SERPENTS IN THE SKY, SNAKES IN THE STORM WATER DRAINS … A REAL LIFE HERPETOLOGICAL
STORY FROM MELBOURNE, AUSTRALIA
By Raymond
Hoser, 488 Park Road, Park Orchards, Victoria, 3114, Australia.
Phone: (03) 9812 3322 Fax: (03) 9812 3355 Mobile:
0412 777 211
E-mail: adder@smuggled.com
Originally Published in the Bulletin of the Chicago
Herpetological Society 42(9)(September 2007):141-147.
INTRODUCTION
The following
is adapted from a report I had to make to a psychiatric hospital in relation to
a "snake problem" they had.
So that readers
may get an insight into the sort of reports made to companies and entities by
"snake consultants" here in Australia, the report that follows is
only slightly altered to suit the readers of this journal.
However readers
should be mindful that what follows is written with the lay person in mind and
in terms of people who do not want to cohabit an area with deadly venomous
snakes.
The
commencement of the story was when I got a call from a woman who had been
alerted to a snake that had fallen from the sky into a courtyard at a sealed
psychiatric hospital/prison.
It was later
ascertained that the snake from the sky, had actually fallen from the roof of a
building in the hospital compound.
This is sealed
from the outside world, by a smooth prison style wall, security monitoring and
the like.
Entry to the
complex is via several locked doors, security checks, metal detectors and
biometric scanning.
In other words,
it seemed impossible for a snake to get inside.
But that was
the beginning of the story of the snake from the sky and the others in the
drainage system.
The report to
the State government follows and gives a full perspective on the situation.
Readers should
be made aware of the fact that the hospital is located in an inner Melbourne
suburb about 5 km in a straight line from the Melbourne city centre.
Melbourne,
Australia's second largest city, is a large densely populated metropolis of
over 3 million people.
Snakes are not
usually associated with inner suburbs by most people, but are in fact common in
inner parts of Melbourne that have remnant bushland and are in proximity to the
Yarra River and tributaries that flow through various parts of the city,
including the CBD.
"Snakebusters"
is the trademarked snake removal service owned by myself which is by far the
best known snake removal service in Australia, having been in existence for
some years and reported in all types of media including evening news bulletins.
During summer
months, I field calls on a daily basis from persons wanting deadly venomous snakes
removed from properties, usually within the city environs.
People pay for
the snakes to be removed, which by law must be released in suitable habitat
away from houses as close as possible to where the snake was found.
While calls are
taken on a 24 hour basis and snakes removed as the calls come in, the vast
majority of calls are during the day and statistics show that the majority of
these are between 3 and 6 PM, which coincides with the warmest part of the day.
Unlike most
other parts of Australia, Melbourne's climate is relatively cool (mid winter
average maximum of 13 degrees Celsius and a mid summer average maximum of 25
degrees Celsius), and hence the activity of the mianly diurnal snakes reflects
the limited options given by the generally cool and erratic weather.
THE REPORT'S INTRODUCTION
At about 5.30
PM on 18 January 2004 I (Raymond Hoser) received a phone call (at
"Snakebusters") to remove a small (about 60 cm) snake seen within the
grounds of the Thomas Embling Psychiatric Hospital at Yarra Bend Road,
Fairfield, in inner suburban Melbourne.
The snake had
been seen about 45 minutes earlier, having "fallen from the sky",
later ascertained to have come off a nearby roof.
I arrived at
about 6 PM and inspected the area for about an hour without seeing the
snake. It had apparently made off into
a thick bed of vegetation that included Ivy and other creeping plants. From here the snake could have gone in
several directions, including to inaccessible places.
The following
week I was phoned by Kate Boylan at the hospital to come in and survey the
grounds with a view to establishing the means of entry for this snake and look
into three other snake sightings in the recent past.
On the morning
of 23 January 2004 I returned to the hospital and was shown by staff around the
grounds in order to establish the likely means of entry by two of the snakes
and ways and means to:
1/ Stop snakes entering.
2/ Deal with snakes upon entry
to the grounds.
3/ Other aspects of the snake
problem at the hospital, including:
·
problems outside the perimeter of
the hospital
·
liability issues
·
the viability of reducing snake
habitat outside the hospital grounds, but adjacent to them.
