About Sue

I am a retired biology professor who has taken up photography to showcase the wonders of nature in my own backyard.

Thank the trees

Each year as Thanksgiving rolls around, I renew my gratitude for the special people in my life. But I usually don’t remember to give thanks for many of the things I just take for granted. So this year, I’m thankful for trees…for the many ecosystem services they provide — for FREE.

…for forests that enrich our lives and uplift our moods as we wander their winding paths.

Forest of Nisene Marks, Aptos CA
Oak forest, University of California Berkeley

…for vast tracts of unending vegetation that pump oxygen into our atmosphere and remove carbon dioxide, helping to manage the climate.

Tropical rainforest of the Panama Canal
Temperate forest of the Porcupine Mountains, Michigan

…for forests and other vegetation that filter runoff to maintain clean water in lakes and rivers and prevent soil erosion

Wolf river near Rhinelander WI
Grass lake slough, Shoreview MN

…for trees that provide food and shelter for wildlife (and food and building materials for us)

My front yard apple crop
A fanciful look at forest animals (composite of many images)

…for forests that improve our urban landscape by providing shade, lowering the air temperature nearby, buffering noise, air, and light pollution, as well as providing a mental and physical escape from the urban jungle.

Central Park, New York city (photo from Architectural Digest)

this post dedicated to daughter Becky, an ecosystem services specialist.

Short days and fat bears

What do these animals have in common during the fall months?

A Black Bear scrounging for goodies on the forest floor in the Grand Tetons, WY, in September 2016. Black bears consume prodigious quantities of food before retreating to their dens for their winter “sleep”.
One of my many chipmunk friends that live in the backyard. This one had its cheeks stuffed full of sunflower seeds and peanuts from the bird feeder — probably taking them down its burrow to add to the food stores for the winter.
A female (or juvenile) Yellow-rumped Warbler was chowing down on Juniper berries in late September. The berries are consumed whole, but the bird’s digestive tract will separate seeds from pulp and excrete the seeds, while cleaving off and digesting the waxy coating of the fruit for a few extra calories. High sugar and fat diets help these migrants put on body fat quickly before they migrate.
Not all Robins migrate — some stay here all winter. But those that do fly south seek out the high carb fruits like crabapples and service berries that allow them to build their fat stores up quickly.

The answer to the question above is that all of these (and many more bird and mammal species) exhibit excessive consumption of food in the fall, technically becoming hyperphagic.

There really are only a few viable solutions to surviving the long, cold winters of the far north: 1) get out of town — migrate! 2) build fat stores to last you several months and sleep as much as possible, and 3) stay active to search for what little food remains, tolerate the cold, but enter a starvation state by metabolizing a lot of of your muscle (when you run out of fat).

The temporary condition of hyperphagia is brought on by decreasing photoperiod — i.e., the continually declining number of daylight hours in the transition from late summer to fall — that triggers the change in an animal’s eating habits. Fortunately, this also happens to be when food is most abundant with the ripening of seeds, fruits, excess numbers of young, naive juvenile animals roaming the countryside, etc. So food is easy to come by and fattening is easily accomplished by overeating.

To take Black bears as a good example of this strategy, consider the following comparisons of its diet and caloric consumption from summer to fall.

In the summer Black bears consume about 5,000-8,000 kilocalories per day. If food and water are restricted at this time, they break down their muscles for energy, may accumulate too much nitrogenous waste in their blood, and may die. They cannot “hibernate” at this time.

In the fall, Black bears become voracious, begin consuming 15,000-20,000 kilocalories and drink gallons of water per day, excreting 1-2 gallons of urine as they metabolize all those calories into fat stores. Then, they stop eating and enter a lethargic, hypo-metabolic state of winter sleep, in which their resting heart rate of 80-100 beats per minute falls to less than 22 per minute and their breathing slows down to 2 or 3 times per minute. For the duration of their winter “sleep” they don’t eat, don’t drink, don’t break down any muscle, and females give birth to their cubs. It’s an amazing physiological transformation.

This is Alaskan brown bear #901 from Katmai National Park, a winner of the Fat Bear annual contest for most immense Fall season body mass. Photo from the New York Times, Oct. 2022.

