Art. # 186
COLD FRONT CLAIMS BIRD LIFES
How birds survive the cold
Photos and text by Stefan Rust
(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.