don’t they die.” Now humans have figured this out. They are pretty smart too.

Lac Pink

2018 Trip to Ottawa, Geology, Natural History, photography

 

 

 Lac Pink

 

Gatineau Park is beautiful–that is actually a pitiful understatement–but it is much more than that. It is fascinating. The same goes for my favorite lake in the park.

There are more than 50 lakes in Gatineau Park, including Lac Pink, (or Lake Pink as it is more prosaically called in English),which is  my favorite. It is one of only 58 known meromictic lakes in North America.  A meromictic lake is a lake where the upper and lower layers of the water in it never mix. That seemed very strange to me.  Normally a lake’s waters mix all the time especially during spring and autumn when the water density and air temperature distribute nutrients and oxygen throughout the lake, more or less evenly.

The water of Lac Pink doesn’t  mix like most lakes because it has a relatively small surface surrounded by steep cliffs that protect it from the wind which would otherwise mix the waters. As a result there is no oxygen in the deepest 7 metres of the lake. The deepest part of the lake has not has not been in contact with the air since the last Ice Age 10,000 years ago. That amazed me.

The lake is beautiful but it is not pink. It is named after the Pink family which were the first non-indigenous owners of it. The lake is actually green, not pink. The reason it is green, a gorgeous green in fact, is because of the presence of microscopic algae. The beautiful green colour is actually a bad sign. The green algae gradually takes over the oxygen in the lake suffocating the life in it. This is a natural process called “eutrophication” which ordinarily takes thousands of years.

However eutrophication can be affected by human activities. For example, Lake Winnipeg is suffering from it because of runoff from agricultural lands, sewage deposit by the City of Winnipeg as well as other municipalities  into the Red River, and other causes.

Because Lac Pink is so popular (I am not the only one who loves is), people have sped up the natural process of eutrophication. At one time eutrophication was  happening so fast it was estimated it would be complete within decades rather than a thousand years. As a result the lake has been rehabilitated. Humans caused the problem and now have come to the rescue of the lake. We can be a force for good or ill. The choice is ours. Conservation efforts have included building platforms and a trail to limit damage by erosion. Volunteers have also helped to plant 10,000 small trees.

Since there is no oxygen at the bottom of Lac Pink there is really only one organism that is able to live there without oxygen. This is a a prehistoric anaerobic organism. It is a pink photosynthetic bacterium, which uses sulphur instead of oxygen to transform sunlight into energy. Imagine that. It transforms light into energy even though it does not photosynthesize. This lake is endlessly fascinating.

Higher up in the lake resides the three-spined stickleback fish, a saltwater fish left behind from the Champlain Sea, which used to cover the region. This little saltwater fish adapted to the lake’s gradual desalination and today lives in the lake’s fresh water.

The Champlain Sea was a temporary inlet of the Atlantic Ocean that was created by retreating glaciers just after the last Ice Age. The Champlain Sea once included much of the land that is now part of Quebec and Ontario and even parts of New York and Vermont. The huge continental ice sheet that covered much of North America during the last Ice Age was so heavy that it depressed much of the rock beneath it. When the Ice Age ended the St. Lawrence and Ottawa River valleys were so low that they were actually below sea levels. These areas flooded with sea water when those massive continental ice sheets from around the world melted and raised sea levels substantially, once those ice sheets no longer dammed the oceans back.

Then the land gradually rose as the Ice sheets were removed. This is called isostatic rebound and is still happening to this day all over Canada, including for example, Lake of the Woods where we have a cottage. The Champlain Sea lasted for about 3,000 years from 13,000 to 10,000 years ago. As a result the sea coast gradually retreated to its current location. Of  course, since the process of isostatic rebound is not yet complete, those coastlines will continue to change. This process will now also be affected by rising sea levels due to climate change. This area, as so many others around the world, will be in for interesting times, not all of which will be benign.

The remaining glaciers fed the Champlain Sea making it more brackish than typical sea water. It has been estimated that the Champlain Sea was as much as 150 metres (490 ft.) higher than the level of the St. Lawrence and Ottawa River valleys today. Scientists are so smart to figure all of this out.

