Evolution Encyclopedia Vol. 3
Chapter 28
THE CREATOR'S HANDIWORK: THE BIRDS
INTRODUCTION
The
freedom of the bird! Able to fly so high and so far! Yet It took careful
design to make them. There Is nothing haphazard about the structure of a
bird. Everything had to be carefully thought out In advance. But, all
aside from most of those basic marvels, In this chapter we will consider
a number of additional ones.
ARCTIC TERN
The arctic tern nests north of the Arctic Circle. When
the summer ends, these birds fly south to spend the next half of the
year on the pack ice near the South Pole! All year long they are either
living in summertime at one of the poles, or traveling between them!
Before
returning to the Arctic when the next northern spring begins, they may
circle the entire continent of Antarctica. By the time they have
returned to their Arctic nesting grounds, they will have completed an
annual migration of 22,000 miles [35,200km]!
BLACKPOLL WARBLER This little bird weighs only three-quarters of an
ounce! Yet in the fall it travels from Alaska to the eastern coast of
Canada or New England, where it stops over and gorges on food, stores up
fat and then waits for cold weather to arrive.
This
journey is about 2,400 miles (3,862 km), over trackless seas, and
requires about 4 days and nights of constant flying. No one is there to
tell the bird where to go, the height at which to fly, or where to turn.
No one is there to feed its tiny three-fourth's ounce body during the
trip. It dare not land on the water. Its tiny brain must guide it by day
by the sun moving across the sky, and at night by the stars; double
navigation!
it seems
almost beyond comprehension, yet the little bird does it. And its
offspring takes the same trip, without ever having been taught the route
or shown any road maps.
RUBY
THROATED HUMMINGBIRD This little fellow weighs only a tenth of an
ounce. That is all: one tenth of one ounce, and much of that is just
feathers. Yet twice each year this hummingbird crosses the Gulf of Mexico, from North
America to South America. Its little wings beat 75 times every second
throughout the 25-hour trip. The experts, who have time to figure out
the mathematics, tell us this amounts to 6 million wingbeats non-stop!
Six million wingbeats in 25 hours with no rest stops.
OTHER
MIGRATING BIRDS The golden plover migrates from the Arctic tundra to
the pampas in Argentina. That is a long distance! But certain sandpipers
migrate a thousand miles beyond the pampas to the southern tip of South
America.
Starting
in Alaska, the bristle-thighed curlew flies to Tahiti and other South
Pacific islands. Such migrations take them across 6,000 miles [9,655 km]
of open seas, with absolutely nothing beneath them to act as markers to
guide them! How can they do it? And their destination is tiny islands in
an extremely large ocean. Men need special navigational equipment to
make such a journey.
STILL
MORE MIGRANTS How can these creatures travel such long distances and
arrive at the right place? How can they have the stamina to do it? Who
taught them what to do, where to go, and how to get there? One thing is
certain: other birds did not teach them. This is obvious when we
consider the cuckoos and Manx shearwaters.
When the
cuckoos of New Zealand travel 4,000 miles [6,437 km) to Pacific islands,
they do so having left their recently-born children behind. After
strengthening for the trip, the young cuckoos later fly that same 4,000
miles [6,437 km) and join their parents on those islands!
Manx
shearwaters migrate yearly from Wales in England
all the way to Brazil.
Left behind are their chicks, which follow after they have grown strong
enough to make the trip. One shearwater
The
young birds have never seen their destinations or been there. They have
never been over the route before. No one showed them a map; no one sat
down and explained where they should go or how they should get there.
OTHER
MIGRANTS It is well known that homing pigeons will find their way
back to where they came from. Taken from their home lofts to any point
625 miles [1,006 km] away, they will return during the daylight of just
one day.
Birds
are not the only creatures that migrate. Insects such as the monarch
butterfly and the locust take long migrations. (When the monarch
migrates, different generations do different parts of the complete
migration cycle.) Eel, salmon and other fish also migrate, and in most
unbelievable and mysterious ways. Whales, porpoises and seals find their
way through vast distances of unmarked ocean waters to distant breeding
grounds. They do this as unerringly as do the birds which fly overhead
to faraway places.
The barn
swallow annually migrates 9,000 miles [14,483 km] from northern
Argentina to Canada.
A major
part of many of these migrations is done at night, and over unmarked
water. Each species follows special routes not taken by other species.
The birds leave their summer nesting grounds only at certain times. They
arrive at certain times. They come back at certain times. Last but not
least, they succeed in what they are doing. They do the impossible, and
get there!
GUIDANCE SYSTEMS How do they do it? Scientists are trying to unravel
the mystery of migrational flight. They have made a few discoveries, but
the discoveries only deepen the mysteries.
The
lesser white throated warbler summers in Germany but winters near the
headwaters of the Nile River in Africa. Toward the close of the summer,
when the new brood of young is independent, the parent birds take off
for Africa, leaving their children behind. Several weeks later, the new
generation take off and fly, unguided, across thousands of miles of
unfamiliar land and sea to join their parents. And they have never been
there before!
German
researchers raised some of the warblers entirely in a planetarium
building. Experiments proved that, within their little bird brains, is
the inherited knowledge of how to tell direction, latitude, and
longitude by the stars, plus a calendar and a clock, plus the necessary
navigational data to enable them to fly unguided to the precise place on
the globe where they can join their parental Talk about dogs that travel
thousands of miles to their masters; we are here considering birds with
the smallest of brains!
Cornell
University scientists were able to figure out that the homing pigeon
determines directions by observing the position of the sun in relation
to the bird's internal calendar and clock.
But that
does not solve the problem of how they get home on overcast days.
Further investigation disclosed that they have directional
electromagnetic abilities also. Tiny electromagnets placed on their
heads destroyed this homing ability on cloudy days, but not on sunny
days. So they have sunlight and some type of internal magnetic compass
as two separate guidance techniques. But what are we talking about here!
A pigeon's brain is no larger than a small bean!
STILL
MORE ON GUIDANCE The indigo bunting is a beautifully-colored bird.
Before September and April, they eat a lot, gain weight, and,
significantly, they start becoming more active at night. Are they taking
some time to match information in their genes with the stars they see
overhead? If they are a year old, the last time they saw those stars was
many months earlier, and those stars were positioned differently at
various times of the night.
Then in
September and April, migration begins. The little birds will fly as much
as 2,000 miles [3,218 km] south or north.
Emlin, a
research scientist, took indigo buntings and put them in a cage so that
they could see the sky at night. In the fall the birds kept facing south
and in the spring they faced north.