THE SIGHTINGS TO DATE
Within previous
weeks (?) four sightings had been made and reported, including two inside the
walls of the hospital and two in the carpark area immediately outside and on
the general grounds of the hospital. In
no cases were the snakes identified by species and any such identification by
lay persons would under normal circumstance be doubted anyway.
This is due to
the fact that lay people usually identify snakes on the basis of colour, which
is not a reliable indicator.
Notwithstanding
this, it was certain beyond reasonable doubt that the snakes in question were
all Tiger Snakes (Notechis scutatus)
(see later in this report).
It was stated
that the snakes were of different size classes and hence included more than one
specimen.
The most recent
sighting (to which I was called) was of a snake that had fallen from the roof
of a building and onto a grassed area.
Clearly that snake did not have an obvious means by which to return to
where it had come from. This led to the
initial view that snakes may be entering the hospital grounds and then were
unable to escape.
Other sightings
were generally within the vicinity of drainage grates or pipes (see later),
leading to the (probably correct) assertion that snakes were entering the
grounds via the underground drainage system.
TIGER SNAKES
That the snakes
in question were Tiger Snakes is not doubted.
In the Fairfield area, they are the only species known to occur and are
one of three deadly species common to many parts of Melbourne.
Snakebusters
receives numerous calls each year from Fairfield, and adjacent suburbs,
including Kew, Ivanhoe, Heidelberg and Abbotsford to remove snakes and all have
been Tiger Snakes.
The only other
species of snake seen in the general area was a large Copperhead (Austrelaps superbus) seen in 2000 in a
jar at a public park in Abbotsford, mislabeled as "Large Brown
Snake".
That snake may
not even have been caught in the Abbotsford area, although this species does
occur further up the Yarra Valley including in Warrandyte, where they are still
less common than Tiger Snakes.
However Copperheads
do not climb onto house roofs and hence probably could not have been the
species seen on 18 January 2004.
The third
deadly species common to Melbourne, the Eastern Brown Snake (Pseudonaja textilis) is most common on
the basalt plains north of the city and while it may travel across suburban
areas, there is no evidence to suggest the species is present in Fairfield.
Furthermore
this species does not climb onto roofs, or use drainage systems to get
around. Instead it moves along
fence-lines and similar and hence could not have gained entry to the inside of
the grounds of the hospital.
Tiger Snakes
are common along the Yarra Valley and by far the most common species of snake
in Melbourne. Snakebusters receives
more calls for these snakes (based on statistics of what we actually catch)
than for all other reptiles put together (snakes and lizards misidentified as
snakes).
In the season
2003-4, we have had calls for this species from the following suburbs:
Laverton, Newport, Abbotsford, Kew, Fairfield, Alphington, Ivanhoe, Eaglemont,
Heidelberg, Preston, Greensborough, Templestowe and numerous other suburbs in
Melbourne.
The snake is a
true generalist in that it is somewhat non-specific in habits. It has literally conquered Melbourne, being
adapted to it's harsh (for snakes) climate in terms of the cool and erratic
weather.
While these
snakes prefer rocky and overgrown habitats, preferably near water, as they like
to have a regular drink, they will wander across areas of seemingly
inhospitable habitat, particularly during hot weather. This is particularly true for subadult
snakes and males in search of mates.
Born at about
17 cm (average 23 a litter) in January to May and growing at about 1-1.5 cm a
month until mature (in the wild state), most take about 3 years to mature and 4
years to reach their maximum size.
Non-growing adult males average just over a metre and females just under
a metre.
These snakes
tend to live on the ground and rarely stray from the ground to climb.
The two
circumstances where the snakes will climb are as follows:
To catch birds
in a nest in a tree or other high structure.
To climb out of
a pipe or drainage hole, in which case the snake simply heads towards to light
at the end.
The snakes are
generalists in that they feed on any vertebrate and even in the wild state will
eat pieces of discarded meat and chicken as dropped by a human.
They do not
need a supply of food where they live as when they are not fed, their body
merely shuts down and stops growing.
Hence these snakes can go for long periods (many months) without food
and survive in apparently sterile areas like the hospital grounds.
Tiger Snakes
are a deadly species and their venom attacks the nervous system.
While they are
slightly slower moving than the average snake, they can still move fast when
warm and agitated. Bites commonly occur when people try to catch and kill them.
Decapitated
snakes may still bite the person attacking them.