There is much evidence of this former sea including the clay plain deposited along the Ottawa and St. Lawrence Rivers that have resulted in such interesting forest types that I travelled through on this trip as well as large wetlands that are home to amazing vegetation, including my favorite, orchids. Other evidence of the sea includes whale fossils and marine shells that have been found near Ottawa and Montreal.  There are also fossils of other oceanic fish such as capelin.

This entire notion of an ocean in this area is astonishing. About 11,000 years ago when the land was so low after the Ice sheets were gone from southern Canada, the Atlantic Ocean rushed into the St Lawrence River Valley filling even the area of current Ottawa with ocean water. In other words, a mere 11,000 years ago there would have been bowhead whales and seals swimming above where we were standing today. I am always amazed that much of Manitoba at one time was the bottom of an ocean, but that was 450 million years ago! Comparatively, 11,000 years ago is just a blink of an eye ago.

Nature constantly astounds! Gatineau Park is an example of that.

2 Incredibly rare species in 1 Day

Natural History, Orchids of Manitoba, Wild flowers of Manitoba

After our return from Iceland, and after realizing I had missed 2 of the best wild flower weeks of the year I was very anxious to get out and see some flowers.  I was not disappointed. In fact it was one of my most amazing natural history jaunts ever! In one day, I saw 2 of Canada’s most rare species—one a flower and one a butterfly!

First I drove to the Tall Grass Prairie Preserve, one of my favorite places. I immediately walked towards the site where the Western Prairie Fringed-orchid (Platanthera praeclara) appear every summer. I was not disappointed.  This is the best place in the world to see this orchid. These orchids used to be fairly common on the prairies but have disappeared with the disappearance of their habitat. I had a little more trouble than normal finding the flowers. That was a bit disconcerting. Where were they I wondered? I soon realized that there were many flowering plants, but all of them without exception were small and short. No huge plants jutted out to the sky as they typically do.  I inferred that this was a result of very dry conditions this spring and summer. The prairie was dry and I concluded the flowers were keeping a low profile in order to conserve their energy and water. I just had to look a little harder to find them, but they were there.

 

 

I quickly set about trying to photograph them. Conditions were tricky. The sun was harsh creating deep shadows. Added to that problem, it was very windy. Trying to photograph these flowers was indeed challenging. I think I did a reasonable job under these difficult circumstances.

When I was done I also noticed a young lady in the field. I had been too absorbed to notice her.  Too absorbed in the flowers to notice a young woman. Imagine that. So I sauntered over (OK I meandered over) to talk to her. What was she looking for? I presumed the Western Prairie fringed too, but I was wrong. She was looking for a butterfly. A very rare butterfly.

She explained that she was employed by the Nature Conservancy of Canada and she was doing a survey of a very rare butterfly called Poweshiek Skipperling (Oarisma poweshiek) (Parker, 1870).  She informed me that this butterfly could be found in only 1 place in Canada and this was it. Just like the Western Prairie Fringed-orchid that is found no where else in Canada. What a double header! I was very fortunate.

Were it not for the woman who worked with the Nature Conservancy there is no doubt I would not have found this butterfly. I had never heard of it before. I actually got only a fleeting look at it as it flew past a larger Fritillary butterfly. She said the skipperling loved Brown-eyed Susans and there were many of these wild flowers here, as I knew.

This skipper is very dark brown, with an orange suffusion along the costa. Below, the hind wings are dark greyish, with white-lined veins. The wingspan is only 24 to 30 mm. According to The Butterflies of Canada by Ross A. Layberry, Peter W. Hall, and J. Donald Lafontaine. University of Toronto Press; 1998 its range is in just a few states west and south of the Great Lakes as well as south-eastern Manitoba—i.e. here. There is only one generation of this butterfly each year and they  have been found in Manitoba between June 23 and July 8. That is not a very large window of opportunity.

It was discovered here in July of 1985, at about the same time as the Western Prairie Fringed-orchid was discovered here. It is believed to becoming scarcer all the time. The problem of course is that its habitat is becoming scarcer. The woman was very pleased to see a specimen that was a pregnant female that appeared to be in very good shape. Hopefully it would produce offspring.

