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					                    Buffalo Project Newsletter
                              – population dynamics and disease control –

                   ___________________________________________________________________

                No. 3                                                                         November 2007

Once again, a hearty welcome from the sultry tropics to the latest news and progress from the buffalo project. In this
edition you can read the next exciting instalment from Glenn on the ethics of buffalo hunting and harvesting, news and
progress on setting up and analysing the life table information, progress on the NT-wide collection of buffalo DNA
and some thoughts and impressions from Melanie (a visiting student and now research associate from France) on
volunteering for a day’s field work on buffalo. Once again we extend an open invitation to all who would like to
contribute articles and thoughts to forthcoming editions of the newsletter. These can be sent directly to either Clive or
Corey (contact information below). We hope you enjoy this instalment.


Buffalo life tables
A ‘life table’ is a powerful tool to study and understand how
populations are behaving, i.e., how they are growing, decreasing
or remaining stable. A life tables (also called ‘mortality table’) is
a table showing the age-specific survival, mortality and fertility
probabilities for a population. It is from such tables that we are
able to derive important life history statistics such as:
    •   the probability of surviving any particular year of age
                                                                         Figure 1. Buffalo herd. Photo: Buck Salau
    •   life expectancy
    •   the proportion of the original birth cohort still alive at the end of a given period and
    •   key information like population growth rate, reproductive rates, age at first breeding and population turnover
        rates

Consequently, life tables are used extensively in biology, epidemiology, and wildlife management; indeed, life tables
form the basis for effective and sound wildlife management.
At present we have two full female life tables from Arnhem Land – one from the commercially harvested population
near Bulman and one from the subsistence-harvested population from our study area in the Cadel River region. The
life tables were constructed using method six in the ecologist’s ‘bible’ – Caughley’s 1977 book Vertebrate Population
Analysis. While not getting into the mechanics of the method, it relies on collecting a cross-sectional sample of
animals (i.e., a snapshot) in a population at a given time. From the number of animals in each of the age classes
(animals were aged by counting dentine layers in their teeth as described earlier and also by live-ageing: looking at
eruption and wear patterns) we can calculate survival and fertility rates. From this information we can calculate the
population growth rates and also those stages which contribute most to population growth (this is called an ‘elasticity’
analysis). Incidentally, the two techniques correlated well.


So what does it all say? Our analyses so far suggest that both populations are being harvested at sustainable levels, but
importantly, we have determined that female survival is one of the principal drivers of population growth, and juvenile
(1-3-year olds) survival is almost as important (see the figure directly below).

                                           0.8

                                           0.6
                               Elastcity




                                           0.4

                                           0.2

                                            0
                                                  Calf                Juvenile             Breeding
                                                                     Age class

 Figure 2. Elasticity analyses for water buffalo from Arnhem Land showing that survival is the vital driver of population behaviour
and that pre-breeding (calf & juvenile) survival in the first three years of life is almost as important as the subsequent 14 years of life
            (termed ‘breeding’ stage). The grey shade areas represent survival while the hatched area represents fertility.


It is this kind of information that will be invaluable when trying to manage buffalo densities in northern Australia
because it is rather unrealistic and practically impossible to remove buffalo completely from the Australian landscape.
The best we can do is to reduce densities to prevent/negate their negative effects on the landscape and to reduce the
risk of spreading disease. This is because at low densities, animals cause less damage and disease is less likely to
spread across wide areas.
DNA sampling

Collecting skin samples from across the Top End continues and we now have samples from Nhulunbuy in the east all
the way through to Kakadu. We also now have, with the help of NAQS, our AQIS partners, samples from what we
believe it the founder population on the Tiwi Islands. Sequencing these skin samples will provide us with information
of population mixing and large-scale movements which will be important for assessing the potential for disease
spread. Work on sequencing the samples has begun with the help of our colleagues Yugi and Shingo at the University
of Kyoto in Japan. The preliminary results show that we are able to differentiate between the various populations,
suggesting some genetic structure between populations, which is really encouraging news for assessing mixing rates.




