Black-tailed Jackrabbit: Big Ears are Good for Living in Hot Deserts!

Black-tailed Jackrabbit:  Big Ears are Good for Living in Hot Deserts!

Dr. James J. S. Johnson

For the sun is no sooner risen with a burning heat, but it withereth the grass, and the flower thereof falleth, and the grace of the fashion of it perisheth: so also shall the rich man fade away in his ways.   (James 1:11)

The sun can provide a burning heat, especially in a hot desert — such as the 3 hot deserts located in America’s Southwest  —  the Sonoran Desert, the Mojave Desert, and the Chihuahuan Desert (the last of which Big Bend National Park is part of).  Yet the Black-tailed Jackrabbit, famous for its gargantuan ears, lives in all of those deserts quite nicely.   So what about those huge ears?  Do they help it to live in hot deserts?

Blacktailed-Jackrabbit-BigBendNP.FredWasmer.jpg

BLACK-TAILED  JACKRABBIT:   El Paso, Texas:  Big Bend Nat’l Park  

Yes!  The jumbo-sized ears of the jackrabbit are not primarily for hearing desert noises, although the rabbits’ ears are used to hear with, of course.  Rather, the most critical importance of having huge (and relatively thin) ears, for the Black-tailed Jackrabbit, is how it providentially equips him (or her) with a heat-shedding advantage  —  a very practical trait for such desert-dwelling lagomorphs.  In short, thanks to God’s bioengineering wisdom, the Black-tailed Jackrabbit controls its body temperature by radiating out excess heat over the relatively large surface areas of its ears!

 

“These large, floppy-eared rabbits inhabit not only the deserts of the [American] southwest, but also large reaches of midwestern prairie. At one time it was supposed that the large ears were used to enhance their hearing ability, but it has been found that their ears perform a far more important function. Laboratory investigations on heat-stressed jackrabbits have indicated that the blood leaving the ear is significantly cooler than the blood entering the ear. During heat stress, a jackrabbit can increase ear blood flow to very high levels through expanded blood vessels. The research indicates that the large, nearly bare ears serve as efficient heat radiators! Thus, even in mid-day heat, this animal may sit in the shade of a bush with its ears erect, and radiate sufficient heat toward the cool portion of the sky (away from the sun) to prevent it from reaching uncomfortable temperatures. Studies on a number of large mammals possessing permanent horns with high blood circulation, have shown that these structures also are used for heat regulation.” [Quoting John Meyer & Kenneth Cumming, “Biology of Grand Canyon”, in GRAND CANYON: MONUMENT TO CATASTROPHE (Santee, CA: ICR, 1994), pages 158-159.]

Thankfully, those gigantic ears really take the heat off those desert jackrabbits!   ><> JJSJ


PHOTO CREDITS:

featured image of standing Black-tailed Jackrabbit: Pinterest

Black-tailed Jackrabbit at Big Bend Nat’l Park:  Fred Wasmer

Blacktailed-Jackrabbit-HugeEars.Pinterest

Woodchucks, Rockchucks, and a Shadowy Holiday

The high hills are a refuge for the wild goats; and the rocks for the conies  [i.e., the Rock Hyrax of Israel  —  a lagomorph mammal with a lifestyle ecologically similar to that of the “rockchuck” (marmot) rodents of America’s western mountain states].   (Psalm 104:18)

Woodchucks, Rockchucks, and a Shadowy Holiday

 Dr. James J. S. Johnson marmot-yellow-bellied-lowcrawling

What do we know, from the Holy Bible, about “marmots”, the herbivorous mammals we call “woodchucks” (or “groundhogs”) and “rockchucks”, other than that they were made on Day # 6, and that their ancestors were preserved during the global Flood by riding inside Noah’s Ark?

There is no specific mention in Holy Scripture, that designates the mammal family that we today call “marmots”, but the Scriptures do refer to rat-like rodents (‘achbarîm = “rats”) plaguing the idolatrous Philistines (see 1st Samuel chapters 5 & 6) —   plus another rodent (שָּׁפָן  = shaphan, the rock hyrax, less accurately known as “rock badger” or “coney”) that fills a marmot-like eco-niche in Israel:

 The rock hyraxes are but a feeble folk, yet make they their houses in the rocks.  (Proverbs 30:26)

The high hills are a refuge for the wild goats; and the rocks for the rock hyraxes. (Psalm 104:18)

Israel’s rock hyrax (שָּׁפָן) is categorized with other “lagomorph” mammals – like rabbits, hares, and pikas, —  as a creature that practice hindgut fermentation digestion (involving a reingestion process variously called “cæcotrophy”, “refection”, “cecophagy”, “coprophagia”, or reingesting “night feces”) —  yet these small lagomorphs do not have divided hooves:

 Nevertheless these ye shall not eat of them that only chew the cud, or of them that only have the hoof cloven: the camel, and the hare, and the rock hyrax, because they chew the cud [literally: they fetch up partially digested (“stirred”) food for re-chewing] but part not the hoof, they are unclean unto you.  (Deuteronomy 14:7). RockHyrax.on-rocks.png

These two Old Testament verses describe 3 important traits of the rock hyraxes — (1) physiologically, they practice hindgut fermentation “refection” (i.e., hindgut-facilitated re-digestion); (2) anatomically, they have undivided (i.e., un-split) hooves, and (3) ecologically, they make nests in rocky habitats. It is the third trait – making homes in rocky places – that is ecologically comparable to many “marmots” that inhabit rocky places outside of the Holy Land.[1]  However, as we shall see, some of the marmot family – groundhogs (a/k/a woodchucks or “whistle-pigs”) – are known to live in non-rocky habitats.

In fact, it is the groundhog (Marmota monax), under its nickname “woodchuck”, that gives rise to this tongue-twister:

How much wood would a woodchuck chuck, if a woodchuck could chuck wood?

A woodchuck would chuck all the wood he could, if a woodchuck could chuck wood!

 Now, to introduce the “marmot” family, first consider that it is classified as a squirrel-like mammal (family Sciuridae), having many traits in common with various squirrel “cousins” (tree squirrels, ground squirrels, chipmunks, etc.):

 SQUIRRELS:    Sciuridae    This [taxonomic] family includes a wide variety of [herbivorous] mammals. Marmots, woodchucks, prairie dogs, ground squirrels, chipmunks, and tree squirrels all belong here.  They have 4 toes on front [feet], 5 on back [feet].  Tail is always covered with hair, [and] is sometimes bushy.  All are active during the daytime except the flying [i.e., gliding] squirrels, which come out only at night.  Marmots, ground squirrels, prairie dogs, and chipmunks all nest in burrows in the ground or beneath rocks or logs.  Tree squirrels and flying squirrels nest in trees.  Most of the ground-living species have a habit of sitting up “picket pin” fashion on their haunches.  This enables them to see over low vegetation and avert danger.  Ground squirrels and chipmunks have internal cheek pouches; most of them store food.