Then he
took them into a planetarium. Those large dome-covered buildings house
very expensive equipment that is able not only to project points of
light where the major stars would be on the sky above,but the equipment
can omit various lights. After painstaking work, blotting out certain
stars and permitting others to shine, it was learned that the small
birds were being navigated by the northern polar stars. This includes
Polaris (the north star), the Big and Little Dipper, Cassiopeia, and
Cepheus.
In one
experiment, he had the north star moved into the western sky, and the
birds began facing west. This and similar activities demonstrated the
importance of that single star over any other single star in the
northern sky.
Then he
took a dozen baby indigo buntings, which had never seen the night sky
before, and set them out in cages. At first, they did not seem to know
directions, but two weeks later, and thereafter, they did. Within two
weeks something had matured in their brains and certain inherited
knowledge became available to them.
How then
does the monarch butterfly navigate as much as a 1,000 miles every
spring and fall when he has a brain far smaller than that of a baby
bird?
Before
concluding this section, it is of interest that the indigo bunting
changes the color of its coat each fall from blue to brown. In the
spring it changes it back to blue. Researchers found that the change was
due to a change in the length of the day. As it shortened in the fall,
something within the brain of the little bird told it to change the
color of its feathers ! In the spring, longer days triggered it
automatically to return to blue. So, in addition to their other
abilities, these little birds automatically time the length of the
daylight hours!
EMPEROR PENGUIN The emperor penguin lives 35 years, and is the
largest of about 12 species of penguins (all of which stay close to the
south polar waters).
Swimming
through the frigid ocean waters past ice floes, the penguins head toward
the shelf of ice. Sighting it, they leap up and land right on it. That
is no easy task, since sighting an object out of water--from
underwater--cannot easily be done.
Then
they begin their march inland. Sometimes walking, sometimes sliding on
their bellies, onward they go for many miles. Arriving at a desolate
place, that is frankly as desolate as all the other places on the
journey, they stop and the female lays one egg onto the males feet. He
quickly covers it with a fold of feathery fur skin and keeps it warm.
For 64 days he stands there, living on body blubber and eating nothing.
At the beginning, the female held it briefly, but soon she leaves and he
cares for them. She spends the next 2-3 months feeding in the ocean.
About 100 penguin males will be in each group, standing a few feet
apart, hatching eggs on their feet.
Soon
after the babies hatch, the females return. But how do they know where
to return to, across the trackless wastes of that white land? This is
another great mystery. If you or I tried to do it in the perpetual
darkness of an Antarctic winter, we would get lost in the wind and
storms. When the females return, the males have lost 20 pounds ]9 kg],
and now they go to the ocean and feed. The females remain and each
gradually regurgitates a stomach-full of food for their little ones.
By
bearing their young in the winter, the children can be young adults
within six months. They need summertime in the Antarctic Ocean to get
ready for the soon-coming long winter.
PTARMIGAN The willow ptarmigan can change its color at will to fit
the environmental background. Other creatures, such as the arctic
PIGEON SORTING No, people are not sorting pigeons; the pigeons
themselves are doing the sorting. Pigeons at Japanese Deer Park,
California, have been trained to sort electrical parts. They are able to
do it faster, better, and longer than people! The problem is that people
rapidly become bored with the task.
HORNBILL The hornbills of Africa and Asia have large bills with what
appears to be a small horn, parallel to the bill, lying on top.
A pair
of hornbills find a hollow tree and they make a hole in the side. Then
they bring clay and wall up the opening until the female can barely
squeeze through. Inside, she continues to wall up the opening to only a
narrow slit, using more mud which the male brings her. Through this
opening the male feeds her 30 times a day as she incubates the eggs and
after they hatch. Soon he is bringing her food 70 times a day! When he
no longer can bring enough food to supply their need, she breaks out the
mud door and flies out. The 3-week-old babies then set to work and patch
up the hole again with mud! Both parents now bring food to the young.
Three weeks later, the little ones break down the opening and fly out.
QUETZAL The quetzal is the national bird of Guatemala, and is,
indeed, very beautiful. It is a foot long, with two 2-foot [61 cm] tail
feathers!
It lives
on fruit which grows on the sides of trees. Much of the time it hovers
as it eats the fruit. But whether it hovers or lands, when it is time to
leave the fruit on the side of the tree, the bird goes through a special
procedure to do so.
The
problem is those long tail feathers. It cannot just fly off or it will
trip over the feathers or they will get caught on something. So it flies
backwards several feet away from the branch, and then hovers for a
moment, flies forward and leaves.
When it
is time to make a nest, the quetzal female prepares it a foot deep in a
rotten tree with nice soft rotten wood inside. After making the nest,
the male helps incubate the eggs. But once again, he has that beautiful
long tail to contend with. He solves the problem by pulling his long
tail up over his head, and then flying backward into the nest!
When the
babies hatch they cannot digest fruit until they are a month old. The
parents automatically know this, and only give them grubs during that
first month. This may seem a little matter, yet if the parents gave them
the wrong food, the babies would die and within one generation there
would be no more quetzals. So from the very beginning, quetzals have
known what to do.
Three
years after birth, the males grow their nice long tails.
HERRING GULL Herring gulls have bright red markings on their bills.
One researcher (Tinbergen) discovered that hungry chicks instinctively peck
at anything red. When they peck at the mother's beak, they receive food.
But they will even peck at a red spot on a piece of cardboard.
OwlsOwls
have soft down on their feathers so they can fly noiselessly, since
their diet is primarily mice and rats. Their eyes are unusually large so
they can see well at night. In the darkness, the retina (black portion
in the middle of the outer eye) becomes very large. If it were not for
owls, the world would be overrun with mice and rats.
The head
of an owl can turn around in almost a complete 360 circle, without
moving its body in the slightest. Then suddenly it snaps its head back
around and begins again. In this manner, it appears to be turning its
head endlessly around and around.
ANTINGThere are 200 different types of birds which rub ants on the
underside of their flight feathers. They crush the body of the ant and a
special acid comes out formic acidwhich is colorless and has a strong
odor.
This
acid helps keep lice off the wings, but also softens and tones the
flight feathers. When the wing beats up, the barbs on the feathers
become unhooked; when the wing beats down, they become hooked again. Ten
times a second this hooking and unhooking occurs. The acid keeps the
feathers in better condition.
Birds
begin "anting" 2-3 days after leaving the nest, but there is no
indication that they are taught to do it.
Many
species will sit on the ground near an ant nest. The ants, concerned to
protect their nest, climb up on the bird's feathers and there release
formic acid, which drives off mites and most other tiny pests.
EYESIGHTAn OWL Can See 100 times better than man at night. The
golden eagle can see a rabbit at two miles.