By another amazing coincidence later in the week I read an article on this butterfly that I have never heard of before, in the Winnipeg Free Press. The article reported that 6 more Poweshiek by the Assiniboine Park Conservatory this week. That sounds like a puny number, but scientists estimate there are only 100 of them left in North America! This may be the most rare species I have ever seen!

The Assiniboine Conservatory had bred the butterflies over the winter in captivity. Last summer the conservancy brought 2 wild female Poweshiek skipperlings  to the Assiniboine Park Zoo for 3 days to lay eggs before releasing the 2 will females back into the wild.

Once the eggs hatched, specialists monitored the caterpillars in a climate-controlled incubator over the winter.  In the lab they placed the skipperlings in a n incubator at a constant temperature of -4ºC to mimic conditions in the wild where normally they would spend the winter under the snow.

The program was very successful. “Every caterpillar survived the winter.”[1]I was extremely lucky to have met this scientist and seen this rare butterfly. What an amazing day on the prairie!

I did not get a good look at the butterfly. It was very small and whizzed by me and I had no chance to photograph it. What a pity.

Other flowers I saw included the following: Western Wood Lily, Creamy Peavine, Common Milkweed, Swamp milkweed, Brown-eyed Susan, Heal-All, andPurple Prairie Clover.I was in heaven, but my luck had only begun.

 

Western Wood Lily or Prairie Lily

 

 

Purple Prairie Clover

What a great way to return to Manitoba. I am blessed.

[1]Erik Pindera, “Endangered butterflies released into wild,” The Winnipeg Free Press, July 5, 2018 p. B3.

Arctic Terns

2018 Trip to Iceland, Birds, Natural History

 

We saw a colony of Arctic terns in southern Iceland. One of these birds attacked me. I guess I got too close to its nest. They are very protective.

One of the most fascinating aspects of birds is their ability, often truly amazing, to migrate, often over amazing distances, and in amazing circumstances.    Why do birds, unlike most animals migrate in the first place?  How do they navigate?  How do they know where to go?   How can they migrate so far, often under very adverse conditions?  In fact, to me the very notion of migration is a vast mystery that I will never understand, no matter how much I learn about it.   Just as one example, among many, some species of shorebirds, a relatively short time after giving birth to their young abandon them to their own devices while they fatten up for the long migration.  Then the adults head south many thousands of miles away, often to South America.  Amazingly, the young, who have never been anywhere in their short lives other than northern Canada, fly south on their own without any guidance from the adults, and turn up at the same place as the adults some weeks behind the adults.  How do they do it?  It is very difficult for us mere humans to fathom such incredible abilities.  It is a profound mystery.

Why does the Arctic Tern migrate literally from one end of the earth to the other, and then later back again?  What drives the bird to do that?  Why do they travel so far to go from one seemingly inhospitable place to another?  I will never understand these things, but will never tire to trying.

Some recent information about Arctic Terns is just downright amazing. The Arctic tern is justifiably famous for its astonishing migration. It is one of the most astonishing stories in a natural world filled with astounding stories. It flies each year from its breeding grounds in the Arctic in the spring and then back again after the summer. The shortest distance between these two points is 19,000 km (12,000 mi). This is the longest migration of any animal in the world! It flies about 2 times farther than scientists earlier believed because its route is not straight. It meanders.

Recently scientists have been able to install very small transmitters onto them so that their track could be monitored. One Arctic tern followed a zig-zag pattern from Greenland to Antarctica and back again each year and in the process racking up 44,000 frequent flyer miles (or 71,000 kilometers), as National Geographicdescribed them.  This is 4,000 miles or 6,440 km more than its nearest competitor the sooty shearwater. The researchers who found out this new information estimated that because the birds often live to be 30 years old over their lifetime they travelled about 1.5 million miles (2.4 million kilometers) which is equal to 3 trips to the moon and back![1]