Quoting William H. Burt, A Field Guide to the Mammals, North America North of Mexico (Boston: Houghton Mifflin, 1980; Peterson Field Guide Series), pages 90-91. In other words, marmots are a special category of large ground squirrels.

  woodchuck-pic-encycbritannica

WOODCHUCK  (a/k/a Groundhog & Canada marmot —  Marmota monax)

This term is used to describe the “groundhog” – the smallest variety of marmot – that habituates the eastern half of the United States, as well as much of the boreal forest of Canada – as the range map [from Wikipedia] below shows.

Woodchuck.RangeMap-Wikipedia.png Canadian mammalogists have described the common Woodchuck as follows:

 The Woodchuck is our smallest marmot. It has brown dorsal fur grizzled with silver-grey, and a reddish-brown ventral pelage.  The head is dark brown with no white markings on the face; the fur on the sides of the neck does not contrast sharply in colour with the fur on the flanks and back.  The front legs are covered with reddish-brown hairs; the dorsal surface of the hind feet is dark brown to nearly black.  The short, nearly flat, bushy tail varies from dark brown to blackish.  …  The posterior pad on the sole of the hind foot is oval in shape.  …  [Ecologically speaking, it habituates] valley bottoms, lowlands and the lower slopes of the mountains, … [living in] open forests, recently cleared forests, agricultural fields, meadows, ravines associated with streams and rivers, road embankments, and campgrounds. In agricultural areas, Woodchuck burrows are most concentrated in edge habitats bordering fields and cleared areas.  Its elevational range in British Columbia is from 350 to 1,250 metres [i.e., ~1,150 feet to ~4,100 feet].

Quoting David W. Nagorsen, Rodents and Lagomorphs of British Columbia (Victoria, Canada: Royal British Columbia Museum, 2005; volume #4 in the Mammals of British Columbia series), page 136-137.

Groundhogs can reproduce quickly, like other rodents. That is helpful for maintaining Groundhog populations, because they are potential prey to several carnivorous predators, including wild canines (wolf, fox, coyote, dog), wild felines (cougar, bobcat, lynx), bears, and even large birds of prey (e.g., eagles).  Survival requires eating on a regular basis, of course, and groundhogs  — being mostly herbivorous – eat grasses of many types, as well as other lawn/meadow ground cover (e.g., clover, dandelions, alfalfa), berries, and even some agricultural crops.  Not completely herbivorous, Groundhogs will sometimes eat insects (grasshoppers, insect larvae, etc.), even snails or nuts.

woodchuck-aka-groundhog-by-tree  Groundhog burrows often have two (or more – maybe 5 or 10!) openings, a main entrance and a “spy hole”, as well as tunnels to the various entrances (to escape predatory home invaders). These underground dens serve various functions – climate control during winter hibernation months, safe haven form hungry carnivores, and various aspects of active family life.  Groundhogs even dig themselves an outhouse-like “excrement chamber”, separate from the “nest” quarters of the burrow.  Tunnelings near the surface can be annoying to human homeowners and farmers, depending upon the “environmental impact” of the Groundhog’s diggings.

The Groundhog has his own seasonal holiday in America (“Groundhog Day”), called Grundsaudaag or Murmeltiertag in Pennsylvania Dutch/German, and called Jour de la Marmotte in Canadian French.

Traditionally this special day is celebrated on February 2nd of each year – and its purpose is to predict whether spring will “come early” or not, i.e., to indicate if springtime-like weather will arrive before the vernal (spring) equinox, after which day the daylight hours “grow” and the nighttime hours “shrink”. So how do we “know” when spring weather will arrive?  If it is a cloudy day on February 2nd – when the groundhog emerges from his hibernation den – the woodchuck cannot see his shadow. For some (unexplained) reason the cloud-cover-prevented shadow is supposed to herald spring weather before the vernal equinox.  Contrariwise, if February 2nd is a sunny day – in Punxsutawney, Pennsylvania – the den-emerging groundhog should see his shadow (due to sunlight being intense enough to cast shadows), forecasting the marmot’s retreat-back-into-the-burrow, symbolizing that more winter weather is coming (and that spring weather will be delayed for another 6 more weeks). Some have said that this predictive “test” is accurate from 3/4 to 9/10 of the time – but others say this is accurate only about 4/10 of the time.  Groundhogs, being apolitical creatures (so far as we can tell), have indicated no official position about the truth or falsity of any supposed “global warming” crisis. groundhogday-cartoon-pic

(Interestingly this tradition was the inspiration for a uniquely Texas “holiday”, “Armadillo Day”, but that’s another “story” not to be covered here!)

In regions west, i.e., mostly west of the Groundhog’s usual habitat regions, many of its “cousins” live in higher elevations, in or near ranges of the Rocky Mountains (or Cascade Mountains). Rockchuck-aka-Marmot.in-rocks.jpg ROCKCHUCK  (various western marmots of North America  —  Marmota species, including the Yellow-bellied Marmot (Marmota flaviventris), as well as its western “cousins, such as the Hoary Marmot (Marmota caligata), the Olympic Marmot (Marmota olympus), and the Vancouver Marmot (Marmota vancouverensis). Unsurprisingly, the name “rockchuck” refers to the rodent’s observable habitat  —  this variety of marmot is found in America’s Great West, especially in (though not limited to) the rocky timberline elevations of America’s Rocky Mountains, where alpine meadow vegetation suffices for such herbivores.

marmot-colorado-on-rocks

Rockchucks are social creatures, living near one another, and the nickname “whistler” (or “whistle-pig”) refers to their practice of whistling alarm when danger approaches. The rockchuck prefers “flight” to “fight” – scurrying for cover inside a rocky hideaway, if a potential predator is perceived as too close.  Some rockchucks, however, have become accustomed to peaceful tourists — and may even approach humans in hope of food, such as a salty PAYDAY candy bar![2]

YELLOW-BELLIED MARMOT  (rockchuck mother and her nursing pups)

Of the western marmots the Yellow-bellied Marmot is the most populous. Its range stretches from as far south as the Sangre de Cristo Range (in New Mexico and Colorado) up into Canada.  Yellow-bellied Marmots reside as far east as parts of South Dakota and the western edge of Nebraska, and as far west as all but the coastal edge of Washington and Oregon, even inhabiting small edges of California. marmot-yellowbellied-rangemap

This variety of rockchuck lives near timberline in the western states of America, yet in Canada it lives at lower elevations (e.g., < 1300 meters in British Columbia).

