Plan to Control Invasive Snakes with Drop of Dead Mice
Guam
February, 2013
Effect
Cause Map
Native bird
population
decimated
Cause
Native spider
population
exploding
Evidence:
High Level
Environmental
Goal Impacted
Balance of
native species
on Guam altered
Brown tree snakes are an invasive species that was inadvertently introduced to
Guam where they have decimated native bird populations and done massive
environmental damage. It’s estimated that there about two million of these
snakes are on the island. The newest plan of attack in the battle to control the
brown tree snake population is to poison the snakes by parachuting dead mice
laced with pain killers onto Guam.
The pain killers are deadly to the snakes if ingested. The mice will be attached
to something called a flagger, which is two pieces of cardboard attached with a
streamer. The flagger should act like a parachute and catch in the tree canopy,
which is where the snakes predominately spend their time. The hope is that
the snakes will then eat the pain killer laced mice, thus reducing their
population. The current plan is to drop about 2,000 mice over an enclosed area
to determine if this is an effective method of brown tree snake population
control. If it works, more dead mice could be headed Guam’s way in the future.
Customer
Service Goal
Impacted
Hundreds of
power outages
See same
cause
AND
Evidence: During the
wet season, 40 times
more webs were
reported on Guam on
Birds are main
predators
Brown tree snakes
eat birds
AND
AND
Native bird
populations
decimated
Evidence: 9 of 12 forest
bird species on Guam
are now extinct..
Possible Solution:
Reduce or eradicate
the invasive
predators
Large population
of invasive
predators on
island
Evidence: The brown
tree snake was first
detected on Guam in
the 1950s.
Power lines and
transmitters
damaged
Evidence: Records show
that more than 1,600
snake-caused outages
occurred from 1978-1997.
It is conservatively
estimated that these power
outages cost several
million dollars each year.
Brown tree
snakes were
accidently bought
Evidence: It isn't known
when exactly the brown tree
snake was bought to Guam,
but it was most likely a
stowaway in military cargo
from the Papua New Guinea
area post World War II.
AND
Brown tree
snake
Brown
tree snakes
population
is
population
large is
Evidence: As many
as 13,000 have
been found per
square mile.
Snakes get into
them
Evidence: When the
snakes climb the power
lines they may
simultaneously touch live
and grounded conductors,
causing faults, short
circuits, and other electrical
damage.
AND
Brown tree snakes
are very good
climbers
Cause Map
?
High Level
Houston Office 281-412-7766
www.ThinkReliability.com
No significant
predator on island
AND
Little
competition
from other
species
Copyright ThinkReliability 2013
Prior to the brown tree
snake, no other large
snake species was on
the island
AND
Snakes eat a
variety of food,
including birds and
lizards
Large supply of
food
AND
Lizard
population
remains large
Only one snake
species native to
Guam
AND
Native species is
small, blind and
feeds on insects
Reproduce
quickly
Evidence: They can
lift three-fourths of
their body .
Process Map
Plan to Reduce the Brown Tree Snake Population on Guam
Dead mice are
laced with
painkillers
Mice are
attached to
parachute-like
flagger
Flagger are pieces of
cardboard attached
with streamers.
Mice are loaded
onto helicopter
Mice are dropped
over target area
Flagger and mice
are caught in
trees
It's important that the mice
get caught in the tree
canopy because that is
where the snakes most of
their time.
Snakes find dead
mice
Snakes ingest
mice
Snakes ingest
mice (and the
pain killers)
Snakes are
poisoned and die
within 72 hrs.
Invasive predator
population
reduced
The end goal is to eradicate the
snakes from the island, but the
test currently proposed is for a
small area. The test should
hopefully show how effective
this technique is for removing
the snakes.