But have you ever wondered if we humans exhibit a similar response to the waning photoperiod and colder days of fall weather? It’s true that humans cannot hibernate the way small rodents do, but could they increase their consumption of carbohydrates and fatten up in the fall and then decrease their daily activity and sleep more in the winter to conserve energy — like bears do? [Side note: carb craving in the fall is a real thing for me — how about you?]

Well, here is the answer, in an article from the New York Times written more than a hundred years ago, back in November 1906. (Click on the image to enlarge it to be readable.)

Apparently, it has been common practice in some cultures (in the past?) that face temporary periods of starvation in winter to prepare multiple loaves of substantially nutritious bread in the fall, prior to beginning a routine of reduced activity and increased bouts of sleeping during long winters. Sleeping with farm animals for warmth was encouraged, I guess.

Drawing from the British Medical Journal May 3, 2000.

Favorite fall “fotos”

My favorite season of the year is almost gone now, but we did manage to see a part of the glorious color changes come through the Minnesota woods this fall. In addition to this year’s contribution (below) to my fall color postings, I wanted to share some of my past favorites as well.

Sometimes, the best photos are captured in places you’re not supposed to be — like the “park personnel only” roads in Fish Lake park, Maple Grove MN this fall. (But the local state patrolman was nice about it.)
Sandhill cranes at Sherburne National Wildlife Refuge, where thousands of cranes gathered in October 2021.
Trumpeter Swans flying over Cloud Lake at sunset in the Porcupine Mts, MI, in October 2018 was a special treat.
I caught a special ray of sunlight streaming through basswood leaves at Roy Lake SP, SoDak, in October 2020.
The Wood Ducks on a local pond in Roseville, MN in October 2021 weren’t the only colorful things there that day — the colorful reflection from the woodland trees was amazing.
Fall color along the north shore of Lake Superior in MN is always spectacular. This shot was taken from about as far north as you can go in MN before you cross into Canada in October 2016.
Fall color along the rivers of the upper Midwest is usually equally spectacular. This shot from the Wolf River near Rhinelander WI was taken on a very cloudy day in October 2017, but the lack of sun didn’t diminish the vibrancy of the color.

Picturesque Lake Bled

In the northwest corner of Slovenia, the city of Bled has one of the most picturesque, postcard-worthy lakes in Europe, complete with its own tiny island (the only island in the entire country)! Like many cities founded in the Middle Ages, Bled has a castle dating to the 11th century that towers above the city on an imposing cliff. According to some, this is the oldest castle in Slovenia, and one of the most popular tourist attractions. Doubly fortified walls surround two courtyards (an upper and lower) providing beautiful views of the lake, the city, and the countryside.

Scenic view of Lake Bled and the island from the lower courtyard of the castle.
City of Bled from the Castle wall. The Austrian border is about 60 miles to the north.
Additional outer fortifications were added to the castle in the 16th century after an earthquake damaged much of the buildings.
View of the lower courtyard and the Romanesque-style tower that was part of the original castle design.
View of the upper courtyard with its small chapel (left) and museum rooms with exhibits of castle history and various armaments.

After walking around the castle for a while, we boarded a small boat (gondola) to row out to the island. Motors are not allowed on Lake Bled, because apparently it is easily polluted. Lack of good water turnover from the few streams flowing in and out coupled with the lack of wind that could cycle water from the bottom to the top surface could make the lake water stagnant. Like some other glacial lakes formed in mountainous areas, Lake Bled is protected from wind by the surrounding mountain ranges.

At a distance, we could appreciate how difficult it must have been to build the castle on that sheer cliff. With its surroundings of high mountains (the Julian alps) and beautiful blue-green lake water, the Bled castle looks like a setting for a fantasy movie.
The flat-bottomed Pletna boat design dates back to the 12th century; each hand-crafted boat is powered by the muscles of the oarsman as he rows with his two,16-foot oars from a standing position in the rear of the boat.
The tiny wooded island has several buildings on it, including a church and a free-standing 170 foot bell tower, which sadly has NO view from its top because of the wire mesh over the windows.

