DEVILS
OF THE ALPINE -
Field Monitoring Program
A camera based Field Monitoring Program of wild
Tasmanian devils (Sarcophilus harrisii) within the Cradle Mountain area.
PROGRAM
DIRECTION:
The field monitoring program is conducted by Devils @ Cradle
staff utilising their combined expertise of local knowledge and scientific experience,these
people are well qualified to implement this project.
PROGRAM
OBJECTIVES:
To establish an ongoing and comprehensive camera based field monitoring program
of wild Tasmanian devils within the Cradle Mountain area.
This program will enable us to gain a better understanding of the wild population
of Tasmanian devils within the Cradle Mountain area. Very little field research
has been conducted on Tasmanian devils due to their elusive nature.
In the last ten years devils have experienced a marked decline in numbers in the eastern 64% of the state. This decline has been linked to an allo-grafting sarcoma known as DFTD (Devil Facial Tumour Disease).
DFTD devils are now formally listed as a Threatened Species having suffered a 50% reduction in 10 years. Very little is known about DFTD and its spread has been closely observed through spot checks performed continuously throughout the state by the DPIW (Department of Primary Industry and Water). These focus on the presence of DFTD in a particular area or population not the long term effects.
The short term objective of the program is to increase the number of cameras we have through grants, sponsorship and donations so we can continue to extend the scope of the study area.
The long term objective is to release devils @ cradle captive bred animals back into the wild, in areas identified through the program as suitable locations. These animals would be monitored through radio tracking devices and assist in the breeding diversity of low density areas in the wild.
PROGRAM
DETAILS:
The Field Monitoring Program is conducted using
remote sensing infra-red digital cameras. The cameras currently used are manufactured
in the United States for wildlife and game monitoring purposes and are available
online from www.camtrakker.com.
The cameras gather data on particular individuals and the number of animals that inhabit the study area. Each individual is documented by an identification proforma and referenced in a data base using the infra-red digital photographs obtained by the camera traps.
The camera traps are erected strategically in the study area in a zone located by observing and following the natural paths (game trails) that devils create over many generations. These paths generally converge as home ranges over lap and are marked by a common latrine site. A slightly open area will be selected to try and limit the number of “false records” or photos taken by moving leaves branches etc. A GPS reading is also taken of the location of the camera trap and recorded.
The devil is naturally very opportunistic and will readily scavenge carrion. The project randomly uses wallaby and possum carcass as an “attractant”, obtained through the Parks and Wildlife field staff, who remove road kill animals from this area. A “drag” is conducted of the carcass, scenting the game trails which will lead back to the camera trap. The carcass will be securely fixed to a star dropper to prevent it being dragged from the site.
Bait Boxes have also been made which
are dug into the ground - the animals turn around constantly sniffing, biting,
digging and exploring which allows shots of all markings, making the documentation
and identification of each individual more accurate.
Camera traps are checked regularly, photographic data downloaded, batteries recharged and set up back in the field. Once the camera trap is set it will take a log of all activity around the carcass and each shot is automatically scribed with the time and date for ease of logging.
The program will see cameras permanently set in a certain part of the study
area for a period of 2 - 3 months only, to avoid developing any dependence by
the local population on the free feeding.
PROGRAM
DOCUMENTATION:
This project is documented in several ways, data is gathered
in a certain area over a certain period - these results are then formatted and
recorded within a data base. They are displayed and used for interpretation
within the devils @ cradle facility and also on the devils @ cradle website
(www.devilsatcradle.com) where they are regularly updated for public viewing
and following.
The formated results are also forwarded onto DPIW - DFTD Project Team for assessment
and feedback.
A data base of all animals observed will be kept in both hard copy through a proforma and electronically.
Pictures will be taken in JPEG format by the digital remote sensing cameras due to the relatively compact nature of the file type. High resolution JPEGS could also be accepted in publications.
photo taken 21st July 2006
SCOPE
OF STUDY AREA:
Tasmanian devils are a gregarious species and have already been
attracted to the devils @ cradle facility through interest in the captive population,
it is considered the CRADLE VIEW property could provide a “hot spot”
for undertaking this study.
