“The birds of the air have nests”
The Lord Jesus, too, drew some of his lessons from the birds
and their behaviour, including their building of nests: “The
foxes have holes, and the birds of the air have nests; but the
Son of man hath not where to lay his head” (Matthew 8:20; Luke
9:58). There are several references to nests in Scripture,
including the prohibition in the Law against taking both a
mother bird and her eggs or young from the nest for food (Deut.
22:6).
Perhaps we give little consideration to the materials that
birds utilise in their nest construction. It might be thought
that any types of twigs and leaves would do. Recent research2
has been revealing, however, that birds deserve the title of
nature’s apothecaries, and that many species actually fumigate
their nests with specific plants in order to protect their
offspring and assist in their survival. Birds’ plumage offers an
attractive environment to a wide variety of microbes and
blood-sucking parasites, which can take refuge in the nest and
infect the vulnerable chicks when they hatch. Defences against
such organisms are therefore vital.
It has been known for a long time that birds add fresh green
foliage to their nests, and there have been competing theories
to explain this behaviour, which is observed in all types of
habitat, from rainforest to desert climates. One researcher,
Peter Wimberger of the University of Puget Sound, Washington
State, in the USA, noticed that birds of prey replenished the
greenery in their nests at specific times, just when their eggs
were incubating and soon after hatching. He wondered whether the
parent birds were making use of the volatile chemicals emitted
by many types of plant leaf to combat dangerous organisms. He
reasoned that this type of behaviour would be more likely in
species which reused nests from the previous year than in those
that built a fresh nest each year. A survey of forty-nine
species of birds of prey revealed that nearly eighty per cent of
nest reusers, such as the bald eagle and common buzzard, added
fresh green leaves to their nests. In contrast, of birds
building new nests each year, such as the tawny owl, barely
forty per cent used green leaves at all. Further research has
revealed a similar pattern in songbirds. Scientists in India
have found that house sparrows furnish their nests throughout
the breeding season with the leaves of the margosa or neem tree.
These contain a chemical called sitosterol, a naturally
occurring insect repellent which also disrupts the egg-laying of
ticks and other parasites. Other scientists have studied
European starlings, which reuse their nests and refresh them
each spring with fresh leaves. Some researchers believe that
this behaviour forms part of the courtship display, but it has
been found that the preferred leaves come, not necessarily from
common species, but from plants which have higher concentrations
of chemical compounds that provide a defence against ticks,
mites and lice.
Protecting the feathers
Birds depend upon the marvellous design of their feathers to
provide both lift for flight and insulation from cold and heat.
However, as mentioned above, bird plumage harbours a diverse
community of bacteria and fungi. Experiments have shown that
chicken feathers in test tubes inoculated with bacteria from
wild bird feathers rapidly fall to pieces, as bacterial enzymes
attack the keratin from which they are made. Clearly these
organisms present a major challenge to birds’ survival, and
birds adopt a range of strategies to combat them. Thus it is
believed that preening, dust-bathing, sunning and possibly
annual moulting may all play a part in maintaining healthy
plumage. Even more unusual activities have been observed. Birds
often pick up and groom their feathers with ants, which are
known to secrete natural antibiotics, while others have been
seen using millipedes, marigold leaves, gardeners’ mothballs and
discarded pieces of citrus fruit, all of which contain known
antibacterial agents. It thus seems that birds possess an
uncanny ability to detect and use a wide variety of naturally
occurring chemicals in order to protect themselves and their
young.
How do birds ‘know’?
The most interesting question is how birds came to have or
to acquire this ability. How can a bird know that the chemicals
produced by certain leaves will repel invading pests and so
choose the right ones to protect its young? Evolutionists must
attribute it to random, chance mutations bringing about genes
which supposedly code for this behaviour and so provide a
selective advantage. But this is simply wishful thinking, with
no supporting evidence. Clearly, before this ability ‘evolved’,
many birds would have been perilously defenceless against the
onslaught of such organisms. Rather, as the Scriptures make
clear, it is God Who has given all creatures their attributes
and ‘programmed’ their behaviour. Thus, in His answer to Job,
the Almighty shows that the failure of the ostrich to make a
nest at all is “because God hath deprived her of wisdom, neither
hath He imparted to her understanding” (Job 39:13- 17). On the
other hand, the hawk, with its soaring flight, and the eagle,
with its lofty nest and amazing powers of sight, by implication,
fly by God’s wisdom (vv. 26-30). All creatures in the living
world, including ourselves, are subject to attack by agencies of
disease and decay: “For we know that the whole creation groaneth
and travaileth in pain together until now” (Rom. 8:22). At the
same time the Creator has provided a careful balance in the form
of an amazing range of defence mechanisms to ensure survival, as
in the case of birds’ use of chemicals. In all these things we
can see the unmistakable signs of the finger of God and of His
supreme wisdom, giving us confidence in the future, when “the
creation itself also will be delivered from the bondage of
corruption into the glorious liberty of the children of God” (v.
21, NKJV).
Footnotes
1 4:13,25; 5:27; 7:33; 8:7(×4); 9:10;
12:4,9(×2); 15:3; 16:4; 17:11; 19:7; 34:20; 48:28,40; 49:16,22;
50:39. This list was compiled and sent to the author by a Sunday
School scholar, following a passing remark made during a Sunday
evening Bible address.
2 “Kills all known germs”, Bryant Furlow, New Scientist, 22
Jan. 2000, pp. 36-9. With thanks to The
Testimony magazine,
http://www.testimony-magazine.org (first
published January 2001) |
