186
Art. # 186
COLD FRONT CLAIMS BIRD LIFES
How birds survive the cold
Photos and
text by Stefan Rust
2014
(In
terms of the Geneva Convention the copyright of these texts belongs to Stefan
Rust)
The U.S.A. climate news announced on the 2nd
of January 2014 that a very cold arctic air mass following a strong cold front
would move in. Affected countries are Missouri, Illinois, …, Namibia, … and
many would experience the coldest temperatures since nearly 20 years. It was
warned that temperatures may drop to near or below zero.
And so it happened. In the weekend of the 4th and
5th January ’14 a, for this time of the year, midsummer, very
unusual cold front, covered some parts of Namibia. Kalkfeld measured zero
degrease Celsius.
Cold temperatures are survivable by most birds. They are
capable of producing 25-30 percent more feathers in the winter than they have
in summer. But this doesn’t work if a cold front moves in unexpectedly during
midsummer as in the case of last weekend. We humans just add more clothing for
the cold but birds can’t. Therefore, besides from shivering in the cold to
generate heat, like humans, birds also fluff their plumage in the cold weather
to provide air spaces for a better isolation.
Many birds such as finches, spurfowls and grouse feed on
seeds just before dark and slowly digest them to create body energy through the
cold night. It is comparable with us humans putting a blog or two on the fire
before going to sleep to have sufficient heat during the cold winter night.
Other kinds of birds, some storks, swallows and cuckoos flee
the cold by migrating to warmer climates during winter.
But why nevertheless quite a few birds, like House Sparrow
and Laughing Dove, succumbed to the cold last weekend?
As some birders in Windhoek might have observed, the cold
weather brought birds back into their gardens. The problem are not the cold
temperatures, these are survivable by most birds. The problem is the covering
of their food source in cities and villages through roads, paving, buildings
and other structures what makes it hard for birds during cold temperatures to
find sufficient food to supply their body with the needed energy to keep them
warm and alive.
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