As a rule,
Tiger Snakes will attempt to bite if cornered or an attempt is made to kill them. In this regard they are one of the more
aggressive species, hence the advice to lay people not to deal with them.
It is worth
noting that as captives these snakes become quite placid and inoffensive and
hence when seen at shows and exhibits are not the same aggressive animals that
are seen in the wild state. Lay people
should not be fooled by the different faces presented by the same species.
Also some
captives may have had their venom glands surgically removed, allowing the
handler to take liberties with the snake, knowing that should a bite occur,
then no serious consequences will result.
ADVICE IF A SNAKE IS SEEN
Hence the
general advice to people who see snakes is to leave them alone, or if in a
situation where they may pose a risk (such as within the hospital grounds) a
licenced snake catcher should be called in to remove and relocate the snake.
If a snake is
seen and a snake catcher is called, the snake should be watched continuously
(as best as possible) until the snake catcher arrives. This includes viewing potential escape
routes.
Do not leave
the area unattended as the snake may move off in an unknown direction and then
not be found by the snake catcher.
Because most
snakes have little if any scent, they are not suited to being found by sniffer
dogs.
Stand at a safe
distance from the snake (more than four metres) and if the snake does move
towards you, then simply run off. If
you are cornered, then stand dead still and wait for the snake to move off
(even if it crawls over you). Snakes do
not generally bite still objects. It is
the movement the snake will strike at.
IF BITTEN
Put a broad
constrictive bandage from the bite site, along the limb to the trunk of the
body.
Stay as still
as possible and get to hospital as quick as possible. It's best to call an
ambulance and/or have a person drive you there. Do not drive yourself to hospital as you may pass out while
driving.
There is no
need to kill or attempt to identify the snake as hospitals have so-called
polyvalent anti-venom which works against all locally occurring snake species.
If these
procedures are followed, then the risk of death from snakebite is remote.
Notwithstanding
this, it is worth noting that even small (newborn) snakes carry deadly venom
and their bite may make a victim very ill.
This is especially so if the recipient has any form of allergy to the
poison, which will not be known until after a bite has happened.
Symptoms of
bite may be almost immediate (within seconds) or take hours to manifest,
depending on a range of factors and hence if in doubt one should go to a
hospital for monitoring for 24 hours (or more) after the bite.
IDENTIFICATION OF TIGER SNAKES
This is not
particularly relevant here as we know this is the species in question.
However for
completeness a summary of the snake is given in terms of identification.
Colour is not a
reliable indicator. Tiger snakes are
known to range from white to black and be with or without bands.
Most in
Melbourne are however yellowish or greyish brown with somewhat indistinct bands.
To separate
Tiger Snakes from the other two deadly species in Melbourne is quite easy.
They have a
broad thickset head, while Copperheads, also a thickset snake have a distinctly
smaller and narrower head. Brown Snakes
are a generally thinner snake with a smaller and narrower head.
Brown Snakes
have distinct eye-brow ridges that the other two species lack, while
Copperheads have white etchings on the lip scales. The other two species have single (one colour) heads. These latter (head) characteristics are a
reliable means to separate the three species.
Snake experts
familiar with the three snakes can usually glance a part of the body of one of
these snakes and immediately know which they are dealing with due to the suite
of other characters that separate them.
All grow to
around a metre as adults, but range from as little as 15 cm total for newborns
to two metres for large adults.
THE ESSENTIALS OF TIGER SNAKE BIOLOGY
In terms of
what snakes need to live, most species Including Tiger Snakes, have the same
basic body plan. Hence in the captive
situation, zoos and keepers can keep widely differing species in identical
cages and feed them the same foods.
Translated to
the wild state, the essential requirements remain the same.
In order of
importance they are as follows:
1.
Thermal requirements
2.
Habitat
3.
Food and water
THERMAL REQUIREMENTS
As reptiles,
snakes cannot regulate their body temperature.
They are controlled by their environment. Tiger Snakes can therefore survive in good health anywhere
between about 4 and 38 degrees Celsius.
Notwithstanding
this, these snakes must have a temperature of about 30 degrees Celcius to best
digest their food and below 20 degrees cannot do such basic functions.
Hence, this species
is pre-adapted to seek a temperature of about 30 degrees at all times if they
can (which in the wild state is obviously an impossible and rarely attained
dream).
That is the
primary pre-occupation of almost all snakes almost all of the time.