HAWKS
AND THE WARREN TRUSSGo into a modern wide warehouse having no
central posts, a flat roof, and no drop ceiling to cover the supports
and gaze upward. You will probably see a Warren truss above your head.
Look at the best of the modern bridges, and you will see it again. Draw
two parallel horizontal lines, one above the other. Between the two
lines draw a straight not curvedzig-zag line back and forth (at 45
angles from the horizontal lines) from top to bottom. You have designed
a Warren truss. It is full of triangles.
That is
the design of the bone structure of hawks. It is the lightest, strongest
engineering structural design known.
Animals
generally have hollow bones to give them more strength with less weight
in those bones. Bird bones must be especially light and strong, so, for
added strength, they will have struts built into their thinner bones.
But hawks need especially strong bones. They must climb quickly, drop at
high speed, and carry heavy
It cost
modern mankind millions of dollars and untold thousands of man-hours to
invent the Warren truss. And here the hawk had it all the time! These
excellent inner diagonal struts which connect the load-bearing bony
beams, give them maximum strength with the least possible bone fiber.
WINGSFlight
requires two forces: lift and push. Lift gets the plane off the ground
and keeps it in the air; push moves it forward. Lift comes from the
wings, and push from the propellers.
On the
forward edge of a bird's wing are specially-designed feathers, called
primaries. The air flows up and over this leading edge of the wing,
providing partial lift. The downstroke of the wing movement provides the
rest of the lift. But on the upward stroke of the wing, the primaries
move upward and backward, providing push. So birds have the equivalent
of both wings and propellers.
FEATHERSA feather grows from pin feathers, and when it reaches adult
size it becomes lifeless. A feather from a wing or tail will have a
shaft with branches. Each branch is called a barb. Each barb has
branches called barbules. These barbules overlap one another and are
hooked together with tiny hooks and eyelets. It is this automatic
hooking mechanism which renders the feather useful for flight.
The
feather is the lightest, strongest thing in the world. Or, to put it
another way, it combines the least weight with the most air-resistance
of any object in the world.
When a
bird molts, it drops feathers from both wings symmetrically. Thus the
balance is more easily preserved than if one wing lost more feathers
than the other. In this way each bird can at all times protect itself
and obtain food.
Birds
frequently preen their feathers. It is important that they do this, for
in this way they clean, oil, and rehook feathers. Birds of the heron
family accumulate a coating of slime on their feathers. To clean it off,
a feather is plucked from one of three special patches of feathers on
the body. Then the heron crushes it into something like talcum powder.
The powder is then applied to the feathers, and it absorbs the slime.
After this is done, the feathers are combed out using a special toe. As
with most other birds, oil from a special oil gland is also placed on
the feathers to condition and waterproof them.
TEMPERATURE GAUGESThe beaks of the malle bird, the brush turkey can
tell temperature to within half a degree Fahrenheit. A mosquito's
antennae can sense a change of 1/300 degree Fahrenheit. A rattlesnake
can sense a change of as little as 1/600 degree Fahrenheit.
EGGSWhich
came first the chicken or the egg? We have all heard that question
before. But it only sounds simple because we have heard it
But
there is more to eggs than appears on the surface:
(1) The
shell has to be strong enough to resist accidental breakage, yet fragile
enough that the chick can get out of it. (2) As the chick grows inside,
more and more water accumulates. The egg must lose the right amount of
water through the shell so that the chick does not drown, does not dry
out, and has enough water for its needs. (3) The original size of the
egg must match the size of the chick just before hatching. (4) Gases
from inside must be able to get out through the shell. (5) There has to
be a special membrane which separates the chick from its wastes. (6)
There has to be a second special membrane which allows it to breathe air
in some way from the outside. (7) Waste products from the chick must be
in the form of insoluble uric acid, not the soluble kind produced by
amphibians and mammals. (7) The egg must be fertilized before the shell
hardens. (8) The chick must be given a small hammer to chip its way out
of the shell, and the sense to use it at the right time.
What are
the chances of all that happening by the random events of "evolutionary
progress"? None; none at all. Yet everything had to be just right when
the very first hatching occurred!
Well,
here are a few more facts about this "simple subject" of eggs:
The
chick has to be able to breathe inside the shell, so the eggshell has
10,000 tiny holes in it for this purpose. You need a microscope to see
them. Under the shell there are not one but two tiny membranes, with
tiny holes in them also.
The baby
chick needs oxygen, but first it must grow something that can take in
that oxygen! For the first several days, it has all the nourishment and
oxygen it needs inside the yolk. Two blood veins gram out of its body
and branch out into hundreds of tiny capillaries. They grow around
inside of the shell, just below the two membranesand they attach to the
lowest of the two. By the 5th day, they are fully in place. The heart is
pumping, air is going through the 10,000 holes, through the membranes,
and into the veins.
The "law
of diffusion" operates here. Because there is lots of oxygen on one side
of the skin or shell, and a small amount on the other side, the gas
wants to get through to equalize. So oxygen passes through the shell and
to membranes and into the veins and gives oxygen to the chick! This
matter of the "simple chicken egg" is becoming more complicated all the
time! And it is all supposed to have evolved by chance? But, by the time
evolution got around to getting started on developing the egg, all the
birds in the world would be dead. And by the time it got ready to figure
out how to make birds successfully grow and hatch from eggs, all the
eggs would have rotted.
The baby
chick uses 61/2 quarts, or 1 1/2 gallons [6.15 liters], of fresh oxygen
while he is inside the shell. He gives off waste gas (carbon dioxide)4
1/2 quarts [4.26 liters] of itwhile he is in the shell. It goes out by
diffusion; there is more inside than outside, so the gas leaves, and
plants use it to give us more oxygen.
Interestingly enough, when the chick first begins, everything he needs
is inside the shell except, after the first few days, the oxygen. The
yolk becomes food for the baby. On the 5th day, 2 veins go into the yolk
and branch out. This brings food from the yolk to the chick.
As fat
inside the yolk is used up, it is replaced by water vapor. That water
vapor must go, for it is a waste product. From the chick it goes out
through veins to capillaries just under the shelland then out by
diffusion through the shell.
But what
takes the place of that water vapor? Oxygen and other important gases
enter through the shell. This air goes into the little sack at the blunt
end of the shell
As the
chick grows, the sack grows also, until it is 15 percent of the egg.
This is important, for when the baby chick is 20 days old, it is so big
it can no longer get enough oxygen from capillaries under the shell The
chick is in serious trouble! It will soon die before hatching! But, no,
instead at that crucial time, the chick jerks it headand punctures a
hole in that air sack! It finds airand now it begins using his lungs for
the first time!