   Figure 3. Locations where skin samples (DNA) have been collected so far. Sites extend from the far western coast of the Gulf of
 Carpentaria through to and including Kakadu National Park, and including the founder population on the Tiwi Islands (pink dots).
                                     Produced using Google Earth® (http://earth.google.com/)


Buffalo immobilization

We are happy to report that our paper on buffalo immobilisation has now been accepted for publication in the
Australian Veterinary Journal. Again we like to thank C. Berthouly and M. Pedrono (BIODIVA-Project) for allowing
us to use their morphometric data which were instrumental for developing the relationships between body
measurements and mass. These body mass predictions then allowed us to present mass-specific dosages of the
immobilising drug we used to capture buffalo for GPS collar deployments.
Ethical considerations

This is our regular feature and in this instalment from Glenn we look at the buffalo meat, export and hunting industries
in Australia.


Buffalo meat, export and trophy hunting – Glenn Albrecht

The buffalo hide industry had ended by the 1950s and in its place small-scale hunting for local meat industry for
human consumption and pet meat commenced. It is at this time that the trophy hunting industry also developed. Allan
Stewart, who ran a trophy hunting and safari business at Nourlangie in Western Arnhem Land gives a first hand
account of both the buffalo meat industry and buffalo trophy hunting in his The Green Eyes are Buffaloes (1969).
After warning the reader about the dangerous and unpredictable nature of the buffalo, Stewart provides an analysis of
the way buffaloes are killed. He suggests that the use of “any calibre less than .303 is inhumane” and even the .303 is
not an effective weapon for killing buffalo. He argues: “There is no denying that the .303 is a reasonable all-round
Territory rifle, and that it will kill buffaloes; but it was designed to kill men, not thick-hided bovines. A buffalo
becomes insensate to shock after the first impact and follow-up shots do not appear to visibly affect it. I have had to
follow a badly wounded bull, on foot, over three miles before it collapsed from a lung shot by a .303.”. Stewart also
observed many occasions where professional buffalo hunters would not be able to kill an adult buffalo with a .303
even after five shots and that his own .375 calibre rifle was more effective.




The capture and export of live buffalo raise considerable animal welfare issues but in the context of the isolation of the
Northern Territory, few people were directly aware of the issues. The use of four-wheel drive vehicles had some
advantages over the horse, especially in the early days with the use of a ‘mechanical arm’ on the vehicle that could be
used to capture and hold an animal exhausted after a long chase. An account from an Indigenous participant gives an
indication of what was involved: “But nowadays we have Buffalo Catchers come in our country every year during dry
season and finish before wet season start. And I like catching wild buffalo. Sometimes it’s dangerous and a little bit of
fun if you know what you’re doing. We chase the buffalo with the Toyota 4 wheel drive put them on the plane so we
can get them easily. Knock ‘em over, strap ‘em on and leave it there for the big truck to load ‘em on then take them to
the yard so they are ready to be transferred to Darwin. Then we sell them to Asian country and they do what they
want, like eat them or keep them for work on rice field.”1

1
    (http://www.ourmessage.org/events/Exhibition_2001/Ken_Ruunga/kenr001p.htm)
The ethics of capturing and transporting large animals has been in the news with respect to live cattle and sheep
exports for some time; however, as the export of large numbers of buffalo from NT is relatively new, not much ethical
attention has been paid to this emerging industry. The animal welfare issues of mustering, capture, yarding, tagging,
de-horning, trucking and finally, live shipping are indeed complex and formidable and apply equally to all animals
being exported.

From the late 1950s the safari and game hunting business was established in Arnhem Land. Tourist and hunters from
all over the world came to the Top End to observe and shoot game. It was reasonably popular to shoot buffalo as a
trophy and game managers such as Allan Stewart made it clear that he preferred to use .375 calibre rifles over the .303
to kill them. He states that “ [with] the .375 I have had clean one-shot kills up to 250 yards” and that he always
allowed two shots to kill an animal on the basis of the toughness of its hide and its tenacity. Simpson, however, did not
share Stewart’s views on the hunting of buffalo. He suggested: “Buffalo-shooting is a business, but it can never be a
sport. Racing up on them in a jeep and pumping bullets into a bull with a big set of horns to mount on a wall as a
trophy has no more validity as hunting than going into a paddock and shooting a dairy cow”

We leave you there with those profound words. The next instalment, again from Glenn, will look at the ethics of the
current buffalo research.