Permission has been gained to utilise a large area of land both Private and Crown for the purpose of this study. Access of the surrounding Conservation areas of the Cradle Mountain National Park, Vale of Belvoir Conservation area and Reynolds Falls Recreation area has been approved by the PWS.
The scope for this study is quite extensive, while confined to the immediate area of Cradle Mountain. This range will allow for a comprehensive study into current numbers, their movements, habits, range, life spans and the presence of Devil Facial Tumour Disease (DFTD) in the Cradle Mountain region.
DEVILS
OF THE ALPINE
Field Monitoring Program Results
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July 2006 saw the commencement of the DEVILS OF THE ALPINE - Field Monitoring Program.
July 2006 - August 2006
female 2 years old
We commenced a two month pilot study on the Cradle View Property intending to fine tune the CamTrakker passive infra-red digital cameras with the aim of capturing quality photographs of devils to be able to identify the animal.
We have developed "bait boxes" that are dug into the ground, these act as an attractant to the animals but do not supply enough food for a dependence to develop. The resolution of the cameras is excellent and by using the "bait boxes" the animals turn around constantly biting, digging and exploring which allows shots of all markings which makes the documentation and identification of each individual more accurate.
The results so far have exceeded our expectations and we have currently taken 161 devil photographs and identified 9 different individuals, including one female with young developing in the pouch. We have identified a representative population of many different ages. Thankfully we have not observed any signs of DFTD in our sample and all animals have been in good physical condition.
The program has taken 71 Eastern quoll pictures and 7 pictures of the highly elusive Spotted-tail quoll, as well as shots of wombats, possums and unwary staff!!
All in all the initial two months have been a success and we look forward to collating and presenting the data regularly at - www.devilsatcradle.com
The intention is to gradually increase the scope of the study to other areas within the Cradle Mt area as we increase camera stocks.
Devils
of the Alpine - Field Monitoring ProgramUpdate
September 2006 - October 2006
We have now expanded the study area for the Field Monitoring Program (FMP) to include a second photo "trap" site approximately 500 metres from the first.
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At this site we have had a number of the same individuals as site 1 but also 6 new individuals. These animals bring the total number of individuals observed in the study to 27.
Unfortunately we have also observed 3 individuals with DFTD (Devil Facial Tumour Disease) at the two trap sites. Therefore the results currently suggest that there is at least a 12% infection rate within the "Cradle View" property. This important information was shared with the DPIW (Department of Primary Industry and Water) DFTD Task Force for inclusion in their studies and to the PWS field staff for accurate interpretation within the area.
Interestingly it currently appears that the devils are feeding for a longer period of time at the second trap site, which may be due to its more isolated location and the security that the surrounding dense vegetation provides. Throughout the study we have only photographed two individuals together at the same site once, therefore they don't appear to be freely feeding together.
We are frequently observing another threatened Tasmanian marsupial, the Spotted-tail quoll which is exciting as they are not in high numbers in this area and like the devil they are notoriously elusive.
We look forward to the continuing success for the FMP and keeping you up to date on the Devils@Cradle Website.
Devils of the Alpine - Field Monitoring Update:
November 2006 - December 2006
This last period has been incredibly successful for the Devils of the Alpine - Field Monitoring Program.
The results show a drop in Eastern quoll activity with only 19 shots being taken in 3 months, increasing the total number of shots taken from 82 to 101. We are yet to identify the number of individual Eastern quolls in the study area.
Through the FMP, we have identified another spotted tail quoll which means that there is an adult male and a female within the study region. This is exciting as it is estimated that there may only be 4000-5000 individuals in the state.