But why
is it that the chick always grows with its head facing toward that sack?
If it faced the other way, it would not punch that hole in the sackand
the chick would die from lack of oxygen. But the head is always faced
the right direction.
Six more
hours of air is given to the chick by punching that hole in the sack.
But then another crisis comes! The air from the sack is about used
up,and a second time it has run out of oxygen! Now, in a last desperate
attemptit hits the shell above its beakand a small hole is made. Air
comes through! Now the chick begins in earnest to punch a hole in the
shell itself. Pecking on the shell, it breaks throughand still more air
flows in.
But this
final rescue would be impossible were it not for a small pointed object
on the top of the chick's beak. This is a tiny "egg tooth" which looks
like an upside-down "W'. Now the chick must work to get out of the
shell, and that very work strengthens its little body. Soon it is out,
and a few days later the egg tooth falls off, for it is no
BIRD
SONGS Bird songs require special body parts. The organ which
produces the song is the syrinx. It is located at the lower end of the
trachea (whereas our larynx is positioned at the top part of the
trachea). Because it is at the bottom in birds, the length of the
trachea can be used as a resonant organ to reinforce the sound, and the
throat can be used to modify the tones. Because birds do not have facial
sinuses to produce resonance, if their syrinx waslike oursat the top
part of the tracheas, we could hardly hear their songs.
FEEDING NICHES Birds fill different "niches" in the scheme of
things. Each type of bird has a special place where it feeds which is
somewhat different than most other birds. Because of this, there is very
little competition among the various birds. Consider this:
Creepers
feed on the bark, going up. Nuthatches feed on the bark, going down.
Woodpeckers feed on the trunk and branches, digging in.
Chickadees feed on the smaller twigs. Kinglets feed on the smaller twigs
and foliage. Warblers feed on the ends of the twigs and in the air.
BODIES OF BIRDS Each bird has the type of feet it needs. Land bird
have short legs and heavy feet; wading birds have long legs; swimming
birds have webbed feet; perching birds have slender legs and small feet;
scratching birds have stout feet and moderately long legs.
Each
bird has just the type of beak it needs. Seed eaters have short, blunt
beaks; woodpeckers have long, sharp beaks; insect-eating birds have
slender beaks; ducks and geese have beaks fitted for gathering food from
the mud and grass; hawks have hooked beaks.
Birds
are designed for lightness, since most of them fly, and many need
buoyancy in the water. The bones are hollow and filled with air. There
are large air sacs in the body. Feathers enclose more air spaces. All
the air inside a bird's body is heated 10-20F above that of a human
body. This heated air gives added lift and buoyancy to the bird.
Because
the air in a bird's body is lighter in weight than anything else, birds
balance by shifting their air load! A bird is able to automatically
shift air from one body air sac to another, so that it can maintain its
balance while flying. If a bird did not do this, it could not maintain
its balance in flight.
A bird
has rib muscles just as we do, but it also has flying muscles also. When
it is resting, a bird breathes by its rib muscles as other animals do.
But when it flies, the rib muscles cease operating-and the ribs become
immobile. This is because the strong flying muscles must have a solid
anchorage on a rigid bony frame. How then does the bird breathe while it
is flying? The wing muscles cause the air sacs to expand and contract,
and this provides oxygen to the bird in flight since its lungs are not
operating properly due to locked ribs. It took a lot of thought to
design that!
Birds
that feed out in open fields will tend to be more brilliantly colored.
This is because they can see their enemies at a distance. Birds living
in the woods and thickets will tend to have protective coloration, since
they cannot as easily escape from enemies.
Water
birds spend much of their time floating on the water, so they have
thick, oily skin and a thick coat of feathers which water cannot
penetrate. Diving birds have a special apparatus so they can expel air
from their bodies. In this way, they become heavier and can stay
underwater more easily.
PARROT BEAK Parrots can move the upper jaw separately from the
skull! But they need to be able to do that, for in this way they can use
the jaws as pincers to grip and climb up and down, as well as in
obtaining food.
CROSSBILL
The crossbill is a bird with an unusual shape to its bill. The two parts
cross somewhat like curved scissors. But why? The crossbill feeds on
pinecone nuts, and it uses its bill to open the pine cones. Of all the
birds, only the crossbill is able to open an pinecone and eat the nuts
inside it.
DUCKS
Have you ever wondered how a duck obtains its food? Along the edges of its
spoon-shaped bill are small teeth. The duck reaches down to the bottom of
the pond and feeds on the mud. It squirts mud through its spoonbill
mouth, and as it does so the small teeth strain out small creatures
which it eats. The mud is spit out.
DOUBLE-COLOR BIRDS When, in the fall, the new feathers appear on many
bright-colored birds, the tips of the feathers are dull in color. During
the winter, these dull tips wear off, and when spring and mating season
arrives, these same birds now have brilliant plumage colors.
HONEYGUIDE The African honeyguide is a small bird which leads people and animals to bees' nests. When it leads a badger to the nest, the badger tears open the nest and both enjoy the honey. But the honeyguide also leads the Boran people of Kenya to the honey nests also. Having found a nest, it will, through flight patterns and calls, alert a Boran to send a group to follow the bird to a honey site. But the Borans initiate the search as well as the bird. They will whistle to call the honeyguide. Arriving, it will lead them by flying a short distance and waiting for them to come. Arriving at the honey nest, they always leave some honey for the honeyguide. Scientists have even seen the honeyguide scouting out bees nests at night, so it could promptly lead a group to it the next morning!
WATER
OUZEL The water ouzel is a regular songbird that flies underwater!
The
water ouzel (pronounced oo-zul) looks like a normal bird, such as a
robin. It has no webbed feet, no fins. There is nothing different about
its appearance in any way from normal song birds.
But,
flying to a rock on the edge of a river, it will jump right in and begin
flying with its wings under the water! The water can be swift, white
water, swirling over rocks, but it matters not. The water can be cold
also! This small bird will dive into ice cold water in the creeks and
rivers in the high country of the Sierra Nevada range. But, wherever it
may be, the ouzel is quite at home in the water.
After
flying for a time, it will land on the bottom and turn the rocks over
with its beak and toes to feed on various water creatures that are
uncovered. Then it will fly up out of the water again.
When it
is time to prepare its nest, the water ouzel flies into a waterfall and
makes its nest on living moss on a rock. Spray from the waterfall keeps
the moss wet and well attached to the rock. So the nest has a secure
foundation. Each time the bird goes to or from its nest, it goes through
that waterfall!