Only 99 steps up to the central courtyard where the church and bell tower are located. If a couple wishes to get married in the church, the groom must carry the bride up the step and into the church in order to ensure a long and happy life together.
In addition to the beautiful and ornate interior, the church has a wishing bell. But wishes are only granted to those who can ring the bell three times with a single pull, and who truly believe in God. (Photo from Fine Stay Slovenia)

Baby dragons in Postojna cave, Slovenia

I’ve visited quite a few famous caves in the U.S., but the amazing caverns carved from karst limestone near Postojna in southwestern Slovenia are the most spectacular I’ve ever seen. They are definitely one of the Wonders of the Natural World.

We walked over the Pivka river bridge and uphill to the cave. This is the river that carved the caverns millions of years ago.
From this unassuming entrance a complex of caverns and passageways runs 24 kilometers (14.4 miles) underground. There are actually four caves, interconnected by the Pivka river, which drains through them.
5 km of the cave is open to the public, the first 3.5 of which is covered by train. The rail system was first installed in 1872, and electric lighting shortly after that. The cave became a tourist destination as early as 1819 with Archduke Ferdinand’s visit, but the cave has graffiti dating to the 1200s!
We followed a very well maintained path up and down through numerous passageways and huge ballrooms over a 1.5 km track to view a huge variety of cave formations. One such ballroom is noted for its exceptional acoustics and is so large it can hold 10,000 people. Symphony orchestras sometimes perform there.
Some of the massive rooms were several stories tall, decorated with all shapes, sizes, colors, and varieties of cave structures. The bridge in this photo was constructed by Russian POWs during WW1.
This is not an effect of multiple colored lights on the cave structures, but are multi-colored columns of stalactites and stalagmites that have fused together over centuries as mineral-laden water seeped through the porous limestone.
Pale white formations are pure calcium carbonate, and darker stained formations have manganese in them.
I thought this collection of stalagmites looked like little people.
A pure white column (called “the Brilliant”) stands right next to a chocolate brown column with thin rods that have gradually fused together. It’s fascinating to think about how the water must have dripped through here to create these shapes.

The Postojna cave system is notable because of all the animal life found there. Over 100 species have managed to survive in the dark, cold (45-50 F), mineral-rich water, including a cave beetle species, a jelly fish relative, crustaceans, pseudo scorpions, and a cave spider species. But the largest and most remarkable cave dweller in Postojna cave is the “baby dragon” or cave salamander or Olm (Proteus anguinus).

The Olm reaches 8-12 inches in length, with a worm-like body, feeble forelegs, and a short tail. It has bright pink, frilly external gills, and basically resembles the aquatic, larval stage of salamanders even when sexually mature (a condition called neoteny). They are completely blind (eyes covered by skin) but have sound and vibration detectors in their elongate head, as well as smell and taste receptors in their nose that help them find prey. (Photo from CNN travel, Dec 2021)

There was some excitement among the cave biologists several years ago when one of the large Olms began to lay eggs. It took quite a while but she eventually laid more than 50 eggs, about 20 of which hatched in about 5 months. The youngsters had normal eyes, but they regressed in size and skin eventually grew over them. When presented with small worms, Olms immediately go on the attack, hoovering them up (like a vacuum cleaner) with their elongate snout.

Photos of a few of other inhabitants of Postojna cave, from CNN travel, Dec, 2021.

Hiking in Croatia

Our next destination on this trip was the laid-back, small beach town of Opatija (pronounced o-pa-ti-a). We had a free day to explore some of the area, while others on our tour were sampling the wines of the Istrian region (northwest peninsula of Croatia). It was perfect weather for a hike in the Učka (pronounced ooch-kah) nature park, about a half-hour drive northwest of Opatija. Park personnel recommended we hike to the highest peak of the park, Mt. Vojak (vo-yak) for the stunning views of the coast. Fall color was almost at peak in the beech forest, so we followed a well-marked trail from the Učka nature park visitor center to the summit of Vojak — about a 1500 foot climb.