Most of the
time this means that the snakes are seeking heat, and/or avoiding cold, except
in the warm days in the warm months when the reverse applies.
On hot sunny
days when the air temperature is 30 degrees or higher, the ground temperature
may well be ten to fifteen degrees hotter.
As snakes crawl
over the ground or rest on it, this is the temperature that counts.
40-45 degrees
is fatal to the snakes (even for just minutes) and hence must be avoided.
It is at these
times that snakes will seek out cooler and shaded southerly (and east facing)
slopes for refuge.
When the
weather cools, the snakes will again seek sunny spots so as to continue feeding
and digestion processes.
If an area's
thermal requirements are unsuitable for snakes, they will either move away (at
least as long as the area remains unsuitable) or if unable to do, simply die.
HABITAT
Habitat is the
second most important requirement of snakes and the feature most readily
identified by lay people.
In the world of
wild animals, snakes are somewhat constrained.
They have no arms, no legs, are deaf to airborne sounds and almost
blind.
Put another
way, they are the slowest animal on the block.
To get over
these disadvantages snakes rely on their cryptic colouration to hide and blend
in with their surroundings.
They will
prefer areas of dense vegetation at ground level, hide in cracks that are too
small for predators such as birds and foxes and when they move will tend to
secrete themselves along edges of buildings where birds cannot readily swoop on
them.
If snakes
cannot find areas of suitable habitat they will tend to move on.
In the context
of a hospital, removal of densely vegetated flower beds will remove incentive
for snakes to reside in a single spot within the hospital grounds.
FOOD AND WATER
While a snake
deprived of food and water will obviously die, these are nowhere near as
essential for the wellbeing of snakes as the other two factors covered.
Snakes can
sometimes go for weeks without water and months without food.
Hence the
absence of either does not mean an absence of snakes.
Notwithstanding
this, areas with plenty of food and water and the essential requirements of
thermal needs and habitat will support large numbers of snakes.
This is why the
Yarra River valley supports a large number of snakes.
Notwithstanding
the above, snakes such as Tiger Snakes overproduce young each year and hence
there is a general movement of subadult snakes to new areas adjoining the
optimal habitat, hence a general flow to areas such as the Thomas Embling
Hospital and the nearby suburbs.
When habitat is
suitable in these new areas, (particularly in the form of overgrown gardens,
fish ponds and so on), snakes are able to live and breed and so the cycle goes
on.
While water is
not an essential requirement for snakes due to their preadaptation to store
water and pass dry urine, the fact is that snakes have a weakness for water and
love to take a regular drink.
In the captive
situation snakes will on most days take a drink from their water bowl,
especially after eating. In the wild
state, this means that a snake will frequent watering points and properties
that have such watering points are favored places for snakes.
In the context
of the Thomas Embling Hospital, this was an important factor enabling snakes to
survive indefinitely within the hospital grounds.
Water
accumulations were seen at the bottom of one of the drainage grates (just
outside the walls, but linked to inside) and may have been present elsewhere as
well.
MEANS OF ENTRY TO THE HOSPITAL
An inspection showed
that the hospital was literally sealed at the walls. The high security walls surrounding the complex are sealed at
ground level and due to their smooth surface could not possibly be climbed by
any snake.
To get into the
building requires biometric scanning and entry through several locked and
sealing doors. No snake could
conceivably enter via this means without being detected and none have
been. Freight is brought in via a large
door that also seals at ground level, including at the edges (ends), meaning
entry from here is also probably impossible and/or hasn't occurred.
The only other
means by which snakes could enter the complex was via the drainage system.
In fact this
was effectively custom made to give the snakes unfettered access to the hospital.
At ground level
there were drains criss-crossing the grounds of the complex. These were interconnected by pipes with
frequent points where a grate presented at ground level. The drop from the grill to the bottom was
usually only a short distance (under a metre) enabling the snakes within to
either bask in the midday sun (while remaining protected by the grill) or to
climb out of the drains (at the corners of the square holes) and through the
grill if desired.
These pipes ran
under the hospital walls and to outside.
To the east of
the hospital was bushland adjacent to the Yarra River, which is known Tiger
Snake habitat. To the south was a
football oval, lined on the south side by the Eastern Freeway. However between this (effectively unpassable
for snakes) oval and the south wall of the Hospital was a densely vegetated
ditch with water holes.
This linear
reserve formed a perfect conduit and funnel for snakes moving east from the
Yarra River towards Merri Creek, which in turn was sited on the west side of
the hospital.