HOARY MARMOT  (a/k/a “mountain whistler” — Marmota caligata)

Another variety of rockchuck is the Hoary Marmot, famous (as its name suggests) for its “senior citizen” hair color, i.e., its fur is dominated by silver-grey.  Hoary marmots tend to live in mountainous places  — but only in America’s northwest corner (i.e., Idaho, Montanan, and Washington), plus montane lands in western Canada and Alaska, north of that corner.  This is the “extra-large”-sized marmot. Marmot-on-rock.closeup.jpg

Perhaps this tongue-twister could be used for the Groundhog’s western cousins:

How much rock would a rockchuck rock, if a rockchuck could rock rock?

But marmots don’t “rock” rocks!  However, being rodents, with ever-growing front teeth, rockchucks might use a somewhat-flat rock as the equivalent of an emery board – to file down his teeth! Maybe doing so provides access to rock-borne minerals that the marmot needs.  Anyway, marmot teeth should be respected, especially by mountain hikers who take naps at timberline.   ><> JJSJ

marmot-front-teeth-closeup


[1] Notice that the Rock Hyrax of Israel is a lagomorph that behaves, ecologically speaking, like the rodents that we call marmots (i.e., rockchucks and woodchucks). This illustrates how animal ecology does not slavishly follow taxonomy.

 Biomes … have animals which occupy particular roles within the ecosystem, tapping particular environmental resources.  These may differ very considerably in their taxonomy from one part of the world to another, but are nevertheless ‘ecological equivalents’.  For example, the South American pampas is grazed by the guanaco [a camel-like mammal], which is the [ecological] equivalent to the Australian kangaroo [a marsupial mammal], the Asiatic ass [an equid mammal] and the North American bison [a bovine mammal] in that it is a relatively large, fast-moving herbivorous animal living in herds.

Quoting Peter D. Moore, “The World’s Biomes”, in The Encyclopedia of Animal Ecology (Oxford, England: Equinox Books, 1991; edited by Peter D. Moore), page 40.

[2] Many years ago this author was hiking up Horn Peak (in the Colorado portion of the Sangre de Cristo Mountains, the southernmost sub-range of the Rocky Mountains). Horn Peak’s elevation is listed as 13,450 feet (4100 meters), slightly above Little Horn Peak (elevation: 13,143 feet/4006 meters).  On a group hike I tired above Little Horn Peak but below the summit of Horn Peak.  Thoroughly exhausted – crawl, rest, crawl, rest, crawl, rest, rest some more – I lay down on the ground for a shut-eye/nap, covering my face with a sweaty (and therefore salty) cloth handkerchief, to avoid getting my face sun-burned while I dozed.  (Having told other hikers what I was doing, as they continued to ascend to the summit, I requested that I be awakened by them on their return trek, as I expected them to return to where I was on their descent, later.  After sleeping for an unknown amount of time I was awakened by someone removing the white handkerchief form my face – it was the up-close face of a Yellow-bellied Marmot!  (I screamed: “What are you doing?” – forgetting that marmots don’t speak English.)  I was rattled!  I had scared the marmot (who perhaps was attracted to the salt on my sweaty handkerchief), but only momentarily.  The marmot gingerly wandered back closer to me, looking at me expectantly – apparently other hikers had given snack food to this marmot, and he was expecting me to do the same.  All that I had remaining, then, of my trail snacks, was a PAYDAY candy bar – a treat composed of peanuts, caramel, and salt – which he gulped down instantly!

payday-candybar

 

SEA OTTERS: Marine Mustelids with an Appetite!

And God said, Let the waters bring forth abundantly the moving creature that hath life, and fowl that may fly above the earth in the open firmament of heaven.  And God created great whales, and every living creature that moveth, which the waters brought forth abundantly, after their kind, and every winged fowl after his kind: and God saw that it was good.  (Genesis 1:20-21)

Sea Otters:   Marine Mustelids with an Appetite!

Dr. James J. S. Johnson

 SeaOtter.floating.png

Sea Otters are surely the cutest marine mammals who live in the seawaters off Alaska’s southern coastlines – they float on their backs, their whiskery faces look wise and kind, sometimes they hold hands (paws), and they care for each other.

The Northern Sea Otter (Enhydra lutris) is the only true “marine mustelid” – i.e., it is a member of the category of mammals called mustelids (the weasel super-family), all the other of which live mostly on land, even its “cousin” the North American River Otter (Lontra canadensis).   It is the smallest of marine mammals – much smaller than cetaceans (such as whales) and pinnipeds (such as walrus and seals) – with male adults weighing from about 80 to 100 pounds, and female adults weighing about 50 to 70 pounds.  Unlike other weasel-like mammals, Sea Otters live in seawater – even giving birth in seawater!

Sea Otters, unlike blubbery whales and walruses, are relatively thin – yet they need to survive the super-cold waters that blubber-loaded marine mammals live in. How do the Sea Otters do it? Unlike pinnipeds and cetaceans, sea otters have no blubber, so their fur must keep them warm.

SeaOtter-fur.magnified-view.png

Sea otter fur is the densest of all mammals (almost 1,000,000 strands of hair/square inch!), consisting of waterproof exterior “guard hairs” over a dense layer of dry underfur, so it insulates from environmental temperature extremes:  “air trapped in its fine fur keeps it warm as well as buoyant.”  [Quoting John Whitaker, Jr., National Audubon Society Field Guide to North American Mammals (1998), page 786.] Unlike animals that periodically “molt” (like birds and reptiles), sea otter fur is shed gradually, year-round.  To stay warm in the super-cold waters off Alaska’s southern coasts, Sea Otters rely on more than their providentially thick fur, they also eat often and a lot – they have a high metabolism!

As a carnivore, the Sea Otter eats mostly animals – including clams, sea worms, squid, octopus, abalone, sea urchin, starfish, and crabs (especially Dungeness Crabs). However, Sea  Otters  consume  so  many  Dungeness crabs,  so  quickly, that  southern Alaska’s  crab  fishermen  are  losing  out – so not everyone thinks of Sea Otters as being “cute”.

JJSJ-with-DungenessCrab.png

Some shellfish are hard to eat, due to tough exoskeleton shells, but Sea Otters are up to the task – they use rocks to crack open clam shells, or abalone shells – sometimes using a rock as an anvil.  Diving Sea Otters also use rocks to dislodge shellfish (such as clams or mussels) that are firmly attached to an underwater substrate.

SeaOtter-eating-octopus.png

Sea Otters are so intelligent, learning to adapt to new information, that they have been observed ripping open metal drink cans, in search of juvenile octopus, because they have learned that small octopuses often use metal drink cans (discarded by human litterbugs in Alaska’s coastal waters) as hiding-places, similar to how hermit crabs will “recycle” uninhabited shells.

