A little mid-winter tropical color

Who doesn’t need a shot of color during the mid-winter blah outdoor landscape of white, brown, and gray? After a monotonous week of fog and gray weather, it was time for a visit to the indoor tropical room of Como Conservatory in St. Paul, MN. Each time I go I find a few new species that have taken up residence there.

The Tropics Room with its mammoth-sized palms, deciduous trees, and pools houses a few exotic bird species, some huge and colorful tropical fish, turtles and tortoises, a monstrous python, a leaf cutter ant colony, poison dart frogs, and a two-toed sloth named Chloe.
What a surprise to find a Sun Bittern grooming itself on a stump overlooking the turtle pond– a spectacularly-feathered bird we saw along one of the rivers of the Pantanal that we cruised in Brazil in 2019. Though it looks plain when its wings are folded, Click here to see the amazing colors of this bird.
Blue-Gray Tanagers are common in the Tropics, and are probably the top of the pecking order among the birds in the Tropics Room. They are primarily fruit eaters, and love to hang out around fruit plantations in northern South America.
Saffron Finches are actually Tanagers, not finches, and are common in South American lowlands outside of the Amazon basin. These birds are cavity nesters, and I think we saw a pair carving out nest hole into the roof thatch on one of the little buildings. They seem to do quite well here in captivity.
The Violaceous Euphonia is a striking little bird about the size of a chickadee and is a true finch. But…its diet is primarily tiny fruits, instead of seeds, like other finches. It is native to forests and second growth (including plantations) in parts of eastern South America. (photo by Debbie Reynolds)
Honeycreepers get their name from their habit of sipping nectar as a primary food source, but the Green Honeycreeper here is more fond of fruit and seeds than nectar. It is also in the Tanager family and is native to Central and northern South America.
One of the permanent residents of this forest is Chloe, a Hoffman’s two-toed sloth. Of all the times I have visited the Tropics Room, I have only ever seen her awake once, when her keeper brought her some delectable vegetation to munch on. She is more than 30 years old, and prefers to be solitary on her tree stump — she apparently bit the male suitor they introduced to the tropics room, and he had to be removed for his own safety!
A rare glimpse of a smiling sloth…
Several rather large tortoises live on the ground floor of the Tropics Room at Como Conservatory. Apparently, they really like carrots, even if they don’t seem to have the right equipment to break them up into smaller pieces.

Naughty bird

Of course I love watching birds in the backyard, but I don’t especially love what some of them do to my house. The woodpeckers are at it again, drilling holes into the redwood siding of the house and the garage. The little Downys do a lot of damage by themselves, but this morning the local Pileated Woodpecker got into the action, and started hammering on the garage with some serious blows.

Incoming male Pileated Woodpecker. There has always been a resident pair of Pileated Woodpeckers in the far backyard, and they are frequent winter visitors near the house to check out the bird feeders.
He looks around, doesn’t see what he wants at the bird feeders, and moves on to the garage. The male has a red mustache (this bird), while the female’s is black.
The little holes in the siding were made by the Downy Woodpeckers, but the much bigger chisel bill of the Pileated could make short work of tearing out huge chunks of the siding. So, I had to chase him off.

Down in the meadow

Looking back over this year’s photos, I found some gems I had overlooked at the time they were taken. During our birding explorations of southern Spain in April-May of 2022, we visited La Dehesa de Abajo (literally, the meadow down below).

The abundance and diversity of wildflowers that carpeted the meadow here was really eye-catching. The building in the background is a “hide” or blind for watching the shorebirds out in the lagoon.

The Dehesa is a nature reserve just 15 miles southwest of Seville located within the greater 52 square miles of the Donana national park and nature park system.

Among the many wonderfully different birds we saw at the Dehesa, the European Bee-eaters were the most colorful and interesting (to me) to watch. These vibrantly colored, slender birds are distant relatives of Kingfishers, but are only found in southern and central Europe, parts of northern Africa and western Asia during the spring and summer. After breeding there, they migrate to tropical Africa for the winter.

You rarely see Bee-eaters individually — especially at this time of year. But just wait…
Not a minute later, the first bird was joined by (I suppose) its mate.

Pairs were actively foraging for insects among the flush of wildflowers in the meadow, with males often bringing food to females, and perching near them. In fact, couples were perched everywhere — often next to each other in small groups.

And then, two more Bee-eaters decided this post made a good resting spot between foraging bouts.

European Bee-eaters are highly gregarious and nest colonially in sandy banks, into which they excavate 5-foot long tunnels for their nest. Both parents incubate the eggs and feed the 5-8 offspring to fledgling. Once out of the nest, adult and juvenile Bee-eaters roost communally in long lines of birds huddled closely together.