Our view of the seaside town of Opatija, on the northwest coast of Croatia, when we arrived the evening before the hike.
Starting up the trail, we found a wide, well-marked, not very steep path with lots of tall beech trees providing shade.
There were a few more rugged rocky sections, but the trail was just a steady climb without the high steps and boulders we usually encounter on the Sierra trails. And the lower altitude and lack of a backpack on this hike made it much more enjoyable!
We passed a few wide, level spots where a few different trails merged, but managed to stay on the correct one. There are chestnut trees in the forest here, and lots of nuts on he ground, but no rodents, that we saw, to eat them. We heard just a couple of birds, but the forest was mostly very quiet.
Finally at the top in about two hours, we found the lookout tower, which was originally built by an Austrian climbing club. The peak at 1401 meters was extremely windy and cool, so we didn’t stay long, except to take in the view.

Park personnel in the souvenir shop in the tower told us that Griffon vultures have nested in the park for the first time this year. Several pairs of the vultures (which are rare in the Balkans) have nested on a nearby island in last years, but park staffers make a concerted effort to rescue the fledglings that often fall into the bay and are not strong enough to fly out of the water.

Views looking southwest down toward Opatija were hazy. On a clear day you can see as far as Venice and the northeastern most coast of Italy. Trieste, Italy is just 50 kilometers (30 miles) west of Opatija.
The descent down Mt. Vojak was far harder than the climb to the peak. Looking toward Italy at the top of this image. Note the small clearing at the bottom of the hill above my husband’s right arm.
The trail was very steep with many loose rocks to slip on. I wished I had my hiking poles!!
You can see the steep angle of this slope, where we probably lost 1000 of the 1500 feet we had climbed.
Only one group of hikers passed us on our way up the peak. But we passed quite a few hikers on our way down that were doing the steep uphill climb to the peak from the north side, rather than the more gentle climb we did from the south side.
Here is that clearing at the bottom of the hill that I pointed out in the image above. It’s a picnic area with a small labyrinth of rocks for those who need a little meditative exercise before the big climb.
And now the easy park of the hike along the contour lines of the mountain (instead of continually crossing them) back to our starting point.
Walking along through the yellow-orange color in the beech forest on a balmy fall day was truly one of the highlights of this trip.
An on to the end of the trail — where a half mile walk on the road brought us back to the visitor center.

Limestone and waterfalls in Plitvice Park, Croatia

Croatia’s largest national park, located in roughly the center of the country, features sheer limestone cliffs that tower above emerald green water and a bounty of large and small waterfalls and cascades that rush down a series of about 16 lakes.

A series of boardwalks at the park takes you around a few of the lakes and waterfalls where you can appreciate the amazing natural processes that create this landscape.

A view from the top of the canyon — you can just barely see the fine white line of the boardwalk trail at the base of the distant limestone cliff face. The highest waterfall in the park is on the right side of the image.
The map of the Plitvice Lakes shows the natural (i.e., not man-made) dams that block the river flow to create the lakes. However, the contours and even placement of the lakes change gradually over time, as the location of dams changes.
Rainfall leaches calcium carbonate from the soft limestone rock and creates channels through the rock to feed an underground river that bubbles up into small ponds and lakes when it reaches harder rock.
The water becomes saturated with calcium carbonate which gets deposited on everything over which the water flows. Vegetation growing along the shore of the lake as well as algae and moss growing at the edge of the lake get a coating of calcium carbonate on them, forming stony barriers to water movement — i.e., dams.
Water flowing over the dams creates cascades and waterfalls that carry the calcium-carbonate rich water further downstream.
More calcium carbonate is deposited on the plants and bacterial colonies creating yet another set of dams and pools above them.
Dams are impermanent structures, because the rushing water dissolves them, only to deposit the minerals elsewhere in slower moving water.
The type of algae that bloom in the calcium carbonate rich waters of the lakes contribute to the unique color of these lakes, which actually change from aqua-colored to teal-colored depending on the season, the temperature, and the algal population bloom.
The lakes are especially beautiful in the fall when the teal green water color contrasts with the rich golds and reds of the forest vegetation.

