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COMMENTS ON DRAFT NH&MRC A Guide to the Use of Australian Native
Mammals in Biomedical Research.
Dr T.R. Grant • Visiting Fellow • School of Biological, Earth
and Environmental Sciences • University of NSW•
C/- PO Box 502 Cronulla 2230 • Landline/fax 02 9527 2862
Mobile [number removed by ONHMRC]
The current text is shown in black and the suggested replacement/correction/addition in
blue font. Notes and/or references relating to the suggested changed text are given.
Page 10 Paragraph 1
It is very important to note that the body temperature of platypuses is lower than that of
most other mammals (mean 32oC and range 29-34º C). They are unable to
thermoregulate effectively at ambient temperatures above about 30º C and should not be
kept at temperatures higher than 25oC.
An ambient temperature of 25oC is within the thermoneutral (“comfort”) zone of the
platypus but a platypus with a body temperature of 25oC is probably hypothermic.
Grant, T.R. and Dawson, T.J. 1978. Temperature regulation in the platypus,
Ornithorhynchus anatinus, maintenance of body temperature in air and water.
Physiological Zoology 51: 1-6.
Grant, T.R. 1983. Body temperature of free-ranging platypuses, Ornithorhynchus
anatinus, with observations on their use of burrows. Australian Journal of Zoology 31:
117-122.
Grigg, G., Beard, L., Grant, T. and Augee, M. 1992. Body temperature and diurnal
activity patterns in the platypus (Ornithorhynchus anatinus) during winter. Australian.
J. Zoology 40: 135-142.
Page 10 Paragraph 2
These nets are best set in shallow water and the wings must be securely weighted to the
streambed so that animals cannot squeeze under them, and are direct to the net entrance.
The cod end of the net should be very securely staked above water level, so that air
spaces exist in each chamber of the net, so that captured animals can breathe. Fyke nets
should be checked at 1-4 hour intervals and must be removed immediately from the
stream if a rise in stream level is anticipated. Platypuses can become progressively
hypothermic if confined in cold water and may become moribund if confined for long
periods, particularly if their fur is disturbed, so that the insulating layer of air is
compromised. It is particularly important to check nets every hour in very cold
conditions and netting in winter should be avoided if possible.
Field experience. I suggest that [name removed by ONHMRC] from the Australian
Platypus Conservancy be consulted for this section on the use of fyke nets, as [name
removed by ONHMRC] group has the most experience in the use of this netting
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technique.
Page 10 Paragraph 3
Mesh (“gill”) nets: platypuses can also be captured using unweighted or lightly
weighted mesh nets (mesh of 8-9 cm; flattened knot to knot). These nets ensure that
animals are able to swim to the surface quickly to breathe, as long as nets don’t become
snagged on submerged obstructions or weighed down by debris or by gilled fish. Mesh
nets must be kept under constant surveillance so that animals can be removed promptly
to prevent them from drowning. The entire length of the net should also be lifted up by
hand from the water at least every hour, or more frequently depending on the numbers
of fish or the amount of debris present at the netting site, to confirm that its entire length
is hanging freely. The use of mesh nets at sites where large numbers of fish occur
should be avoided if possible. The presence of large numbers of fish can increase the
probability of platypuses being drowned, the activity involved in clearing fish from the
nest can reduce platypus capture rates and high mortality of native fish species can
occur. Because platypuses are largely nocturnal, nets are best set in late afternoon and
must be closely monitored from the bank by briefly using a spotlight and/or night scope
every 10-15 minutes. When an animal is captured it should be disentangled quickly
from the net (see below for handling) and placed in a hessian or cloth sack (inside these
their fur should dry rapidly: see below). The animals should then be transferred almost
immediately into a dry cotton or calico bag (e.g. flannelette pillowcase).
There is really no such entity as a “standard unweighted gill net”. Multifilament nets,
which sink when they become wet, are becoming harder to obtain and a number of field
workers now use monofilament (“nylon”) nets, which need to be lightly weighted to
make them sink. The nets should not to be monitored continuously using a spotlight, as
this can dissuade platypuses from approaching the nets. In many instances entangled
platypuses at the surface will not rapidly tire but rest quietly at the surface, only
struggling when they are exposed to the spotlight.
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They should ideally be held at ambient temperatures below 25oC and should never be
held at temperatures exceeding 30ºC. They can be held safely in securely tied bags, in a
quiet, dark location, such as a holding crate or inside a vehicle. During this time each
animal should be checked at least every hour to ensure that it is quiet and comfortable.
Any animal showing signs of agitation (continuous scratching, failure to settle) or
discomfort should be given priority for processing and/or immediate release. Special
attention should be given to any animal showing lethargy after capture. A small
number of individuals showing this have suddenly died of causes not yet identified in
detailed post mortem examinations, following several instances of this occurring. Any
animals showing lethargy within the first 30 minutes to an hour of capture should be
released immediately.
Field experience and see body temperature references above. 25oC is within the
thermoneutral (“comfort”) zone of the platypus but temperatures above this should be
avoided, especially over 30oC
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Animals can be individually marked permanently using microchips inserted under the
skin between the scapulae, …….
Page 11 Paragraph 4
Platypuses can rapidly die if exposed to ambient temperatures above 30ºC.
Unless it is essential to answering a specific research question, adult platypuses should
not be brought into captivity in the breeding season, as during this period they exhibit
elevated levels of stress hormones and are more susceptible to mortality (see
Handasyde et al. 2003), males are more aggressive and females may be carrying eggs or
have dependent young left in nesting burrows. Where possible juvenile platypuses
should be selected to bring into captivity. At this stage many would be dispersing from
their natal area, probably being more likely to adapt to captive conditions and
established breeding adults animals would not be being removed from a wild
population.
Page 12 Paragraph 2
Platypuses consume large amounts of food for their body size, thus zoos with
experience in platypus maintenance must be consulted about appropriate diet and
volume of food before bringing animals into captivity (see also Jackson et al. 2003).
Page 12 Paragraph 6
Tissue samples for DNA can be taken from the large area of webbing on one of the
front feet or from the smaller areas of webbing on the rear feet.
Some workers sample skin from the rear feet.
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….. however Taronga Zoo in NSW and Healesville Sanctuary in Victoria, have
successfully bred platypuses a number of times.
As far as I am aware these two zoos are the only institutions to date that have bred the
platypus.