Noting the
smooth face of the Hospital wall on the East side and the similarly
impenetrable open ground of the oval and freeway to the other side of this
ditch, it is clear that snakes would be naturally funneled into the ditch or
any pipe running under the hospital wall.
The ditch
itself provided excellent habitat for the Tiger Snakes in terms of vegetation
and water.
Notwithstanding
this, the ditch itself had fundamental limitations in terms of it's long-term
utility as Tiger Snake habitat and this no doubt contributed to the entry of
snakes into the hospital grounds and the timing as well.
Snake movements
are seasonal and also in direct response to prevailing weather.
In cooler
months they tend to remain on north and west facing slopes, where they can take
advantage of the maximum sunlight to warm themselves.
Snakes do not
need the sun itself, but rather the heat and while the two are commonly
confused by lay people, snakes usually "bask" in the safety of dense
ground level vegetation such as Ivy and other creeping plants or debris, where
sunlight is either dappled, or when a snake may be able to "bask"
completely concealed under the warming leaves of the vegetation.
While snakes
may actively search for food, many species, including Tiger Snakes are also
ambush predators in that they may instead choose to site themselves on
so-called "runs" where they lie in wait and merely strike at food
that passes within range.
So-called
"runs" also tend to be along building edges, where rodents and lizards
travel so as to avoid predation from large birds that patrol the open spaces.
As weather
warms up, the need to bask is reduced, enabling the snakes means to travel to
new areas in search of food and habitat from where safety from summer heat can
also be obtained.
The east facing
slope to the east of the hospital would therefore be colonized by snakes in the
summer months.
In hot weather
as seen in much of December 2003, the snakes would in turn seek densely
vegetated areas, including the ditch to the south of the wall of the
hospital. As the weather cooled in
January 2004, this south facing ditch would become suboptimal and hence snakes
would seek warmer places.
As a rule,
snakes move to higher more exposed (to sun) ground and west facing slopes when
weather cools and hence it'd be safe to assume a continued movement by the
snakes along the south aspect ditch in a westerly direction and towards the
carpark of the hospital.
The swamp and
overgrown vegetation there provided optimal habitat for the snakes.
If and when the
weather warmed up, the movement would be more-or-less reversed with the snakes
heading back in an easterly direction.
In other words,
the movement of the snakes would be either up and down the ditch parallel to
the south wall of the hospital, or even through the hospital itself, noting the
east/west exits of pipes from within the hospital.
I was unable to
ascertain the location of the outfalls of the pipes inside the hospital in
terms of where they ran out of the grounds.
But so long as they ran either east, west or south of the hospital,
snakes could gain entry.
Notwithstanding
this and based on the pattern of sightings in the hospital grounds, it'd be
fair to assume that the snakes were gaining entry to the grounds from the car
park side of the hospital.
This also means
that if the weather warms up again in late January and February 2004, more
snake sightings in the hospital are likely, and regardless of what cleaning up
of plant beds within the hospital grounds is done.
It's also worth
noting that the Merri Creek to the west of the hospital is also Tiger Snake
habitat and that snakes may be coming from there.
Without
knowledge of the drainage outfalls in terms of this area, any firm conclusions
are not possible.
However, there are
open grassed areas between the hospital and the gully and movement across here
at ground level is effectively impossible. Hence the suspected original source
of the snakes is more likely to be the east side of the hospital, rather than
the west side and that's notwithstanding the fact that sightings haven't been
in this part of the complex.
There is
another important consideration in terms of movements of snakes.
In the wild
state, snakes choose to move in a given direction.
They will tend
to move in a straight line to where they choose to go. Variation in the straight line movement is
mainly due to physical impediments such as rocks, logs, patches of open ground
and the like.
In terms of
open ground, this will be avoided and snakes will try to move around it.
In terms of
roads, snakes will commonly move along the edges for some time before
ascertaining that they have no choice but to run the gauntlet across open
ground (and cross).
In terms of a
site like the Thomas Embling hospital, snakes would encounter the wall and the
clear ground around the perimeter and seek an alternative means to cover the
distance and remain concealed.
Hence the
importance of the drainage pipes and/or the ditch on the south side.
SNAKE ON THE ROOF
The snake
reported on 18 January was first seen falling off a roof of a building.