WHITE-COLLARED SWIFT The white-collared swift is found in the Mexican
jungle and, like the water ouzel, also flies through waterfalls!
The
white-collared swift is a powerful flyer and can go 80 miles [129 km]
per hour. In many ways, this swift is completely unlike the water ouzel,
but in one way it is very similar: It builds its nest behind waterfalls.
But, in addition, when not nesting, the white-collared swift continues
to make its home behind waterfalls when not nesting; something that
ouzels do not do.
SNAIL
KITE The snail kite is a hawk like bird which lives in the
southeastern U.S. swamps. It soars over the swamp looking for large
snails, called "apple snails." Every so often one rises to the surface
for air. Swooping down, it seizes the snail before it sinks again, and
carries it off to a tree limb where it proceeds to eat the snail. But
the shell is strong and the kite could not eat it except for the fact
that the curve of the kite's bill exactly matches the curve of the
snail's opening!
SUGARBIRD Here is a bird that depends on one bush for everything. The
sugarbird lives in the mountains of South Africa, and has a 4-inch
[10cm] body, and a 10-inch [25-cm] tail.
The
protea bush, growing on those same slopes, is large-about 7 feet [21 dm]
tall and very bushy. The sugarbird goes to its pink flowers and sips the
nectar. It also eats bugs, flies, and worms that come to the flowers.
The bill
of the bird is long, round and narrow just right for sipping the sugar
water in the flower. A problem is that the flower, which is also long
and narrow, curves downward. But the bill of the bird has exactly the
same angle of curve, and it is also a downward curve! So the sugarbird
need only go up to the flower and reach down in and take the nectar.
But more
than a long, narrow, curved bill is needed. There is also a pump in the
bird's throat, with a pipe leading from the pump to the bill. That pipe
is its tongue which it twists into a pipe shape.
Both the
bird and the bush are obviously designed for one another.
But
there is more: The sugarbird makes its nest in the protea bush, but only
makes its nest when the bush is blooming throughout the summer. In this
way, the bird can feed nectar to its children. Along with grass, the
nest is made from dead protea bush twigs which the bird finds underneath
the bush.
Inside
the stick nest, the bird places soft, white fluff for the baby birds to
sit on. Where does that fluff come from? It is dried-up petals which
earlier fell from the protea bush.
For its
daily drink of water, upon arising, the bird obtains water from the
leaves. The same dew which fell on the bush at night also provides
enough wet leaves that the bird takes its bath by flying into the
branches and shaking itself. As it does so, water showers down upon it,
providing it with a morning shower bath!
Occasionally the bird must search elsewhere for food, but that does not
happen very often. For the most part, the bush provides for all the
needs of the sugarbird.
CANADA GEESE As do a number of other creatures, the Canada goose
mates for life. As the geese are flying in "V" formation, if one mate
goes down from sickness or injury, the other will go down with it and
stay with it till it is able to fly again.
When
landing on the water, these large birds lift their wings at the last
moment to cut speed, and then run on the water for a distance, and then
alight on it. Taking off, they begin running on the water again as they
pick up speed for flight.
The
first day the goslings are hatched, the female leads them immediately
into the water. The male goes ahead and beats on the water with its
wings to frighten away enemies.
When
they migrate, Canadian geese fly in the long "V" formations you have
seen in the sky in order to reduce air resistance on the entire flock.
The leader meets the full force of the wind, so they take turns leading.
Scientists now know that they navigate by the stars.
SNIPE The
snipe has two special feathers that jut out at right angles when it
makes a dive, resulting in a loud buzzing noise. The snipe only makes
this buzzing sound on two occasions: (1) when it is ready to mate, and
(2) when a storm is coming that will hit later that day or night. For
OILBIRD
In the deep, dark caves of northern South America is to be found a strange
bird. The oilbird (Steatornis caripensis) gets its name from the natives
that rob its nests, boil the squabs for their high oil content, and then
store and use the oil to flavor their food.
A major
part of the life of this bird is spent in total darkness in those caves.
The young are hatched in total darkness, fly around in the caves without
hitting the walls or other birds, and eventually emerge with their
parents during the night to search for tropical fruits.
How can this bird fly around the cave without striking something? The answer is that it uses sonar. The oilbird emits distinct evenly-spaced clicks. The return time for the echo tells the bird what is in front of it, which is not only boulders and cave walls, but other flying birds as well!
No one
ever taught the oilbird how to do this. It was born with the ability.
When scientists plugged the ears of two of the birds, they found that
they collided with the walls, thus proving that sonar was being used.
SUNBIRD The sunbird of Africa has metallic colors: blue under its
chin, bright red on its chest, and shining black feathers on its back.
Its bill
is 2 inches (5.08 cm] long and slightly curved to match the flowers,
with a special tongue which curie and sucks out the sugar water. When it
encounters extra-long flowers, the bird pokes a small hole at the base
of the flower and sucks out the nectar. A built-in pump is in its throat
to draw the nectar up its bill and down into its stomach.
It
pollinates flowers with its feathers. Just as bees do, the sunbird only
goes to one species of flower at a time; in this way cross-pollination
is insured.
When the
sunbird arrives at the African mistletoe flower, it has to tell the
flower to open up! If the bird did not do so, that flower would always
remain clod. Carefully, the bird puts its long bill inside a slit in the
flower. This triggers the flower, and it opens immediately, shoots out
its anthers, and hits the bird with pollen all over its feathers. Then
the bird goes to the next mistletoe and pollinates it, repeating the
process.
Evolutionists declare that all flowers were made millions of years
before insects and birds. But if that was true, then the flowers had to
wait millions of years before being pollinated.
EAGLES, HAWKS, AND BUZZARDS These large birds have to be able to see
very well, so they have been given excellent eyesight. They can climb
high in the sky, as much as a mile up and then as they ride on thermals
(rising warm air currents), they gaze down and are able to see a mouse
or a rabbit on the ground.
Their
brain causes the eyes to be able to zoom in and make things look closer,
or zoom out and see regularly when they land in a tree or on the ground.
If that did not happen, they could not see things less than 40 feet [122
dm] away.
In the
morning they do not leave the tree they roosted in during the night
until it warms up. Then they fly off on rising air currents, and soon they
look like gliders, floating in the sky.
PIGEONS AND DOVES When their young hatch, both parents produce a milk
in their throats, and open their mouths. The baby doves and pigeons
(squabs, they are called) reach into their parents' throats and get the
milk that is there. Here is how it works in more detail:
As the
parent stands before the squabs, it opens its mouth wide, and a special
pump turns on, pumping up the milk into its throat. A baby sticks its
head into a parent's mouth and sucks it in. They continue to eat in this
way for at least a week, and then are ready for grains and worms.
