Part I of this article looked at some wonders of animal
migration and briefly examined the implications of these
facts for the theory of evolution. This part continues with
an examination of some marvels of animal navigation.
Tristan da Cunha is a group of six small
islands named after the largest and northernmost one of the
group. The islands lie in the South Atlantic almost four
thousand miles south of the equator, and over two thousand
miles away from each of the three surrounding continents --
Africa, South American and Antarctica.
The southernmost island of the group, Nightingale, which has
an area of less than 38 square miles, lies about 20 miles
southwest of Tristan da Cunha. Its coastal cliffs are the
nesting site of a sea bird whose common name is the greater
These birds feed during the summer months in the North
Atlantic, from Newfoundland to Scandinavia. They set out in
the autumn from their various feeding areas and fly between
7000 and 8000 miles over featureless ocean to nest on
Though only a tiny dot of land afloat in millions of square
miles of virtually empty ocean, several million shearwater
somehow find their way to it, unerringly, every single
How they manage to converge on this small piece of land is as
yet a mystery. This ability appears to be so incredible that
one author was prompted to refer to it as a "miracle of
But as difficult as this capability may seem, it pales in
comparison to what some other animals can do. Birds that fly
high can at least detect an island from a reasonably great
distance. The scope of vision of turtles, however, is surely
far less. Nevertheless, turtles too somehow manage to home
onto a tiny bit of land awash in the open seas.
Ascension Island lies a few thousand miles north of
Nightingale, slightly more than 500 miles south of the
equator, midway between Africa and South America and about
1400 miles from the nearest Brazilian coast. There is no
other land in between. Not more than about seven miles at its
widest point with a total area of 34 square miles, the island
was difficult for humans to find before the invention of
modern navigational aids. Its highest point is Green Mountain
(2,817 feet) and is visible from sea level only when one gets
to within a few miles of the island.
The island is mainly inhospitable to life, with no surface
streams and little indigenous vegetation. But it is to the
sandy beaches of this tiny island that the globally
endangered green sea turtles, who can lift their heads but a
few inches above the water, gravitate to nest between the
months of January and April.
Green turtles that have been tagged on the island have been
recovered on the coast of Brazil, 1,400 miles away. And these
turtles come back to Ascension Island year after year. Five
turtles tagged in one breeding season returned to the island
in a later breeding season, four to the same beach.
How do animals do it? How can they navigate across open ocean
to find a pinpoint of land more than a thousand miles, or
even thousands of miles, away? How does a turtle keep its
bearing despite inclement weather, wind, waves, and ocean
currents? No one really knows.
But for the past half century, ever since these sorts of
abilities of animals were formally recognized by the
scientific community, scientists have been trying to discover
the methods with which animals orient, navigate, home and
migrate. And what they have discovered is nothing less than
They have discovered, naturally, that many animals are
endowed with senses and abilities that we humans clearly
lack. Some of these abilities had indeed hitherto not even
For example, they have found that animals can hear sounds we
cannot, can smell odors we cannot, and can see parts of the
spectrum or things like the polarization of light that we
have no inkling about from our unaided senses. And despite
its seeming impossibility, animals can even detect, and
meaningfully use, the earth's magnetic and electrical
Virtually all animals studied have been found to possess an
extremely accurate biological clock that tells the animal the
precise time of day. Some species regulate their activity by
lunar phase -- i.e. they know precisely what part of the
month it is. And many species, such as migratory birds, even
possess an accurate annual clock. They instinctively can tell
precisely what season it is even though they are placed in
total isolation and in uniform conditions with no clue about
the world outside.
Many animals use the sun as a compass to accurately tell
direction and are not at all fooled by the sun's movement
across the sky. They compensate accurately for its movement
even when they are placed indoors with no clue as to the
whereabouts of the sun.
At least one species (the beach amphipod) has been found
which can navigate using the moon. Doing this is extremely
complex, much more complicated than using the sun for such a
purpose. The sun at least moves in a fairly regular way
across the sky from day to day. Its position in the sky
hardly varies from one day to the next.
The moon, however, has a very different pattern of movement.
Because the earth rotates on its axis, the moon appears to
move across the night sky during the course of every night.
But the moon also moves on its own accord. It travels in a
circle around the earth. The direction of this motion is
opposite to the motion caused by the earth's revolution.