Tiger snakes
will climb buildings in order to get birds from nests and similar. The building roof from which the snake fell
was connected to the ground via a vine growing up. The snake could have climbed this. Tiger snakes have a weakness for young birds and snakes on roof's
in these situations are seen most years by snakebusters.
Alternatively
in the case of the hospital, it is likely that the snake may have climbed up a
pipe starting at ground level or lower, to emerge at the end, which happened to
be on the roof.
When moving
through drainage pipes or other sealed environments, snakes will tend to head
towards the light and emerge wherever the pipe ends, or the exit is.
The pipes were
relatively narrow and could be easily climbed by the snakes, even if their
surfaces were smooth.
If in a sealed
environment such as under a house, the snake will as a matter of course move
towards the light and attempt to escape via the hole through which the light
shines.
In terms of
"falling off the roof", snakes literally jump.
They tend to
stretch their body outwards as much as they can before falling and then as they
fall, they land in a so-called break fall, much like a person does when doing
judo.
The snake is
not injured in any way and due to their relatively light weight, it's maximum
velocity is not terribly fast, enabling them to fall/jump and survive from any
height (the only exception being very large pythons).
OTHER SITES WHERE MOVEMENT IN DRAINAGE PIPES OCCURS
It is probably
quite common for snakes to use drainage pipes as movement conduits, although
there are few if any cases in the literature.
Snakebusters
have received a number of calls for snakes in suburbs far removed from likely
habitat. While movement along
fencelines and the like cannot be discounted, the crossing of major roads,
including freeways is most likely to be through pipes on some occasions.
In 2002, we
removed a Tiger Snake from the Hill of Content Bookshop in Bourke Street,
Melbourne city. The snake had been seen
the previous night emerging from a drain in the street before it crawled under
the shop's door.
A Sydney-based
snake catcher Charles Acheson does regular removals of Red-bellied Black Snakes
(Pseudechis porphyriacus) from the
Homebush Bay, Sydney Olympics site.
The snakes at
the Homebush Bay Complex tend to be found emerging from the drainage grates
that are scattered across the complex and include open areas where the only
source of entry is the drainage grate.
In other words
the snakes are moving around the complex via the drainage system.
In 1983 I
retrieved a Red-bellied Black Snake that had emerged from a drainage grate in
Lawson Street, Redfern, in inner city Sydney.
Red-bellied
Black Snakes are similar to Tiger Snakes in most respects and tend to replace
them in warmer more humid areas, such as wetter parts of the East coast.
THE SWAMP IN THE CARPARK AREA
This was
optimal Tiger Snake habitat for several reasons.
The area had a generally
neutral or westerly aspect, which is preferred by snakes. Vegetation was overgrown and at ground level
ran over dark basalt boulders with honeycomb underneath. In Melbourne this is optimal. Snakes can bask on the dark heat gathering
rock and hide amongst the vegetation and rocks themselves without being
detected.
While there
were some pathways running through the swamp, most of it was effectively unused
by people and hence the sort of place that snakes would like.
Besides the
thermal and habitat attributes, the water bodies were permanent as evidenced by
the mature Limnodynastes tasmaniensis
(frogs) tadpoles seen in the water.
These frogs are one of the preferred foods of the snakes.
Finally, the
swamp formed a so-called "habitat end point", in that it represented
an area at the end of a line of potential habitat. To the immediate west end of the swamp was road and then mowed
grassed field. As snakes funneled here in
an east-west direction, they would find they could not go further and hence accumulate
at this point.
Hence it'd be
reasonably expected that the number of snakes here would be large.
These
situations occur in the wild state as well (for example as in a rock outcrop at
the end of a long ridge, or the end of an island, or end of a sand dune) and
snake catchers know that these are the best places to look to find the snakes.
A further point
of note is that as a generalization snakes don't like their own kind. Other than when mating (and sometimes
overwintering), snakes are solitary animals that will avoid one another if
given the chance. That's why when they
are seen, they are usually seen on their own.
In the wild
state, when two snakes see one another, they will usually have a sort of stand
off, evidenced by raised heads and excess tongue flicker with the dominant
(larger) snake getting right of way and the smaller one moving elsewhere.
This also
explains the movement of snakes away from the swamp area (itself the end of a
funnel) and why snakes have been seen in suboptimal parts of the carpark.
It also means
that sightings in the carpark may occur again in future.