French impressions – a day at Beatrice Hill research farm – Melanie Hamel

24 April 2007: Buffalo day
                                                     Cindy and I wake up at 05:30; Clive comes to pick us up in
                                                     Darwin around 06:30 to bring us to Beatrice Hill farm close to
                                                     Adelaide River. The idea is to weigh and measure about 50
                                                     known-age water buffalo on the Department of Primary Industries’
                                                     research farm. After 1.5 hours driving on the Stuart Highway, we
Figure 4. Beatrice Hill farm. Photo: Melanie Hamel
                                                     arrive close to our field site. I don’t 20 know anything about the
place, but it’s all a bit eerie. As the sun is going up, a mysterious fog rises from the cool and humid grassland and
comes around our 4WD. I can easily imagine a cowboy
suddenly appearing, riding his horse and holding a lasso to
get the buffalos we still didn’t see. I don’t really know why,
but I expect to live a very Territorian day… When the fog
disperses, we can see the first animals standing
                                                                 Figure 5. Swamp buffalo at Beatrice Hill. Photo: Melanie Hamel
there: wild, shy and… huge! We try to get used to the idea we will have to face them for several hours… Clive stops
somewhere close to a fence and explains to us what he has planned for the day and the kind of the measurements we
will be doing. The arrival in Beatrice Hill Farm satisfies my previous assumptions: typically Australian. A big farm in
the middle of nowhere, the red ground and some tractors surrounded by green grasslands (the wet season is ending).
Buffalos are here and walk toward us in a dust cloud, very impressive but exciting in the same time.

                                           Beatrice Hill Farm is a research farm were farmers work with researchers.
                                           We talk a bit with the farmers around a shaded table with some hot drinks,
                                           then we learn about the equipment. A big wooden box where the animals will
                                           be weighed, then the crush which immobilises them and allows us to do our
                                           measurements (sometimes!).
                                           Those machines make terrible and

 Figure 6. Work shed Beatrice Hill farm.   violent noises but we get use to them
 Photo: Melanie Hamel
                                           very quickly. This is real Australia.
Farmers are kidding us, “poor French girlies”, but we rapidly manage things!
Two species live here: swamp buffalos and river buffalos. River buffalo are
too big for the measurements we want to do so presently don’t interest us. At
midday, after the weighing, sizing and sexing of around 50 water buffalo we        Figure 7. Crush and weighing platform at
                                                                                   Beatrice Hill farm. Photo: Melanie Hamel
head off to Fogg Dam for lunch, and then onto the local pub for well-earned
beer. I begin to understand why I love field work so much.


Activities

Finally, a brief overview for the next few months.

   •   October – November 2007 – recover the collars from the buffalo

   •   December 2007 – attend Australian Wildlife Management Society meeting and present information on buffalo
       population structure and behaviour

   •   Complete DNA sequencing

   •   Continue data analyses and paper writing
Thanks

We thank A. Ferguson, B. Salua, J. Schmidt & B. Cookson (NAQS), P. Carmody (NT Parks and Wildlife Service), J.
Rostron, M. Rostron, V. Rostron and M. Ryan (Djelk Rangers), I. Gurry (Parap Veterinary Surgery), K. Mines, R.
Renny and E. Hayward (Charles Darwin University), C. Crossing, B. Lemke, D. Lindner, M. Haupt (University of
Pretoria), F. Holzträger and R. Upton (Novartis South Africa), F. Hunter, I. Munro, C. Murakami, T. Noiduna, P.
Peters and the Adjumarllar Rangers, M. Rathsmann, B. Redunz, A. Tessman (Jayrow Helicopters), and H. Stone
(Poisons Branch, Northern Territory Government), P. Wise and the Dhimurru Rangers, W. Marika, N. Marawilli and
the Laynhapuy Yirralka Rangers. We extend special thanks to C. Berthouly and M. Pedrono (BIODIVA-Project) for
allowing us to use their morphometric data.


Publications

McMahon, C. R. & Bradshaw, C. J. A. (In press) To catch a buffalo: field immobilisation of Asian swamp buffalo
using etorphine and xylazine. Australian Veterinary Journal.



Project Partners:




For more information, please contact Dr. Clive McMahon (email: clive.mcmahon@cdu.edu.au,
tel: 08 8946 7726) or Dr. Corey Bradshaw (email: corey.bradshaw@cdu.edu.au, tel: 08 8946
6713) at Charles Darwin University

				
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