SeaOtter-with-RockAnvil.eating-SeaUrchin.png

In fact, God has designed anatomical “pockets” for carrying both rocks and food items, when a Sea Otter is diving underwater.   Sea  otters  have  loose  armpit  skin (a “pouch”),  for  carrying food, or rocks  (thus  freeing  up  their  “hand” paws)  to  use  as anvils  (when  they crack  open  sea urchins or bivalves, like  clams  and limpets and  mussels).  Webbed  hind  paws  are  useful  for  swimming  and  diving, sometimes  150 feet  deep,  to  collect  their  underwater  prey.

SeaOtters-in-underwater-kelp-forest.png

The underwater brown kelp “seaweed forest”  is  a favorite   habitat  for  hunting  food.  Sea Otters not only find food in the underwater kelp “forests”, they protect the kelp – by eating Sea Urchins, because Sea Urchins can quickly decimate kelp forests if no Sea Otters are available to keep the Sea Urchin population in check.  Sea Otters also make use of kelp seaweed in another way – they wrap themselves in the seaweed, and become secured in place as if wearing a floating “seatbelt”, while they float in tidewater, asleep.  Securely tied to the anchored seaweed, the Sea Otters (who are “belted” in for a nap) will not be washed out to deep seawaters by the tides.

In other words, the relationship of Sea Otters to giant kelp (i.e., brown algae seaweed) is one of “mutual aid”, because both kelp and otter populations benefit from their interactions with each other. SeaOtter-seaweed-seatbelt.png

Where does the Sea Otter usually live? Its primary range covers the coastal tidewaters of Alaska’s Aleutian Islands archipelago chain, plus its south-central and southeastern coastlines, down the Canada’s British Columbia coasts, even to the Pacific coastline of the State of Washington.         ><> JJSJ


Dr. James J. S. Johnson’s background includes a love for animal ecology and the colder climates of the world. In addition to his (current) creation science education-focused work for ICR-SOBA, he has taught bioscience/ecology courses for Dallas Christian College and ACSI, written ecology-related curriculum for LeTourneau University, and served as lecturer aboard 9 international cruise ships, including 4 cruise ships  visiting  Alaska  (Norwegian Wind, Norwegian Sky,  Radiance of the Seas,  Rhapsody of the Seas).

seaotter-pair-in-icy-water

 

MOLES: Digging for the Glory of God

In that day a man shall cast his idols of silver, and his idols of gold, which they made each one for himself to worship, to the moles and to the bats, … for fear of the Lord ….” (Isaiah 2:20-21a).

Mole.being-held-by-human-hand.jpg

MOLES:   DIGGING  FOR  THE  GLORY  OF  GOD

James J. S. Johnson

The day will come, before Messiah (Jesus) returns in power and judgment, when God-rejecting idolaters will cower in fear, trying to hide in the earth, knowing that their accountability is ripe: “In that day a man shall cast his idols of silver, and his idols of gold, which they made each one for himself to worship, to the moles and to the bats, … for fear of the Lord ….” (Isaiah 2:20-21a). The English word “mole” (in KJV) is a translation of the Hebrew noun chapharpêrâh, derived from the verb châphar, meaning “to dig” – and digging is what moles are best known for doing.   (For illustrations of the Hebrew verb châphar, “to dig”, see Genesis 21:30 &  Ecclesiastes 10:8.)

How do moles dig?

“The mole excavates its burrow by backward strokes and lateral thrusts of the front feet.  Loose earth is moved and pushed to the surface by thrusts of the front feet.  In excavating shallow runs, the mole merely pushes up the earth to form a ridge, again by lateral thrusts of the front feet while the mole is turned partly on its side.” [Quoting David J. Schmidly, THE MAMMALS OF TEXAS (Univ. of Texas Press, 2004), page 60.]

Who taught the mole to do such underground digging, and to do it so successfully that moles live all over much of America? Who equipped the mole with the anatomy it needs to do this subterranean work?

molehill-diagram-showing-underground

Those who intelligently design and/or carefully operate oil-drilling equipment can appreciate the digging powers of moles, because digging underground is an art! Innovative petroleum engineers deserve to be appreciated for their underground earth-burrowing technology.  If you think serious underground digging is “simple” try drilling for oil  —  or try to mine out minerals from under the earth!

But oil-drilling equipment cannot reproduce itself into generation-after-generation families of their kind – yet moles reproduce successfully, all around America, and we don’t notice or appreciate it. God, however, deserves praise for equipping the humble mole for its down-to-earth (or rather, down-under-the-earth) station in life.

Moles are created to dig and they do – to God’s glory! Their Creator is worthy of worship (Revelation 4:11).  Idolatry is foolish; we should avoid it in whatever form it appears (1st John 5:21), as we seek to harness each day as a day of worshipping our soon-coming Lord Jesus, the Maker of Heaven and Earth (John 1:3).   ><> JJSJ

mole-with-earthworm


Dr. James J. S. Johnson, as a boy, learned to recognize the surface evidence of moles’ shallow burrowing.   Since his boyhood he has tried to appreciate the human life God gave him, and to recognize what God prioritizes  –  so as to avoid “making mountains out of molehills”.

POLAR BEARS: ROUGH, TOUGH, AND COOL

POLAR  BEARS:  ROUGH,  TOUGH,  AND  COOL

Dr. James J. S. Johnson

Let a man meet a bear robbed of her cubs, rather than a fool in his folly. (Proverbs 17:12)

PolarBear-by-IceFloe.png

What are Polar Bears like? Polar Bears (Ursus maritimus) are often called “white bears” because their fur looks like a slightly yellowish white. Designed for a polar lifestyle, a Polar Bear has small rounded ears, a muscular hump behind his or her neck, large claws on each of its large paws, and huge and powerful body.  Its large furry feet are well-designed for walking on snow and ice.  Its amazing fur is perfect for insulating the bear’s body from the super-cold temperatures (and freezing winds) of the polar North.

Are Polar Bears “marine mammals” or “land mammals”? Or should they be called “ice bears”? Polar bears routinely live on sea ice for months, and can swim (“dog paddle” style) for days – one did so for 9 days!  Where do they live?  The icy cold waters of the Arctic Ocean are the primary home range of the Polar Bear, especially in many ice floes that float about the saltwater, as well as the coastlands that touch those waters.  They can smell seals a mile away or buried under 3 feet of snow.  They have good ears and eyes.   (Sometimes they stand, to see distant objects better.)

PolarBear-Leapfrogging-Ice.jpg

Although floating ice is their “principal place of business”, polar bears are at home hunting on land (and swimming in the ocean).

