The biters and the bitten:
snake management in Victoria
Nick Clemann Arthur Rylah Institute for Environmental Research
Department of Environment and Primary Industries, Heidelberg
Arthur RylahInstitute
Flora, Fauna &Freshwater Research
Who am I?
Threatened Fauna Program Leader Arthur Rylah Institute
Dep’t Environment & Primary Industries (Heidelberg)
Most of my work is in Victoria, but have worked in Uzbekistan, USA, Argentina, Kazakhstan
What we’ll cover today
• The human side of human-snake interactions
• Common Victorian snakes – identification challenges
• What happens to relocated snakes - radiotracking
• Snakebite
Threatened wildlife 1
Augmentation
(Spotted Tree Frogs, Mt Pygmy Possums)
Reintroductions (BT Rock Wallaby)
Relocating nuisance /
dangerous wildlife
Magpies Possums
Kangaroos Bees
SNAKES
Threatened wildlife 2
Ad hoc relocations
(Growling Grass Frogs, Striped Legless Lizards
etc.)
Translocation – a generic term
Snakes have had a bad rap ever since that little incident with the apple in the Garden
of Eden…
Of all animals encountered in suburbia, snakes were the least desired around homes Davies, R.G., Webber, L.M. and Barnes, G.S. (2004). Urban wildlife
management – it’s as much about people! In: Urban Wildlife: More Than Meets the Eye. Eds Lunney, D. & Burgin, S. Royal Zoological Society of New South Wales.
Australia’s snake fauna is unique – and not in ways that make them
endearing
European invaders learnt early that the potential for many Aussie species to kill was unmatched
anywhere on Earth…
“I may mention that the bite of most of them in that country is almost instantaneously fatal”
Alexander Marjoribanks 1840 WRT Botany Bay
“If a snake bites you in this country, instant death follows. One of the most deadly and common snake’s bite is so bad that the person bit only shivers and falls dead immediately”
William Coke 1827
• ~ 60 licensed catchers in Victoria (~35 in greater Melb / Geelong areas)
• Current strategy - capture and relocation
5 km or less
Victorian snake management
DEPI permit: release “on public land within 5km of capture”
Scale of relocations?
Fate of snakes?
Impact at both donor & release sites?
2 key issues:
Human dimensions opinions, biases, motivations, knowledge and behaviours of people and organisations involved in human-snake conflict
Biological / ecological implications of translocating snakes effects of capture / relocation on individuals,
impacts on conspecifics and other species at both the “donor” and release sites
Human dimensions
We* conducted questionnaire surveys of:
1. Licensed snake catchers (n = 45)
2. Residents (n = 225?) - won’t cover this today
*Clemann, N., McGee, T. and Odgers, J. (2004). Snake management on private properties in
Melbourne, Australia. Human Dimensions of Wildlife 9(2): 133-142.
Clemann, N. (2006). Practices, experiences and opinions of snake catchers and their clients in southern Australia. The Victorian Naturalist 123(6): 383-389.
Snake catcher’s questions
• Number of call-outs / year?
• % calls resulting in capture?
• Months with highest number of calls?
• Species involved?
• Single or multiple release sites?
• Criteria used to choose release sites?
Results - Snake catchers (n=14)
• Call-outs / year: ~ 50 - 60 (ra. 2 – 550 / year)
• Proportion resulting in capture: ~50 - 70% (ra. 30 - 100% - one catcher translocates 300 / season!)
• Est. 1000 – 2000 translocated around Melb / Geelong each year
Months of calls received to remove snakes
024681012
September
October
November
December
January
FebruaryMarch Ap
ril
No.
con
trol
lers
who
rece
ived
cal
ls
Snake species caught by licensed controllers
02468
101214
Tiger S
nake
Copperh
ead
Easter
n Brown S
nake
Red-bell
ied Blac
k Sna
ke
Other s
pecies
No.
con
trol
lers
who
catc
h ea
ch s
peci
es
Geographic trends
Tiger Snakes predominate N, W and SW of Melbourne
Copperheads to the E and SE
Snake catchers
How far are snakes moved? – Most < 5 km (as per permit)
– others 10 – 50 km
Sites used for release: – “crown land within 5 km”
– Parks / reserves (e.g., Braeside Pk)
– “no comment” - 300 snakes / year
2 use same release site (incl. the one who releases 300 / season!)