Four
days before the babies emerge, both the mother and father somehow know
that the egg is about to hatch. This excites them and they stimulate the
gland in their bodies that produce that milk. By the time the squabs
have come out of the shells, there are lots of enzymes, and milk
production begins.
WHIPPOORWILL The whippoorwill is the well-known southeastern U.S.
bird which flies at night. There are bristles on either side of its
beak, and these can feel the bugs as it flies. Quickly, turning its
head, it eats them.
The
whippoorwill is one of the only birds that hibernates. It remains
through the cold winter and sleeps. While its body temperature is
normally 104F (40C), it drops 40F during hibernation to 60 (15.51/2).
When the temperature goes down to 38F (3.3C) and stays there a few days,
then the whippoorwill searches for a place to hibernate between some
rocks and begins its long sleep.
A
whippoorwill only needs 1/3 ounce (9.36 g] of food to keep it alive and
well during the approximately 100 days it hibernates. During that time,
no breathing or pulse will be detectable.
Not only
can the whippoorwill take the cold, it can withstand terrific heat. When
the weather becomes too hot, the whippoorwill slows its body rate
(breathing, heart rate, etc.) to 1 /30th that of normal. So, both in
summer and winter, the Whippoorwill adapts by slowing its metabolic
rate.
The
Egyptian vulture is about the size of a raven, and it eats the eggs of
other birds-especially large ostrich eggs. The eggs of an ostrich are so
large and strong that they cannot be opened by pecking them.
In the
Serengeti! National Park in northern Tanzania, the Egyptian vulture
(Neophron percnopterus), has been photographed throwing rocks to break
ostrich eggs so the bird could eat them. Various species of birds may be
standing nearby, wishing they too could eat some of the egg, and will
watch the Egyptian vulture in action, but will never try to do what it
does. They seem not to be able to understand how it accomplishes the
egg-breaking, but they know !t can do it.
Seeing
the egg, the Egyptian vulture goes into action. It hurries here and
there, searching for a rock of just the right size. Picking up a stone
in its beak, the vulture raises its head as high as possible and then
throws the stone at the ostrich egg. Sometimes two birds will take turns
throwing stones at an egg. When rocks were not nearby, the vultures will
range as much as 50 yards [46 m] away looking for them. These birds have
been known to hurl stones as large as a pound in weight. About 50
percent of the time the vulture hits the target directly. Crack/splash!
It is dinnertime.
Checking
this out, scientists found that the Egyptian vulture will hurl stones at
anything that is egg-shaped, regardless of the size; but it will ignore
anything not egg-shaped.
Other
tool-users include chimpanzees which occasionally use sticks as tools to
dig termites and ants out of their nests. A Liberian chimpanzee was
observed using a rock to pound open a palm kernel. A small finch in the
Galapagos Islands uses a cactus needle to dig worms out of holes in
wood. Several other examples of tool-using animals are known.
COWBIRD It is well-known that the cowbird in America, and the cuckoo
in England, lay their eggs in other birds' nests. In one research study,
young male cowbirds were only paired with song-less female cowbirds from
another locality, where the cowbird song is distinctly different. (Keep
in
MARVELOUS HUMMINGBIRD The Peruvian marvelous hummingbird, truly is
marvelous! It has iridescent green, yellow, orange, and purple feathers
which glint in the sunlight as it flies and hovers over flowers. While
most birds have 8 to 12 tail feathers, the marvelous hummingbird is
unique in having only four. Two of those four are long, pointed,
thorn-shaped feathers. They are 6 Inches long, which is 3 times longer
than the birds body. On the end of each of these two long narrow
feathers, is a large, wide fan! Their surface area is almost as large as
the hummingbird's wings! With such feathers, the little bird should
hardly be able to fly, yet it can, and for a special reason: The marvelous
hummingbird has complete control over those two feathers! At will, it
can bend and tilt them in any direction. In flight it uses them to help
maneuver, at rest, it can move them in various directions. During mating
season, it signals with them. They are like little semaphores.
HUMMINGBIRD The ruby-throated hummingbird beats its wings at an
incredibly rapid speed: 50 to 70 times a second! It requires an immense
amount of energy to do that. If a 170 pound (77 kg] man expended energy
at the rate of the hummingbird, he would have to eat and digest 285
pounds [129 kg] of hamburger or twice his weight in potatoes each day in
order to maintain his weight. In addition, he would have to evaporate
100 pounds [45 kg] of perspiration per hour to keep his skin temperature
below the boiling point of water.
PALM
SWIFT
The ways that different creatures live is incredible. No two
seem to be exactly alikeand some are so very different as to be
astounding.
The palm
swift lives in Africa and, with its long, narrow wings, can fly 70 miles
[112.6 km] per hour. It flies as much as a mile high in the sky eating
bugs flying in the air. A sensitive barometer is in its brain, and it
can know when storms are approaching. When that happens, it will fly at
right angles to the storm and thus avoid it.
The palm
swift only lands on trees or buildings, never on the ground. With its weak
legs, it would have to climb a tree to take off!
This
swift builds its nest in the sand palm tree. Using sticky saliva, it
glues some of its feathers to the back side of a palm leaf. Then it will
lay its eggs, catch and glue them to the feathers! What a strange nest;
always on the verge of falling to the ground, but never doing so. Next,
the bird
Researchers trying to figure out this strange procedure, decided that
the wind blowing the palm leaves back and forth, substitutes for turning
the eggs! After 19 days, the eggs hatch.
But now,
more problems! Now the emerging babies will fall out of the nest! But
no, instead, each of the tiny chicks digs its claws into the leaf and
hangs on! Although each baby is born with weak legs, yet it has strong
claws. The parents feed them for a week, and then the babies crawl to
the stem of the leaf where they are fed a couple more weeks. Then they
fly away.
WOODPECKER The redheaded woodpecker spirals up the tree trunks. It
pecks, then listens for a grub moving or turning. If no sound, it moves
on.
The
woodpecker also pecks for three other reasons: to send messages to other
woodpeckers, to store acorns and other nuts in holes, and to dig holes
for a nest. These nesting holes are 1 foot [30.48 cm] deep and 5 inches
[ 12.7 cm] wide. After vacating them, more than 30 other species of
birds will later use those holes for nests.
The
woodpecker has extremely strong neck muscles. It tenses them and they
vibrate. When it pecks, it aims straight down, perpendicular to the
wooden surface. If it did not do this, the offset pressure would tear
its head off.
The
woodpecker has special spongy bones to protect its brain, and its bill
is stronger than that of any other bird.