How are Polar Bears as different from other bears? Unlike the dish-faced profile of a Brown Bear (such as a “Grizzly”), the Polar Bear’s head shape is more straight-faced, like a Black Bear, yet is ears as smaller, so its overall head-muzzle shape is slightly more longish and cone-shaped than that of a Black Bear.  Also, unlike the high shoulder hump of a Brown Bear (including that of a “Grizzly”), the rump of a Polar Bear, like that of a Black Bear, is the highest part of the bear’s body, when walking on all four paws (as opposed to when standing or walking on two feet, like a human – which all bears can do, but usually do not do).  The diet of the Polar Bear is different, too, because it is meat almost all the time—though it can and will eat berries and other foods when convenient.  Black Bears and Brown Bears are more omnivorous (eating a mix of animal flesh and plant food, such as berries, mushrooms, acorns, flowers, pine cones, and roots)—although they certainly enjoy fresh meat when it is available, especially fish (as Alaska’s Brown Bear population is famous for its “all-you-can-eat” fishing).

polarbear-looking-over-ice

How are Polar Bears similar to other bears? Genetically speaking, all true bears are part of the same biogenetic family.   This includes the Brown Bear, the Black Bear, and the Polar Bear – as well as the Sun Bear, Sloth Bear, Spectacled Bear (but does not include the so-called “Panda Bear”).  One illustration of this hybridization was reported in National Geographic magazine, by John Roach:

Last week, DNA analysis confirmed that the bear’s father was a grizzly and his mother was a polar bear [Ursus maritimus]. … Fossil evidence of prehistoric polar bears is difficult to find, because polar bear ancestors lived in conditions that were poor for bone preservation, [David] Paetkau [of Wildlife Genetics Int’l] says. But the two species probably diverged ‘less than a million years ago’.   By contrast, North American black bears [Ursus americanus] and grizzly bears [Ursus arctos] diverged about five million years ago, he says. … On the other hand, the warming Arctic environment is causing some animals to shift their range northward. It’s possible, Paetkau says, that grizzly bears and polar bears may have more offspring-producing encounters in the future.

Quoting John Roach, NATIONAL GEOGRAPHIC (May 16, 2006 issue).  In other words, all true bears descend from a pair of bears that survived the global Flood aboard Noah’s Ark.  Accordingly, they can interbreed, genetically, and sometime do – either in the wild, or in captivity, or both. PolarBear-head-above-seawater.png

How do newborn Polar Bear babies survive the harsh sub-freezing temperatures of the polar North?

Dens offer pregnant [polar bear] females protection from the cold and predators while they give birth and rear their cubs. The temperature inside a [polar bear] den is often just below freezing [!] and fluctuates much less than outside temperature. The temperature inside a den can be 38°F (21°C) warmer than outside, and the warmth reduces energy use, which is important for small cubs and for females without access to food.

Quoting Andrew Derocher, Polar Bears: Complete Guide to their Biology and Behavior (Baltimore: Johns Hopkins University, 2012), p. 155, as quoted in James J. S. Johnson, “Why We Want to Go Home”, Acts & Facts, 44(4):20 (April AD2015), posted at www.icr.org/article/why-we-want-go-home .

Although baby polar bears are conceived during spring, the uterine implantation of bear embryos (like those of other bears, as well as mustelids and seals) is delayed until autumn (when mama bears enter their “maternity ward” dens), ensuring that the births, about 2 months later, occur in winter (i.e., during hibernation), so that the family’s den exodus is timed for spring (months later), when food availability is optimal, and when the infants are developed enough to travel to, and onto, sea ice.  (See Andrew Derocher, Polar Bears, pages 172-173.)

polarbear-winter-den-diagram

Blue whales at birth are about 2% of their mother’s weight, humans about 6%, bats around 30%, and some rodents over 50%. Each polar bear cub is only 0.2% to 0.3% of its mother’s mass. Polar bear cubs at birth are extremely small relative to the size of their mother. A cub weighs about 1.5 pounds (0.7 kg) while its mother can easily top 440 to 660 pounds (200-300 kg).

Quoting Derocher, Polar Bears: Complete Guide to their Biology and Behavior, page 177.

In other words, Polar Bear babies are quite tiny compared to their mamas; in fact, amazingly (when you consider the growth they are designed for) they are even tiny compared to human babies! Compared to Polar Bear newborns, human newborns have birth weights that are about 5 times heavier!

polarbear-newborns

Since polar bear cubs are born so small, after the protein-loaded antibody-rich colostrum, they need super-rich “get-fat-quick” milk to grow!

Polar bear milk … can be 46% fat. Fat content declines as cubs get older … as low as 5% just before the mother stops producing milk [~ 2.5 years after birth]. Protein content varies from 5% to 19%; sugars can constitute 6%. Minerals make up less than 2% of the milk, which has a variety of vitamins including A, B, D, and E.

Polar bear milk … is low in lactose (a sugar) but high in specialized sugars called oligosaccharides … [which] have an antibacterial role.

[Quoting Andrew Derocher, Polar Bears, p. 180.]

polarbear-mama-with-twin-nurselings

After being weaned from Mama’s milk, what is the favorite food of a Polar Bear? Seals!  Especially Polar Bears are known for eating seals – especially Ringed Seals (Pusa hispida) and Bearded Seals (Erignathus barbatus). To do this they must learn to hunt, ranging the ice floes of the Arctic Ocean, and sometimes ranging on land, or swimming in the ocean.  But, thanks to God’s caring bioengineering, Polar Bears are designed for trekking long distance on slippery ice—their feet (paws) are a perfect fit for their icy habitat.

Microscopic examination of polar bear feet reveals their ice-handling design features. It turned out that the pads of a polar bear’s foot are covered with small soft papillae [small bumps], which increase friction between the foot and the ice. There are also small depressions in the sole….

[Quoting Ian Stirling, Polar Bears (Ann Arbor, MI: University of Michigan Press, 1998), page 25, as quoted in Brian Thomas, “Beetles and Bears Inspire Technologies”, ICR News, posted 2-26-AD2016.]

Polar bears, eating blubber-loaded seals (as they try to store fat and protein for the coming winter), like to “pig out” –  they can eat 20% of their body weight in one meal!   (Calculate what 20% pf your body weight would be!)  Males often weigh 700-1800 pounds; females ~ ½ that, at 350-1000 pounds!

polarbear-eating-seal

Polar bears are happy to eat humans, too, if they can get at them! How emphatically, therefore, the Scriptures caution against meeting a “fool in his folly”:

Let a man meet a bear robbed of her cubs, rather than a fool in his folly. (Proverbs 17:12)

Does anyone eat Polar Bears? Actually, yes, though usually it is the Polar Bear that is the predator!  When desperate enough, humans have been known to hunt and kill—and eat (!)—Polar Bears.

polarbear-young-atop-mama

In one famous situation of shipwrecked sailors, in Svalbard (a small group of islands north of Russia), sailors ate ten of them!