11 use different sites – based on location of capture or species
involved
– some mentioned fear of “overpopulating” release sites
Snake catchers
How are release sites selected?
– “5 km radius of capture”
– as far from residents as possible
– as close to capture site as possible
– “suitable habitat” - rocks, water, food, few predators etc.
– where other snakes observed
• Large scale, ongoing issue
• Current strategy not a permanent solution – most residents have to call in catchers
numerous times
• People taking matters into their own hands? – risk of being bitten
– breaking law
Tiger Snake Notechis scutatus
photographs by Peter Robertson
Lowland Copperhead Austrelaps superbus
Highland Copperhead Austrelaps ramsayi
Photographs by Peter Robertson
Eastern Brown Snake Pseudonaja textilis
www.snakecatchers.com.au
www.australianmuseum.net.au
Red-bellied Black Snake Pseudechis porphyriacus
White-lipped Snake Drysdalia coronoides
Effects of relocation on Tiger Snakes - spatial ecology / activity patterns
What happens to relocated snakes? A radio-tracking study
Butler, H., Malone, B. and Clemann, N. (2005). The effects of translocation on the spatial ecology of tiger snakes (Notechis scutatus) in a suburban landscape. Wildlife Research 32, 165-171.
Butler, H., Malone, B. and Clemann, N. (2005). Activity patterns and habitat preferences of resident and translocated tiger snakes (Notechis scutatus) in a suburban landscape. Wildlife Research 32: 157-163.
Clemann, N. and Butler, H. (2005). Venom ‘spitting’ during handling in an Australian elapid snake. Herpetofauna 35(2): 83-84.
Clemann, N. and Butler, H. (2006). Carrion scavenging by the Tiger Snake Notechis scutatus. Herpetofauna 36(1): 2-4.
Clemann, N., Butler, H. and Malone, B. (submitted). Thermal biology of tiger snakes (Notechis scutatus) in a suburban parkland in south-eastern Australia: a radio-telemetric study of translocated and resident snakes. Journal of Thermal Biology
Most previous research on relocated snakes from Nth America (mainly Rattlesnakes – major ecological differences to Australian snakes)
Westerfolds Park 123 ha urban
parkland ~15 km E of Melbourne
0
2
4
6
8
10
12
14
16
18
460-559 560-659 660-759 760-859 860-959 960-1059
Snout-vent length (mm)
Num
ber o
f sna
kes
Size of Tiger Snakes caught at Westerfolds Park
Transmitter size meant we needed snakes 760 mm snout-vent length ≥
• Resident snakes (2F / 4M) caught at Westerfolds
• Relocated snakes (4F / 4M) caught by snake catchers within 5 km of study site
• Catchers asked not to release at Westerfolds prior to / during study
Challenges of fitting transmitters to beasts that lack limbs and a defined neck…
• Following surgery / recovery, residents released at capture point
• Relocated snakes released at random points in “suitable habitat”
• Tracked 2 - 5 times / week
3 estimates of home range
100% Minimum Convex Polygon (MCP)
95% Harmonic Mean (Home Range)
50% Harmonic Mean (Core Range)
MCP (ha ± 1SE) 95% HM ‘Home Range’
50% HM ‘Core Range’
Residents 3.30 ± 2.07 4.30 ± 1.769 0.957 ± 0.299
Trans. 19.45 ± 9.764 25.36 ± 8.125 1.331 ± 0.385
Range:
t = -1.731 d.f. = 11
P = 0.111
t = -2.805 d.f. = 11
P = 0.017
t = -0.748 d.f. = 11
P = 0.470
Residents Trans.