The idea that
snakes and other reptiles can be funneled in directions is not new.
Field workers
use so called drift fences and pit traps to capture reptiles in bushland and desert
areas with a high degree of success.
HABITAT FOR SNAKES WITHIN THE HOSPITAL GROUNDS
The grounds of
the hospital were generally sterile and not good for snakes.
Buildings
tended to run flush to the ground and vegetation in garden beds was
sparse. Lawns were mowed short. It was evident that a significant number of
people utilized the area which runs against the preference of snakes for areas
that humans don't frequent.
However not all
was bad for the snakes.
Several garden
beds consisted of little more than densely matted ivy and other vegetation that
formed an impenetrable shield for snakes that may reside within.
Some buildings,
including the horticulture building also had walls that didn't run flush to the
ground and then wooden floorboards that formed a crack between it and the
ground underneath. While such a
building was not a good site for a snake to live, it did provide a good short
term refuge for snakes passing within the grounds and a means of escape if
seen.
Part of the
general habitat for the snakes included the fact that the Ivy beds did in some
cases run to the drainage holes and hence it formed a complete habitat package
for the snakes.
By selecting
sunny or shady sides of buildings as desired to suit thermal requirements and
drainage holes as a source of water, snakes could survive within the hospital
grounds indefinitely and perhaps undetected.
WHERE THE SNAKES WOULD HIDE
While snakes
would use drainage pipes as conduits, it's unlikely that these would be the
preferred resting place in the grounds of the hospital. Instead the snakes would more likely be
found resting at or near ground level under the matted vegetation in the garden
beds, or more preferably under cover such as rock or rubbish, itself in the
garden beds.
ELIMINATING ENTRY OF SNAKES FROM WITHIN THE HOSPITAL
WALLS
The only means
by which this could be done was by blocking and sealing the drainage grates
with fly wire or similar.
This was at
first deemed not viable as the result would be drain blockage and flooding.
Hence it seemed
that entry of snakes to the hospital grounds cannot be stopped.
However as a
second best solution it was decided to block all drains with wire that would be
kept clear and cleaned regularly.
ELIMINATING SNAKES INSIDE THE HOSPITAL GROUNDS
Noting that
entry cannot be blocked, the next matter of note is dealing with snakes already
in the hospital grounds and those likely to enter.
The thermal
attributes of the grounds effectively cannot be altered and dealt with, leaving
habitat as the important consideration.
First and
foremost the overgrown creeping vegetation at ground level should be removed.
This will both
remove habitat for the snakes and also make sighting of specimens easier.
Snakes entering
the grounds will thus be encouraged to move on and in any event be more easily
detected as they move about in search of suitable habitat.
As discussed,
it'd be wise to have a snake catcher such as myself present at the time the
creeping Ivy and similar vegetation is removed. This could be done within a day.
Notwithstanding
this, regrowing shoots of ivy would have to be poisoned and it could take a
year or two to remove all the offending vegetation.
Along the south
wall of the hospital (on the inside) was a ditch with thick bulrushes. This also constituted optimal habitat for
Tiger Snakes.
Discussion in
terms of removing the bulrushes indicated problems removing this vegetation.
The best option
would be it's complete removal, but failing this, staff should be made aware of
the snake risks posed by it's retention.
Cracks and
holes in buildings and walls at ground level should be eliminated. This will in turn eliminate impenetrable
hiding spots for mobile snakes. This
may be difficult in terms of the horticulture building, but should be possible
elsewhere.
ELIMINATING SNAKES IN THE CARPARK AREA
This is also
problematic and involves a decision by management as to whether or not it wants
a sterile wildlife free area, or to retain an area of natural beauty, which
will as a matter of course also have snakes.
Overgrown and
dense ground cover should be removed and regularly trimmed to remove hiding
places for snakes as best as possible.
This includes
the dense bulrushes and other vegetation in the water proper and at the water's
edge.
In terms of the
rocks in the area, these should be filled in underneath as best as possible to
remove optimal hiding spots for snakes.
The best means
to do this is to dig under them, fill in the gaps with cement and then cover
with dirt (thinly) so that the cement isn't noticeable.
Even a complete
razing of the swamp area will not remove the likelihood of snakes in the area
and so perhaps the best option is to make the area snake unfriendly (within
reason) and then to deal with the problem as it arises.