In effect, at any particular time of night, it is not in the
same location as it was on a previous night or as it will be
on a subsequent night. From day to day its position changes
by about 12 degrees, or about one 15th of the visible sky.
The animal which uses the moon to navigate also happens to
use the sun for the same purpose during the daytime. This
implies that it possesses a dual tracking system for finding
its way around.
Then there is navigation by stars. So far only birds that
migrate by night have been found to possess this
Sylvia_curruca by Martin Mecnarowski
This is why sylvia curruca is so special. It is one of
the few species that possesses this ability and was one of
the first species with this ability to be studied carefully.
(In fact, the experiments were conducted with several species
of related birds, all sylviids. For sake of simplicity,
however, I will lump these results together as if the
experiments were done on a single species.) What was found is
To be sure, the experiments with the sylviids were done
before certain facts about navigational abilities in general
were discovered and before some techniques for studying such
things were fully developed. So there exist some criticisms,
or at least questions, about the original findings.
Nevertheless, the original experiments still stand and have
never actually been refuted. They are consistently reported
in recent books on animal and bird migration.
Let's look at the details of these birds' abilities. If true,
these facts present an incredible spectacle of the natural
world. And even if not completely true, even if the facts are
only those that critics are willing to accept, they are more
than sufficiently awesome to warrant careful attention.
Sylvia curruca's common name is the lesser
whitethroat. It is a warbler (a type of songbird) that lives
in northern Europe during spring and summer and migrates to
sub-Saharan Africa during the autumn. It is a nocturnal
migrant, flying only at night.
It was noticed that these birds were somehow using the stars
to orient themselves for migratory flight. To test precisely
how, some birds were taken into a planetarium and shown
different views of the night sky. When shown the autumn night
sky as it would appear in their home locale during migratory
season, these birds aligned themselves and attempted to fly
in the direction of their migratory route.
This was true even when the stars on the planetarium ceiling
were rotated in such a way that what appeared to be south was
really north. When they were shown only diffuse weak light,
however, the birds aligned themselves only randomly. Both
these facts showed that the birds were using the
configuration of the stars for finding direction, not some
other cue, such as the earth's magnetism.
To get to Africa, the birds generally fly southeast from
northern Europe, passing over Bulgaria and Turkey. When they
come to the area of Cyprus, they turn due south, cut across
the Mediterranean and head straight up the Nile valley. They
then disperse over a fairly large area of mid-Africa.
As they fly south from northern Europe, the positions of the
stars are constantly changing. So the experimenters wanted to
see what would happen if these birds were taken on an
imaginary migratory flight.
Guess what? As they changed the star map the birds changed
course. When shown the constellations as they would appear
over the northern parts of the their trip, their alignment
direction was generally southeast. But when the configuration
of the stars appeared as it would over Cyprus, the birds
changed direction and headed due south, just as they would in
real life. Then when they were shown the sky as it appears
over their final destination, they became totally
disinterested in migratory behavior. They thought they were
at the end of their migratory flight and settled down to
More interesting, these birds were able to find their way to
their destination even when they were taken on an imaginary
flight to a locale which they had never experienced. When
shown an image of a night sky over Lake Balkash in Siberia,
several thousand miles to the east of where they would
normally be and a place to which they had never been, they
turned due west to get back to where they belonged.
The image was then changed gradually to give the appearance
of actual flight to the west. As soon as the stellar
configuration gave the birds the appearance of being over
Romania, the birds changed course, and began heading south,
the direction they must take to get to the Nile valley.
Show these birds a totally unrealistic sky, however, and they
get totally confused. They face in all different directions.
Since this type of configuration never happens in reality,
they have no way of knowing where they are.
The abilities displayed by these birds are uncanny. For these
birds to use the stars as they do, they must (a) have a very
accurate map of at least some of the stars and know
accurately the position of these stars at each time of year
and day; and (b) have a fantastically accurate internal clock
that tells them both day of year and time of day.
But there were more surprises in store for the experimenters.
