Eric, I have been looking for proper evidence that rationalizes the use of non-glider heat sources for joeys that are left in the next (pouch) for long periods by their mothers.

The use of reptile heat rocks is somehow controversial, but I have been using them successfully with my troope in fact I have one in each of three large cages. But their use has been a leap of faith as I have not until now found such evidence.

Anyway, I came across an article on thermoregulation in sugar gliders (reference and absract below). Essentially what the abstract implies is that *YOUNG* sugar gliders do not have the ability to maintain the proper body tempurature when mom and dad are out of he nesting area.

I may be drawing a conclusion too quickly, but based on this study, it stands to reason that an alternate heat source would be called for and surely in the instance of joey rejection.

'Not sure if this is a proper topic for gliderpedia, so I am postin it in the GP public forum for you and others to vet the topic.

Here is the abstract I found on the subject:

Development of thermoregulation in the sugar glider Petaurus breviceps (Marsupialia: Petauridae)
Joanne C. Holloway a1 c1 p1 and Fritz Geiser a1
a1 Zoology, School of Biological Sciences, University of New England, Armidale, NSW 2351, Australia
Abstract: Young, relatively undeveloped sugar gliders Petaurus breviceps have been observed to be left alone in the nest while the mother forages and may be subject to considerable thermal or energetic stress. As no information is available on the development of thermoregulation in this species, which begins reproduction in winter, we measured resting metabolic rate (RMR), body temperature (Tb) and thermal conductance over a range of ambient temperatures (Ta) in 10 sugar gliders from c. 55 days of age until they had grown to adult size. Sugar gliders were unable to maintain a stable Tb over a Ta range of 30–15 °C until the age of 95–100 days, although they raised RMR somewhat as Ta decreased. Further growth resulted in a steady decrease in mass-specific RMR, an increase in Tb and a substantial decrease in thermal conductance. Our study shows that young gliders below the age of 100 days rely largely on heat produced by adults to maintain a high Tb, but are well able to cope with regular falls in Tb of > 10 °C and a concomitant decrease of RMR. This thermal tolerance and reduction in energy expenditure should allow the mother to forage and replenish her own body fuels while her offspring are left alone in the nest.
(Accepted November 3 1999)*****************Correspondence:
c1 All correspondence to J. Holloway at present address.
p1 Present address: School of Biological Science, University of New South Wales, Sydney, NSW 2052, Australia. E-mail: j.holloway@unsw.edu.au

So does anyone else here use heat rocks or care about whether or not to use them?

I think you may have misinterpreted this abstract. Abstracts are supposed to follow a very rigid pattern, and this is an example of it. The abstract begins by stating the hypothesis, in this case it would be are unattended offspring "subject to considerable thermal or energetic stress?" The next part of the abstract briefly describes the experiment. The final section of the abstract states the conclusion. In this case, the conclusion or answer to the hypothesis is no. The offspring's body is able to adapt by lowering its metabolism.

This abstract mentions offspring starting at 8 weeks of age on to adulthood. What interests me the most is that the abstract refers to this age as being "relatively undeveloped." It goes on to state that things normalize at around 14 weeks. The Merck vet manual gives 16 to 17 weeks as a time frame for joey weaning. www.sugarglider.com/gliderpedia/index.asp?birth I'm mentioning this because there seems to be a trend with breeders for selling joeys at 8 weeks out of pouch, which seems to be extremely young. This fork could probably be an entirely seperate discussion.

To get back on topic, as for using a heat source for abandoned joeys, I would say yes. This seems analogous to using heat for incubating eggs. For normal joey rearing, especially considering that most captive environments are climate controlled, a heat soruce seems unnecessary.

Thanks Eric for taking a look!

I have heard from Jamie and others that heat rocks are not good because they cannot always be regulated properly. They say their vets have special blankets that are heated but they are only used in special circumstances. So based on this advice, I unplugged our heat rocks (sniff).