Just catching up on a few post re. the Peregrine Falcons demise during the
late 1950-60s.
I had a phone call back in those days from the head of the Fisheries and
Wildlife in Shepparton ( As they were called in those days) the late Jim
Crozier an ex-Military Policeman feared by many a poacher in the Goulburn
Valley. Vic .area and hated by lots of ex-Servicemen.
I was told he had been asked to locate all the Peregrines Nests in the area
and would I help by showing him the ones in the Swamps around Corop and
along the Goulburn, Campaspe and Broken Rivers etc
By now Australia was starting to wake up to the fact that D D T had entered
the food chain of humans plus birds, animals etc and was thought to be
causing several cancers etc and in the bird world it was causing the
Peregrine Falcon to lay soft shelled eggs which were collapsing under the
weight of the parent and he told me that the soft shell was allowing
bacteria to get into the embryo and destroy it.
The Falcon was being effected by eating birds, animals etc that were
feeding on grain, insects etc or fish living in streams contaminated with D
D T .
D D T came to be known as the Wonder Chemical during World War 2 where it
was used extensively for the control of Malaria carrying Mosquitoes which
in turn helped control Typhus and other insect borne diseases, plus it was
used to try and control Head Lice and Bed Lice in the troops.
After the war it was used worldwide in the control of agriculture pests in
the farming communities, it was cheap to make, lasted a long time in the
environment and was highly effective.
By 1960 Eighty Million Kilograms was produced annually.
Malaria in 1946 was epidemic but by 1950 in the U S A it was almost zero.
By the 1960s the Peregrine had declined worldwide and had completely
disappeared from the Eastern States in the U S A , the Bald Eagle was
decimated almost to extinction and a dramatic drop in the numbers of
Pelicans and in England it was found to have entered the food chain and 40%
of all butter sold in England and 60% of cream sold in the U S A was
contaminated by D D T.
It accumulates in the fatty tissues and can travel long distances in the
upper atmosphere and today it can be found where it was never used like in
the Artic and the Antarctic spread there by water and air.
The Peregrine was like the Canary in the Coal Mines it gave humans the
warning that chemical pollution was disrupting the environment and being top
of the food chain was being greatly affected,
Its use was banned in the U S A in 1972 and England followed in the early
1980s and Australia as usual was fifteen years behind America, but it wasn't
until 2001 that a worldwide ban was brought in, it was effective in most
countries but there are still some countries that use it to this day.
The Falcons were very territorial in our district and although the swamps
covered a few hundred hectares I never found more than one nest in each
swamp and along the rivers they were several Kms apart.
They nested in the hollows high up in the big River Redgums and after
showing Jim I wished him luck in getting someone up to them, Red Gums are
famous for large branches breaking off them with very little weight applied.
At the time it didn't seem to have had the same effect on the Falcons living
in the cities due to the fact that their main diet of Feral Pigeons ,Gulls
etc were not eating contaminated grain etc, the country Falcons main diet
was wild ducks ( It was called the " Duck Hawk " in most country areas in
those days ) which lived on water insects ,Fluke snails and in our area when
the Sub. Clover was being irrigated their main diet was Crickets, the waters
were contaminated from rain and irrigation run off and the crickets were
living in cracks in the ground that had been sprayed some times for many
years.
The numbers of breeding pairs plummeted in the district that we surveyed and
although I don't live there these days, up until I left the numbers had
never fully recovered.
An interesting sideline to the story is there is a lot of research going on
regarding Alzheimer's and D D T ,the people with Alzheimer's have four times
the level of D D T in their bloodstreams than those that don't have the
disease.
Makes you think. don't it ????
Barney
<HR>
<BR> Birding-Aus mailing list
<BR>
<BR> To change settings or unsubscribe visit:
<BR> http://birding-aus.org/mailman/listinfo/birding-aus_birding-aus.org
</HR>
|