In 1743 a Russian ship bound for Arctic walrus-hunting grounds was blown off course and trapped in ice off the coast of Svalbard … Four sailors [who faithfully prayed, as Russian Orthodox ‘Old Believers’, to God for His providential care] went shore with only two days’ supplies to look for an abandoned hut they knew about on the island.

[Quoting David Roberts, Four Against the Arctic: Shipwrecked for Six Years at the Top of the World (2003), intro.]  The stranded Russians weathered a stormy night in the hut.  When they returned, to where the ship had been, the ship and its icepack were both gone, apparently blown out to sea and destroyed by the storm.  To survive there, for 6+ years, they made spears, bows and arrows, from driftwood, eventually killing 250 animals to eat, including 10 polar bears, some arctic foxes, and many caribou, plus scurvy grass.  The one sailor who refused to eat scurvy grass died (you guessed it – he died of scurvy).  The other 3 survived, thankfully, to be eventually rescued during AD1749, by another off-course Russian ship of “Old Believers”.

On the other side of the (polar North) world, Alaskan Eskimos have hunted Polar Bears, for many centuries, sometimes with success—even using bow and arrows!

polarbear-shot-by-alaskan-archer

Much more could (and should) be said—and appreciated—about that amazing ice-floe-trekking carnivore of the super-cold North, the Polar Bear. But for now, as you consider the meat-and-blubber-hungry habits of the ravenous Polar Bear, be thankful that God did not make you an Arctic Ocean-dwelling seal—who must surface through an “ice hole”, periodically, for air.) Because sometimes more than breathable air awaits a  vulnerable seal, just above the surface!  Yikes!

polarbear-displaying-teeth

In other words, be glad that the Lord made you exactly whom you are (Psalm 102:18), with a life of blessings in the present (Acts 14:17), plus a wonderful future, so long as you believe in the Lord Jesus Christ (Luke 10:20)!    ><>  JJSJ


Dr. James J. S. Johnson’s background includes a love for animal ecology and the colder climates of the world. In addition to his (current) creation science education-focused work for ICR-SOBA, he has taught bioscience/ecology courses for Dallas Christian College and ACSI, written ecology-related curriculum for LeTourneau University, and served as lecturer aboard 9 international cruise ships, including 4 cruise ships  visiting  Alaska  (Norwegian Wind, Norwegian Sky,  Radiance of the Seas,  Rhapsody of the Seas).

A DOXOLOGICAL VIEW OF GRASSES

A Doxological View of Grasses,

with Special Attention to Matthew 6:28-30 and Luke 12:27-28

 James J. S. Johnson, JD, ThD, MSGeog

grass-field-with-wildflowers-prairie

And God said, Let the earth bring forth grass, the herb yielding seed, and the fruit tree yielding fruit after his kind, whose seed is in itself, upon the earth: and it was so. And the earth brought forth grass, and herb yielding seed after his kind, and the tree yielding fruit, whose seed was in itself, after his kind: and God saw that it was good. (GENESIS 1:11-12)

Each blade of grass is a soil-rooted witness, giving evidentiary proof of God’s Creatorship. Furthermore, each blade of grass is a growing doxology, directing us to worship the LORD.

Recently Mike Matthews, of Answers in Genesis (and Editor-in-chief of ANSWERS magazine), observed the following truth about grasses, calling them “green factories”:

These [grasses] are God’s creation. They perform a fundamental biological process—photosynthesis—that still astounds scientists. The thousands of chemical equations [that describe the grass-housed photosynthesis process] would fill a wall. Yet every day, these green factories churn out the sustenance of life. They remind me that a lowly sinner like me can glorify my Maker and Life-giver, who gave His life for me.

[Quoting Michael Matthews, “Green Factories”, ANSWERS, 11(4):86 (October-December 2016), emphasis added.]

ppt-hummock-grasses-triodia

Now that is sound science!—that is meaningful analysis of what grasses are really here for, revealing details of God’s immeasurably creative glory, simultaneously with recognizing the value of His bioengineering providence. Why? So that we can better know and appreciate our God for Who He really is! If our hearts are not stirred to worship, we have failed to understand the meaningful value of His creation.

Grass seems so plain, so un-exciting – it dominates many parts of the world, so we deem it common-place (see Job 5:25).

But a careful study of grasses, observing the many moving parts within their complicated living systems (and interactions with their environments), leads to an appreciation for their God-designed purposes, programs, and complexities.

ppt-montana-bluegramagrass-c4

Yet it is not enough to learn the “geeky” science data (such as the biochemical mechanisms that power the plant photosynthesis pathways), such as whether this or that plant uses the C3 version (or the C4 version) of carbon dioxide-to-carbohydrate photosynthesis.c4-photosynthesis-compared-to-c3-diagram

Even so, the ecological and agricultural details — far beyond the scope of this short perspective article — exhibit how God uses growing grasses, which are here today and gone tomorrow (Isaiah 40:7-8), to feed both mankind and many animals.

He causeth the grass to grow for the cattle, and herb for the service of man: that he may bring forth food out of the earth. (PSALM 104:14)

If we, as creatures who owe God glory and gratitude, fail to personalize the lesson that His living creation provides—including doxological lessons from blades of grass—we have failed to be true creation scientists. The ultimate purpose for learning about grasses is to glorify God and enjoy Him forever, as the Westminster Confession reminds us (see also 1st Corinthians 10:31 & John 10:10).

Recently I participated in an evening lecture series, at ICR, called “Grassland Habitats: God’s Providence in Plain View — Living in Prairies and Pampas, Steppes and Savannas (Grasses, Grazers, Grazer-Grabbers, and Grasshoppers)”.

ppt-grasshopper-in-grass

Suffice it to say, the opportunities for learning about bioengineering details that God has designed, programmed, installed, and maintains – in the various grasslands of the world – could be packaged as a full-length college course (such as APOL 557, “Grasslands and the Genesis Mandate”, an elective in ICR’s Master of Christian Education degree program).

And it’s not just above-ground photosynthesis that grasses facilitate, because the root systems of grasses, unseen by humans, busily perform many valuable functions – such as processing nitrogen compounds in ways that facilitate protein synthesis (e.g., in legumes), mineral recycling, the hydrologic cycle, and abatement of soil erosion. Grasses work hard, honoring God by their very existence and operations – regardless of whether any humans “have eyes to see” it or not.

ppt-grassland-with-pronghorn

But why is there no emphasis on the doxological aspect of grasses?

Once again, listen to the insights of Mike Matthews, as he hits the bull’s-eye on what is usually missing from “natural science” publications, and even from many “geeky” studies in “creation science” literature.

First, what’s with the photo on the last page [of ANSWERS magazine, October-December 2016 issue] ?

