Wide
Wings on the Winds
.
With a wingspan of over three meters (about 9 feet!) — the
largest of any bird alive today — the wandering albatross can fly thousands of
miles, even around the world, gliding for long periods in search of fish or
squid. Due to their long wings, taking off from the sea surface is by far their
most energetically demanding activity, requiring four times more energy than
gliding flight. Since albatrosses are heavy birds, aerodynamic efficiency is
even more critical to their success when flying over oceans. So, it is not
surprising that God has providentially equipped them with continuous
environmental tracking systems that adjust flight decision-making to current
meteorological conditions, especially wind speeds and wind patterns.
BY JAMES J. S. JOHNSON, J.D., TH.D.
Wandering albatrosses have the largest wingspan of any living
bird, so they live much of life soaring above the oceans.
With their wings — and a lot of winds — it is no wonder that
their use of wind-power would be studied by scientists, as a recent report
illustrates.
And, because albatross males are bigger, they need more wind.
A new study of albatrosses has found that wind plays a bigger
role in their decision to take flight than previously thought, and due to their
differences in body size (males are 20% bigger than females), males and females
differ in their response to wind.
With a wingspan of over three meters (about 9 feet!) — the
largest of any bird alive today — the wandering albatross [Diomedea exulans]
can fly thousands of miles, even around the world, gliding for long periods in
search of fish or squid.
Birds search for prey in flight and capture it after landing on
the sea surface.
Due to their long wings, taking off from the sea surface is by
far their most energetically demanding activity, requiring four times more
energy than gliding flight.
The recent 7-year-long study was published in the Journal
of Animal Ecology on June 19, 2020.
That day is the inaugural “World Albatross Day,” a new conservationist
holiday invented to promote awareness and concern for albatrosses of the world.
We have demonstrated in a soaring seabird that behaviour is
adjusted flexibly to wind conditions, and that due to differences in flight
morphology, males were more likely to modulate flight decisions to wind than
females.
Their reliance on stronger winds for energy‐efficient flight may also explain the preference of males
for windier habitats … where the greater availability of oceanic habitat
promotes segregation between the sexes.
Because birds are heavier than air, they must practice
successful aerodynamic take-off and flight movements to fly.
Since albatrosses are heavy birds, aerodynamic efficiency is
even more critical to their success when flying over oceans.
So, it is not surprising that God has providentially equipped
them with continuous environmental tracking systems that adjust flight
decision-making to current meteorological conditions, especially wind speeds
and wind patterns.
Large soaring birds are particularly well‐adapted to exploit a dynamic airspace, extracting kinetic
energy from wind for soaring–gliding flight.
This substantially reduces time spent flapping, which is
metabolically costly compared with gliding.
Their large wingspans and high wing loading (mass per unit wing
area) enable rapid flight speeds through the air, and some species,
particularly seabirds, travel vast distances in search of patchily distributed
prey.
However, unfavourable or unpredictable winds can increase time
and energy costs of movement.
Activities such as taking‐off, which requires intense flapping flight, are
energetically demanding in windless conditions, so individuals … modulate
decision‐making so that
these activities are assisted by wind.
Accordingly, the research team investigated and quantified how
male and female albatrosses make use of winds at sea.
Using GPS loggers, researchers tracked the flight patterns of
over 300 albatrosses from two major populations in the Southern Ocean, one of
the windiest areas on the planet.
By combining tracking data with computer modelling, they found
that the seabirds wait on the sea surface for winds to pick up before
attempting to fly again.
They also found that males, which are 20% bigger than females,
wait for stronger winds to help them take off from the ocean surface and
sustain their flight.
The study results were due to the “sexual dimorphism” of the
albatrosses.
This is just a fancy way of saying that the birds’ physical
appearances (in this case, relative physical size) differ according to sex.
University of Liverpool seabird ecologist and lead author
of the study, Dr Tommy Clay, said: “Albatrosses are the oceans’ great
voyagers and are well-known for their ability to glide on winds with barely a
flap of their wings. Our study reveals that albatross behaviour is fine-tuned
to the winds they encounter. In order to save energy, birds rely on strong
winds for take-off, males more so than females.”
Specific findings included quantification of albatross flight
decision-making (such as whether to rest in ocean water, versus take off for
above-ocean soaring to forage for food), correlated to weather conditions,
especially wind speeds.
Of course, the idea that heavy birds efficiently utilize air
currents for launching into the sky, in order to minimize the energy spent
getting aloft, in not new.
Even the Old Testament in Job 39:26-27 illustrates awareness of
that ecological fact of avian life.
Rising hot-air currents routinely blow in from south of Israel,
so hawks can “catch a ride” simply by stretching out their wings southward,
just as sailors harness wind to power boats at sea.
Gliding and soaring on extended wings reduces air resistance as
well as the hawk’s need to burn energy by flapping.
Likewise, when God commands wind to blow, eagles can “mount
up” (literally, “cause to fly”) upon rising thermal air currents — as if
they were elevators — and glide almost effortlessly until they spy food far
below with their super-powerful distance vision.
Whether you observe an albatross near the Antarctic, or an Iceland Gull near the Arctic, the flight of birds is a marvelous display of God’s avian aero-engineering.
*Dr. Johnson is Associate Professor of Apologetics and Chief Academic Officer at the Institute for Creation Research.
The
Institute for Creation Research (ICR)
wants people to know that God’s Word can be trusted in everything it speaks
about—from how and why we were made, to how the universe was formed, to how we
can know God and receive all He has planned for us.
After
50 years of ministry, ICR remains a leader in scientific research within the
context of biblical creation. Founded by Dr. Henry Morris in 1970, ICR exists
to conduct scientific research within the realms of origins and Earth history,
and then to educate the public both formally and informally through
professional training programs, through conferences and seminars around the
country, and through books, magazines, and media presentations.
https://www.icr.org/article/wandering-albatross-wide-wings-on-the-winds/
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