BioBlitz Pt.3 - Canopy Mist Netting
As part of our BioBlitz
preparations at the end of the last phase, a group of GVI Amazon volunteers (myself
included) assisted Lana – the avian field staff member – in setting up a canopy
mist net to try and catch different bird species.
A mist net is somewhat similar to a badminton
net, made of very fine strands and multiple layers, each with pockets to gently
hold birds that have flown into the net.
Nets are checked at regular intervals and captured birds are carefully removed,
identified, measured and then released. Normal mist nets are about 3m high; the idea
with the canopy net is to string the net high up in the trees to study
canopy-dwelling species. After a few practice set-ups around base (the
technique is a VERY complicated system of rope and pulleys), we set off to the
road to find a suitable location, somewhere with two trees of equal heights
with clear space in between to put the net up. Using an adapted methodology
from a paper published in the 1960’s, we got our two hoist lines over some
pretty high branches by a slow process of shooting a sock filled with sand up
into the trees until we finally achieved our goal. Once these were up we could
build the rope frame that would enable us to move the net up and down in order
to get the birds out and all of this used a series of metal loops to hold it in
place. After a long day we set off back to base, looking forward to trying it
out the next day.
Our rolled-up canopy mist net up in the trees, soon to be unfurled (note the black line stretched across, marked with arrows) |
However, as with many science experiments, not everything goes
as one would expect. The main problem we encountered was that at this height,
it was difficult to keep tension in the net. We attempted to fix this using the
limited resources we have at base. Six poles, some duck tape and some string
later, we had a net that was tight enough that our catch would not see the net
and also stay in the net once caught.
Having fixed our first issue, we reset the nets but unfortunately, we were
thwarted again – despite our efforts at improvements we couldn’t move the net
high enough to catch the toucans that seemed to live directly in our net
vicinity! Instead, not wanting our hard work to go to waste, we decided to try
and catch bats in the hopes of adding something new to the species list. This
would also give us an opportunity to get an up-close look at these elusive
creatures that normally just speed past our heads.
We are still hopeful
for toucans in the net someday soon, but until then we are satisfied with the
large fruit bat that chewed a hole in the net!
Lois Mayhew – GVI Amazon Long-term Conservation
Intern
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