Until recently scientists could not find a tracker light enough to be carried by a tern. Now they use one that is 1/20thof an ounce or 1.4 grams. The researchers also learned that terns often stop for month in the open Atlantic Ocean possibly to “fuel up” on small fish and crustaceans before continuing their awesome (for once that word really does apply). Even more surprisingly, they don’t take the shortest route. Instead they zig and zag literally across the ocean and back again! Some wondered why they would zigzag so much. For example, the terns from Greenland don’t fly straight up or down the Atlantic. Instead they “hopscotch from Antarctica to Africa to South America to the Arctic.”[2]Even though this is a detour of several thousand kilometers because they zigzag across the Atlantic Ocean, The birds appear to be following huge spiraling wind patterns in the atmosphere, avoiding flying into the wind,” according to Carsten Egevang one of the researchers.[3]

Though scientists are not sure why these amazing birds take such a long journey nearly from pole to pole, they believe it must be that the terns find rich feeding grounds in the waters of the poles. Why else would they do it?

 

 

[1]“World’s Longest Migration Found–2X Longer Than Thought,”National Geographic(Jan 2010)”

 

[2]“World’s Longest Migration Found–2X Longer Than Thought,”National Geographic(Jan 2010)

[3]Carsten Egevang, “World’s Longest Migration Found–2X Longer Than Thought,”National Geographic(Jan 2010)

Deserts

Natural History, religion

 

What is a desert? That is not as simple as I thought. Deserts are defined by water—or rather, by the absence of water. Dryness and sunlight are what deserts are all about. Buckets of sunlight, rather than buckets of rain. Plants or animals that don’t like that cannot survive here. Some plants, amazingly, even prefer the south facing side of the mountain.

Geographers define deserts as land where evaporation exceeds rainfall. I was surprised to learn that there is no specific amount of rainfall that serves as an agreed upon criteria as what is and what is not a desert. Deserts range from extremely arid regions to those that are ample for the support of life. Geographers classify rainfall into semi-deserts that are ones that have precipitation between 150 and 300 to 400 mm per year. So called “true deserts” are those that have rainfall below 150 mm per year and extreme deserts as those with rainfall below 70 mm per year.

Deserts occupy about 26% of the continental areas of the world. Deserts occur in 2 distinct belts. One is between 15º and 35º latitude in both the Northern and Southern hemispheres—the Tropic of Cancer and Tropic of Capricorn.

There are 14 deserts in the world (depending on who is counting) with an area larger than 52,000 sq. km (20,100 sq. mi.). It may surprise some that the largest desert in the world is not the Sahara desert. It is only the second largest. The largest is Antarctica not often thought of as a desert, but that is what it is. Antarctica has 14,000,000 sq. km. and the Sahara with 9,000.000 sq. km.

There are 5 distinct deserts in the American Southwest: the Sonoran, The Chihuahuan, The Great Basin, and the Mojave. Some also include the Colorado as a separate desert. Although each is a desert, each is also different.

The Sonoran Desert, where we have been living for the 4th year,  is semi-arid desert and it covers part of southern California and Arizona as well as northern Mexico. Because of summer’s “monsoons” and winter storms this is the wettest of all the North American deserts. It is most well known for its iconic tall Saguaros cactus some of which can reach 50 feet in height.

The Great Basin is the most characteristic of the Southwest with its canyon, mesas, buttes, and cliffs.

The Mojave Desert is a large desert that spreads across northern Arizona, Nevada, and California. It is dry most of the year but a small amount of winter rain can bring it to life.

The Chihuahuan desert is found mainly in Mexico but reaches north to Albuquerque, New Mexico, so we spent some time in it too.

One of the things that struck me about the desert was the amazing way that plants grow there. If you have a pine forest, unlike our pine forests, the trees are not crowded. They are well spaced. Where shrubs cover a mountainside, they do so in the most spotty of fashions. Vegetation never covers the ground, even where it grows best. The plants demand space from all around them—like snooty royalty.

The plants even want some separation from those fantastic rocks that I love so much. Usually they are found well-spaced, like surprisingly obedient school children. Willa Cather put it well. She said,

From the flat red sea of sand rose great rock mesas, generally Gothic in out-line, resembling vast cathedrals. They were not crowded together in disorder, but placed in wide spaces, long vistas between them. This plain might once have been an enormous city, all the smaller quarters destroyed by time, only the public buildings left.