I’d like to open my heart wide here. … I’m a literature guy. What fires my engines each morning is not the [geeky] details of science, as interesting as they are. It’s knowing God better. …

For a believer to know Him is to be devoted to Him. It means being so overwhelmed by the perfections (or glories) of His being –and by His creation—that we can’t help but renew and deepen our dedication to serve Him with our whole heart, soul, mind, and strength.

The term devotional has gotten a bad rap these days. For some reason, it has the connotation of light and fluffy. The root meaning is just the opposite. It’s associated with love, loyalty, enthusiasm, worship. …

The Almighty God is so glorious that He effortlessly tosses priceless gems into every nook and cranny of our lives. Everywhere we look, even lowly blades of grass, the Lord gives us reminders of His grace and majesty.

[Quoting Michael Matthews, “Devotional Isn’t a Trite Word”, ANSWERS, 11(4):10 (October-December 2016), emphasis added.]   Finally!  It’s about time that someone emphasized the valuable role of devotional theologyand doxological creation apologetics.  (Apologetics is firstly a matter of “sanctifying the Lord God” in our hearts — only secondarily is it a matter of providing witness of God’s truth to those with ears to hear — see 1st Peter 3:15).

Yes, Mike, we see countless doxologies in creation, every day, if we “have eyes to see” it. God’s providential care and splendor are ubiquitous (Acts 14:17), so there is no excuse for us to lose our “first love” for Him (Revelation 2:4).

ppt-creatorship-is-clearly-seen-grassland

The ultimate reality and focus of all creation is not primarily about people, even though humans are quite valuable – the main reality is about God being the Creator!  All of creation, therefore, especially our own lives, can and should be an ongoing doxology for Him (Revelation 4:11). And yet, that doesn’t mean we should shirk or flee from the “geeky” side of creation studies; rather, we should harness such observations for God!

In fact, the Lord Himself emphatically encouraged the study of wildflowers and field-grasses, according to Matthew (6:28-30) and Luke (12:27-28)  —  and I must thank my research assistant, Jared Watkins (of Tyndale Theological Seminary), for the New Testament Greek research  that undergirds these philological insights.

matthew6-28-30-philology-slide

Specifically, Matthew reports Christ using an imperative verb that means to intensely learn, to thoroughly study (καταμαθετε) – to carefully observe (i.e., what empirical scientists call “research”). Matthew’s verb is related to the Greek noun translated “disciple” — so our study of wildflowers and field-grasses should involve the due diligence of a disciple!

But there’s more. Luke complements Matthew’s record, reporting that Christ also used an imperative verb meaning to intensely mind, to thoroughly think through (κατανοησατε) – to carefully understand (i.e., what empirical scientist call “analysis”).

luke12-27-28-philology-slide

In short, Christ’s exhortations – preserved in Scripture by Matthew and Luke – obligate us to practice faithful-to-the-details “research and analysis”, so that we can reverently and admiringly appreciate God’s providence, for the supposedly “simple” wildflowers and field-grasses.

And the photosynthetic (and other) providences of such “green factories” point to even greater providences — including God’s personalized care for our own lives and futures.

Accordingly, paying attention to these grassy “green doxologies” can and should encourage us to expect God’s greater providences in our own lives, as higher creatures – being uniquely created with life in God’s own image – plus having our lives salvaged from our sinfulness by the completed redemptive work of His crucified-and-resurrected Son, our Lord Jesus Christ (Psalm 102:18; Ephesians 2:8-10, Luke 10:20).

So, if I am obedient, daily, to Matthew 6:28-30 and to Luke 12:27-28, I will daily recognize that (so-called) “simple” blades of grass, plus their underground root systems, are Earth-rooted doxologies, pointing our minds and hearts heavenward.   ><>  JJSJ

ppt-prairiedog-in-prairiegrass


 

HARBOR SEALS: Swimming, Diving, Guided by Super-Sensitive Whiskers

James J. S. Johnson, JD, ThD, MSGeog, CNHG

harborseal-on-rock-statenislandadvance-newspaper-photo

They that go down to the sea in ships, that do business in great waters, these see the works of the LORD, and His wonders in the deep. (Psalm 107:23-24)

Those who fish at sea, and other who “go down to the sea in ships”, have many occasion to see God’s “wonders in the deep”.  All creatures of the oceans and their coast-waters fit that category – because all such sea creatures, by their very lives and life cycles, are “wonders” in water, who give witness of God’s glory and providence, showcasing the amazing Creator He is.  One such example of is the Harbor Seal.

harborseal-2-on-ice-floe

The HARBOR SEAL (Phoca vitulina), known in Great Britain as the “Common Seal”, is a creature well-known to the Vikings of old, as is documented below.  These fine-finned marine mammals are impressive (if not peerless) swimmers and divers, and they can tolerate a wide range of temperatures (warm, lukewarm, cool, and super-cold!).  And, thanks to the super-sensitive whiskers that God designed and installed upon them, Harbor Seals know just where to go, as they chase fleeing fish!

Harbor Seals are the world’s most common temperate-water seal, often found along the temperate water coastlines (and continental shelves) of the Northern Hemisphere – in both the northern Atlantic and northern Pacific Oceans, and in coastal estuaries, and sometimes even as far south as Portugal! Oddly, one subspecies (Phoca vitulina mellonae) lives only in freshwater.

Seals were well-known for their swimming skill, as is illustrated by the following quotation from an old Viking saga: “There was a man whose name was Gunnar [Hamondsson] … a tall man in growth, and a strong man – best skilled in arms of all men. He could cut or thrust or shoot if he chose, as well with his left as with his right hand, and he smote so swiftly with his sword, that three [swords] seemed to flash through the air at once. He was the best shot with the bow of all men, and his arrows never missed their mark. … He could swim like a seal [emphasis added], and there was no game in which it was any good for anyone to strive with him; and so it has been said that no man was his match….