More (Zagreb) zoo faces

There were a few European or Eurasian representatives of the mammal fauna in the Zagreb zoo, but most of their mammals were native to Africa and Southern Asia. The zoo here has done an excellent job of providing as much natural habitat for the animals as possible, while still allowing them to be easily observed by zoo visitors. Enclosures with clean, clear glass facing zoo visitors allowed photographers up-close looks at the animals, and occasionally direct contact with them looking back at us. What a treat!

Gibbon females are usually blond-brown while the males are dark brown to black. They are native to Southeast Asia and Indonesia.
There were three gibbon females in this large enclosure that featured a diverse set of ropes and limbs for them to move about on — and they did, chasing each other from one end of the rope set to the other with incredibly graceful acrobatics.
Not quite the eye contact I wanted, but close.
Meerkats are a type of highly social mongoose that live in southern most Africa in open, arid habitats. As cooperative breeders, they split up parental care duties, sentry watch-dog duty for the colony, and burrow maintenance, while colony members forage for insects or small vertebrates to eat. No interest in posing in this group, though.
But this one, probably a sentry keeping an eye on nosy photographers posed very nicely for me.
Dwarf Mongoose is another highly social mongoose species, living in east and central Africa. They forage for insects in their arid desert habitat with the help of a couple of different hornbill (bird) species. The birds warn the mongoose about the presence of raptor predators and the mongoose stir up insects that the birds also can eat. A rather nice partnership!

While we walked around the zoo, we could hear a male lion roaring intermittently. When we finally found the lion enclosure, the male was sleeping next to an old rubber tire — not exactly the perfect pose for the king of the jungle.

When the male finally started his territorial roar again, he positioned himself under an acacia, completely out of the spectator’s view.
One of three females in the lion enclosure, all pretty unimpressed with the male.
Serval cats are found throughout sub-Saharan Africa except in rainforest. Though it doesn’t look like it in this image, they are medium-sized, slender cats with very long legs. They are solitary hunters, active both day and night, locating the presence of their prey by sound and then jumping high in the air to pounce on them.

Zoo faces

Zagreb, capital of Croatia, is a bustling city of old and new — ornate buildings dating to its boom period as part of the Austria-Hungary empire and sleek high-rise skyscrapers built after the Balkan War. There is a lot to explore in Zagreb, and many unique dishes to try, but yesterday afternoon was the time to explore the Maksimir Park Zoo. The zoo exhibits were spacious, nicely landscaped areas with glass separating animals from humans, which allowed me to get some good close-ups. Birds from Europe and Africa were pretty well represented.

Hooded Crows are one of the most numerous birds in Balkan cities. They forage in flocks in open areas, garbage dumps, and gardens — not finicky eaters!
Gray Herons can be found throughout mid-latitude Europe as far east as the Ural mountains. They are the size of North American Great Blue Herons and seem to be the apex predators in European aquatic ecosystems, where they eat anything they come across including baby ducks.
Gray Herons are certainly well-named with all those gray feathers to ruffle and preen.
Eurasian, or Common Cranes are one of four crane species that are not currently endangered. They are about the same size as Sandhill Cranes, and like that species, they breed at higher Eurasian latitudes but migrate to overwinter in more southerly Mediterranean habitats.
White Storks, which we saw a lot of on our spring adventures in Spain, are found in eastern and southeastern (Balkan countries) Europe in the summer, but migrate to central and Southern Africa to spend the winter. They are notable for their rooftop nest creations that may get so large, they encompass entire chimneys.
This poor, bedraggled peafowl male had lost his glorious tail, but still had some spectacular iridescent color in his neck and body feathers. He wandered around in the zoo, free to forage in any penned area he could get into.
Eurasian Spoonbills are common and widespread across Central Europe and Asia, found anywhere there is a good supply of shelled and unshelled invertebrates to feed on. They are not as pretty as their North American cousins, the Roseate Spoonbill, but forage in a similar manner by moving their spatulate bill slowly through the water to “feel” for small fish, crustaceans, etc. swimming nearby that they then scoop up.
I thought these two African (or Gray) Crowned Cranes were the stars of the zoo birds in Zagreb. They are Central African, not Eurasian birds, but their golden crowns, light blue eyes, and red accents on the head and neck make them popular attractions at zoos.
Like other crane species, Crowned Cranes are good dancers during their courtship. I thought this pair might entertain us with some dance moves, but alas, it was just a little chase activity instead.