We have also secured some amazing shots of a lesser long eared bat flying through the study site as a devil triggered the passive infra-red cameras with its movement. Another unusual photo was taken within the last week of a male spotted tail quoll and a large pademelon in the same frame. These two species are recognised as predator and prey. Why the pademelon was around the bait is uncertain but it may show that they will consume some flesh or the digested plant material in the intestines as brush tailed possums do. Also the cameras have identified Forest Ravens scavenging at night on the bait stations, which again is unusual as they are recognised as a diurnal species.
December and January is the time where young devils disperse from the maternal den. Accordingly the population increases and then decreases sharply as the young recruit into the population. Weaker juveniles and adults can not deal with the increased competition levels and attrition is severe. We have observed a noticeable jump in identified individuals in the study area. Last quarter there were 26 known animal, now it is 38. These animals showed varying body conditions with both adult and juvenile devils appearing emaciated. It will be interesting over the next quarter to observe the success of the young and also which adults succumb to attrition as we enter into the breeding season.
This period has seen an increase in the number of DFTD cases and also the number of newly identified devils. Despite an increase in the suspected DFTD cases the maximum percentage of observed animals affected is equal to last quarter at approximately 13%.
One adult female was reported in the study area killed by a vehicle. This animal was killed 800m east of Leary's Corner, was clearly emaciated and had an advanced case of DFTD.
Several
animals were observed with lacerations on the jowls and neck which indicates
mating behaviour. If so there is a correlation with an early start to the oestrus
cycle in our captive females. Oestrus usually occurs in mid to late February.
This may be occurring early due to the mild dry winter we experienced and the
short sharp cold burst and then hot dry summer we are experiencing. This may
have altered the animal's natural rhythms. It may also indicate the intense
level of competition at the moment with so many young dispersing. It will be
interesting to monitor the breeding season over the next quarter.
DEVILS
OF THE ALPINE - Field Monitoring Program Update
January 2007- February 2007
This period has proved very interesting as we have seen a marked
decline in devil activity as the animals have come into oestrus and started
mating.
The total number of devils has increased from 38 to 59 due to an expansion in the range of the study area to approximately 40 square kilometres of private property and reserve. Through ongoing donations we have purchased another 2 camtrakker units to monitor these more remote regions. These units are placed out and checked weekly and have shown some excellent specimens and no signs of DFTD. With an increase in total numbers of observed individuals and no more confirmed DFTD cases, the DFTD level is at its lowest recorded within the study at 5%.
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This is a positive outcome but the results may be indicating that during the summer period high levels of competition from dispersing young and increased population density has caused the death of the animals affected by DFTD. Devils that can not compete tend to succumb to starvation, which is also what happens with individuals with DFTD. Increased competition from dispersing young would potentially accelerate the effects of DFTD on a population. It will be interesting to see if the observed occurrence of DFTD increases throughout the year as more animals that may have been infected present observable lesions.
Despite the increase in total number of devils observed, the activity levels at each site (indicated by the number of individual photos taken each night), has decreased. This may be caused by the start of the oestrus cycle, a greater interest in breeding and denning and a reliance on fat reserves built up over the summer.
Many of the juveniles have been successful over summer, with a number establishing their range around the cradle view property. These individuals are seen frequently on the property and at the camera sites.
We have also observed another 3 individual spotted tail quolls. It is theorised that Spotted tail quoll numbers could be on the increase due to a decline in devil numbers and the reduction in levels of competition. . However it is more likely that we are observing more quolls due to expanding the study area.
A concern is the total lack of Eastern quolls observed in the last quarter. We have not taken one shot of an Eastern Quoll in over 3 months. Hopefully this is not indicating a crash in the population. We will be watching very closely over the next quarter for any other indicators of Eastern quoll population decline.
DEVILS
OF THE ALPINE - Field Monitoring Program Update:
March 2007 - May 2007
This period showed initially a complete lack of devil activity due to continued mating. The mating season seemed to be longer than usual with many animals within the captive population mating in April rather than March. Towards the end of the quarter, devil activity increased dramatically.