[Quoting from Chapter 19, NJAL’S SAGA. See, accord, Magnus Magnusson & Hermann Pálsson, NJAL’S SAGA (New York: Penguin Classics, 1982).]   Vikings, including Gunnar’s Icelander contemporaries, were obviously impressed with the superlative swimming skills of seals!

harborseal-swimming-wikipedia

As a marine mammal, the Harbor Seal is a “pinniped” – i.e., it has fins, not feet. Also, it is earless (i.e., bearing no external ears) and carnivorous (eating animals of the sea). Being mammals, the seal mothers (“cows”) breastfeed their children (“pups”), as do mothers of all mammal species. Regarding size, the adult Harbor Seal ranges from 5 to 6 feet long, with bulls (males) a bit larger than cows). Body weight can approach 375 pounds!

harborseal-newenglandaquarium

The Harbor Seal’s four flippers are ideal for swimming (as well as for diving and surfacing), and are not designed for a lot of “shore duty” walking, so seals move on land by undulating, like a caterpillar. These flippers have webbed digits – like finders or toes blended together – which can be used to scratch, groom, or provide defensive movements – and they stroke powerfully for precision swimming.

harborseal-haulout-germany-colony-beach

But daily life, for a harbor Seal, is not all about swimming – they often “haul out” on shoreline or harbor-water rocks (or sandy beaches), to rest, to bask, to molt, to nurse babies, to give birth, and even to congregate with other seals for defense (e.g., against predators who cannot leave the seawater, such as orcas, a/k/a killer whales). Mother seals usually nurse their suckling pups at low tide. Ironically, seal reproduction occurs at sea. Like humans, seal gestation lasts for about nine months; after birth, on shore, lactation lasts for about 4 to 6 weeks, with the birth weight of baby pups (as much as 35 pounds) doubling (i.e., to as much as 70 pounds) by the time they are weaned off their mother’s fat-rich milk. Within hours of being born the seal pups can dive and swim – and their future lives will continue that habit for years to come.

When it comes to life at sea – and the Harbor Seal’s true home is the water – the pinnipeds display their Creator’s design-bioengineering to imagination-stretching levels (or depths!). Although Harbor Seals sometimes sleep on land, they can even sleep in the water, subconsciously surfacing for air as needed. Diving, and swimming, underwater, is a seal’s quintessential element – whether that be in the ocean, an estuarial bay (i.e., “harbor”), or some freshwater river flowing into the sea.

harborseal-underwater-channelislands-calif-coast

These seals can dive even more than a half-mile deep, when searching for food, and can remain underwater for about 40 minutes (though most dives last only around 5 minutes) – then they must return to the surface, to replenish their air for breathing. When seals dive into the ocean, their God-given interactive sensor-systems (which measure oxygen levels) and pre-programmed instincts adjust their physiology to their underwater diving needs.

When the seal’s face is submerged, it automatically holds its breath, its heartbeat slows by up to 90% and its blood circulation is reduced, except to the most vital organs, the heart and brain. … The dive reflex is responsible for the seal’s ability to remain submerged for long periods. The harbor seal breathes out before diving, reducing its buoyancy. Also, the harbor seal has a very high blood / volume ratio, about 1.5 times that of a human. This allows a large amount of oxygen to be carried in the bloodstream instead of the lungs. The harbor seal has high myoglobin levels, allowing high levels of oxygen to be carried in the bloodstream and tissues, about 2.5 times that of a human.

[Quoting from AquaFacts: Harbour Seals (Phoca vitulina), posted by Vancouver Aquarium Marine Science Center, 2005, pages 1-4, citing Steve Kleene’s “A Medical Marvel: the Diving Seal”, SEA FRONTIERS, 35:370-374 (Nov.-Dec. 1989).

harborseal-oregonzoo-closeup-whiskers

Even the sea’s whiskers help – the nerves inside seal whiskers help sense underwater pressure changes; the whisker nerves trigger internal physiology adjustments that are needed to optimally respond to those changing underwater pressures.

When waters are murky, how do seals find fish? They don’t have a sonar apparatus like whales, and yet they somehow hunt successfully in the dark.

It turns out that the seals follow fish trails by sensing very subtle water pressure changes with their whiskers. In a study published in the Journal of Experimental Biology, investigators trained harbor seals to give a visual signal indicating the direction of a “swimming” rubber fin that mimicked a fish. They then blindfolded and placed headphones on the seals to test their ability to hunt without sight or sound cues.

Not only were the seals able to detect the “fish’s” movements, their whiskers may be able to distinguish even more precise information than just their prey’s whereabouts. Senior author Wolf Hanke of the Marine Science Centre at the University of Rostock, Germany, told BBC News, “They seem to be able to discriminate between different shapes, which might even mean they discriminate between different species of fish.”

The authors found evidence that the seals track the direction that a fish swims by sensing its underwater wakes, or trails of slightly disturbed water, that linger for up to 35 seconds. To do this, seals detect and interpret “the structure and spatial arrangement of the vortices” that spin off from a fish’s underwater trail.

Not only can seals detect the vortices, but they can sense the “high water velocities” behind a swimming fish even after the fish is long gone. Water that trails a fish flows just a little faster than the surrounding waters. Somehow, the seal must automatically subtract the resistance caused by its own motion through the water in order calculate the exact location of its moving dinner. …
The best explanation for the origin of these complex creatures remains the one presented in Genesis–that on the fifth day of creation, God said, “Let the waters bring forth abundantly the moving creature that hath life,” and it was so [Genesis 1:20].

[Quoting Brian Thomas, “Seal Whiskers Track Fish Trails”, ICR News (June 22, 2010), citations omitted here, posted at http://www.icr.org/article/seal-whiskers-track-fish-trails/  .]

harbourseal-eating-salmon

As warm-blooded mammals, Harbor Seals need to burn food energy to keep warm. Blubber helps to insulate the seal’s core but food energy is a must, constantly! So, to maintain their body temperature, especially while they swim in super-frigid seawaters, they must eat a lot – and they are habitually hungry!

harborseal-vs-octopus-whoa

Harbor Seals frequently feast on cod, sea bass, mackerel, anchovy, whiting, herring, hake, sole, flounder, some crustaceans (including crabs and shrimps), small-sized octopus or squid, sometimes salmon or trout, or maybe even a sea-duck – eating about 5% of their body weight each day! Humans (like me) can enjoy a similar “marine platter”, but not in the large portions that adult seals voraciously consume, to fuel their minimum daily nutrition requirements! (To compare seal appetites to your own metabolic habits, multiple your own body weight by 5%, then imagine eating that much each day!)

harborseal-on-beach-by-seagull-oregondeptfw

Harbor Seals don’t really “chew” their food, though – rather, they bite and they tear, they crush with their molars, then they quickly swallow whatever meat they eat.  Perhaps a fitting greeting to a Harbor Seal would be “Bon appetit!  But seals have a right to be hungry, and to eat a lot, because God made them to operate that way – they have a lot of work to do, as they eat and swim and dive, always displaying God’s marvelous bioengineering !

O LORD, how manifold are Thy works! In wisdom hast Thou made them all: the earth is full of Thy riches. So is this great and wide sea, wherein are things creeping innumerable, both small and great beasts.   (Psalm 104:24-25)

[An earlier version of this article appeared as “Harbour Seal: Nordic Natural Heritage (Spotlighting Amazing Creatures of the Vikings’ Natural World)”, in Viking History & Heritage Review, January AD2005 issue, pages 4-6.]
><>  JJSJ

harborseal-displaying-forefin-brett-klaproth