We have joined a great Thylacine group on facebook run by Wade Francis
The Thylacine Open Debate and Discussion Page
Dr Sleightholme and Cameron Campbell have responded to members questions..
We have our responses from Dr Sleightholme and Cameron Campbell.
Here is what we were sent.......
Both Cameron Campbell and I thank you for the invitation to participate
in the Q&A session for your Facebook group. First, a little about
our backgrounds:
Dr Stephen Sleightholme is author of several
scientific papers on the thylacine and Project Director to the
International Thylacine Specimen Database. Now into its 6th revision,
the ITSD is the culmination of a major cooperative effort between
museums and universities that hold specimens of the thylacine
(Thylacinus cynocephalus), to produce the first comprehensive study of
all that is known to physically remain of this unique species. In 2005,
the ITSD was presented with a prestigious Whitley Award, the first time
in the history of the awards that a citation had been presented for a
database.
Cameron Campbell is Curator of the online Thylacine
Museum and author of several scientific papers on the thylacine. The
Thylacine Museum is a world class educational resource and the most
comprehensive source of information on the thylacine available anywhere
on the web, or for that matter, in any conventional museum display. Now
into its 18th year, the museum was an early pioneer in internet
education, being one of the first natural history websites. The latest
revision brings together expert opinion from many disciplines, and this,
combined with its many interactive features, ensures that the site
appeals to both the amateur naturalist and academic alike.
1/Warren Darragh- Does the study of wet specimens and the fossil record support Bergman rule?
Stephen responds:
As far as I am aware, no research has been undertaken to support or
reject Bergman’s rule with respect to the thylacine. Few thylacine
specimens (wet or dry) note the place of capture, most only recording
that they originated from Tasmania. Because of this omission in
provenance, we are unable to state that thylacines caught in the colder
highlands were larger than those caught in the warmer lowlands.
2/Branden Holmes- Is he going to publish the paper he was working on
with Heinz Moeller about thylacine dentition before Moeller passed away?
Stephen responds:
At present, no further work has been undertaken on this paper, as other
projects have taken precedence. That said, it is an area that Cameron
and I may return to at some future date.
3/Warren Darragh- How evident is sexual dimorphism in thylacine?
Stephen responds:
Sexual dimorphism is evident in the thylacine, with adult males being
around 14% larger than adult females. It should be noted that this
figure is based on a limited study of 28 animals [18 male and 10
female]. In this sample, the mean male total body length from the nose
to the tip of the tail was found to be 1.61m, and the mean female total
body length 1.38m.
4/Nicole Dyble- Wonder if males would also
have larger head and generally larger in size like other marsupial
carnivores....but can be difficult to determine gender in juveniles.
Cameron responds:
With respect to the thylacine’s head, there is a marked difference in
the skull size between the sexes, the male thylacine having a
proportionately larger skull with a longer face. The skull of the female
is distinguishable from that of the male by its smaller size, shorter
muzzle, less expanded zygomata, and with respect to its dentition,
smaller but proportionally larger teeth.
5/Branden Holmes- Any papers currently in the process of being written/accepted/published?
Stephen responds.
Cameron and I have three papers in production. A paper entitled “The
International Thylacine Specimen Database (6th Revision - Project
Summary & Final Report)” is currently in review for publication in
the Australian Zoologist later this year. A second paper entitled
“Stripe pattern variation in the coat of the Thylacine (Thylacinus
cynocephalus)” is submission ready, and a third paper describing two
previously unknown photographs of thylacines at the London Zoo is
currently being written.
6/Warren Darragh- In various commercial
productions on the thylacine there have been differing views on the
animals maximum jaw gape. What would be your estimate be?
Cameron responds:
The gape angle is often quoted as being in the order of 120 degrees.
This however, is a gross exaggeration, as opening the jaw more than 80
degrees would violate the integrity of the joint.
7/Louise Sherratt=Does he think they are still alive?