Birds that had been reared in isolation from other birds,
reared in sealed areas and with only very limited exposure to
the night sky, or none at all, were taken into the
planetarium and shown the night sky as it appears over their
home territory in the autumn at the time they ought to be
migrating. After only a few moments of hesitation, these
young, inexperienced birds, faced in the direction they ought
to face to begin their migration to Africa, a land they had
never seen, using a system of navigation they had never used
and information that could not have been known to them
The conclusion is inescapable. These birds are born with some
knowledge of the features of the night sky etched into their
brains. Precisely what comprises this information is one of
the subjects of controversy. But the essential conclusion has
been corroborated from later experiments on a number of other
bird species which migrate at night. At least several
different kinds of birds instinctively use information
provided by the stars to determine migratory routes.
Different mechanisms, however, seem to be used by different
species. The sylviids may be an exception rather than the
The experiments with inexperienced sylviids were done under a
stationary planetarium sky. The fact that the sylviids were
able to orient under such a condition meant that they could
tell direction merely by looking at the configuration of the
stars, at the geometric shapes formed by the bright and less
bright stars. This in turn implies that they must be born
with preexisting knowledge about star patterns, a proposition
with which scientists are extremely uncomfortable (for good
reason, no doubt).
Experiments with other species, however, have found that
other species at least use a somewhat less spectacular method
for identifying direction. One species, the indigo bunting,
seems to know where south lies not by looking for star
configurations in a stationary sky, but by looking at the way
in which the sky rotates. The stars in the north make small
semicircles during the night, while the stars in the south
make very large semicircles in an equal amount of time.
It is assumed that the buntings discern north by observing
the area of the sky which has the least rotation. They
instinctively know that their direction of migration in the
fall is opposite the direction of this least rotation, of
course making adjustments as necessary for the precise angle
But even the slightly less amazing ability of the indigo
bunting implies that these birds' genes "know" (believers in
evolution have to say "stumbled by chance on") much about the
world around them. They know that there is day and night,
that at night there are points of light in the sky, that
these points of light move, that these points of light move
differently in different regions of the sky, and that it is
possible to determine direction by observing how these points
of light move. And after all this is discerned, the genes
instruct the bird which way to fly.
In essence, no matter what is involved, it must be concluded
that some birds are born with a genetic program that matches
the reality of the world in a very precise way.
The implications of all of this for evolution is easy to
understand, especially in light of the arguments made in part
I of this article. Several features of these particular facts
make the argument against evolution very compelling. To do
justice to these arguments however, requires a whole other
article, which, G-d willing, is forthcoming.
For now though, a single quote from an article by an expert
in the field, who strongly believes in evolution, should
suffice to make the point.
The article, by Kenneth P. Able written in '80, reviews three
decades' worth of findings and studies regarding animals'
abilities to orient, navigate and home. The author generally
attempts to minimize the wonder of it all by arguing that
animals are really not using incredibly sophisticated or
complex mechanisms to find their way. Whenever possible he
posits an alternative mechanism, such as a refined sense of
smell or sound, that would make navigation and homing a less
But the author encounters a slight difficulty with which he
cannot contend. During the late '70's, scientists tracking
the migration route of the monarch butterfly discovered that
large numbers of these butterflies spend winters in Mexico in
a small patch of mountainous forest surrounded by miles and
miles of forest which all looks alike.
This is all Able has to say about this amazing phenomenon:
"The recent discovery in Mexico of very localized winter
roosts inhabited by staggering numbers of monarch butterflies
. . . leads one to wonder how the butterflies find these
isolated, but traditionally used, sites at the end of a
flight that may well exceed 2500 km. . . . [There is no
reason to think that any individuals return to the winter
roost a second time. The monarch butterfly lives a short
period of time. The butterflies that head back to Mexico in
the fall are all the children, grandchildren or even great-
grandchildren of those who left to go north in the spring.]
For the autumn migration of these butterflies to be goal-
directed in the absence of any opportunity for learning
requires a seemingly impossible level of complexity for
genetic engineering. Similar problems surround the first
autumn migrations of young birds, discussed below [this
discussion includes the abilities of the sylviids]."
Need more be said?
Although Able is not willing to admit it (the most he can get
himself to say is "seemingly impossible"), this is about as
strong a concession as one can expect from a believer in
evolution. I have yet to encounter one that is stronger.
But that's his hang up.
We, however, who know the existence of a Borei Olom
from our historical experience, should have no difficulty
recognizing the facts for what they are. And we can certainly
be proud and aggressive in broadcasting these facts to all
who will listen. Birds and butterflies loudly proclaim: "We
are creatures of an awesome Creator and not the products of