WOOD
DUCK The wood duck makes its nest in a hole 40 feet [122 dm] up in a
tree! The female lays eggs, but does not set on them until they are all
laid. In this way they will hatch at the same time.
She
pulls feathers from her chest to line the nest, and then while setting
on the eggs her body temperature 94F [34C]is exactly the amount of heat
needed by the eggs. The male feeds her while she is setting on the eggs.
As the
time nears for the eggs to hatch, she peeps to the unhatched chicks.
They peep back. She quacks some more. She is telling them that she is
their mother and that they must listen to her and obey her when she
warns of danger. Researchers have proven that if she does not do this,
they will not obey her afterward.
One day
after they are hatched, they leave the tree! They must do this for their
safety. But they are not only very tiny (only 3 inches (7.62 cm] long),
but they are also a foot [30.5 cm] deep down inside a hole that is 40
feet [122 dm] up in the air!
That
second day after they are hatched, the mother flies to the ground and
calls up to them. They obey her voice and, one by one, jump out of the
nest and down, down to the ground far below they fall.
How do
they do this? The little creatures are covered with down, but have no
feathers yet. Using their egg tooth with which to grip the sides, they
crawl up to the entrance of the hole. Then out they go! Because they are
so light, they land without being hurt. If they did not jump they would
die, for she never goes back up there again to feed them.
BLACK
SKIMMER This is a sea bird which does literally that: it skims over
the surface of the water. The top of its bill is 4 inches (10.16 cm],
but the bottom half is 41/2 inches [11.43 cm]. The skimmer uses it as a
fish trap.
While
flying over water, the skimmer drops to about 6 inches above the
surface, and lowers its bottom bill so that it is dragging in the water.
There are special nerves in the lower bill, so the bird can always know
how much of it is dragging in the water. With this automatic depth
gauge, the lower bill is kept exactly 4 inches [10.16 cm] in the water.
As soon as it touches a fish, the upper bill shuts and catches it.
Flying
at 20 miles (32 km] per hour and striking its bill against a fish should
break the bird's neck! But this does not happen, for it has very
powerful neck muscles. As soon as it strikes a fish, its tail
automatically goes down, slowing it to 10 miles (16 km] per hour.
In
addition, the continual wear on that lower bill should cause
considerable damage over a period of time, but instead that lower bill
is constantly growing to compensate for the fact that it is continually
being worn down! (Only the lower bill keeps growing; the upper one does
not.)
In
addition, this bird saves 50 percent of its flying energy, because there
is very little wind next to the water.
Because
it has a 4-foot (12 dm] wingspread, it only needs to slightly flutter
its wings in order to keep flying steadily. That is important. If it had
shorter wings, it would have to flap them, and the wings would dip into
the water, quickly slowing the bird.
With
this creature as with all the others, everything was obviously
thoughtfully planned out in advance.
The
skimmer is the only bird in the world with cat eyes! The pupils of its
eyes are like vertical narrow slits, and after dark they widen so it can
see the fish at night. According to evolutionary theory, this proves
that the skimmer must be closely related to cats! Except for its eyes,
it surely does not look like a cat.
When a
fish is caught, it is taken back to the babies who grab it out of their
parent's mouth. But they could not grab the fish if their bottom bills
were like those of their parents, longer on the bottom. So the baby birds
have the same size bills on both top and bottom. Later, when they are
ready to fly and catch their own, the bottom bill grows a half-inch
(1.27 cm] longer. When is that time? Exactly 6 weeks after birth, and
right on
MORE
ABOUT BIRDS During World War I, parrots were kept on the Eiffel Tower
to warn of approaching aircraft long before they could be heard or seen
by human observers. The parrots had far better hearing than the people
did.
A young
robin will eat the equivalent of 14 feet [43 dm] of earthworms a day.
In the
1840s, pigeons would carry European news from ships approaching the U.S.
to newspapers along the Atlantic coast. In spite of having traveled all
the way to one or more European nations and back, those pigeons still
knew where home was and how to get to it.
The
albatross has the largest wingspread of all: 10 to 12 feet [30-37 cm]
from tip to tip. When a young bird leaves the nest, it may not touch
land again for 2 years. Day and night it glides above the ocean,
occasionally landing on the water.
With few
exceptions, birds do not sing on the ground. They sing while flying or
while sitting on something above the ground. Exceptions include the
turnstone and some American field sparrows.
The
African eagle swoops down at more than 100 miles [161 km] per hour, and
can suddenly brake to a halt in 20 feet [61 dm].
A
parrot's beak can close with a force of 350 pounds [159 kg] per square
inch.
Every
bird must eat half its own body weight every day in order to survive.
Young birds need even more.
The
ancient Vikings from Norway navigated on the ocean with ravens.
Releasing them one by one, the men watched to see where they would go.
If the raven flew back to where it came from, they continued sailing
west. If it flew in a different direction, they would change course and
follow its flight path in search of new lands. They knew the raven could
sense distant land better than they could. Stories passed down from
generation to generation from Noah's time may have encouraged them to
try releasing ravens in the ocean, and they found it worked.
When a
woodpecker beats on a dry, resonant branch of a tree to talk to other
woodpeckers in the vicinity, the duration and rhythm of the drumming
tells whether what species it is, and whether it is a male or female.
Then another woodpecker, by pecking on a branch or hollow tree, replies
and tells what it is.
The
hoatzin when full grown is about the size of a medium turkey, but has
claws on its wings. Not long after birth, while still naked and without
feathers, it uses those claws to crawl up, down, and along tree branches!
The yolk
of a bird's egg is connected to the shell by albumen "ropes." When the
mother bird begins incubating the egg, these ropes break. Because of
this, the mother bird must rotate her eggs every so often. If she does
not do this, the yolks will not remain in the center while the chicks
are
BIRD
NESTS There are probably as many different nests as there are birds;
here are a few to think about:
The
weaverbirds of Africa weave grasses and other fibers into hanging nests.
A variety of weaving patterns are used.
Social
weavers build woven apartment houses, with thatched roofs 15 feet [45
dm] across. They locate strong tree branches and build the roof, then
groups of individual pairs gather under that roof and make their own
family nests. Before it is finished, over a hundred nests may be housed
under one roof. (When necessary, they add on to the diameter of the
roof.)
The
tailorbird of southern Asia sews leaves together, using threads it
obtains from cotton, bark fibers, and spider-webs. Carefully punching
holes along the edges of the leaves, it then pulls the thread through it
all and laces it up like shoes. The end is knotted, or spliced to a new
piece so the sewing can go on. The result is a big leaf cup, and all of
it done by the bird using its bill.