Cameron responds:
Stephen and I recently published a paper in the Australian Zoologist
entitled “A retrospective assessment of 20th century thylacine
populations”, in which we presented the first comprehensive study of the
thylacine’s post-1900 range, based on the retrospective analysis of
1167 geo-referenced capture, kill, and confirmed sighting reports, from
1900 to 1940. In the paper, we examined the probable causes of
population collapse, and discussed the possibility that the species
survived into the 1940s and beyond. We concluded that the thylacine
certainly survived beyond Benjamin’s (the last known captive thylacine)
demise in 1936, and that the species was extant in the 1940s and
probably beyond. As to its present-day survival, my answer would be
possibly, as one cannot easily dismiss the Naarding sighting in 1982, or
Col Bailey’s sighting in 1995, as misidentifications. Understandably,
the scientific community demands a body or proof photograph / video to
confirm the continued existence of the species, and to date, that has
not been forthcoming.
8/Christine Mats- And if yes, does he think it's more likely to be on the mainland or Tasmania-New guinea?
Cameron responds:
I would think it far more likely that the thylacine survives in
Tasmania than on the mainland. That said, one cannot discount all
mainland sightings. The 1973 Doyle footage from South Australia and the
1984 Kevin Cameron photographs from Western Australia are rather
interesting, and take some explaining if we dismiss them as being a
thylacine. Much of New Guinea’s rugged interior remains unexplored to
this day, and it is anybody’s guess as to whether the thylacine still
survives on the island. Certainly, the thylacine was present there
during the Pleistocene, as indicated by the discovery of fossil remains.
Prior to about 1930, there were an estimated 1 million people living
in New Guinea that were unknown to the outside world, so it is
interesting to speculate on what as yet undiscovered species (including
mammals) might possibly exist in the dense forests of the island’s
mountainous, difficult to traverse interior.
9/Warren Darragh- How might a citizen scientist get access to the international thylacine database?
Stephen responds:
The sixth revision of the International Thylacine Specimen Database
will be released online towards the end of 2017, and will be accessible
through an academic portal on the Thylacine Museum website.
10/Steve Crawford-As a carnivorous marsupial, how was its locomotion in
respect to its prey. Did they primarily use stamina or ambush as its
main hunting strategy?
Cameron responds:
The thylacine is a
pursuit predator and employs various hunting strategies dependent upon
the nature of the prey being hunted, and whether it is hunting alone, or
as a member of a larger family unit. This is discussed in detail on the
Thylacine Museum website, at the links given below:
http://www.naturalworlds.org/…/bi…/behaviour/behaviour_5.htm
http://www.naturalworlds.org/…/bi…/behaviour/behaviour_6.htm
http://www.naturalworlds.org/…/bi…/behaviour/behaviour_7.htm
11/Mike Williams- How different was the locomotion of thylacines compared to canids..?
Cameron responds:
The thylacine is digitigrade, and like dogs and cats, walks on its
toes. A major difference between the feet of the thylacine and those of a
canid is that there is no webbing present between the thylacine’s toes.
Thylacines also have proportionately longer rear limbs as compared to
canids, giving them a rear-to-front sloping back, and a loping gait.
Please see the following Thylacine Museum pages for further details:
http://www.naturalworlds.org/…/b…/behaviour/behaviour_10.htm
http://www.naturalworlds.org/…/b…/behaviour/behaviour_11.htm
12-Warren Darragh- As a follow up on the gait question- how does
convergent evolution, combined with the need for predators to be
efficient in their movement help explain (or not) post extinction
sighting reports claiming thylacine have an awkward gait- when members
of the canine do not?
Cameron responds:
I would prefer not
to use the term “post extinction” in the context of sightings, as we do
not yet know with certainty if the extinction event has occurred. The
thylacine was / is perfectly adapted to the environment in which it
hunted. It is a stealth predator, and as such, is not designed for long
bursts of speed. Numerous historical reports mention that the thylacine
has an unusual gait, often described as loping. Anatomically, this
would not necessarily be inefficient in comparison to the gait of a
canid.
