Miraculously providing simple explanations
for things that are, in reality,
EXTREMELY COMPLICATED !
What is BRUMATION, and
why won’t my BEARDIE
EAT in WINTER?
Many inexperienced keepers become understandably
concerned when their pet reptiles become lethargic
and refuse to eat with the onset of cooler weather. At
this time of year, reptile retailers and vets are inun-
dated with calls from owners requiring reassurance
that there is nothing wrong with their animals, and
information on how to manage them during this
period. a dramatic drop in heart rate and respiration, a
reduction in body temperature (often to a level close
to ambient temperature) and torpor. Prior to entering
hibernation, the animals prepare by consume large
amounts of food, which is conserved in fat deposits.
Hibernating bears can also recycle proteins and urine.
Hibernation may last for days, weeks, or even months,
depending on conditions and the species involved.
Dormancy is a strategy used by many different types
of organisms to survive periods when the prevailing
environment is not suitable for normal activity and
growth. Metabolic activity is minimised and stored
energy reserves are used to ‘ride out’ seasonally
unfavourable conditions. Perhaps the most obvious
example of this is deciduous trees, which use cues of
reducing photoperiod and temperature to shed their
leaves and enter a dormant phase in winter, during
which their metabolic processes are pretty much
halted. Bulbs and many herbaceous perennials also
become dormant in winter. Similarly, hibernation is a
familiar concept amongst mammals, and is utilised by
many rodents, bears, bats and hedgehogs. This coin-
cides with times when there is a shortage of food (and
often also low temperatures) and is characterised by If it is imperative for warm-blooded (endothermic)
animals to avoid a scarcity of food during winter, then
this becomes doubly important for cold-blooded
(ectothermic) animals like reptiles, which are unable
to regulate their body temperature independently of
the environment. At the very time when it is typically
more difficult to find food, activity is inhibited by lack
of sufficient warmth. Brumation is similar to hiberna-
tion, and its onset is brought about by similar climatic
cues (together with barometric pressure and an
innate ‘body clock’). It usually begins around late
autumn and entails a general lethargy and abstinence
from eating. Many reptiles will seek out a suitable site
for brumation (called a hibernaculum) that provides
some insulation from the elements – some turtles will
even brumate underwater.
Left: many insects
also exhibit periods
of dormancy. Here,
a large group of
Boxelder Bugs
(Boisea trivittata)
emerge from a
house after winter
hibernation.
Image by Melinda
Fawver.
Right: Central
Bearded Dragons.
Image by Eric
Isselee.