E
agles stand accused of
killing lambs. But seeing
an eagle at a lamb carcass
is not sufficient evidence
to pass judgment on him. To prosecute the guilty party, we need all
the available evidence to prevent
innocent parties, with-out trial, being sentenced to death. During this
trial we shall be presenting some
evidence which demonstrates that
most of these lambs were dead before the eagle arrived on the scene
of the crime, Eagles are scavengers,
unlike the stealthy caracal or jackal,
they will stand on a dead lamb in
full view of people, a fact that
sometimes wrongly leads to prosecution. Eagles often scavenge on
the afterbirth of ewes during lambing season and sit and wait for her
to finish lambing. In this document
we would like to show you how to
conduct an investigation on your
farm to find out who the guilty party was. In the unlikely event that an
eagle is implicated, at the end of
this guide you will also find some
tips on how to minimize these losses without having to resort to capital punishment. This individual still
has a very important role in the
community and the death penalty
will leave a big empty space in the
ecology of your farm.
Did the lamb die before or after
birth?
As in any trial, certain lines of evidence carry more weight than others. Biologists often quote the low
percentage of lamb bones in eagle
prey remains. But they have no way
of knowing whether the eagles
killed or scavenged these lambs.
The best evidence of lamb-killing
comes from carcass inspections in
the camps where ewes are lambing.
Examinations are often the most
reliable method of finding out how
the lamb actually died. Extensive,
world-wide investigations
(including some in South Africa)
repeatedly show that all predators
(including dogs, caracals and jackals) rarely account for more than
one percent of lambs born. As
much as 15 percent of lambs born,
however, usually die non-violently.
The biggest killer of lambs, as most
farmers know, is the lack of bonding between the lamb and its mother, and sub-sequent starvation and
exposure. If the lamb carcass is relatively fresh (the best way to ensure
this is to search the lambing camps
early each morning), then the cause
of death can usually be determined
by a simple post-mortem examination which involves skinning the
lamb, preferably from the top of
the neck down. These are the signs
to look for:
Many lambs die before or during
their birth and are dead on arrival.
If the hooves still have soft membranes underneath, this indicates
that the lamb has not stood up and
walked around. If the lamb hasn't
breathed, the lungs will be a deep
scarlet colour rather than light pink
and spongy. For the more serious
investigator, look for a blood clot at
the end of the blood vessel serving
the umbilicus — absence of the clot
indicates that the lamb was stillborn. A lamb that suffered during
birth would be covered in bright
yellow myconium and possibly died
during or shortly after birth.
Was the lamb healthy, did it drink
before death?
A healthy lamb will have solid white
fat attached to the heart and kidneys. This fat looks red and jelly-like
in a starving lamb. Heart fat is metabolized first. Other signs that indicate starvation are: the absence of
milk or curd in the stomach; and
the absence of white fluid (called
chyle) in the lymph vessels draining
the intestine, sometimes very difficult to notice. Predators often seek
out weak individuals and this is an
important element in natural selec-