Sights of Sarajevo

Our Balkan adventure continued with a journey from Dubrovnik, Croatia north over rugged mountains and overgrazed valleys in Bosnia and Herzegovina to Sarajevo, the cultural, financial, and political capital of this country. The contrast between the two countries is quite stark.

Towns in Bosnia-Herzegovina that sustained damage in the Balkan War in the early 1990s had new construction next to buildings destroyed in the war that were never rebuilt, either because the owners had died or simply walked away to restart their lives elsewhere.

Throughout its history, Bosnia-Herzegovina has been a melting pot of religions and ethnicities — catholic Croats, orthodox Serbs, and Muslim Bosnians — mostly living together in cooperative tolerance of each other, with many inter-faith marriages and mixed families. In our walk through the old part of the city we found a Catholic cathedral, an Orthodox Church, a mosque, and a Jewish temple within just a few blocks of each other.

The enormous Serbian orthodox cathedral was completed in 1868, and is one of the largest orthodox churches in the Balkans.
The Sacred Heart catholic cathedral was completed in 1887 and was damaged but not destroyed in the Balkan war.
Down the street from the cathedrals is one of the 100 mosques that can be found in Sarajevo.
There are many old and stately buildings along the river that runs through Sarajevo, almost all of which suffered substantial damage from shelling in the Balkan war. Most have been reconstructed but pock marks from shrapnel dot their exterior walls in some cases.
The main shopping street is pedestrian only, lined with apartments above and small shops on the ground floor.
Further east on this street, the high rises give way to specialty areas like the leather street, the coppersmith street, and many small restaurants serving “fast” and “slow” food. Leisurely strolling while looking is the favorite past time here.

Sarajevo was the site of the 1984 Winter Olympics, when the independent Balkan countries of today were united as Yugoslavia. Life was good, productivity was high, and people felt they had good lives following 40 years of rule by their benevolent dictator Josep Tito.

And then things fell apart as the influence of communism waned, Balkan countries began to assert their independence, and Serbia made an attempt to pull it all back together. Their troops surrounded the jeweled capital of Bosnia in early 1992, and began to pound away with shells and mortars fired from tanks that lined the hills above the city for more than 1400 days, the longest siege in the history of modern warfare. The Serbs were successful in cutting off water, gas, power, and food, and more than 14,000 people were killed in the city, one third of them children before the siege ended in early 1996. In addition to the shelling from the tanks, snipers picked off civilians as they attempted to forage for food, wood, water, etc.

Photos from a museum illustrate how people gathered the supplies they needed, often walking long distances to get just a small bag of grain. Food was exorbitantly expensive and so people often traded their jewelry or other valued possessions for what they needed.
The bold red line indicates the position of the Serbian army that surrounded Sarajevo from 1992-1996. The brown smudge at the narrowest constriction of the Serbian line was the airport which was guarded by UN peacekeeping forces.

Bosnian army soldiers began constructing a tunnel from houses in the Olympic village area (asterisk below arrow) under the airport runway to a village on the other side of the airport outside Serbian forces in spring 1993 in order to bring food and supplies into the city and as an escape route for some to leave the city.

The 900 meter “tunnel of hope” was completed in 3 months in 1993. It was lined with wood, had electrical and gas lines as well as a ventilation shaft and rails for sliding carts along its entire length. But it was only about 5 feet high, which made carrying heavy sacks in a stooped posture over the almost 1 kilometer distance even harder.

A view of the farm fields and airport today, where the tunnel was dug 30 years ago.

When the war ended, the solution to representative governance of this mixed population in Bosnia-Herzegovina was the election of not one but three concurrent presidents (one Croat, one Serb, and one Muslim) who would rotate in the position every 8 months for four years, along with 14 parliaments and 136 ministries. A confusing solution to the problem of equal representation of all religious/ethnic affiliations to say the least!