A Case Study of DFTD and its Near Extinction of Tasmanian Devils

This case study examines the near extinction of Tasmanian devils (Sarcophilus harrisii) due to Devil Facial Tumor Disease (DFTD). The Tasmanian devil, the largest carnivorous marsupial, is now primarily found in Tasmania and is classified as an endangered species by the IUCN. DFTD, a transmissible facial tumor first observed in 1996, has decimated the Tasmanian devil population, leading to secondary infections, bone loss, and organ failure. Studies indicate that low genetic diversity and restricted geographical distribution hinder the development of resistance to DFTD. Conservation efforts, such as the Save the Tasmanian Devil Program, include establishing captive populations and geographical redistribution to improve genetic biodiversity. Recent research suggests that crossbreeding with other marsupials and focusing on cancer genome mutations could enhance the species' ability to combat the tumor. The case study emphasizes the need for improved management practices to ensure the survival of the Tasmanian devil.

DECLINE OF MARSUPIALS IN
NORTHERN AUSTRALIA
A CASE STUDY OF ITS NEAR EXTINCTION OF TASMANIAN
DEVILS (Sarcophilus harrisii) BECAUSE OF DFTD

INTRODUCTION
 Tasmanian Devil is a carnivores
member of the Dasyuirade family.
 It belongs to the Marsupial infraclass
of mammalian class.
 Currently Tasmanian devil are found
only in the island state of Tasmania
of Australia.
 Earlier it was present in mainland as
well but got extinct over the period
of time (Hamede, et al. 2013).

SPECIES ATTRIBUTES
 Tasmanian Devil is the largest carnivores
marsupial of the world.
 Lives in a solitary environment in most parts
of the day.
 Strong muscular build with a very strong bite.
 High rate of reproduction and polygamous in
nature.
 It is considered that they extinct from main
land Australia 3000 years back (Wells, et al.
2017).

CONSERVATION STATUS
 Tasmanian devil has been given the status of
“Endangered species”: by IUCN.
 It is also a member of the Red list issued by IUCN
which is a list of threatened species.
 A conservation project has been initiated by IUCN
and UN in Maria Island of Tasmania for this species
to ensure its protection, reproduction and disease
free.
 Earlier it was considered as a threat to live stock
and hunted but that did not caused the extinction.
DFTD named tumor is found in most of the studies
as the primary cause of leading the species to
endangered level (Hollings, et al. 2014).

DEVIL FACIAL TUMOR DISEASE
(DFTD)
 DFTD is a transmissible facial tumor found in
Tasmanian devil.
 It was first imaged in 1996 and diagnosed in
1997 in the species.
 Locally aggressive tumor.
 Secondary infection, loss of bone, metabolic
starvation and organ failure after tumor
causes the death of animal in 4-6 months.
 Genetic mutation has been identified as the
primary cause for development of this
disease (Deakin, et al 2012).

RECENT STUDIES AND PUBLICATIONS
 According to the study conducted by Pearse
et al (2011) Devil facial tumor disease (DFTD)
is the primary reason why they reached to
the stage of endangered species.
 It is a transmissible form of cancer which
causes variants or mutation in the
chromosome of Tasmanian devil.
 Study indicates that Tasmanian devil have low
genetic diversity and restricted geographical
distribution which make them less likely to
develop any resistance against DFTD.

 According to the study conducted by Hamede et al,
(2011) far northwest of Tasmania i.e. maria islands are
the only place in world where a wild population of
Tasmanian devil is present which is disease free.
 It is also found in the study that geographical location of
the species creates a phenotype and genotype based
difference in the species and also in the strain of tumor
DFTD.
 This should be considered as a base for finding a
solution to the problem and protect the species from an
extinction.
 If resistant alleles are present in species in some location
of Tasmania then it should be spread to other locations
as well.

SAVE THE TASMANIAN DEVIL PROGRAM
 According to the data published by
“save the Tasmanian devil program”
publications backed by Tasmanian
government state that nearly 95
percent of the population of species
is wiped out by DFTD disease after
its diagnosis in 1997.
 In year 2005 captive population was
established under the program to
ensure that species does not get

DISTRIBUTION OF DFTD

 DFTD causes disturbance in the reproductive cycle of
females, collapse in synchronized breeding event, loss
of appetite and a loss of older age classes as well.
 I t mainly spreads through close contact between one
devil to another (usually biting) which transfers the
tumor cells directly from one animal to another.
 Repeated trapping of animals, The road kill project and
involvement of all agencies and public at large was
done for better collection of information and data about
disease.
 Below is the image of a typical DFTD struck Tasmanian
devil.

IMPROVEMENTS ON EXISTING
MANAGEMENT
 One of the prime findings of the
recent studies done on Tasmanian
devil is that genetic diversity and
geographical redistribution is needed
to make the species stronger against
DFTD.
 In current management practices for
saving the Tasmanian devil
improving their genetic bio diversity
is not yet fully included or

 Cross breeding between other
species of Marsupials and Tasmanian
devil might help in developing
stronger genes which can later be
introduced in the original species and
their ability to fight back the tumor
can be improved.
 Murchison, et al (2012) stated in
their study that the cancel lineage
was originated in the female