For the first time in this study we experienced technical difficulties with 2 of our camera units and also the computer system! One camera unit was out of action for a month while new parts were obtained, which limits some of the results obtained this quarter. Thanks to the crew at Camtrakker for the swift responses and replacement of the unit battery which proved faulty!
We have seen a rise in the number of Eastern quolls observed this quarter, which is pleasing as last quarter no activity was recorded. Spotted tail quoll activity is becoming quite frequent with several individuals at site 1, 2 and 3 regularly photographed. As we move into the next quarter both species of quoll will be breeding which will probably limit our observations of their behaviour.
We are currently not recording any individuals within the four study sites with DFTD. We have seen a steady decline of individuals observed with DFTD which is positive. We suspect that as the young dispersed over summer the levels of competition grew and it was not only providing tremendous rates of attrition on the young devils but those weakened with DFTD. We may see the rate of DFTD increase again with the progression of winter as the level of contact was increased through breeding over this quarter.
First Eastern Quoll Photographed for 3 months!
DEVILS
OF THE ALPINE - Field Monitoring Program
Update: 1st of July 2006 - 30th of June 2007
July 1st 2007 marked one full year (12 months) of the Devils of the Alpine - Field Monitoring Program. During this time we have taken 1758 photographs of Tasmanian devils and confidently identified a possible 77 individuals.
Tragically 4 of these 77 individuals have been identified with DFTD, one of which was killed by a vehicle on Cradle Mountain Road near Leary's Corner.
The occurrence of Devil Facial Tumour Disease (DFTD) in the population as a percentage of the total number of individuals observed has declined sharply from 11.5% at its maximum to 5.2% (see below). This is a very positive finding and may indicate that there is some resistance to DFTD in the Cradle Mountain area or that the population within an alpine area is more solitary in its activity and therefore less efficient at spreading the disease.
7 individual Spotted-tail quolls were observed through 243 photographs. 4 male,
2 female and 1 juvenile (killed by a vehicle on Cradle Mountain Road) None of
these individuals showed any signs of lesions, supporting the idea that DFTD
is restricted to the Tasmanian devil population.
Approximately 10 Eastern Quolls were observed over the 12 months through 104
photographs. Initially this species was photographed much more frequently than
the Spotted -tail quoll and Tasmanian devil but the rate of capture has declined
through the second part of the study. This may indicate that the animals are
becoming trap shy. Hopefully it does not indicate that the Eastern Quoll population
is declining.
This initial 12 months of research has provided us with a greater understanding of the Tasmanian devil population around Cradle Mt. and the current effects of DFTD however, the Program is ongoing and we look forward to learning more over the next 12 months. We will keep you updated on the results throughout next year and beyond!
Statistical
summary of initial 12 months of study -
Study area - Cradle View property 9.92ha and Middlesex Station
Tasmanian
devil
Total photographs - 1758
Total individuals - 77
Adult Males - 35
Adult Females - 34
Juveniles - 8
Confirmed DFTD Cases - 4 (5.2.% of observed)
Injured devils Rehabilitated -1
Spotted
Tail Quoll
Total photographs - 243
Total individuals - 7
Male - 4
Female - 2
Juvenile - 1
Eastern
Quoll
Total photographs - 104
Total individuals - Approximately 10
Wade Anthony and Chris Coupland
Devils of the Alpine Project
The 'Devils of the Alpine Project' was created by the devils @ cradle team to voluntarily support two priority conservation programs that we
consider crucial to assist in the survival of the Tasmanian devil in the spectacular World Heritage wilderness area of Cradle Mountain.
The Project focuses its efforts and the funds received on these two priority programs;
1. A Captive Breeding Program (CBP) to support a healthy insurance population of Tasmanian devils and -
2. A research based Field Monitoring Program (FMP) which utilises remote passive infra - red cameras to monitor the population of Tasmanian devils in the Cradle Mountain area.