DEALING WITH THE SNAKE PROBLEM
In essence, no
amount of work and preparation will eliminate Tiger Snakes from the Thomas
Embling Hospital and immediate environs.
Staff should be
made aware of the problem and in areas where the public (and patients) are
likely to go and encounter snakes, warning signs should be erected.
Staff should be
trained in terms of dealing with snakes, including first aid and to that extent
snakebusters will be happy to come to the hospital and do a full lecture on
this at a pre-arranged time.
Management
should also be aware of the likely seasonal snake occurrences (in that
sightings each year tend to fit a well-defined pattern) and should have a
management plan to reduce the snake friendliness of the habitat and garden beds
within the hospital grounds and immediate surrounds.
In terms of the
ditch on the south side of the hospital wall, management should seriously
consider removing the sitting bodies of water and dense ground level
vegetation, even though it was obviously planted to obscure the unsightly wall
of the hospital from the people who would use the adjacent field.
Perhaps trees
and other plants on stems could be planted and the ditch itself flattened to
present a flat ground surface.
In terms of
snake sightings, "snakebusters" should be called to remove them as
and when they are seen.
Covering the
ditch on the inside of the south wall, while expensive, may reduce the snake
risk further, but still not eliminate it and frankly is probably not
worthwhile.
LIABILITY ISSUES
Not being
lawyers, snakebusters cannot give good legal advice on this.
However the
following points are noted.
Vicroads were
said to be liable in terms of two recent snake incidents in Melbourne. At Deer Park, they were alleged to be liable
for a snakebite that occurred as a result of their failure to clear land that
led to a person being bitten by a snake that was present on the land.
The ultimate
outcome of that case, which got media reports on it, isn't known.
However
following this incident, a man at Epping (Mr. Ken
McDonald at 10 Lauren Court, Epping, Victoria)
approached Vicroads to fix a fence and adjoining reservation where snakes had
been seen and Vicroads paid up immediately.
No questions were asked and they sim[ply paid up, which is contrary to
the way that department usually operates.
This was in
January 2004.
Snakes are a
tricky area in terms of the law in that they are regulated
("protected") and therefore it is illegal to kill and interfere with
them in any way, unless licenced.
Other than
licenced snake removers like "snakebusters", persons with scientific
or photographic permits and authorized wildlife officers, no one is allowed to
catch, kill or interfere with reptiles in this state, probably meaning less
than 100 out of the 4 million odd Victorians can legally interfere with (wild)
snakes in any way.
In other words
snakes and snakebite are a potential goldmine for lawyers and persons who may
be bitten.
Hence, avoiding
snakebite is the best option and thus the recommendation to post warning signs
and to warn relevant people who may enter or use the hospital.
Noting the
legal situation in terms of snakes, the general recommendation to have sighted
snakes removed by snakebusters also seems the most sensible option as well, as
and when needed.
FINAL (MAIN) RECOMMENDATIONS
·
Remove Ivy and creeping vegetation
within hospital grounds and replace plant beds with plants on stems as opposed
to creeping varieties.
·
Block holes at ground level on
buildings as practicable and put wire over all drainage routes and “seal” in as
much as to prevent snake movement via the drainage system into the hospital.
·
Clear and modify as practical the
swamp area near the carpark to reduce snake habitat, including reducing
vegetation in and adjacent to the water bodies and on a regular basis to
counter regrowth. Fill in gaps under
rocks if possible.
·
Consider removal of bulrushes within
the hospital grounds.
·
Have staff formally briefed by
"snakebusters" in terms of snakes, snakebite and what to do when
snakes are seen.
·
Call "snakebusters" to
remove snakes from grounds as and when seen.
This is a 24 hour service.
REPORT DATED 26 JANUARY 2004
Snakebustersâä
PO Box 599
Doncaster, Victoria, 3108.
Phone: 0412
777 211
E-mail: go to:http://www.snakebusters.com.au/sbsboo1.htm">
http://www.snakebusters.com.au
END NOTES:
In the two year
period since the completion of the report (to March 2007), three more snakes
have been removed from the hospital complex, but all outside the walled area,
indicating that the measures indicated in the recommendations have had at least
some measure of success. The major
recommendations had been adopted by the hospital management.
the Snakebusters bookings page at:
http://www.snakebusters.com.au/sbsboo1.htm
Urgent inquiries phone:
Melbourne, Victoria, Australia:
(03) 9812 3322 or 0412 777 211