The Uromastyx genus
also known as Spiny Tailed Agamas or Dab Lizards
Uromastyx in captivity
As I have already stated, the basic information for keeping these fascinating
animals can be found in my
Uromastyx caresheet. There are areas of
special concern, or which can be expanded upon, that I document below.
I must repeat that long term survival of these species as with many others) in
captivity depends on attention to their habitat and behaviour in the wild and
maintaining Uromastyx in captivity in the long term still remains a challenge.
They are NOT an animal for someone new to keeping lizards.
Accommodation
My Care sheet sets out the basic concept. This can, however, be improved for the
benefit of the animals and visually.
Expanded polystyrene can be used to represent the shapes of rocks and rock
faces. This will need overlaying with several coats of PVA adhesive mixed with
sand. This is both visually attractive and will protect the polystyrene which
the animals would rapidly shred otherwise. One can also use various resins with
sand sprinkled on them before they set. In this case the polystyrene must first
be protected by a few coats of PVA as the resin might attack it. This is a job
best carried out in the open air and a mask is recommended. Obviously the
animals should not be placed in the vivarium until this is thoroughly dried and
odour free.
A sprinkling of silver sand over the floor of the cage will allow the easy
removal of dried faecal material and dried up food remnants with the aid of a
fine sieve (such as a kitchen flour sieve – but get your own – the household
authorities might be upset if you use theirs!)
There is little to add to my caresheet comments regarding heating and lighting.
The critical factors mentioned therein are both UV and broad spectrum (daylight)
lighting, a basking hot spot and a good temperature gradient.
Diurnal and Annual cycles.
There are a great many misapprehensions about the desert environment in which
these animals live. It is certainly hot, very hot; but temperatures can drop
dramatically at night and there are significant seasonal differences. Our job is
to emulate this as closely as is practical.
Once again, these cycles are covered in my care sheet but their importance
cannot be over-stated. These natural rhythms are essential to the long term
well-being of the animals and equally important the brumation period, brief as
it might be, is critical to egg and sperm formation and, indeed, to the
triggering of breeding behaviour in the spring.
Breeding
Mating is preceded by the typical Agamid “press-ups”. The male will then circle
round in front of his potential mate clearly showing off what a splendid
specimen he is. An unreceptive female may hiss and puff at the male and if he
persists she may attack him. Others might simply try to run away and the male
will pursue her. Occasionally a female will flip over onto her back to avoid
being mated although it is unclear if this is a submissive gesture or simply
selecting a posture in which mating is impossible.
Sooner or later mating will probably take place in typical lizard fashion with
the male placing his tail beneath the female’s with their cloaca opposed to each
other.
With a single pair sometimes there will be no attempt at mating at all. The
temporary introduction of another male to induce rivalry will often address
this. This must always be supervised very closely. Normally, after mutual
display, puffing and hissing one male will run way with little more than a
parting nip of the tail. He should however be removed immediately and the
remaining male will almost certainly be inspired to mate.
Once the female has been mated, she in turn will tend to become more
belligerent. She will resist further mating attempts but is also likely to
defend the potential egg-laying site. This is the period during which females
might well inflict wounds on the male and other females. The gravid female will
become fatter and fatter until she is distinctly pear-shaped.
Silver sand, as with most lizards, makes an ideal egg-laying medium although it
need not be as damp as with most other lizard species. Neither, however, should
it be bone dry. The depth of sand required varies largely according to the
species size. Animals such as U. flavifasciata need about a foot while little
more than 6 inches is fine for U. geyrii.
Eggs are laid at some point between May and July. With some individuals there
will be some exploratory digging in the few days immediately preceding
egg-laying, others give no clue at all. It will, in either case, be obvious when
the female has laid as she will appear thin and dehydrated and certainly
exhausted. At this time plenty of moist leafy, calcium enriched food must be
provided. A few extra super-giant mealworms seem beneficial both before and
after laying.
The eggs should be removed for incubation. Once again, the incubating medium
should not be as damp as with most lizards. If using vermiculite then 1 part of
water to two parts vermiculite by weight is about right. (For most other lizards
the ratio is 1:1). Temperatures should be about 31C but a small variation in
either direction won’t matter. Typical incubation periods are around 90 days.
Infertile or poorly developed eggs may occur in small numbers in an otherwise
good clutch and could be attributable to almost any factor – but most are down
to husbandry. Entire clutches of such eggs are of more concern. While it is
possible that either the male or female are infertile it is far more likely to
once again be a husbandry issue – although in such cases it is more serious and
probably detrimental to the health of the animal as well.
Rearing young
As hatchlings and for the first few months of their lives, Uromastyx can be kept
in quite large groups of 12-15 animals. They should be closely observed to
ensure that bullying and/or excessive domination doesn’t take place. Even if
this is not seen taking place there will be other clues such as animals hiding
away, bite marks appearing or some individuals lagging well behind in growth
rates. Once again, separation is the solution.
Young can be accommodated in a suitable, well ventilated vivarium with a UV
tube. A basking area is essential to ensure a temperature gradient together with
suitable hiding places. Feeding is much the same as the adults but on a smaller
scale.
Injuries and general health concerns
Like many Agamids, fights between individuals of the same sex can occur.
Occasionally females may pick on a male but rarely vice-versa. As a general rule
two males should not be kept together. Two or more females alone, or with a
male, seldom produce problems but females can become aggressive towards one
another and even the male when they are gravid or do not wish to be mated.
Needless to say, whatever sex mix you may have it is important to keep an eye
open for aggressive interaction and, if necessary, separate the animals as
necessary. Probably the ideal is to keep them only in pairs and even then to
have suitable accommodation to allow their separation if need be.
Even with the best endeavours, however, injuries can occur. Mating behaviour,
which should not be confused with aggression, may leave females with substantial
scar tissue. Even these should be checked to determine if treatment is
necessary. Particular attention should be paid to any wounds which produce
swelling, especially on the limbs where wounds are almost certainly the sign of
aggression rather than mating. Any such swelling almost certainly indicates that
some form of infection has taken hold.
In such cases, a specialist veterinarian should be consulted. X-rays may be
necessary and a swab to establish the type of bacteria to establish the most
appropriate antibiotics.
On occasion animals can become stressed and this can lead to loss of appetite
and condition. This also can arise from aggression, but factors such as their
accommodation, heating, lighting and food may also be relevant. Even if
everything appears fine and yet an animal starts to lose weight, especially if
you see the upper limbs becoming emaciated (a healthy Uro will always have plump
thighs!) and stops feeding properly then these are clear indications that
something is seriously wrong and the vet should again be consulted.