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This year's Captive Breeding Program has been a successful one with 5 pouch young being born at the facility, the arrival of 5 juveniles from the south of the state has also given this program greater gene diversity. The captive poulation now houses 16 devil.
The success of the FMP relies on the contribution of grants, donations and sponsorship to fund the various equipment required while the field work is conducted by devils @ cradle staff and other volunteers.
The goal for the project over the next 12 months is to continue breeding healthy devils, increase the field monitoring work and raise more significant amounts of money to assist with the sustainability and development of these programs.
The longer term goal for these programs is to contribute to a state wide insurance population of devils through a coordinated breeding program. In time these animals could possibly be released into the wild in areas identified throughout the FMP to assist with breeding diversity and monitored through radio tracking technology to follow their progress.
Local organisations, businesses and visitors to devils@cradle have provided the initial funds to kick off the FMP which has been collecting data since July 2006.
Thanks to Organisations and businesses below;
Cradle Mountain Parks and Wildlife Service
Tourism Tasmania
Cradle Mountain Tourism Association
Cradle Mountain Wilderness Gallery
The many tourists and visitors who have personally donated to devils@cradle.
Wade Anthony - devils @ cradle Director
We will continue to upload results regularly over the next 12 months.
DEVILS
OF THE ALPINE - Field Monitoring Program
Update:
1st of July 2006 - 30th of September 2007
This quarter has again seen an increase in the number of Tasmanian devils identified! At least 81 individuals are present within the study area (39 males and 38 females).
This shows that there is still a slight bias 0f 1.26 males to each female within the Cradle Mountain Region. The DOA-FMP has now been in operation for 15 months. The study still commonly identifies new Tasmanian devils. This suggests that the population is quite dense within the study area.
No further images were obtained for either Spotted tailed or Eastern Quolls. We have 7 Spotted-tailed quolls identified and have yet to determine individuals for Eastern quoll, but estimate that there may be as many as 10 individuals on the "Cradle View" property alone. Both Quoll species breed through the winter months so one would expect most individuals to have "gone to ground" because of it.
No DFTD positive individuals have been identified with DFTD throughout this quarter. This means that as a percentage of total number of observed individuals we have witnessed another decline from 6.5% to 6.2% with DFTD.
One would expect that the population would be at its seasonally lowest due to the increased levels of competition throughout the winter months and any remainingindividuals with DFTD in the population would have succumbed to the disease through this time. Also this quarter is approximately 6 months since the breeding season and it is generally accepted that most individual will have shown symptoms of DFTD within 6 months. So despite the increased levels of contact present from breeding we have still not seen an increase in the condition over time. That may indicate that there is some genetic resistance within the Cradle Mountain population.
Chris
Coupland
Devils@Cradle
Statistical
summary of initial 12 months of study -
1st of July 2006 - 31st September 2007
Study area - Cradle View property 9.92ha and Middlesex Station
Camera
sites
1. site 1 - GPS Location (UTM) 55GDP105951
2. site 2 - GPS Location (UTM) 55GDP109949
3. site 3 - GPS Location (UTM) 55GDP134983
4. site 4 - GPS Location (UTM) 55GDP195953
Tasmanian
devil
total photographs - 2218
total individuals - 81
Adult Males - 39
Adult Females - 38
Juveniles - 8
Confirmed DFTD Cases - 3 (3.7% of observed)
Potential DFTD Cases - 2
Maximum percentage of DFTD in observed - 6.2%
Roadkill devils in Cradle Region - 1
DFTD positive roadkill - 1
Injured devils Rehabilitated -1
Spotted Tail Quoll
Total photographs - 243
Total individuals - 7
Male - 4
Female - 2
Juvenile - 1
Eastern Quoll
Total photographs - 104
Total individuals - Approximately 10
Devils of the Alpine - Field Monitoring Program
The first 12 months of data has been collated and formally documented.
This will be peer review published in a local journal this month.
Please feel free to down load the PDF file by following the link below.