The
swift of Southern Asia makes its nest out of saliva. Gradually layer
after layer is built up until a cup-shaped nest is attached to the sides
of a cliff. The famed "bird's nest soup" of Southern Asia is made from
these nests.
The nest
of the peduline tit is rounded with a small entrance hole and appears to
be made of felt. A skeletal structure is first made of woven grass, then
overlaid with downy plant fibers pushed through the grass mesh. Finally
still finer fibers are pushed into the larger fibers. These nests are so
beautiful and sturdy that they have been used as purses or even as
children's slippers.
The
horned coot locates quiet water and then builds an island! The bird
laboriously carries over and piles up about 2-3 feet [61-91 cm] of small
stones until it dears the surface of the water; then a nest is built on
top, using vegetation. The bottom of the stonework may be as much as 13
feet [40 cm] in diameter. More than a ton of stones may have been
carried in for the project!
MALLEE FOWL The mallee bird lives in the Australian desert and does
not appear to be anything special, until you take time to watch it
carefully. Having done so, you are stunned with what you learn.
In May
or June, the male mallee bird makes a pit in the sand with his claws. He
continues until it is the right size: about 3 feet [9 dm] deep and 6
feet [18 dm] long! Then it is filled with vegetation of various
kinds, anything that will rot. But leaves from the mallee bush are
especially used, hence the name given to the bird.
As the
heap decays, it produces heat. The male waits for warm rains. When they
come, the rains soak up the vegetation and start it heating. Soon it is
up to over 100F [38C] at the bottom of the pile. The bird waits until it
is down to 92F [33C]. It continually it tests the sand with its amazing
beak.
If the
female tries to lay eggs on the pile before it is 92F, the male will
chase her away. He has a thermometer in his beak, and knows exactly how
warm it is, so well in fact, that he can identify temperature to within
half a degree!
When the
right temperature is achieved, he calls his wife and she lays an egg on
the dry leaves. Every day she returns and lays another egg, until about
30 of them are there. The male then covers them with sand and uncovers
and turns the eggs every other day.
The sand
holds the heat in, especially at night when the temperature drops to 50F
[10C]. But at night he tests the temperature within the sand, and if it
becomes too cold, he piles on more insulating sand. The next day, he
will test it again and take off extra sand. If he did not do this, the
nest would get too hot. He cannot let the eggs overheat even a half
degree!
This
goes on for 7 weeks until the first chicks hatch. Each chick comes out
of the egg, using its egg tooth, and then crawls out of the sand rapidly,
in spite of the fact that it may have to go up through as much as 2 feet
of sand!
Arriving
at the top, it is fully able to fly and is on its own. Neither mother
nor father give it any attention, training, feeding, or care from the
moment it is ready to hatch, onward. When it grows up, it does just as
its parents did.
How can
the offspring know to do the complicated procedures that its parents
did, if it never watched them or was taught anything by them? Even Isaac
Asimov is astonished:
"The
chick of the mallee fowl never knows either of its parents. As soon as
it burrows out of the mound in which its mother built her nest, the
chick is able to fly and is left entirely on its own. No mother mallee
has ever been seen with a brood."Isaac Asimov, Asimov's Book of Facts
(1979), p. 118.
PETREL The black-rumped petrel is 2 feet [6 dm] long with a
wingspread of 4 feet [12 dm]. An ocean bird, it is also called the
"Peter bird," or "little Peter," because from shipboard, it appears to
walk on the water. Flying low and slowly over the surface with its feet
down, it is looking for fish, and so only appears to be water walking.
The
black-rumped petrels know at nesting time to migrate from wherever they
are in the broad Pacific, to the Hawaiian islands. How they get there is a
mystery, but they do it.
Arriving, they go to Haleakala, the highest mountain on the island of
Maui, Hawaii. This mountain is said to have the widest crater of any
volcano in the world. These petrels nest in that
The
female lays only one egg, and the reason is simple: it requires so much
energy for the two parents to bring just one chick to maturity! They set
on this egg longer than is done for any other bird in the world: 55
days.
It takes
3 weeks just for the egg to form within the mother! This is because the
yolk in the egg must be so rich. The baby will have to live on that yolk
for 55 days. She lays the egg, and the male sets on the egg for 2 weeks.
During that time she is down skimming the surface of the sea eating
fish. Then she flies up and sets on the egg for the next two weeks while
the male goes down to the ocean to eat.
There is
not much oxygen at that high elevation, and it is very dry. Both factors
could injure the chick within the egg. This is because most eggs absorb
oxygen and emit water through tiny holes in the shell. But this egg
shell has fewer holes in it than any other bird eggs! In fact, it has
just the right amount of holes to let the water vapor out in the proper
amounts, not too much and not too little.
Yet
there are fewer holes in the egg, and the thinner air at that high
altitude ought to mean less oxygen to go into the shell. But it is a
scientific fact that oxygen travels through eggshell faster at high
altitudes, and gases come out faster also! So this egg has, in all
respects, been designed in advance for high altitudes. "Designed in
advance," that is, because if it were designed later on, all the petrel
chicks would have long since died in their shells before the design was
properly worked out.
After
the chick is hatched, it stays in the nest for 4 months! The great
horned owl cares for its chick for a full 5 weeks, and that is
considered a long time. But the petrel is fed by its parents for 4
months! This is because it grows so slowly.
The
parents fly down to the ocean and catch fish and small squid and bring
it up to their chick. But the problem is that they are simply unable to
provide their infant with enough food. Why should that be a problem,
since it is only one chick? Watch birds in your backyard: both parents
are continually flying to and from the nest bringing food to their
babies. But the nest of the petrels is 10,000 feet [3048 m] in the air,
in a very wide crater, with sides that drop off at an angle thus
increasing the distance to the bottom. Beyond the foot of the mountain,
there is additional travel time to the ocean, which is the only place that
petrels can obtain their food. The parents have to fly so far to bring
food to their chick, that they simply cannot bring it enough nourishment
as it grows larger. Thus we encounter another insoluble problem. But it
also has been solved.
The
mother and father petrel produce a special oil in their stomachs. It is
a rich red oil, and is nutritionally packed! As they are down skimming
the ocean surface and eating to the full, their bodies make this
concentrated oil out of much of the food they are eating. Arriving back
at the nest, they regurgitate this oil and feed it to their baby, along
with some fresh fish or squid.
You have just completed
Chapter 28 The Creator's Handiwork THE BIRDS
NEXT Go to the next chapter in this series,
CHAPTER 29 HISTORY OF EVOLUTIONARY THEORY