| Habitat:
Historically, thylacines
were found throughout Tasmania, with their preferred habitat being a mosaic
of dry sclerophyll forest, wetlands and grasslands. Flannery (1990)
states:
"The Thylacine appeared
to occupy most types of habitat except dense rainforest. Open eucalypt
forest was thought to be prime habitat".
Harris (1808),
when referring to the thylacine's natural habitat, states:
"It inhabits amongst caverns
and rocks in the deep and almost impenetrable glens in the neighbourhood
of the highest mountainous parts of Van Diemen's Land".
Guiler (1985)
states:
"The distribution
of thylacines bore no relation to altitude. They were found throughout
the state, and, if anything, favoured the coastal plains and scrub.
However, open savannah woodland was used extensively by thylacines and
they were not 'confined to the mountainous regions' as was so frequently
stated in the literature".
.
| A
thylacine at the Beaumaris Zoo (SB), circa 1911. |
Sleightholme & Campbell (2015), in their comprehensive assessment of
20th century thylacine populations, state that:
"The far south-west therefore, appears to have supported a small resident
population of thylacines, primarily along its coastal fringes. Inland,
the southern buttongrass plains supported few thylacines, and in all probability,
this population would have been transient".
They continue:
"Infrequent human incursions into the south-west certainly account for
why so few thylacines were recorded, but other, more intrinsic factors
operated to constrain thylacine numbers namely, climate and scarcity of
game. Guiler (1961), states that:
"The greatest numbers of thylacines were caught in the driest parts of
the state".
Rainfall typically exceeds 1600mm per annum in the far south / south-west
and consequently, the area is unlikely to have been the preferred habitat
of the thylacine. Laird (1947) attributed the coarse grasses of the
region to the paucity of game, and this too would have undoubtedly restricted
thylacine numbers:
"Marsupial food grasses diminish in area, quantity and quality as environment
changes towards the remote regions of the west and south-west. Eastern
food grasses are substituted by rank herbage wherein none but the toughest
species survive. Such areas have never, held large quantities of
game, and probably never will".
Historical reports from bushmen, prospectors, and explorers confirm Guiler
and Laird's observations. In the Mercury of the 8th June 1946 (p.
21), the Quinn brothers of Ellendale, all of whom were seasoned bushmen,
state:
"It is a recognised fact that this animal does not, from choice, inhabit
that type of country. Old hands in our district maintain this to
be so. Our own experience over many seasons of trapping in the remote
western and south-western areas forces us to subscribe to this view. Some
say that trappers are indirectly responsible for hastening the extinction
of the tiger by killing out the game, thereby depriving it of food, (yet)
you have a few thousand square miles of country that has never had a snare
on it. You can?t blame the snares if there are no tigers in that
area, and we would say there are not. The scarcity of game is attributable
solely to the lack of feed. Without feed no animal will thrive".
In support of the Quinn brothers' letter, Mr. J. Mayher, a prospector from
Queenstown, states:
"I have prospected over most of the state and am satisfied the tiger does
not inhabit this type of country".
The scarcity of game was a frequent observation in early 20th century exploration
of the area:
The Huon Times of the 19th July 1927 (pp. 3-4) states:
"A systematic search of the surrounding country was made for game, but
we were all very disappointed at the results. Practically no traces
of game were encountered".
The Mercury of the 27th October 1928 (p.13) states:
"The game near the coastline was plentiful, but there was not much of it
inland".
Sleightholme & Campbell conclude that the southwest of Tasmania, inland
from the coast, does not appear to have been favoured thylacine habitat.
Home
Range:
All of the historical
evidence seems to confirm that a male / female pair bond exists
between thylacines of breeding age, and that bond functioned within
a fixed home range.
|
Young adults and older animals lead solitary existences, travelling many
miles and skirting the fringes of fixed-range territories until they partner
up and establish new territories, or in the case of older individuals,
die. The Queenslander newspaper of the 25th February 1932
(p. 43) notes:
"As a rule the male animal is a lone hunter and
keeps to one particular district. At certain times of the year, however,
presumably during the mating season, he will travel over long distances
in search of a mate. During four successive years a male wolf was traced
over a distance of 170 miles as it |
.
.
| An
image from a 1933 motion film
of a thylacine at the Beaumaris Zoo (QD) in Hobart. |
. |
journeyed to the north-west
of the Island, by the sheep it killed en route. Each night a dead
sheep was found, minus liver and kidneys, at intervals of 20 miles or so
from the last, and then finally, in the fifth year, the marauder was caught
in a trap".
Thylacine social structure,
therefore, appears to exhibit both territorial and non-territorial behaviour.
Historical accounts from trappers support territoriality, as even when
thylacines faced persecution, they rarely moved out of their home area.
Guiler & Godard (1998) state:
"Evidence obtained
from the Woolnorth station diaries and old trappers gives clues as to the |
|
| thylacine's habits. Tiger hunts
are described in the diaries and the evidence quite strongly suggests that
the animal made little attempt to move away from an area even in the face
of persecution. This implies that thylacine has a home range, if
not a defined territory and is a view supported by A. Youd of Deloraine,
who trapped in the Lake Adelaide - Golden Valley region, and said that
'once you found where they lived then all you had to do was stick at it
until you caught them'. A similar assumption was suggested by Wilfred
Batty in his account of the shooting of a thylacine in Mawbanna
in 1930, when he made the point that the animal had been in the area for
some time prior to the shooting. This also supports the home range
theory". |
.
| Within the literature,
much variance exists with respect to the size of a thylacine's home range
with conservative estimates of 25km² (9.65 m²) to upper range
estimates approaching 250km² (96.52m²). Guiler & Godard
(1998a) give an estimate of between 55km²
(21.23m²) and 88km² (33.97m²) and this measure appears to
have been accepted by most modern authors.
Lair:
It is known that thylacines
make use of a lair (or lairs) within their home range. In a letter
addressed to the editor of the Mercury, published on the 12th December
1945 (p. 3), retired trapper, Mr. G. E. Randall of Hobart states: "I
have inspected their lairs and have at times discovered one male and three
females, and vice versa".
The Victorian newspaper,
"The Morwell Advertiser", of the 23rd June 1916 (p. 2), makes the following
comment on the thylacine's use of lairs: "They use hollow logs, etc.,
to camp in, and cover long distances, rarely coming out in the daylight".
The Queenslander newspaper
of the 25th February 1932 (p. 43) notes:
"They are found only
in the roughest and most densely timbered parts of the island, and make
their homes in the hollows among the rocks and in logs. There they
lie during the greater part of the day".
The Queenslander newspaper
of the 15th November 1934 (p. 40) notes:
"During the day the
animal lies quiet in caves, under rocks, and in hollow logs".
The Mercury of the 28th
September 1940 (p. 11) notes:
"The thylacine, or
tiger, hides her young in a rough nest in scrub or a cave".
The lair is in the form
of a sheltered area, usually a small cave, or hollowed tree stump.
The floor of the lair is lined with dry fern and leaf litter bedding.
From the lair, the thylacines hunt from dusk to dawn when their natural
prey species is active, and rest within the lair during the heat of the
day. The lair offers a degree of protection to the young whilst out
of the pouch. It is very likely that there are several lairs within
each home range, and progressive movement between them prevents local depletion
of game stocks. |
.
.
|
Thylacine lair on St
Paul's River, December 1902. Photo: La Trobe Collection (State Library
of Victoria).
|
Shown above is the only known photograph
of an actual thylacine lair (Paddle 1992). It was taken by Dudley
Le Souéf, the Director of Melbourne Zoo, in December
of 1902. Its occupant was captured and transported to Melbourne Zoo. |