13.2 62.8
11.5 59.6
1.8 2.7
0
0.2
0.4
0.6
0.8
1
1.2
October November December January February March
Residents
Translocated
Pro
porti
on o
f day
s th
at s
nake
s ch
ange
d lo
catio
n
Frequency of movements ( 5 m) ≥
0
50
100
150
200
250
October November December January February March
Residents
Translocated
Dis
tanc
e pe
r mov
emen
t (m
) Distance per movement
Relocated snakes - large initial movements, then continue to move more than twice as far as residents
(mean 140 vs. 64 m, 2-way ANOVA with month and
group as the factors, F1,273 = 9.605, P = 0.002)
• Half the relocated snakes left park, crossed Yarra River, entered adjacent private properties
• Some property owners not happy about this...
• When returned back to the park, several snakes returned to these properties
• Relocation did affect snakes – Animal welfare issues? – Spread of disease / parasites? – Genetic considerations? – Impact on conspecifics, competitors, predators, prey,
humans…?
• Potentially moving human-snake conflict from one area to another – Liability issues?
• What happens over other seasons / study sites / to other species?
• Worth trialing alternative management, such as short-distance relocation or “Living with Snakes”?
Heath shows his bitten finger, and thanks the staff of the Austin Hospital for effective treatment...
Good students are hard to come by…try not to let them die!
Source: Shine 1991
Red-bellied Black Snake Pseudechis porphyriacus
Eastern Brown Snake Pseudonaja textilis
Source: Shine 1990
Tissue necrosis following a bite from a South American Terciopelo
(Bothrops asper )
Source: Shine 1991
With the recent discovery of a new Taipan, approximately 80% of the snakes thought to be the most deadly on Earth occur in Australia
Snakebite management
• Be prepared – how many ‘snake’ bandages do you have? (Setopress bandages best)
• Don’t panic…at least not for long…
• Do not wash the bite sight – swabs can be used by doctors to identify the snake
• Both parts of ‘Pressure-Immobilisation’ 1st Aid technique are vital
Snakebite management
• No wandering around – bring transport to the victim
• Once bandaged, immobilise limb any way you can
• What if bite is on face / neck? What if I’m a hundred miles up a track with no vehicle and communications?
Immediately: If others are present, have someone phone for medical assistance. If unable to phone, send someone for help.
Reassure the patient and encourage them to remain calm and still.
Applying a pressure immobilisation bandage
As soon as possible, apply a broad pressure bandage from below the bite site, upward on the affected limb (starting at the fingers or toes, bandaging upward as far as possible). Leave the tips of the fingers or toes unbandaged to allow the victim’s circulation to be checked. Do not remove pants or trousers, simply bandage over the top of the clothing.
Bandage firmly as for a sprained ankle, but not so tight that circulation is prevented. Continue to bandage upward from the lower portion of the bitten limb.
Apply the bandage as far up the limb as possible to compress the lymphatic vessels.
Bind the splint firmly, to as much of the limb as possible, to prevent muscle, limb and joint movement. This will help restrict venom movement. Seek urgent medical assistance now that first aid has been applied.
First Aid for Bites on the Hand or Forearm 1 As soon as possible, apply a broad pressure bandage from the fingers of the affected arm, bandaging upward as far as possible. Bandage the arm with the elbow in a bent position, to ensure the victim is comfortable with their arm in a sling. Leave the tips of the fingers unbandaged to allow the victim’s circulation to be checked. 2 Bind a splint along the forearm. 3 Use a sling to further prevent limb movement.
It is vital to now apply a splint. Bind a stick or suitable rigid item over the initial bandage to splint the limb. Secure the splint to the bandaged limb by using another bandage, (if another bandage is not available, use clothing strips or similar to bind). It is very important to keep the bitten limb still.
Source: Australian Venom Research Unit