| Diet (continued):
Paddle (2000)
states: "An overview of the known and suggested native prey species
of the thylacine suggests that it was a generalist: individual thylacines
feeding on a wide variety of small to medium sized species,
sometimes opportunistically, taking specimens that crossed their paths,
at other times deliberately, by stalking and individual pursuit; while
small family groups hunted larger, socially grouped prey".
Attard et
al. (2011) state: "Whether or not T. cynocephalus was well adapted
to kill prey approaching or exceeding its own body mass remains a contentious
issue".
Moeller (1968)
noted: "Thylacine body weight varies considerably throughout the records
but anything between 15 to 35 kilograms seems to be the general consensus".
Paddle (2000) notes: "the average weight
for an adult thylacine as being 65 pounds or 29.5 kilograms".
With most mammals, and in particular marsupials, the maximum body mass
is often two to three times that of the mean for the species. If
we take Paddle's mean of 29.5kg, then thylacines of 60kg+ (132lbs) will
no doubt have existed in the general population, although it must be noted
that these would have been exceptional individuals.
The early British settlers introduced sheep into Tasmania in commercial
numbers around 1820. The breed of choice was the small but hardy
Merino sheep, renowned for the fine quality of its wool. Analla &
Serradilla (1998) give the following growth weight references for Merino
sheep: |
.
.
Growth weights for Merino
lambs to 90 days of age.
Source: After Analla &
Serradilla (1998).
|
.
The
body weight of Merino lambs up to 90 days old are below the average thylacine
body weight of 29.5kg as quoted by Paddle, and therefore would have been
relatively easy prey for the thylacine to dispatch. Another important
factor that needs to be considered in the argument is a known characteristic
of sheep when pursued; sheep, if chased, will eventually lie down:
"Dogs are very peculiar
in their nature, and often very innocently chase sheep. And so are sheep
peculiar, for, when chased by dogs, they will immediately give up and lie
down, and then it is that dogs destroy them" (Tyler et al. 1873).
This idiosyncrasy of
sheep would have been exploited by a pursuit predator like the thylacine;
a prone sheep would have offered little resistance, making for an easy
kill.
Thylacines appear to
have been at their most destructive during the lambing season, as is often
noted in the Tasmanian press. The Mercury newspaper of the 26th April
1884 (p. 1) notes: "The tiger, or more properly, wolf, is peculiar to
Tasmania only, as also is the devil. Both are destructive to sheep,
particularly at lambing time, when they infest the vicinity of the runs".
The Launceston Examiner of the 7th October 1893 (p. 8) notes: "The native
tiger, it is very much to be regretted, still has to be reckoned with very
seriously at Woolnorth, and is at times the cause of somewhat considerable
losses amongst the lambs". The killing of a six month old lamb
by a thylacine was noted in the Hobart Town Gazette and Van Diemen's Land
Advertiser of the 3rd November 1821 (p. 2): "On Sunday last, about 4
o'clock in the afternoon, as one of the shepherds belonging to Mr. Edward
Abbott, jun. was looking after his master's flock, while grazing at his
farm, at Russell's Falls, near New Norfolk, the sheep were suddenly frightened
at the sight of one of these ferocious animals. They immediately
ran down a hill; and the man, having a dog with him, soon perceived the
Hyena pursuing the flock right a-head, when he made a sudden spring among
the sheep, and fastened upon a lamb, which he immediately killed.
The man then ran up with his dog; but the Tyger made off before he could
reach the spot: the dog however shortly after came up with the Hyena, when
he turned round and attacked the dog, who, with the assistance of his master,
at last managed to kill him. The lamb was rather large, about 6 months
old. The Tyger measured 6 feet from the nose to the extremity of
the tail; and is the second one that has been killed on nearly the same
spot within the last twelve months".
If Attard's findings
are proven correct, and the thylacine's skull has inherent deficiencies
that would not permit it to engage in a violent struggle with its prey,
then its method of kill certainly compensates for these failings.
To infer, against historical witness, that such structural weakness made
the thylacine incapable of killing sheep, ignores both the innate characteristics
of sheep when chased, and the thylacine's method of kill.
.
| A
thylacine at the Beaumaris Zoo (QD) by an unknown photographer (circa 1920s). |
. |
No discussion on the diet
of the thylacine would be complete without comment on the alleged practice
of "blood-feeding". The Argus
newspaper of the 12th March 1909 (p.7), notes the recent publication of
a book by Geoffrey Watkins Smith entitled "A Naturalist in Tasmania",
in which he makes reference to blood feeding:
"Of the mammals found
only in Tasmania, the best known are the thylacine, or native tiger, and
the native devil, of which Mr. Smith gives an interesting account.
By lesson of its destructive habits the tiger is regularly hunted and trapped,
and must before very long become extinct. Mr. Smith was therefore
careful to gain all the information he could with regard to it. The
mischief it does is greatly enhanced by the fact that it makes only one
meal off a sheep, merely sucking the blood from the jugular vein and perhaps
devouring the kidney fat".
This was the first published
account of blood-feeding noted in scientific literature. Unfortunately,
the concept was taken on board by subsequent authors without reference
to the validity of the original source. G. W. Smith never encountered
a thylacine on his visit to Tasmania, so his account is anecdotal.
The only 19th century
references to blood-feeding are to be found in two editions of a regular
weekly column in the Mercury newspaper entitled "Through Tasmania".
In edition 48, published on the 17th July 1884 (p. 1), it states:
"It is all nonsense
about the tiger merely sucking a sheep's blood, not eating it, for in some
as much as a quarter of a sheep has been found, but there is evidence of
one tiger after killing and eating as much of a sheep as satisfied hunger,
having killed and sucked the blood of a second".
In edition 49, published
a few days later on the 26th July 1884 (p. 2), it notes:
|
"The tiger refused the snares, walked round to where he could cross the
fence easily and killed two sheep right off, eating the shoulders, and
by way of a moistener killed and sucked the blood of a third".
As these stories were
published only days apart and penned by the same author, it is highly probable
that they came from the same source. |
.
Thylacine
at the London Zoo by L. Medland (circa 1902). This is the male thylacine
that was purchased from C. Hagenbeck (animal dealer) and was resident at
the zoo from 19th March 1901 until its death the following year on the
1st February 1902.
Another
photo of this individual is shown
here. |
|
Adye Jordan (1987),
an experienced bushman, and the trapper responsible for the capture of
Melbourne Zoo's last thylacine, made the following comment on blood feeding:
"Its eating and drinking
habits are easily observed and I strongly contradict these people who have
so often described the tiger as a blood sucking animal".
It is highly questionable,
therefore, that the practice of blood-feeding existed, and if it did occur,
it must have been an extremely rare event. From a biological perspective,
it would make little sense for the thylacine to hunt prey solely to feed
on its blood. Quite simply, it would not warrant the energy expended
in the kill. It seems likely that the stories of bloodthirsty thylacines
were nothing more than concocted fireside myths to further demonise
the species. |