Despite their name (and they do eat a lot of bees, wasps and hornets), male Bee-eaters catch larger items like dragonflies and butterflies to feed to their mates during courtship. We watched a pair of Bee-eaters in this ritual for a few minutes as the male made several trips to feed his mate. The first image is a composite of his flight in. The second image shows him bringing a dragonfly to her (barely visible in his beak), and the third composite image shows his departure on another foraging trip.

Although Honeybees do make up 60-80% of their diet, their collective impact on the bees in an area is minimal; studies found that they ate less than1% of the worker bees from a particular hive. Bee-eaters do remove the sting from the bee before swallowing by bashing it against a tree limb or fence post.

Such gorgeous little birds, and such fun to watch. But there is much more to see in this richly diverse area of Donana, Europe’s largest national park. More on this topic later.

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.

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.

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.

Eat and/or be eaten

Sometimes you’re the predator, sometimes you’re the prey…

I walked around a small reconstructed cabin at Fort Ridgley state park wanting to peer in the windows at the back and see what the interior looked like.

A nice old log cabin — but what’s of interest here?

In the process I almost stepped on a leopard frog sitting in the grass near the sidewalk. The frog jumped to the base of the cabin, scaring a grasshopper (that I presume had been sitting on the sidewalk) to jump higher on the wall to avoid the frog.

It’s doubtful that the leopard frog will be able to grab this grasshopper for a meal now — sorry.

But then I noticed a “pack” of garter snakes creeping toward the corner of the cabin near the frog.

The snakes emerged from cracks between the stones at the base of the cabin.
Garter snake on the prowl — can it “taste” the frog waiting around the corner with those special receptors at the end of their tongues?

Local Minnesota photographer Paul Sundberg captured just such an event on a recent canoe trip in the Boundary Waters when he spied a garter snake engulfing an American Toad. Once consumed, the toad made quite a large bulge in the snake’s body.

Sometimes you’re the predator — sometimes you’re the meal! And so on up the food chain.

Red-shouldered Hawk chowing down on a snake, from the Everglades FL. Photo from the NPS

Winter preparation

It’s too early for us (humans) to start thinking about winter with its short days, cold temperatures, and blah landscapes. But not too early for the 13-lined ground squirrels that live out on the short grass meadows and prairies near Fort Ridgley state park. For them, it’s a race to eat enough to fatten up so they can hibernate in their deep burrows before cold weather arrives and the grasses dry up and their seeds disperse.

These small seed-eating rodents scurry around the meadows in late summer, scarfing up as much seed as they can find. Most will be consumed and turned into body fat, and some may be stored in their burrows for an early spring snack.

These ground squirrels are aptly named for the 13 dark brown and white stripes that line their backs. They can be found anywhere there are grassy meadows in the central part of the North America from Texas to southern Canada. But you’ll only find them above ground for about six months of the year. The rest of the time they are hibernating (deep sleep) in a deep burrow beneath the prairie plants.

I think these might have been young of the year — they were quite slim and small. Adults typically fatten up and go into hibernation long before their offspring do.

The coloration is apparently good camouflage for them as they run through blotchy patterns of grasses heavy with dark stripes of seed heads, and the striped pattern may help reduce their visibility to their number one predator – the Northern Harrier.

Rodents, like the ground squirrels, are one of the favorite prey in the diet of Northern Harriers. These long-winged raptors fly back and forth across grassy fields listening (not necessarily looking) for movements of small mammals as they fly. They are easily identified by the white rump patch in both the brown plumaged females and the grey plumaged males.
Northern Harriers have a round facial disk, similar to owls, that helps collect sound and transmit it to their asymmetrically placed ears so they can localize exactly where the sounds are coming from. (Photo by the Missouri Department of Conservation)
13-lined Ground Squirrels don’t seem particularly social; their burrows are not placed near each other, and they live and forage individually, unlike prairie dogs. These little squirrels seemed particularly naive and tolerated me approaching on foot, so they might well wind up in a Harrier’s gut sometime if they aren’t cautious.
It was interesting to watch how they handled the grass stems with their forepaws to harvest the seed.

Sometime in October all the ground squirrels will disappear underground to sleep away the winter cold in a state of torpor in which respiration is profoundly depressed from 100-200 breaths per minute during activity to one breath every 5 minutes in deep torpor. In addition, they usually do not eat or drink for almost all of the hibernation period, but survive in a very low metabolic state by oxidizing their fat stores.

Blog break — photos I wish I had taken

Backyard Biology is on a break until the end of August, but I highly recommend you visit the following website to enjoy the amazing photography of Grand Marais, MN photographer Paul Sundberg, as he chronicles life in a Robin’s nest from egg to fledging. What a treat!


As the worm turns…into baby birds.